SAfE transport: wearing face masks significantly reduces the spread of COVID-19 on trains.

COVID-19 has had a substantial impact globally. It spreads readily, particularly in enclosed and crowded spaces, such as public transport carriages, yet there are limited studies on how this risk can be reduced. We developed a tool for exploring the potential impacts of mitigation strategies on public transport networks, called the Systems Analytics for Epidemiology in Transport (SAfE Transport). SAfE Transport combines an agent-based transit assignment model, a community-wide transmission model, and a transit disease spread model to support strategic and operational decision-making. For this simulated COVID-19 case study, the transit disease spread model incorporates both direct (person-to-person) and fomite (person-to-surface-to-person) transmission modes. We determine the probable impact of wearing face masks on trains over a seven day simulation horizon, showing substantial and statistically significant reductions in new cases when passenger mask wearing proportions are greater than 80%. The higher the level of mask coverage, the greater the reduction in the number of new infections. Also, the higher levels of mask coverage result in an earlier reduction in disease spread risk. These results can be used by decision makers to guide policy on face mask use for public transport networks.

Silicon nitride optical phased array based on a grating antenna enabling wavelength-tuned beam steering.

An optical phased array (OPA) in silicon nitride (SiN) is conspicuously highlighted as a vital alternative to its counterpart in silicon. However, a limited number of studies have been conducted on this array in terms of wavelength-tuned beam steering. A SiN OPA has been proposed and implemented with a grating antenna that incorporated an array of shallow-etched waveguides, rendering wavelength-tuned beam steering along the longitudinal direction. To accomplish a superior directionality on a wavelength-tuned beam steering, the spectral beam emission characteristics of the antenna have been explored from the viewpoint of a planar structure that entails a buried oxide (BOX), a SiN waveguide core, and an upper cladding. Two OPA devices having substantially different thicknesses of the resonant cavities, established by combining the BOX and SiN core, were considered theoretically and experimentally to scrutinize the spectral emission characteristics of the antenna on beam steering. Both of the fabricated OPA devices steered light by an angle of 7.4° along the longitudinal direction for a wavelength ranging from 1530 to 1630 nm, while they maintained a divergence angle of 0.2°×0.6° in the longitudinal and lateral directions. Meanwhile, the OPA fabricated on a substantially thick BOX layer featured a limited steering performance to attain a stabilized response over a broad spectral region. We examined the influence of the cavity thickness on the spectral response of the antenna in terms of optical thickness. Based on the two antenna characteristics, it was confirmed that the grating antenna emitted the beam with a higher efficiency when the optical thickness of the cavity corresponded to odd integer multiples of the quarter wavelength. This work is a considerable strategy for designing a stabilized SiN OPA over a desired spectral region.

Highly efficient broadband silicon nitride polarization beam splitter incorporating serially cascaded asymmetric directional couplers.

The implementation of a polarization beam splitter (PBS) on a silicon nitride platform remains challenging owing to its relatively low index. We therefore propose a silicon nitride PBS that exploits serially cascaded asymmetric directional couplers (ADCs), leading to a high polarization extinction ratio (PER) over a broad bandwidth. The ADC spatially routes incident light through polarization-selective mode coupling under a small footprint of 112 µm. The proposed PBS does not require an active phase control. It is thus effectively realized via a single-step lithography process. The measured transverse-electric and transverse-magnetic PERs were determined to be above 23 dB and 10 dB over an 80-nm bandwidth, respectively, spanning λ=1520-1600nm. The proposed device is thus anticipated to play a key role in providing polarization diversity in photonic-integrated circuits.

All-Around Electromagnetic Wave Absorber Based on Ni-Zn Ferrite.

Exploring a convenient, scalable, yet effective broadband electromagnetic wave absorber (EMA) in the gigahertz (GHz) region is of high interest today to quench its expanding demand. Ni-Zn ferrite is considered as a potential EMA; however, their performance study as a scalable effective millimeter-length absorber is still limited. Herein, we investigated EM wave attenuation properties of Ni0.5Zn0.5Fe2O4 (NZF) samples substituting Mn ion in place of Fe3+ as well as Zn2+ within a widely used frequency range of 0.1-9 GHz. Through composition optimization, Ni0.5Zn0.4Mn0.1Fe2O4 (NZM0.1F) EMA demonstrates excellent microwave absorption performance accompanied by simultaneous maximum reflection loss (RL) of -50.2 dB and wide BW of 6.8 GHz (with RL < -10 dB, i.e., attenuation >90%) at an optimum thickness of 6 mm. Moreover, the attenuation constant significantly increases from ∼217 to 301 Np/m with Mn doping. The key contribution arises from magnetic-dielectric properties synergy along with enhanced dielectric and magnetic losses owing to cation chemistry and site occupation in spinel NZF. In addition, porosity is induced in the system by a controlled two-step heat treatment process that promotes total loss with multiple internal reflections of the EM wave. Furthermore, RL is simulated by varying incident EM wave angles for the NZM0.1F sample displaying its angle insensitivity up to 50°. Our results reveal NZM0.1F as a futuristic environment-friendly microwave absorber material that is suitable for practical high-frequency applications.

Years lived with disability (YLDs) for 1160 sequelae of 289 diseases and injuries 1990-2010: a systematic analysis for the Global Burden of Disease Study 2010.

BACKGROUND: Non-fatal health outcomes from diseases and injuries are a crucial consideration in the promotion and monitoring of individual and population health. The Global Burden of Disease (GBD) studies done in 1990 and 2000 have been the only studies to quantify non-fatal health outcomes across an exhaustive set of disorders at the global and regional level. Neither effort quantified uncertainty in prevalence or years lived with disability (YLDs). METHODS: Of the 291 diseases and injuries in the GBD cause list, 289 cause disability. For 1160 sequelae of the 289 diseases and injuries, we undertook a systematic analysis of prevalence, incidence, remission, duration, and excess mortality. Sources included published studies, case notification, population-based cancer registries, other disease registries, antenatal clinic serosurveillance, hospital discharge data, ambulatory care data, household surveys, other surveys, and cohort studies. For most sequelae, we used a Bayesian meta-regression method, DisMod-MR, designed to address key limitations in descriptive epidemiological data, including missing data, inconsistency, and large methodological variation between data sources. For some disorders, we used natural history models, geospatial models, back-calculation models (models calculating incidence from population mortality rates and case fatality), or registration completeness models (models adjusting for incomplete registration with health-system access and other covariates). Disability weights for 220 unique health states were used to capture the severity of health loss. YLDs by cause at age, sex, country, and year levels were adjusted for comorbidity with simulation methods. We included uncertainty estimates at all stages of the analysis. FINDINGS: Global prevalence for all ages combined in 2010 across the 1160 sequelae ranged from fewer than one case per 1 million people to 350,000 cases per 1 million people. Prevalence and severity of health loss were weakly correlated (correlation coefficient -0·37). In 2010, there were 777 million YLDs from all causes, up from 583 million in 1990. The main contributors to global YLDs were mental and behavioural disorders, musculoskeletal disorders, and diabetes or endocrine diseases. The leading specific causes of YLDs were much the same in 2010 as they were in 1990: low back pain, major depressive disorder, iron-deficiency anaemia, neck pain, chronic obstructive pulmonary disease, anxiety disorders, migraine, diabetes, and falls. Age-specific prevalence of YLDs increased with age in all regions and has decreased slightly from 1990 to 2010. Regional patterns of the leading causes of YLDs were more similar compared with years of life lost due to premature mortality. Neglected tropical diseases, HIV/AIDS, tuberculosis, malaria, and anaemia were important causes of YLDs in sub-Saharan Africa. INTERPRETATION: Rates of YLDs per 100,000 people have remained largely constant over time but rise steadily with age. Population growth and ageing have increased YLD numbers and crude rates over the past two decades. Prevalences of the most common causes of YLDs, such as mental and behavioural disorders and musculoskeletal disorders, have not decreased. Health systems will need to address the needs of the rising numbers of individuals with a range of disorders that largely cause disability but not mortality. Quantification of the burden of non-fatal health outcomes will be crucial to understand how well health systems are responding to these challenges. Effective and affordable strategies to deal with this rising burden are an urgent priority for health systems in most parts of the world. FUNDING: Bill & Melinda Gates Foundation.

Disability-adjusted life years (DALYs) for 291 diseases and injuries in 21 regions, 1990-2010: a systematic analysis for the Global Burden of Disease Study 2010.

BACKGROUND: Measuring disease and injury burden in populations requires a composite metric that captures both premature mortality and the prevalence and severity of ill-health. The 1990 Global Burden of Disease study proposed disability-adjusted life years (DALYs) to measure disease burden. No comprehensive update of disease burden worldwide incorporating a systematic reassessment of disease and injury-specific epidemiology has been done since the 1990 study. We aimed to calculate disease burden worldwide and for 21 regions for 1990, 2005, and 2010 with methods to enable meaningful comparisons over time. METHODS: We calculated DALYs as the sum of years of life lost (YLLs) and years lived with disability (YLDs). DALYs were calculated for 291 causes, 20 age groups, both sexes, and for 187 countries, and aggregated to regional and global estimates of disease burden for three points in time with strictly comparable definitions and methods. YLLs were calculated from age-sex-country-time-specific estimates of mortality by cause, with death by standardised lost life expectancy at each age. YLDs were calculated as prevalence of 1160 disabling sequelae, by age, sex, and cause, and weighted by new disability weights for each health state. Neither YLLs nor YLDs were age-weighted or discounted. Uncertainty around cause-specific DALYs was calculated incorporating uncertainty in levels of all-cause mortality, cause-specific mortality, prevalence, and disability weights. FINDINGS: Global DALYs remained stable from 1990 (2·503 billion) to 2010 (2·490 billion). Crude DALYs per 1000 decreased by 23% (472 per 1000 to 361 per 1000). An important shift has occurred in DALY composition with the contribution of deaths and disability among children (younger than 5 years of age) declining from 41% of global DALYs in 1990 to 25% in 2010. YLLs typically account for about half of disease burden in more developed regions (high-income Asia Pacific, western Europe, high-income North America, and Australasia), rising to over 80% of DALYs in sub-Saharan Africa. In 1990, 47% of DALYs worldwide were from communicable, maternal, neonatal, and nutritional disorders, 43% from non-communicable diseases, and 10% from injuries. By 2010, this had shifted to 35%, 54%, and 11%, respectively. Ischaemic heart disease was the leading cause of DALYs worldwide in 2010 (up from fourth rank in 1990, increasing by 29%), followed by lower respiratory infections (top rank in 1990; 44% decline in DALYs), stroke (fifth in 1990; 19% increase), diarrhoeal diseases (second in 1990; 51% decrease), and HIV/AIDS (33rd in 1990; 351% increase). Major depressive disorder increased from 15th to 11th rank (37% increase) and road injury from 12th to 10th rank (34% increase). Substantial heterogeneity exists in rankings of leading causes of disease burden among regions. INTERPRETATION: Global disease burden has continued to shift away from communicable to non-communicable diseases and from premature death to years lived with disability. In sub-Saharan Africa, however, many communicable, maternal, neonatal, and nutritional disorders remain the dominant causes of disease burden. The rising burden from mental and behavioural disorders, musculoskeletal disorders, and diabetes will impose new challenges on health systems. Regional heterogeneity highlights the importance of understanding local burden of disease and setting goals and targets for the post-2015 agenda taking such patterns into account. Because of improved definitions, methods, and data, these results for 1990 and 2010 supersede all previously published Global Burden of Disease results. FUNDING: Bill & Melinda Gates Foundation.

Multiobjective Optimization of Silver-Nanowire Deposition for Flexible Transparent Conducting Electrodes.

Optimizing the spin coating of silver nanowires to form transparent conducting electrodes (TCE) is guided by machine learning (ML). A good TCE has two competing characteristics: high transmittance and high conductance. Optimization using a scalar figure of merit, as often done in the field, cannot satisfy the independent requirements for transmittance and conductance imposed by specific applications. By performing a Pareto front analysis based on ML models, we show that the desired outcomes of transmittance ≥ 75% and sheet resistance ≤ 15 Ω/sq are challenging but can be achieved using processing parameters identified by ML analysis.

Reconfigurable fiber-to-waveguide coupling module enabled by phase-change material incorporated switchable directional couplers.

In silicon photonics, grating-assisted fiber-to-waveguide couplers provide out-of-plane coupling to facilitate wafer-level testing; however, their limited bandwidth and efficiency restrict their use in broadband applications. Alternatively, end-fire couplers overcome these constraints but require a dicing process prior usage, which makes them unsuitable for wafer-level testing. To address this trade-off, a reconfigurable fiber-to-waveguide coupling module is proposed and designed to allow for both grating-assisted and end-fire coupling in the same photonic circuit. The proposed module deploys a switchable directional coupler incorporating a thin layer of phase-change material, whose state is initially amorphous to render the coupler activated and hence facilitate grating-assisted coupling for wafer-level testing. The state can be altered into crystalline through a low-temperature annealing process to deactivate the directional coupler, thus facilitating broadband chip-level coupling through end-fire couplers. All the components encompassing conjoined switchable directional couplers as well as the grating and end-fire couplers were individually designed through rigorous simulations. They were subsequently assembled to establish the proposed reconfigurable coupling module, which was simulated and analyzed to validate the selective coupling operation. The proposed module gives rise to a low excess loss below 1.2 dB and a high extinction ratio over 13 dB throughout the C-band, when operating either under grating-assisted or end-fire input. The proposed reconfigurable coupling module is anticipated to be a practical solution for flexibly expediting the inspection of integrated photonic circuits on a wafer scale.

Dispersive silicon-nitride optical phased array incorporating arrayed waveguide delay lines for passive line beam scanning.

As optical phased arrays (OPAs), used as solid-state beam scanning elements, swiftly stride towards higher efficiency and faster scanning speed, the line beam scanner is emerging as a viable substitute for its counterpart relying on point-beam-incorporated raster scanning. However, line-beam scanners require active phase shifters for beam scanning; thus, they consume more power and have complex device designs. This study proposes and demonstrates a dispersive silicon-nitride OPA that allows for passive wavelength-tuned steering of a line beam with an elongated vertical beamwidth. To steer the line beam passively covering the two-dimensional field of view, we deployed an array of delay lines with progressive delay lengths across adjacent channels. Furthermore, adiabatic tapers that allow precise effective array aperture adjustment are used as emitter elements to flexibly realize different vertical beamwidths. Combinations of different delay-length differences and taper tip-widths resulted in beam coverage (lateral × vertical) ranging from 6.3° × 19° to 23.8° × 40° by tuning the wavelength from 1530 to 1600 nm. The main lobe emission throughput was as small as - 2.8 dB. To the best of our knowledge, the embodied OPA is the first demonstration of a passive line beam scanner facilitating an adjustable beam coverage with quick operation and enhanced efficiency.

Comprehensive evaluation of cardiovascular efficacy and safety outcomes of SGLT2 inhibitors in high risk patients of cardiovascular disease: systematic review and meta-analysis.

OBJECTIVES: To demonstrate a magnitude of the cardiovascular benefits, concomitantly analyzing the safety outcomes of sodium-glucose cotransporter 2 inhibitor (SGLT2-I) comprehensively, as a class effect in a larger sample size combined from recent randomized control trials. METHODS: We searched electronic databases using specific terms and evaluated 6 efficacy and 10 safety outcomes. Odds ratios (ORs) and 95% confidence interval (CI) were used to compare two interventions. RESULTS: Five studies (n = 41 267) were included, among which 23 539 received SGLT2-I. The SGLT2-I group favored reduction in major adverse cardiovascular events (OR, 0.78; 95% CI, 0.62-0.98; P = 0.03), cardiovascular death (CVD) or heart failure hospitalization (OR, 0.60; 95% CI, 0.46-0.80; P = 0.0004), rate of hospitalization for heart failure (OR, 0.56; 95% CI, 0.44-0.72; P < 0.00001), CVD (OR, 0.68; 95% CI, 0.50-0.93; P = 0.01), all-cause mortality (OR, 0.67; 95% CI, 0.48-0.93; P = 0.02) and myocardial infarction (OR, 0.79; 95% CI, 0.64-0.99; P = 0.04) when compared to the placebo group. Safety analysis showed higher diabetic ketoacidosis (DKA) rate in SGLT2-I group (OR, 2.33; 95% CI, 1.40-3.90; P = 0.001); in contrast, major hypoglycemic events were significantly lower (OR, 0.79; 95% CI, 0.73-0.87; P < 0.00001). AKI was significantly higher in the placebo group (OR, 0.76; 95% CI, 0.65-0.88; P = 0.0004). There were no statistically significant effects on other outcomes. CONCLUSION: In selected high-risk patients of cardiovascular disease, the SGLT2-I is a potential effective class of drugs for improving cardiovascular outcomes and all-cause mortality without an increased risk of all other major complications except DKA on this meta-analysis.

Meta-Analysis Evaluating Outcomes of Surgical Left Atrial Appendage Occlusion During Cardiac Surgery.

Surgical left atrial appendage occlusion (S-LAAO) has become a common procedure performed in patients undergoing cardiac surgery; however, evidence to support this procedure remains inconclusive. This meta-analysis aims to assess the efficacy of S-LAAO in terms of ischemic stroke, postoperative atrial fibrillation, and all-cause mortality. A thorough literature review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. We identified 10 relevant studies for our meta-analysis. It included 6,779 patients who underwent S-LAAO and 6,573 who did not undergo LAAO. In terms of ischemic stroke, the S-LAAO cohort had a lower events (pooled odds ratio [OR] 0.655 (0.518 to 0.829), p = 0.0004) compared with the non-LAAO cohort. S-LAAO cohort also had lower events of all-cause mortality (pooled OR 0.74 (95% confidence interval 0.55 to 0.99), p = 0.0408) when compared with the non-LAAO cohort. In regards to postoperative atrial fibrillation, there was no difference between the 2 groups (pooled OR 1.29 (95% confidence interval 0.81 to 2.06), p = 0.2752). In conclusion, S-LAAO was associated with lower events of ischemic stroke or systemic embolism and all-cause mortality when compared to the non-LAAO group.

Hepatic Involvement in Systemic Sarcoidosis.

BACKGROUND Sarcoidosis is a systemic disease that can affect any organ, including the liver. It is manifested by the presence of non-caseating granulomas within involved organs, most commonly the pulmonary, lymphatic, and hepatic system. Unlike pulmonary or lymphatic involvement, hepatic involvement is usually asymptomatic and it is underdiagnosed. Here, we report a case of a patient with a history of pulmonary sarcoidosis who developed hepatic sarcoidosis. CASE REPORT 68-year-old female with pulmonary sarcoidosis with a 2-week history of severe abdominal pain and epigastric tenderness presented to our center. Abdominal magnetic resonance imaging (MRI) demonstrated mild hepatic fibrosis and cirrhosis. A thorough workup was performed including a liver biopsy which showed chronic non-necrotizing granulomas consistent with sarcoidosis. She was started on prednisone and subsequently improved. The patient was symptom-free on follow-up 1 month later. CONCLUSIONS The majority of patients with hepatic sarcoidosis are usually asymptomatic, with only 5-30% presenting with abdominal pain, jaundice, nausea, vomiting, and hepatosplenomegaly. In rare cases, hepatic sarcoidosis can lead to cholestasis, portal hypertension, cirrhosis, or Budd-Chiari syndrome. Treatment with steroids is the mainstay of therapy; however, in severe cases, patients may require liver transplantation. This case report demonstrates that hepatic sarcoidosis is a serious condition, and if not treated, can lead to portal hypertension and cirrhosis. In patients with sarcoidosis, early detection and longitudinal follow-up is important in preventing overt liver failure.

Lung Cancer Screening in the Community Setting.

BACKGROUND: Lung cancer has high incidence and high mortality burden, particularly because it is typically diagnosed in later stages. The National Lung Screening Trial demonstrated a lung cancer-specific mortality benefit in high-risk current and former smokers with yearly low-dose chest computed tomography (CT). Lung cancer screening is thus recommended, but it is unclear whether the results of the National Lung Screening Trial can be replicated in community settings. METHODS: A retrospective review was performed of the lung screening program over its first 5 years, 2012 to 2016. Patients' demographics, initial screening results, follow-up, and management results were analyzed in relation to the National Lung Screening Trial results. Annual adherence was defined as returning for imaging within 1 year + 90 days. RESULTS: A total of 1,241 persons underwent initial screening over the 5-year period; 78.6% of findings were benign, and only annual repeat low-dose chest CT was recommended. A total of 29 cancers were identified in 26 participants (2%), of which 72% were stage I. The annual adherence rate to repeat imaging after a low-risk baseline scan was 37%, and the any follow-up rate was 51% despite programmatic efforts to follow screening recommendations. When positive findings required more intensive evaluation, most commonly by repeat chest CT scan, adherence was 88%. A total of 1.1% of all participants had invasive biopsies for benign results. Complications of biopsy were minimal. CONCLUSIONS: This review demonstrates that a community-based program can approximate the results of the National Lung Screening Trial in detecting early lung cancers. Further study of the adherence phenomenon is essential.

Social inequalities in adult oral health in 40 low- and middle-income countries.

OBJECTIVE: This study evaluated social inequalities in adult oral health across several low- and middle-income countries. METHODS: We used data from 40 countries that participated in the World Health Surveys. Participants' socio-economic position was assessed using the wealth index. Oral health was assessed using two perceived measures, namely total tooth loss and whether they had any problems with their mouth and/or teeth during the last 12 months (perceived needs). Absolute and relative wealth inequalities in oral health were measured using the slope index of inequality (SII) and the relative index of inequality (RII), respectively, after adjusting for participants' sex, age and education. RESULTS: There were wealth inequalities in total tooth loss and perceived needs in most countries. However, significant monotonic gradients were found in 21 countries for total tooth loss and in 18 countries for perceived needs. Two distinctive patterns of social inequality in oral health were found across countries using the RII and the SII. For total tooth loss, pro-rich inequality was found in 25 countries (significant RII/SII in eight countries) and pro-poor inequality was found in 15 (significant RII/SII in three countries). For perceived needs, pro-poor inequality was found in 26 countries (significant RII/SII in six countries) and pro-rich inequality was found in 14 (significant RII/SII in five countries). CONCLUSIONS: The well-documented social gradient in adult oral health favouring the rich was not present in all low- and middle-income countries. Pro-poor inequalities in total tooth loss, and particularly in perceived dental-treatment needs, were observed in some countries.

Income inequality, disinvestment in health care and use of dental services.

OBJECTIVE: To explore the interrelationships between income inequality, disinvestment in health care, and use of dental services at country level. METHODS: This study pooled national estimates for use of dental services among adults aged 18 years or older from the 70 countries that participated in the World Health Survey from 2002 to 2004, together with aggregate data on national income (GDP per capita), income inequality (Gini coefficient), and disinvestment in health care (total health expenditure and dentist-to-population ratio) from various international sources. Use of dental services was defined as having had dental problems in the last 12 months and having received any treatment to address those needs. Associations between variables were explored using Pearson correlation coefficients and linear regression. RESULTS: Data from 63 countries representing the six WHO regions were analyzed. Use of dental services was negatively correlated with Gini coefficient (Pearson correlation coefficient -0.48, P < 0.001) and positively correlated with GDP per capita (0.40, P < 0.05), total health expenditure (0.45, P < 0.001), and dentist-to-population ratio (0.67, P < 0.001). The association between Gini coefficient and use of dental services was attenuated but remained significant after adjustments for GDP per capita, total health expenditure, and dentist-to-population ratio (regression coefficient -0.36; 95% CI -0.57, -0.15). CONCLUSION: This study shows an inverse relationship between income inequality and use of dental services. Of the two indicators of disinvestment in health care assessed, only dentist-to-population ratio was associated with income inequality and use of dental services.