Exposure to air pollutants has been previously associated with respiratory viral infections, including influenza, measles, mumps, rhinovirus, and respiratory syncytial virus. Epidemiological studies ...have also suggested that air pollution exposure is associated with increased cases of SARS‐CoV‐2 infection and COVID‐19–associated mortality, although the molecular mechanisms by which pollutant exposure affects viral infection and pathogenesis of COVID‐19 remain unknown. In this review, we suggest potential molecular mechanisms that could account for this association. We have focused on the potential effect of exposure to nitrogen dioxide (NO2), ozone (O3), and particulate matter (PM) since there are studies investigating how exposure to these pollutants affects the life cycle of other viruses. We have concluded that pollutant exposure may affect different stages of the viral life cycle, including inhibition of mucociliary clearance, alteration of viral receptors and proteases required for entry, changes to antiviral interferon production and viral replication, changes in viral assembly mediated by autophagy, prevention of uptake by macrophages, and promotion of viral spread by increasing epithelial permeability. We believe that exposure to pollutants skews adaptive immune responses toward bacterial/allergic immune responses, as opposed to antiviral responses. Exposure to air pollutants could also predispose exposed populations toward developing COIVD‐19–associated immunopathology, enhancing virus‐induced tissue inflammation and damage.
Epidemiological studies have suggested that air pollution exposure is associated with increased cases of SARS‐CoV‐2 infection and COVID‐19–associated mortality. In this review, we suggest potential molecular mechanisms by which pollutant exposure could affect viral infection and pathogenesis of COVID‐19. We have focused on the potential effect of exposure to nitrogen dioxide (NO2), ozone (O3), and particulate matter (PM) since there are studies investigating how exposure to these pollutants affects the life cycle of other viruses.
Objectives
To present the results of a systematic literature search aimed at determining to what extent the radiation dose can be reduced with iterative reconstruction (IR) for cardiopulmonary and ...body imaging with computed tomography (CT) in the clinical setting and what the effects on image quality are with IR versus filtered back-projection (FBP) and to provide recommendations for future research on IR.
Methods
We searched Medline and Embase from January 2006 to January 2012 and included original research papers concerning IR for CT.
Results
The systematic search yielded 380 articles. Forty-nine relevant studies were included. These studies concerned: the chest(
n
= 26), abdomen(
n
= 16), both chest and abdomen(
n
= 1), head(
n
= 4), spine(
n
= 1), and no specific area (
n
= 1). IR reduced noise and artefacts, and it improved subjective and objective image quality compared to FBP at the same dose. Conversely, low-dose IR and normal-dose FBP showed similar noise, artefacts, and subjective and objective image quality. Reported dose reductions ranged from 23 to 76 % compared to locally used default FBP settings. However, IR has not yet been investigated for ultra-low-dose acquisitions with clinical diagnosis and accuracy as endpoints.
Conclusion
Benefits of IR include improved subjective and objective image quality as well as radiation dose reduction while preserving image quality. Future studies need to address the value of IR in ultra-low-dose CT with clinically relevant endpoints.
Key Points
•
Iterative reconstruction improves image quality of CT images at equal acquisition parameters.
•
IR preserves image quality compared to normal-dose filtered back-projection.
•
The reduced radiation dose made possible by IR is advantageous for patients.
•
IR has not yet been investigated with clinical diagnosis and accuracy as endpoints.
Under the Affordable Care Act (ACA), more than 30 states have expanded Medicaid, with some states choosing to expand private insurance instead (the "private option"). In addition, while coverage ...gains from the ACA's Medicaid expansion are well documented, impacts on utilization and health are unclear.
To assess changes in access to care, utilization, and self-reported health among low-income adults in 3 states taking alternative approaches to the ACA.
Differences-in-differences analysis of survey data from November 2013 through December 2015 of US citizens ages 19 to 64 years with incomes below 138% of the federal poverty level in Kentucky, Arkansas, and Texas (n = 8676). Data analysis was conducted between January and May 2016.
Medicaid expansion in Kentucky and use of Medicaid funds to purchase private insurance for low-income adults in Arkansas (private option), compared with no expansion in Texas.
Self-reported access to primary care, specialty care, and medications; affordability of care; outpatient, inpatient, and emergency utilization; receiving glucose and cholesterol testing, annual check-up, and care for chronic conditions; quality of care, depression score, and overall health.
Among the 3 states included in the study, Arkansas (n=2890), Kentucky (n=2898, and Texas (n=2888), there were no differences in sex, income, or marital status. Respondents from Texas were younger, more urban, and disproportionately Latino compared with those in Arkansas and Kentucky. Significant changes in coverage and access were more apparent in 2015 than in 2014. By 2015, expansion was associated with a 22.7 percentage-point reduction in the uninsured rate compared with nonexpansion (P < .001). Expansion was associated with significantly increased access to primary care (12.1 percentage points; P < .001), fewer skipped medications due to cost (-11.6 percentage points; P < .001), reduced out-of-pocket spending (-29.5%; P = .02), reduced likelihood of emergency department visits (-6.0 percentage points, P = .04), and increased outpatient visits (0.69 visits per year; P = .04). Screening for diabetes (6.3 percentage points; P = .05), glucose testing among patients with diabetes (10.7 percentage points; P = .03), and regular care for chronic conditions (12.0 percentage points; P = .008) all increased significantly after expansion. Quality of care ratings improved significantly (-7.1 percentage points with "fair/poor quality of care"; P = .03), as did the share of adults reporting excellent health (4.8 percentage points; P = .04). Comparisons of Arkansas vs Kentucky showed increased private coverage in the former (21.7 percentage points; P < .001), increased Medicaid in the latter (21.3 percentage points; P < .001), and higher diabetic glucose testing rates in Kentucky (11.6 percentage points; P = .04), but no other statistically significant differences.
In the second year of expansion, Kentucky's Medicaid program and Arkansas's private option were associated with significant increases in outpatient utilization, preventive care, and improved health care quality; reductions in emergency department use; and improved self-reported health. Aside from the type of coverage obtained, outcomes were similar for nearly all other outcomes between the 2 states using alternative approaches to expansion.
Visual Tracking: An Experimental Survey Smeulders, Arnold W. M.; Chu, Dung M.; Cucchiara, Rita ...
IEEE transactions on pattern analysis and machine intelligence,
07/2014, Letnik:
36, Številka:
7
Journal Article
Recenzirano
Odprti dostop
There is a large variety of trackers, which have been proposed in the literature during the last two decades with some mixed success. Object tracking in realistic scenarios is a difficult problem, ...therefore, it remains a most active area of research in computer vision. A good tracker should perform well in a large number of videos involving illumination changes, occlusion, clutter, camera motion, low contrast, specularities, and at least six more aspects. However, the performance of proposed trackers have been evaluated typically on less than ten videos, or on the special purpose datasets. In this paper, we aim to evaluate trackers systematically and experimentally on 315 video fragments covering above aspects. We selected a set of nineteen trackers to include a wide variety of algorithms often cited in literature, supplemented with trackers appearing in 2010 and 2011 for which the code was publicly available. We demonstrate that trackers can be evaluated objectively by survival curves, Kaplan Meier statistics, and Grubs testing. We find that in the evaluation practice the F-score is as effective as the object tracking accuracy (OTA) score. The analysis under a large variety of circumstances provides objective insight into the strengths and weaknesses of trackers.
Inflammation as a central mechanism in Alzheimer's disease Kinney, Jefferson W.; Bemiller, Shane M.; Murtishaw, Andrew S. ...
Alzheimer's & dementia : translational research & clinical interventions,
2018, Letnik:
4, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Alzheimer's disease (AD) is a progressive neurodegenerative disorder that is characterized by cognitive decline and the presence of two core pathologies, amyloid β plaques and neurofibrillary ...tangles. Over the last decade, the presence of a sustained immune response in the brain has emerged as a third core pathology in AD. The sustained activation of the brain's resident macrophages (microglia) and other immune cells has been demonstrated to exacerbate both amyloid and tau pathology and may serve as a link in the pathogenesis of the disorder. In the following review, we provide an overview of inflammation in AD and a detailed coverage of a number of microglia-related signaling mechanisms that have been implicated in AD. Additional information on microglia signaling and a number of cytokines in AD are also reviewed. We also review the potential connection of risk factors for AD and how they may be related to inflammatory mechanisms.
Bleeding manifestations in patients with immune thrombocytopenia (ITP) range from mild skin bruises to life-threatening intracranial hemorrhage (ICH). Severe bleeding is distinctly uncommon when the ...platelet count is >30 × 10(9)/L and usually only occurs when the platelet count falls <10 × 10(9)/L. Based on estimates from clinical studies, ITP registries and administrative databases, the frequency of ICH in patients with ITP is ~0.5% in children and 1.5% in adults. Estimates of severe (non-ICH) bleeding are difficult to obtain because of the lack of standardized case definitions; the lack of a universally accepted, ITP-specific bleeding assessment tool; and the omission of reporting bleeding outcomes in many clinical studies. In practice, the presence of bleeding should dictate whether or not treatment is needed because many patients, especially children, can be safely managed with observation alone. Guiding principles for the management of ITP, based on the bleeding risk are: (1) Decide when treatment is needed and when it can safely be withheld; (2) for patients with chronic ITP, use the least toxic treatment at the lowest dose; (3) emergency treatment of severe thrombocytopenia-associated bleeding requires combination therapy; and (4) early aggressive therapy may result in durable platelet count responses.
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