Multi-exposure Approach Research Articles

Spin-decoupled and phase-multiplexed liquid crystals element enabling intensity-controllable holography based on rewritable photoalignment SD1

ABSTRACT Azobenzene photoalignment (PA) material SD1 is of significance in fabricating planar liquid crystals (LC) elements because of their high sensitivity and rewritability. Herein, the influence of exposure energy density on the rewriting process of SD1 is studied via the analysis of the alignment quality of the LC layer. Based on such unique erasability of SD1, a multi-exposure approach of preparing the spin-decoupled LC devices is presented experimentally, confirming multiple phase structures can be integrated into a single component. the relative weight for the two kinds of orientation structures can be controlled by exposed energy density, successfully enabling the intensity-editable holographic functionality. Our work might offer an entirely new perspective on studying the rewriting mechanism of SD1 stuff and open an effective avenue for developing the LC-based integrated apparatus.

Prenatal dietary exposure to chemicals and allergy or respiratory diseases in children in the EDEN mother–child cohort

IntroductionMaternal exposure to food chemicals may increase the risk of allergy and respiratory disorders in offspring. We aimed to assess the association of prenatal dietary exposure to single chemicals and chemical mixtures with allergy or respiratory events reported before age 8 y in children. MethodsWe included 1428 mother–child pairs enrolled in the EDEN mother–child cohort. Maternal dietary exposure to 209 chemicals and eight associated mixtures was investigated. Allergic and respiratory diseases (wheezing, asthma, allergic rhinitis, eczema and food allergy) were reported by parents between birth and age 8 y. Associations with the studied outcomes were evaluated with three approaches based on adjusted logistic regression, estimating odds ratios (ORs) and 95 % confidence intervals (CIs). First, food chemicals were considered individually, with correction for multiple testing. Second, chemicals selected by elastic net regression were considered simultaneously in a multiple exposure model. Third, predefined mixtures were introduced in the same adjusted logistic regression. Results are expressed as odds ratio (OR[95 % CI]). ResultsPrenatal single exposure to 74 food chemicals was associated with higher risk of allergic rhinitis. Prenatal single exposure to 11 chemicals was associated with higher risk of wheezing. In the multi-exposure approach, risk of wheezing was associated with the pesticides diazinon and triadimenol, and polycyclic aromatic hydrocarbon 5-methylchrysene. Phytoestrogen resveratrol was negatively associated with lower risk of both wheezing and allergic rhinitis, and mycotoxin monoacetoxyscirpenol was negatively associated with risk of eczema. Finally, a chemical mixture composed mainly of trace elements, furans and polycyclic aromatic hydrocarbons, was associated with higher risk of allergic rhinitis (1.33 [1.02;1.73]). ConclusionPrenatal dietary exposure to chemicals was associated with risk of allergic rhinitis or wheezing up to age 8 y. A few chemicals were associated with other allergic and respiratory diseases. Larger prospective studies are needed to confirm these findings.

A multi-exposure approach to study telomere dynamics in childhood: A role for residential green space and waist circumference.

BackgroundTelomeres are vulnerable to various environmental exposures and lifestyle factors, encompassed in the exposome. Recent research shows that telomere length is substantially determined early in life and that exposures in childhood may have important consequences in setting later life telomere length. ObjectivesWe explore in a child population the associations of 17 exposures with telomere length and longitudinal telomere change. MethodsChildren (2.8–10.3y at baseline, 51.3% boys) were followed-up for five to seven years. Relative telomere length was measured at baseline and follow-up using quantitative real-time PCR. Exposures and lifestyle factors included: body composition (body mass index and waist circumference), dietary habits (sugar- and fat-rich food intake, vegetables and fruit intake), psychosocial stress (events, emotions, behaviour), sleep duration, physical activity, and residential environmental quality (longterm black carbon, particulate matter exposure, and residential green space). Cross-sectional (n=182) and longitudinal (n=150) analyses were assessed using linear regression models, adjusting for age, sex, socioeconomic status and multiple testing. ResultsOur longitudinal analyses showed that higher residential green space at baseline was associated with (β=0.261, p=0.002) lower telomere attrition and that children with a higher waist circumference at baseline showed a higher telomere attrition (β=−0.287, p=0.001). These two predictors were confirmed via LASSO variable selection and correction for multiple testing. In addition, children with more unhealthy exposures at baseline had a significantly higher telomere attrition over the follow-up period compared to children with more healthy exposures (β=−0.200, p=0.017). DiscussionWaist circumference and residential green space were identified as predictors associated with telomere attrition in childhood. These results further support the advantages of a healthy lifestyle from early age onwards and the importance of a green environment to promote molecular longevity from childhood onwards.

The impact of socio-economic and environmental factors on the spatial patterns of cancer incidence in Israel: A registry-based cohort study

BACKGROUND AND AIM: Spatial methods usually used to identify geographical health risk differences. Only a few studies used semi-individual latent multi exposure approach, to investigate the socioeconomic and environmental factors that explain cancer risk spatial patterns. Our aim is to evaluate spatial clusters of cancer and to determine the impact of both socioeconomic and environmental factors on the spatial patterns of cancer incidence in Israel by applying generalized additive models (GAMs). METHODS: The current study is a registry-based cohort study. The data include the 1995 Israeli Central Bureau of statistics census (N=1,066,714) linked to the Israeli Cancer Registry data. In addition, ambient exposures were determined including: particulate matter with a diameter size that is equal to or smaller than 2.5µm, normalized difference vegetation index derived from satellite data, nitrogen oxides. We first used the global and local Morans’ I in order to identify cancer incidence clusters. RESULTS:During 17 years of follow-up (1998-2015) there were 62,049 new cancer cases among 1,022,637 participants in the 1995 census. Cancer incidence were clustered by geographical area (global Moran’s I Index =0.054, p-value0.000). Cancer clusters were located mainly in the northern district of Israel (surrounding Haifa region) and in the center part of Israel (surrounding Tel-Aviv region). CONCLUSIONS:The spatial clusters of cancer incidence in Israel can be attributed to socioeconomic and environmental risk factors. Further analysis will be conducted to evaluate the spatial associations with the socioeconomic and environmental factors using spatial modeling. KEYWORDS: socio-economic factors, environmental epidemiology, spatial statistics, particulate matter, cancer incidence, green space

Identification of Gene-Diet Interactions Impacting Glycemic Biomarkers in the Multi-Ethnic TOPMed Cohorts

ObjectivesIdentification of robust gene-diet interactions impacting cardiometabolic traits has been limited due to low statistical power and poor replication across populations. Emerging statistical methods increase power by simultaneously testing genetic interactions with multiple exposures, an especially appealing strategy for complex and highly-correlated dietary traits. Furthermore, meta-analysis across ancestrally and behaviorally diverse populations may allow for more robust discoveries. Here, our objective was to leverage multi-exposure interaction tests in a diverse set of cohorts to identify interactions involving macronutrient ratios and impacting multiple biomarkers of glycemia. MethodsSeven cohorts from the TOPMed consortium (total N ∼ 20,000) contributed whole-genome sequencing data, self-reported dietary data, and glycemic trait measurements (fasting glucose and insulin (FG and FI) and hemoglobin A1c). Three macronutrient ratios were defined to model realistic dietary exchanges and minimize collinearity: carbohydrate: fat, polyunsaturated: saturated fat, and fiber: carbohydrate. For each glycemic trait outcome and common genetic variant, we fit a model including all three ratios and their genetic interactions, with joint significance testing in each cohort followed by cross-cohort meta-analysis. ResultsFour variants showed promising sub-threshold signals (p < 1 × 10–7), though none reached genome-wide significance. For example, diet ratios collectively interacted with rs2276620 in the oxysterol-binding OSBPL6 gene to influence FG (p = 6.5 × 10–8) and rs114448070 in the beta cell function-associated KAT2B gene (p = 5.4 × 10–8) to influence FI. These associations were contributed to by multiple cohorts and multiple dietary factors, emphasizing the value of this multi-cohort and multi-exposure approach to GDI variant detection. ConclusionsOur approach takes advantage of population diversity and multi-faceted dietary exposures to understand genetic effects on the diet-glycemia relationship and support the development of genome-based precision nutrition. Our results will be updated with additional cohorts and gene-based tests using rare genetic variants, which are less common but may have stronger effects. Funding SourcesKEW is supported by an NIDDK T32 award.

Short review: Air pollution, noise and lack of greenness as risk factors for Alzheimer's disease- epidemiologic and experimental evidence

The number of patients with Alzheimer's disease (AD) is likely to triple in a few decades as the world's population ages. Given the high personal and societal burden of this disease, it is imperative to identify its risk factors. The etiology of AD is still not fully understood, but environmental factors have emerged as plausible important risk factors on the population-level. In this short review, the author summarizes literature on air pollution, noise and (lack of) greenness as risk factors for AD. In conclusion, a link between air pollution and AD is supported by experimental studies as well as epidemiological studies, although a multi-exposure approach is lacking in most epidemiological studies. Although evidence is much more limited regarding noise and (lack of) greenness as risk factors for AD, future epidemiological studies should have a multi-exposure approach in order to separate potential effects of air pollution, noise and lack of greenness. Given the heavy toll of AD on individuals and society, as well as the ubiquitous nature of environmental factors, a link between environmental stressors and AD deserves special attention.

Agri-food activities in jeopardy—A territorial analysis of risks from natural hazards

According to the Disaster Risk Reduction (DRR) approach, this paper aims to return a method to assess disaster risk from adverse natural events as a function of hazard, exposure, and vulnerability. Focusing on the Italian agri-food sector as a case-study and considering municipality-level data, a multi-hazard and multi-exposure approach is followed for risk assessment. In particular, both synthetic indicators and cluster analysis are performed. With regard to the implementation of DRR measures, this work suggests to devote proper attention to high-vulnerability municipalities.

Application of a Colored Multiexposure High Dynamic Range Technique to Radiographic Imaging: An Experimental Trial to Show Feasibility.

The aim of this study was to evaluate the feasibility of applying the high dynamic range (HDR) technique to radiographic imaging to expand the dynamic range of conventional radiographic images using a colored multiexposure approach. An appropriate study object was repeatedly imaged using a range of different imaging parameters using a standard clinical x-ray unit. An underexposed image (acquired at 80 keV), an intermediate exposed image (110 keV), and an overexposed image (140 keV) were chosen and combined to a 32-bit colored HDR image. To display the resulting HDR image on a regular color display with typically 8 bits per channel, the Reinhard tone mapping algorithm was applied. The source images and the resulting HDR image were qualitatively evaluated by 5 independent radiologists with regard to the visibility of the different anatomic structures using a Likert scale (1, not visible, to 5, excellent visibility). Data were presented descriptively. High dynamic range postprocessing was possible without malalignment or image distortion. Application of the Reinhardt algorithm did not cause visible artifacts. Overall, postprocessing time was 7 minutes 10 seconds for the whole process. Visibility of anatomic structure was rated between 1 and 5, depending on the anatomic structure of interest. Most authors rated the HDR image best before individual source images. This experimental trial showed the feasibility of applying the HDR technique to radiographic imaging to expand the dynamic range of conventional radiographic images using a colored multiexposure approach.

An improved multi-exposure approach for high quality holographic femtosecond laser patterning

High efficiency two photon polymerization through single exposure via spatial light modulator (SLM) has been used to decrease the fabrication time and rapidly realize various micro/nanostructures, but the surface quality remains a big problem due to the speckle noise of optical intensity distribution at the defocused plane. Here, a multi-exposure approach which used tens of computer generate holograms successively loaded on SLM is presented to significantly improve the optical uniformity without losing efficiency. By applying multi-exposure, we found that the uniformity at the defocused plane was increased from ∼0.02 to ∼0.6 according to our simulation. The fabricated two series of letters “HELLO” and “USTC” under single-and multi-exposure in our experiment also verified that the surface quality was greatly improved. Moreover, by this method, several kinds of beam splitters with high quality, e.g., 2 × 2, 5 × 5 Daman, and complex nonseperate 5 × 5, gratings were fabricated with both of high quality and short time (&amp;lt;1 min, 95% time-saving). This multi-exposure SLM-two-photon polymerization method showed the promising prospect in rapidly fabricating and integrating various binary optical devices and their systems.

MO-D-BRC-06: A Multi-Exposure Approach to Improve Image Quality for Linac-Based Cone Beam Computed Tomography (CBCT)

Purpose: Recently we demonstrated the use of a 1‐D grid placed between the source and patient to directly reduce scatter, and correct the remaining scatter in cone‐beam computed tomography(CBCT). However, that technique required two 360° gantry rotations to acquire an entire image dataset. The purpose of this study was to investigate the feasibility and potential improvements of a multi‐exposure approach, which takes two or more partial projections at each gantry position with a rapidly oscillating grid to acquire the full dataset in one rotation. Methods: A Trilogy CBCT system was used for the experiment. Grids with various septa‐to‐interspace‐ratios (SIR) were tested. A grid with higher SIR may reduce scatter more effectively, but requires a larger number of exposures at each gantry position for full projection data. The multi‐exposure technique was simulated using multiple rotations, with the grid manually shifted after each rotation with a distance equal to the grid interspace, instead of multiple exposures at each gantry position, with the grid shifted after each exposure. Scatter‐to‐primary‐ratio (SPR) was measured and compared for various object thicknesses and grids with various SIRs. CBCTimages were reconstructed after scatter correction for two grids with SIR of 1 and 3, corresponding to 2 and 4 exposures at each gantry position, and compared with conventional CBCT. Results: SPR was reduced linearly with increasing SIR. The scatter artifacts were removed after scatter correction for both grids. The contrast‐to‐noise‐ratios (CNRs) of three phantom inserts with different densities were 20.5, 13.2, and 6.9 for conventional CBCT. The corresponding CNRs were improved to 23.5, 15.8, and 7.9 with the grid of SIR=1, and to 27.2, 18.3, and 8.7 with the grid of SIR=3. Conclusion: Initial results suggest that the multi‐exposure approach may improve CBCTimage quality by removing scatter artifacts, increasing CNR without increasing scanning time.