302 research outputs found
Autofluorescence Lifetimes in Patients With Choroideremia Identify Photoreceptors in Areas With Retinal Pigment Epithelium Atrophy.
The purpose of this study was to investigate fundus autofluorescence lifetimes in patients with choroideremia and to identify tissue-specific lifetime characteristics and potential prognostic markers.
Autofluorescence lifetimes of the retina were measured in two spectral channels (498-560 nm and 560-720 nm) in patients with choroideremia and age-matched healthy controls. Furthermore, autofluorescence intensities and spectral-domain optical coherence tomography (OCT) data were acquired and compared to fundus autofluorescence lifetime data.
Sixteen eyes from 8 patients with advanced choroideremia (mean ± SD age, 55 ± 13 years) were included in this study and compared with 10 age-matched healthy participants. Whereas fundus autofluorescence intensity measurement identified areas of remaining retinal pigment epithelium (RPE), autofluorescence lifetime maps identified areas with remaining photoreceptor layers in OCT but RPE atrophy. In these areas, mean (±SEM) lifetimes were 567 ± 59 ps in the short and 603 ± 49 ps in the long spectral channels (+98% and +88% compared to controls). In areas of combined RPE atrophy and loss of photoreceptors, autofluorescence lifetimes were significantly prolonged by 1116 ± 63 ps (+364%) in the short and by 915 ± 52 ps (+270%) in the long spectral channels compared with controls.
Because autofluorescence lifetimes identify areas of remaining photoreceptors in the absence of RPE, this imaging modality may be useful to monitor disease progression in the natural course of disease and in context of potential future therapeutic interventions
SUBFOVEAL NODULE IN COATS' DISEASE: Toward an Updated Classification Predicting Visual Prognosis.
To determine the prevalence, clinical characteristics and nature of subfoveal nodules in Coats' disease and the associated impact on the long-term visual outcome.
Consecutive cases of Coats' disease with foveal exudation were retrospectively reviewed. The presence of a subfoveal nodule or macular fibrosis was recorded. Clinical characteristics, retinal imaging, and outcome were analyzed by comparative analysis. The histopathological description of an enucleated eye with subfoveal nodule was performed.
Among 40 patients presenting unilateral Stage 2B or 3A1 Coats' disease, a subfoveal nodule was detected in 21 patients (52.5%). The median follow-up was 4.7 years. Nineteen patients (47.5%) did not present a subfoveal nodule. Three patients (15.8%) without subfoveal nodule and 21 patients (100%) with subfoveal nodule progressed to a macular fibrotic scar (P < 0.0001), and the mean time of macular fibrosis onset was 11.0 ± 2.6 months. Final visual acuity was significantly worse in patients who presented a subfoveal nodule at diagnosis (P = 0.01). Of 18 cases with subfoveal nodule who underwent fluorescein angiography, retinal-retinal anastomosis and neovascularization were detected in 13 (72.2%) and 2 eyes (11.1%), respectively. Histopathological analysis of a subfoveal nodule revealed an aggregate of proteinaceous material including fibrin, spindle cells, macrophages, and pigmented cells.
The presence of a subfoveal nodule at presentation is a predictive factor for macular fibrosis development and worse visual outcome in patients with Coats' disease. These observations suggest an updated classification introducing two subcategories within Stage 2B: without subfoveal nodule (Stage 2B1) and with subfoveal nodule (Stage 2B2)
Convergence of a semi-discretization scheme for the Hamilton--Jacobi equation: a new approach with the adjoint method
We consider a numerical scheme for the one dimensional time dependent Hamilton--Jacobi equation in the periodic setting. This scheme consists in a semi-discretization using monotone approximations of the Hamiltonian in the spacial variable. From classical viscosity solution theory, these schemes are known to converge. In this paper we present a new approach to the study of the rate of convergence of the approximations based on the nonlinear adjoint method recently introduced by L. C. Evans. We estimate the rate of convergence for convex Hamiltonians and recover the O(sqrt{h}) convergence rate in terms of the L^infty norm and O(h) in terms of the L^1 norm, where h is the size of the spacial grid. We discuss also possible generalizations to higher dimensional problems and present several other additional estimates. The special case of quadratic Hamiltonians is considered in detail in the end of the paper
Homogenization of weakly coupled systems of Hamilton--Jacobi equations with fast switching rates
We consider homogenization for weakly coupled systems of Hamilton--Jacobi
equations with fast switching rates. The fast switching rate terms force the
solutions converge to the same limit, which is a solution of the effective
equation. We discover the appearance of the initial layers, which appear
naturally when we consider the systems with different initial data and analyze
them rigorously. In particular, we obtain matched asymptotic solutions of the
systems and rate of convergence. We also investigate properties of the
effective Hamiltonian of weakly coupled systems and show some examples which do
not appear in the context of single equations.Comment: final version, to appear in Arch. Ration. Mech. Ana
Stigma experienced by people living with HIV who are on methadone maintenance treatment and have symptoms of common mental disorders in Hanoi, Vietnam: a qualitative study
Background: Stigma around human immunodeficiency virus (HIV), injection drug use (IDU), and mental health disorders can be co-occurring and have different impacts on the well-being of people living with HIV (PWH) who use drugs and have mental health disorders. This stigma can come from society, health professionals, and internalized stigma. A person who has more than one health condition can experience overlapping health-related stigma and levels of stigma which can prevent them from receiving necessary support and healthcare, serving to intensify their experience with stigma. This study investigates HIV, drug use, and mental health stigmas in three dimensions (social, internalized, and professional) around PWH on methadone maintenance treatment (MMT) who have common mental disorders (CMDs) including depression, anxiety, and stress-related disorders in Hanoi, Vietnam.Please check and confirm whether corresponding author's email id is correctly identified.The cooresponding author's email is correct Methods: We conducted semi-structured, in-depth interviews (IDIs) (n = 21) and two focus group discussions (FGDs) (n = 10) with PWH receiving MMT who have CMD symptoms, their family members, clinic health care providers, and clinic directors. We applied thematic analysis using NVIVO software version 12.0, with themes based on IDI and FGD guides and emergent themes from interview transcripts. Results: The study found evidence of different stigmas towards HIV, IDU, and CMDs from the community, family, health care providers, and participants themselves. Community and family members were physically and emotionally distant from patients due to societal stigma around illicit drug use and fears of acquiring HIV. Participants often conflated stigmas around drug use and HIV, referring to these stigmas interchangeably. The internalized stigma around having HIV and injecting drugs made PWH on MMT hesitant to seek support for CMDs. These stigmas compounded to negatively impact participantsâ health. Conclusions: Strategies to reduce stigma affecting PWH on MMT should concurrently address stigmas around HIV, drug addiction, and mental health. Future studies could explore approaches to address internalized stigma to improve self-esteem, mental health, and capacities to cope with stigma for PWH on MMT. Trial registration: NCT04790201, available at clinicaltrials.gov
Alcohol use as a mediator of the effect of two alcohol reduction interventions on mental health symptoms of ART clients in Vietnam
We aimed to examine the mediating role of alcohol use in the pathway from the interventions to depression and anxiety symptoms using data from a randomized controlled trial among people living with HIV (PWH) with hazardous alcohol use (n = 440) in Thai Nguyen, Vietnam. Participants were randomized into either a combined intervention (CoI), a brief intervention (BI) and a standard of care arm. Both interventions were based on cognitive behavioral therapy and motivational enhancement therapy. Alcohol use was measured as the percentage of days abstinent from alcohol in the last 30 days. Symptoms of depression and anxiety were measured with the Patient Health Questionnaire-9 and Generalized Anxiety Disorder-7 scales. Alcohol use was a significant mediator of the effects of two alcohol interventions on depression symptoms, but not anxiety symptoms. There were significant indirect effects via alcohol use of both interventions on depression symptoms at 12 months (CoI: mean difference (MD) = â0.134; 95%CI: â0.251, â0.035); (BI: MD = â0.141; 95%CI: â0.261, â0.038). There were no significant direct or total effects of the interventions on either symptoms at 12 months. Interventions with a dual focus on mental health and alcohol disorders are needed to determine optimal ways to tackle these common comorbidities among PWH
Effects of Two Alcohol Reduction Interventions on Depression and Anxiety Symptoms of ART Clients in Vietnam
Little is known about the potential mental health impacts of cognitive behavioral therapy and motivational interviewing interventions that focus on alcohol reduction among people with HIV (PWH). Our study aimed to assess the impact of two evidence-based alcohol reduction interventions on depression and anxiety symptoms of antiretroviral therapy (ART) clients with hazardous alcohol use. We conducted a secondary data analysis of data from a three-arm randomized controlled trial among ART clients in Thai Nguyen, Vietnam that evaluated the impacts of two alcohol reduction interventions in Vietnam. ART clients 18 years old or more with hazardous alcohol use (based on the Alcohol Use Disorders Identification Test-Consumption) were enrolled and randomized into one of three arms: Combined intervention, Brief intervention, and Standard of care (SOC). Symptoms of depression, measured with the Patient Health Questionnaire-9, and anxiety, measured with the Generalized Anxiety Disorder-7 scale, were assessed at baseline and 3, 6, and 12 months post-intervention. Generalized estimating equations were used to evaluate the effects of the interventions on depression and anxiety symptoms. The prevalence of depression and anxiety symptoms at baseline was 25.1% and 16.1%, respectively. Decreases in depression and anxiety symptoms were observed in all three arms from baseline to 12-month follow-up. There were no significant differences in depression and anxiety symptoms among participants receiving either intervention, relative to the SOC. Interventions with a dual focus on alcohol and mental health are needed to achieve more pronounced and sustainable improvements in depression and anxiety symptoms for PWH with hazardous alcohol use
Comparing a standard and tailored approach to scaling up an evidence-based intervention for antiretroviral therapy for people who inject drugs in Vietnam: Study protocol for a cluster randomized hybrid type III trial
Background: People who inject drugs (PWID) bear a disproportionate burden of HIV infection and experience poor outcomes. A randomized trial demonstrated the efficacy of an integrated System Navigation and Psychosocial Counseling (SNaP) intervention in improving HIV outcomes, including antiretroviral therapy (ART) and medications for opioid use disorder (MOUD) uptake, viral suppression, and mortality. There is limited evidence about how to effectively scale such intervention. This protocol presents a hybrid type III effectiveness-implementation trial comparing two approaches for scaling-up SNaP. We will evaluate the effectiveness of SNaP implementation approaches as well as cost and the characteristics of HIV testing sites achieving successful or unsuccessful implementation of SNaP in Vietnam. Methods: Design: In this cluster randomized controlled trial, two approaches to scaling-up SNaP for PWID in Vietnam will be compared. HIV testing sites (n = 42) were randomized 1:1 to the standard approach or the tailored approach. Intervention mapping was used to develop implementation strategies for both arms. The standard arm will receive a uniform package of these strategies, while implementation strategies for the tailored arm will be designed to address site-specific needs. Participants: HIV-positive PWID participants (n = 6200) will be recruited for medical record assessment at baseline; of those, 1500 will be enrolled for detailed assessments at baseline, 12, and 24 months. Site directors and staff at each of the 42 HIV testing sites will complete surveys at baseline, 12, and 24 months. Outcomes: Implementation outcomes (fidelity, penetration, acceptability) and effectiveness outcomes (ART, MOUD uptake, viral suppression) will be compared between the arms. To measure incremental costs, we will conduct an empirical costing study of each arm and the actual process of implementation from a societal perspective. Qualitative and quantitative site-level data will be used to explore key characteristics of HIV testing sites that successfully or unsuccessfully implement the intervention for each arm. Discussion: Scaling up evidence-based interventions poses substantial challenges. The proposed trial contributes to the field of implementation science by applying a systematic approach to designing and tailoring implementation strategies, conducting a rigorous comparison of two promising implementation approaches, and assessing their incremental costs. Our study will provide critical guidance to Ministries of Health worldwide regarding the most effective, cost-efficient approach to SNaP implementation. Trial registration: NCT03952520 on Clinialtrials.gov. Registered 16 May 2019
Measurement of the branching fraction
The branching fraction is measured in a data sample
corresponding to 0.41 of integrated luminosity collected with the LHCb
detector at the LHC. This channel is sensitive to the penguin contributions
affecting the sin2 measurement from The
time-integrated branching fraction is measured to be . This is the most precise measurement to
date
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