Tailoring the depth of focus for optical imaging systems using a Fourier transform approach

We show how to tailor the depth of focus for an optical system using pupil functions obtained from a Fourier transform approach. These complex amplitude and phase pupil functions are encoded onto a single liquid-crystal spatial light modulator. Experimental results show excellent agreement with theory and indicate the power of this approach

Temporal Lau effect: Noncoherent regeneration of periodic pulse trains

We present an optical method for implementing the temporal Talbot effect with a spectrally incoherent optical source and a linear dispersive medium, at the first-order dispersion regime. We state the condition for achieving this effect, here denoted as the temporal Lau effect

Identification and quantification of microplastics in wastewater using focal plane array-based reflectance micro-FT-IR imaging

Microplastics (<5 mm) have been documented in environmental samples on a global scale. While these pollutants may enter aquatic environments via wastewater treatment facilities, the abundance of microplastics in these matrices has not been investigated. Although efficient methods for the analysis of microplastics in sediment samples and marine organisms have been published, no methods have been developed for detecting these pollutants within organic-rich wastewater samples. In addition, there is no standardized method for analyzing microplastics isolated from environmental samples. In many cases, part of the identification protocol relies on visual selection before analysis, which is open to bias. In order to address this, a new method for the analysis of microplastics in wastewater was developed. A pretreatment step using 30% hydrogen peroxide (H2O2) was employed to remove biogenic material, and focal plane array (FPA)-based reflectance micro-Fourier-transform (FT-IR) imaging was shown to successfully image and identify different microplastic types (polyethylene, polypropylene, nylon-6, polyvinyl chloride, polystyrene). Microplastic-spiked wastewater samples were used to validate the methodology, resulting in a robust protocol which was nonselective and reproducible (the overall success identification rate was 98.33%). The use of FPA-based micro-FT-IR spectroscopy also provides a considerable reduction in analysis time compared with previous methods, since samples that could take several days to be mapped using a single-element detector can now be imaged in less than 9 h (circular filter with a diameter of 47 mm). This method for identifying and quantifying microplastics in wastewater is likely to provide an essential tool for further research into the pathways by which microplastics enter the environment.This work is funded by a NERC (Natural Environment Research Council) CASE studentship (NE/K007521/1) with contribution from industrial partner Fera Science Ltd., United Kingdom. The authors would like to thank Peter Vale, from Severn Trent Water Ltd, for providing access to and additionally Ashley Howkins (Brunel University London) for providing travel and assistance with the sampling of the Severn Trent wastewater treatment plant in Derbyshire, UK. We are grateful to Emma Bradley and Chris Sinclair for providing helpful suggestions for our research

Abatacept in patients with rheumatoid arthritis and interstitial lung disease: A national multicenter study of 63 patients

OBJECTIVE: Interstitial lung disease (ILD) is one of the most serious complications of rheumatoid arthritis (RA). In the present study, we aimed to assess the efficacy of abatacept (ABA) in patients with ILD associated to RA. METHODS: National multicenter, non-controlled, open-label registry study of RA patients with ILD treated with ABA. RESULTS: 63 patients (36 women) with RA-associated ILD undergoing ABA therapy were studied. The mean ± standard deviation age at the time of the study was 63.2 ± 9.8 years. The median duration of RA and ILD from diagnosis were 6.8 and 1 year, respectively. RA was seropositive in 55 patients (87.3%). In 15 (23.8%) of 63 patients the development of ILD was closely related to the administration of synthetic or biologic disease modifying anti-rheumatic drugs. After a follow-up of 9.4 ± 3.2 months, two-thirds of patients remained stable whereas one-quarter experienced improvement in the Modified Medical Research Council scale. At that time forced vital capacity remained stable in almost two-thirds of patents and improved in one out of five patients assessed. Also, diffusing capacity of the lung for carbon monoxide remained stable in almost two-thirds and showed improvement in a quarter of the patients assessed. At 12 months, 50% of the 22 patients in whom chest HRCT scan was performed due persistence of respiratory symptoms showed stabilization, 8 (36.4%) improvement and 3 worsening of the HRCT scan pattern. Eleven of 63 patients had to discontinue ABA, mainly due to adverse events. CONCLUSION: ABA appears to be an effective in RA-associated ILD.Funding: This work was partially supported by RETICS Programs, RD08/0075 (RIER) and RD12/0009/0013 from ‘‘Instituto de Salud Carlos III’’ (ISCIII), Spain

Is there a link between wealth and cardiovascular disease risk factors among Hispanic/Latinos? : Results from the HCHS/SOL sociocultural ancillary study

OBJECTIVE: To examine the relationship between wealth and cardiovascular disease risk factors among Hispanic/Latinos of diverse backgrounds. DESIGN: This cross-sectional study used data from 4971 Hispanic/Latinos, 18-74 years, who participated in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) baseline exam and the HCHS/SOL Sociocultural Ancillary Study. Three objectively measured cardiovascular disease risk factors (hypertension, hypercholesterolemia, and obesity) were included. Wealth was measured using an adapted version of the Home Affluence Scale, which included questions regarding the ownership of a home, cars, computers, and recent vacations. RESULTS: After adjusting for traditional socioeconomic indicators (income, employment, education), and other covariates, we found that wealth was not associated with hypertension, hypercholesterolemia or obesity. Analyses by sex showed that middle-wealth women were less likely to have hypercholesterolemia or obesity. Analyses by Hispanic/Latino background groups showed that while wealthier Central Americans were less likely to have obesity, wealthier Puerto Ricans were more likely to have obesity. CONCLUSION: This is the first study to explore the relationship between wealth and health among Hispanic/Latinos of diverse backgrounds, finding only partial evidence of this association. Future studies should utilize more robust measures of wealth, and address mechanisms by which wealth may impact health status among Hispanic/Latinos of diverse backgrounds in longitudinal designs

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Wigner distribution in optics

In 1932 Wigner introduced a distribution function in mechanics that permitted a description of mechanical phenomena in a phase space. Such a Wigner distribution was introduced in optics by Dolin and Walther in the sixties, to relate partial coherence to radiometry. A few years later, the Wigner distribution was introduced in optics again (especially in the area of Fourier optics), and since then, a great number of applications of the Wigner distribution have been reported. While the mechanical phase space is connected to classical mechanics, where the movement of particles is studied, the phase space in optics is connected to geometrical optics, where the propagation of optical rays is considered. And where the position and momentum of a particle are the two important quantities in mechanics, in optics we are interested in the position and the direction of an optical ray. We will see that the Wigner distribution represents an optical field in terms of a ray picture, and that this representation is independent of whether the light is partially coherent or completely coherent. We will observe that a Wigner distribution description is in particular useful when the optical signals and systems can be described by quadratic-phase functions, i.e., when we are in the realm of first-order optics: spherical waves, thin lenses, sections of free space in the paraxial approximation, etc. Although formulated in Fourier-optical terms, the Wigner distribution will form a link to such diverse fields as geometrical optics, ray optics, matrix optics, and radiometry. Sections 1.2 through 1.7 will mainly deal with optical signals and systems. We treat the description of completely coherent and partially coherent light fields in Section 1.2. The Wigner distribution is introduced in Section 1.3 and elucidated with some optical examples. Properties of the Wigner distribution are considered in Section 1.4. In Section 1.5 we restrict ourselves to the one-dimensional case and observe the strong connection of the Wigner distribution to the fractional Fourier transformation and rotations in phase space. The propagation of the Wigner distribution through Luneburg’s first-order optical systems is the topic of Section 1.6, while the propagation of its moments is discussed in Section 1.7. The final Section 1.8 is devoted to the broad class of bilinear signal representations, known as the Cohen class, of which the Wigner distribution is an important representative