bluuebunny/crossref_metadata_2025 huggingface dataset:
Formulation of diffraction efficiencies of binary phase gratings for array illumination with ultrashort pulse beams
Authors: Amako Jun , Nakano Hidetoshi
Published: October 2021

We present simple formulas for the diffraction efficiencies of a binary
phase grating that performs array illumination with ultrashort pulse
beams. Using scalar diffraction theory, we formulated the efficiencies
as a function of pulse spectral width by Fourier-transforming the
complex-modulated frequency spectra of diffracted pulses in the
far-field region. From the analytical simulations, we found that pulse
array uniformity departs from unity as the spectral width increases,
or the pulse duration decreases, thereby limiting the attainable split
counts. This finding can be considered in the design of gratings for
delivering controlled amounts of pulse energies to diffraction orders
of interest.
K-series approximation of vectorial optical fields for designing diffractive optical elements with subwavelength feature sizes
Authors: Ho I-Lin
Published: October 2021

Diffractive optical elements (DOEs) are widely applied as compact solutions for desired light manipulations via wavefront shaping. Recent advanced chip applications further require their feature sizes to move down to the subwavelength, which inevitably brings forth vectorial effects of optical fields and makes the typical scalar-based theory invalid. However, simulating and optimizing their vectorial fields, which are associated with billions of adjustable parameters in the optical element, are difficult to do, because of the issues of numerical stability and the highly-demanding computational cost. To address this problem, this research proposes an applicable algorithm by means of a wave-vector (k) series approximation of vectorial optical fields. On the basis of the semi-analytical rigorous coupled wave analysis (RCWA), an adequate selection scheme on k-series enables computationally efficient yet still predictive calculations for DOEs. The performance estimations for exemplary designs by the finite difference time domain (FDTD) method show that the predicted intensity profiles by the proposed algorithm agree with the target by just a fractional error. Together with optimizing the geometrical degrees of freedom (e.g., DOE depth h) as compensation for errors from the truncation of k-series, the algorithm demonstrates its outperformance by one or two orders of magnitude in accuracy versus the scalar-based model, and demands only a reasonable computational resource.
Highly sensitive detection of plant growth regulators by using terahertz time-domain spectroscopy combined with metamaterials
Authors: Du Xiaoxue , Zhang Xiaodong , Wang Yafei , Ma Guoxin , Liu Yong , Wang Bin , Mao Hanping
Published: October 2021

The rapid and sensitive detection of plant-growth-regulator (PGR) residue is essential for ensuring food safety for consumers. However, there are many disadvantages in current approaches to detecting PGR residue. In this paper, we demonstrate a highly sensitive PGR detection method by using terahertz time-domain spectroscopy combined with metamaterials. We propose a double formant metamaterial resonator based on a split-ring structure with titanium-gold nanostructure. The metamaterial resonator is a split-ring structure composed of a titanium-gold nanostructure based on polyimide film as the substrate. Also, terahertz spectral response and electric field distribution of metamaterials under different analyte thickness and refractive index were investigated. The simulation results showed that the theoretical sensitivity of resonance peak 1 and peak 2 of the refractive index sensor based on our designed metamaterial resonator approaches 780 and 720 gigahertz per refractive index unit (GHz/RIU), respectively. In experiments, a rapid solution analysis platform based on the double formant metamaterial resonator was set up and PGR residues in aqueous solution were directly and rapidly detected through terahertz time-domain spectroscopy. The results showed that metamaterials can successfully detect butylhydrazine and N-N diglycine at a concentration as low as 0.05 mg/L. This study paves a new way for sensitive, rapid, low-cost detection of PGRs. It also means that the double formant metamaterial resonator has significant potential for other applications in terahertz sensing.
Sensitivity tailoring of an all-fiber bend sensor based on a dual-core fiber unbalanced Michelson interferometer
Authors: Budnicki Dawid , Parola Itxaso , Szostkiewicz Łukasz , Markiewicz Krzysztof , Wilczyński Krzysztof , Kuklińska Małgorzata , Mergo Paweł , Napierała Marek , Nasiłowski Tomasz
Published: October 2021

In this work, a compact all-fiber bend sensor based on a dual-core microstructured optical fiber has been manufactured and characterized. The sensor relies on the unbalanced Michelson interferometric technique realized by attaching a piece of silica fiber to one of the fiber cores acting as the unbalancing element. Three probes with different lengths of the unbalancing element have been experimentally tested for sensitivity tailoring analysis. Additionally, a theoretical model has been developed for comparison and verification of the results. Good linear behavior of the spectral shift with bend has been measured and it has been proven that the sensitivity of the sensor depends on the length of the unbalancing element and the orientation of the cores. Higher sensitivities are achieved for shorter lengths of the unbalancing element and orientation of the core axis parallel to the bend direction. The highest sensitivity reported is 9.97 pm/µm for the case of 34 µm of unbalancing element and orientation of 0 degrees.
Optimization of retina-like illumination patterns in ghost imaging
Authors: Cao Jie , Zhou Dong , Zhang Yingqiang , Cui Huan , Zhang Fanghua , Zhang Kaiyu , Hao Qun
Published: October 2021

Ghost imaging (GI) reconstructs images using a single-pixel or bucket detector, which has the advantages of scattering robustness, wide spectrum, and beyond-visual-field imaging. However, this technique needs large amounts of measurements to obtain a sharp image. Numerous methods are proposed to overcome this disadvantage. Retina-like patterns, as one of the compressive sensing approaches, enhance the imaging quality of the region of interest (ROI) while maintaining measurements. The design of the retina-like patterns determines the performance of the ROI in the reconstructed image. Unlike the conventional method to fill in ROI with random patterns, optimizing retina-like patterns by filling in the ROI with the patterns containing the sparsity prior of objects is proposed. The proposed method is then verified by simulations and experiments compared with conventional GI, retina-like GI, and GI using patterns optimized by principal component analysis. The method using optimized retina-like patterns obtains the best imaging quality in ROI among other methods. Meanwhile, the good generalization capability of the optimized retina-like pattern is also verified. The feature information of the target can be obtained while designing the size and position of the ROI of retina-like patterns to optimize the ROI pattern. The proposed method facilitates the realization of high-quality GI.
Plasmonic alloy nanochains assembled via dielectrophoresis for ultrasensitive SERS
Authors: Dong Jun , Zhao Kangzhe , Wang Qianying , Yuan Jiaxin , Han Qingyan , Gao Wei , Wang Yongkai , Qi Jianxia , Sun Mengtao
Published: October 2021

It is great challenge and interesting for researchers to fabricate substrates for enhanced Raman and sensor, and assemble some easy-to-synthesize metallic nanomaterials into controllable nanostructures with special morphologies and arrangements, via alternating current (AC) electric field. The Au-Ag alloy nanoparticles (Au-Ag alloy NPs) colloidal suspension with excellent dispersibility synthesized by wet chemical method, and the morphology of the assembly can be well controlled by regulating the frequency of the AC electric field. Au-Ag alloy nanochains array (Au-Ag ANCs) with dense plasmonic “hot spots” is formed when the AC electric field of 4Vpp-30kHz is applied, which is supported by the result of finite element method (FEM) numerical simulation. Experimental results demonstrate that Au-Ag ANCs show excellent SERS activity: Au-Ag ANCs can detect both Rhodamine 6G (Rh6G) and crystal violet (CV) in the magnitude order of 10−10 M, and the Raman peaks intensity and analyte concentration has a strong linear correlation (R2 is 0.99339 and 0.95916, respectively). Besides, the introduction of Au-Ag ANCs makes the Raman spectra intensity of thiram (a pesticide) with a concentration of 30 ppm on the surface of the blank ITO glass significantly enhanced, and it can detect thiram with a concentration as low as 0.03 ppm. In addition, Au-Ag ANCs substrate exhibits great uniformity and stability, so they have considerable application potential in the field of quantitative detection of trace substances.
Phase-only color rainbow holographic near-eye display
Authors: Yang Xin , Jiao Shuming , Song Qiang , Ma Guo-Bin , Cai Weiwei
Published: October 2021

Color rainbow holography can realize color holographic 3D display without speckle noise under white light illumination. However, traditional color rainbow holograms used for high-resolution static color 3D display or near-eye color display are amplitude-type, resulting in low diffraction efficiency due to the presence of conjugate light. In this Letter, a phase-only color rainbow holographic near-eye display is demonstrated. The calculation of a phase-only color rainbow hologram is realized by combining a band-limited diffraction and a bi-directional error diffusion algorithm with high-frequency blazed gratings coded to control longitudinal dispersion. When the wavelength of illumination light is deviated from the designated wavelength of the hologram, only a certain wavefront aberration is caused, but there is no conjugate light. The phase-only color rainbow holographic near-eye display of both a 2D color image and a 3D scene are implemented by optical experiments. It has potential applications in head-mounted 3D augmented reality displays without vergence-accommodation conflict.
Reversible fast to slow-light transition originating in the optical analog of EIA-EIT transformation in optical resonators
Authors: Naweed Ahmer
Published: October 2021

Coupled-resonator-induced transparency (CRIT) and coupled-resonator-induced absorption (CRIA) are the all-optical analogs of electromagnetically induced transparency (EIT) and electromagnetically induced absorption (EIA), and enable an optical pulse to propagate subluminally and superluminally in integrated photonic systems, respectively. Here, we describe the results of a theoretical study, which reveals a reversible CRIA-CRIT transition using coupled optical ring resonators. Analogous to the dispersion reversal occurring in the EIA-EIT transition, the dispersion also reverses during the CRIA-CRIT transition. Besides the EIA-EIT crossover analogy, we describe additional analogs of the coherent atomic phenomena arising in the CRIA-CRIT transition. We also discuss the specific conditions that lead to strongly enhanced dispersion. Furthermore, in contrast to the previous studies on coupled resonators, we reveal acquiring a critically and undercoupled slow-light CRIT from an overcoupled fast-light CRIA. Our experimentally viable study provides a route for the dynamic control and reversal of dispersion, which, among other, is important for quantum information technology, the Fresnel light dragging effect, temporal cloaking, and enhanced performance of the optical devices.
Incidence and predictors of attrition among patients receiving ART in eastern Zimbabwe before, and after the introduction of universal ‘treat-all’ policies: A competing risk analysis
Authors: Tlhajoane Malebogo , Dzamatira Freedom , Kadzura Noah , Nyamukapa Constance , Eaton Jeffrey W. , Gregson Simon
Published: October 2021

As HIV treatment is expanded, attention is focused on minimizing attrition from care. We evaluated the impact of treat-all policies on the incidence and determinants of attrition amongst clients receiving ART in eastern Zimbabwe. Data were retrospectively collected from the medical records of adult patients (aged≥18 years) enrolled into care from July 2015 to June 2016—pre-treat-all era, and July 2016 to June 2017—treat-all era, selected from 12 purposively sampled health facilities. Attrition was defined as an absence from care >90 days following ART initiation. Survival-time methods were used to derive incidence rates (IRs), and competing risk regression used in bivariate and multivariable modelling. In total, 829 patients had newly initiated ART and were included in the analysis (pre-treat-all 30.6%; treat-all 69.4%). Incidence of attrition (per 1000 person-days) increased between the two time periods (pre-treat-all IR = 1.18 (95%CI: 0.90–1.56) versus treat-all period IR = 1.62 (95%CI: 1.37–1.91)). In crude analysis, patients at increased risk of attrition were those enrolled into care during the treat-all period, <34 years of age, WHO stage I at enrolment, and had initiated ART on the same day as HIV diagnosis. After accounting for mediating clinical characteristics, the difference in attrition between the pre-treat-all, and treat-all periods ceased to be statistically significant. In a full multivariable model, attrition was significantly higher amongst same-day ART initiates (aSHR = 1.47, 95%CI:1.05–2.06). Implementation of treat-all policies was associated with an increased incidence of ART attrition, driven largely by ART initiation on the same day as HIV diagnosis which increased significantly in the treat all period. Differentiated adherence counselling for patients at increased risk of attrition, and improved access to clinical monitoring may improve retention in care.
Estimating the mortality burden of large scale mining projects—Evidence from a prospective mortality surveillance study in Tanzania
Authors: Lyatuu Isaac , Winkler Mirko S. , Loss Georg , Farnham Andrea , Dietler Dominik , Fink Günther
Published: October 2021

We set up a mortality surveillance system around two of the largest gold mines in Tanzania between February 2019 and February 2020 to estimate the mortality impact of gold mines. Death circumstances were collected using a standardized verbal autopsy tool, and causes of death were assigned using the InSilicoVA algorithm. We compared cause-specific mortality fractions in mining communities with other subnational data as well as national estimates. Within mining communities, we estimated mortality risks of mining workers relative to other not working at mines. At the population level, mining communities had higher road-traffic injuries (RTI) (risk difference (RD): 3.1%, Confidence Interval (CI): 0.4%, 5.9%) and non-HIV infectious disease mortality (RD: 5.6%, CI: 0.8%, 10.3%), but lower burden of HIV mortality (RD: -5.9%, CI: -10.2%, -1.6%). Relative to non-miners living in the same communities, mining workers had over twice the mortality risk (relative risk (RR): 2.09, CI: 1.57, 2.79), with particularly large increases for death due to RTIs (RR: 14.26, CI: 4.95, 41.10) and other injuries (RR:10.10, CI: 3.40, 30.02). Our results shows that gold mines continue to be associated with a large mortality burden despite major efforts to ensure the safety in mining communities. Given that most of the additional mortality risk appears to be related to injuries programs targeting these specific risks seem most desirable.
Vaccine rollout strategies: The case for vaccinating essential workers early
Authors: Mulberry Nicola , Tupper Paul , Kirwin Erin , McCabe Christopher , Colijn Caroline
Published: October 2021

In vaccination campaigns against COVID-19, many jurisdictions are using age-based rollout strategies, reflecting the much higher risk of severe outcomes of infection in older groups. In the wake of growing evidence that approved vaccines are effective at preventing not only adverse outcomes, but also infection, we show that such strategies are less effective than strategies that prioritize essential workers. This conclusion holds across numerous outcomes, including cases, hospitalizations, Long COVID (cases with symptoms lasting longer than 28 days), deaths and net monetary benefit. Our analysis holds in regions where the vaccine supply is limited, and rollout is prolonged for several months. In such a setting with a population of 5M, we estimate that vaccinating essential workers sooner prevents over 200,000 infections, over 600 deaths, and produces a net monetary benefit of over $500M.
Job satisfaction among healthcare workers in Ghana and Kenya during the COVID-19 pandemic: Role of perceived preparedness, stress, and burnout
Authors: Afulani Patience A. , Nutor Jerry John , Agbadi Pascal , Gyamerah Akua O. , Musana Joseph , Aborigo Raymond A. , Odiase Osamuedeme , Getahun Monica , Ongeri Linnet , Malechi Hawa , Madadi Moses Obimbo , Arhinful Benedicta , Kelly Ann Marie , Awoonor-Williams John Koku
Published: October 2021

The COVID-19 pandemic has affected job satisfaction among healthcare workers; yet this has not been empirically examined in sub-Saharan Africa (SSA). We addressed this gap by examining job satisfaction and associated factors among healthcare workers in Ghana and Kenya during the COVID-19 pandemic. We conducted a cross-sectional study with healthcare workers (N = 1012). The two phased data collection included: (1) survey data collected in Ghana from April 17 to May 31, 2020, and (2) survey data collected in Ghana and Kenya from November 9, 2020, to March 8, 2021. We utilized a quantitative measure of job satisfaction, as well as validated psychosocial measures of perceived preparedness, stress, and burnout; and conducted descriptive, bivariable, and multivariable analysis using ordered logistic regression. We found high levels of job dissatisfaction (38.1%), low perceived preparedness (62.2%), stress (70.5%), and burnout (69.4%) among providers. High perceived preparedness was positively associated with higher job satisfaction (adjusted proportional odds ratio (APOR) = 2.83, CI [1.66,4.84]); while high stress and burnout were associated with lower job satisfaction (APOR = 0.18, CI [0.09,0.37] and APOR = 0.38, CI [0.252,0.583] for high stress and burnout respectively). Other factors positively associated with job satisfaction included prior job satisfaction, perceived appreciation from management, and perceived communication from management. Fear of infection was negatively associated with job satisfaction. The COVID-19 pandemic has negatively impacted job satisfaction among healthcare workers. Inadequate preparedness, stress, and burnout are significant contributing factors. Given the already strained healthcare system and low morale among healthcare workers in SSA, efforts are needed to increase preparedness, better manage stress and burnout, and improve job satisfaction, especially during the pandemic.
Effect of the COVID-19 pandemic on health facility delivery in Ethiopia; results from PMA Ethiopia’s longitudinal panel
Authors: Zimmerman Linnea A. , Desta Selamawit , Karp Celia , Yihdego Mahari , Seme Assefa , Shiferaw Solomon , Ahmed Saifuddin
Published: October 2021

Objectives

To examine the effect of COVID-19 on health facility delivery in Ethiopia.

Design

We used longitudinal data with a pre-post exposure to the pandemic to assess change in facility delivery patterns nationally and by urban and rural strata. We conducted design-based multivariable multinomial logistic regression comparing home, lower-level facility, and hospital delivery with date of birth as a spline term, with a knot indicating births before and on/after April 8, 2020.

Setting

Six regions in Ethiopia, covering 91% of the population.

Participants

Women were eligible to participate if they were currently pregnant or less than six weeks postpartum and were recontacted at six weeks, six months, and one year postpartum. 2,889 women were eligible and 2,855 enrolled. Data used in this paper come from the six-week interview, with a follow-up rate of 88.9% (2,537 women).

Results

In urban areas, women who delivered during the COVID-19 pandemic had a 77% reduced relative risk of delivering in a hospital relative to women who delivered prior to the pandemic (aRRR: 0.23, 95% CI: 0.07–0.71). There were no significant differences between the pre- and COVID-19 periods within rural strata where the majority of women deliver at home (55.6%). Overall, the effect was non-significant at a national level. Among women who delivered during the COVID-19 pandemic, 20.0% of urban women said COVID-19 affected where they delivered relative to 8.7% of rural women (p-value = 0.01).

Conclusion

We found that delivery patterns in urban areas changed during the early months of the COVID-19 pandemic, but there was no evidence of large-scale declines of hospital delivery at the national level. Concerns about COVID-19 transmission in health facilities and ensuring lower-level facilities are equipped to address obstetric emergencies are critical to address. COVID-19 will likely slow progress towards increasing rates of institutional delivery in urban areas in Ethiopia.
Economic impact of dengue in Singapore from 2010 to 2020 and the cost-effectiveness of Wolbachia interventions
Authors: Soh Stacy , Ho Soon Hoe , Seah Annabel , Ong Janet , Dickens Borame Sue , Tan Ken Wei , Koo Joel Ruihan , Cook Alex R. , Tan Kelvin Bryan , Sim Shuzhen , Ng Lee Ching , Lim Jue Tao
Published: October 2021

The release of Wolbachia-infected mosquitoes is a promising disease intervention strategy that aims to control dengue and other arboviral infections. While early field trials and modelling studies suggest promising epidemiological and entomological outcomes, the overall cost effectiveness of the technology is not well studied in a resource rich setting nor under the suppression approach that aims to suppress the wild-type mosquito population through the release of Wolbachia-infected males. We used economical and epidemiological data from 2010 to 2020 to first ascertain the economic and health costs of dengue in Singapore, a high income nation where dengue is hyper-endemic. The hypothetical cost effectiveness of a national Wolbachia suppression program was then evaluated historically from 2010 to 2020. We estimated that the average economic impact of dengue in Singapore from 2010 to 2020 in constant 2010US$ ranged from $1.014 to $2.265 Billion. Using empirically derived disability weights, we estimated a disease burden of 7,645–21,262 DALYs from 2010–2020. Under an assumed steady-state running cost of a national Wolbachia suppression program in Singapore, we conservatively estimate that Wolbachia would cost an estimated $50,453–$100,907 per DALYs averted and would lead to an estimated $329.40 Million saved in economic costs over 2010 to 2020 under 40% intervention efficacy. Wolbachia releases in Singapore are expected to be highly cost-effective and its rollout must be prioritised to reduce the onward spread of dengue.
Mobile health intervention for promotion of eye health literacy
Authors: Sharma Indra Prasad , Chaudhry Monica , Sharma Dhanapati , Kaiti Raju
Published: October 2021

Purpose

Improving eye health awareness in the underserved population is a universal eye health priority. The ubiquity of cell phones and internet usage provides new and innovative opportunities for health promotion. This study evaluated the effect of mobile health intervention (text message link) to promote eye health literacy (EHL) of priority ocular morbidities.

Methods

This study was an intervention evaluation and employed a two-armed pre-test post-test approach. Baseline assessment on EHL was performed on 424 university students. Participants were categorised into intervention and control groups, using the 1:1 allocation ratio. The intervention and control group received a text message alone and text message with a link, respectively. EHL was assessed via a self-administered questionnaire. The primary outcome measures were changes in EHL scores between baseline and one month post-intervention. Descriptive analysis was performed to assess the cost-effectiveness of the intervention.

Results

With low attrition and a response rate of 95.6%, 409 responses were eligible for analysis. The mean age of the participants (49.4% males and 50.6% of females) was 19.9±1.68 years. Baseline EHL scores were low, and there was no correlation with a demographic profile (all p<0.05, CI 95%). The demographic characteristics were similar between the two groups (for all, P <0.05, CI 95%) at baseline. The EHL scores improved in both groups between the pre-and post-test assessment; however, improvements were statistically significant only in the control group. The one-month post-intervention EHL scores were also higher in the intervention group compared to the control (p≤0.001, CI 95% for all). The total cost incurred for the intervention used was 11.5 USD.

Conclusion

Text message link demonstrated effectiveness for improving the EHL scores; the low baseline EHL scores substantially improved with intervention. The text message link intervention is a cost-effective method and could be considered in advocating for eye health in developing countries, particularly during global emergencies.
Health system capacity and readiness for delivery of integrated non-communicable disease services in primary health care: A qualitative analysis of the Ethiopian experience
Authors: Tesema Azeb Gebresilassie , Abimbola Seye , Mulugeta Afework , Ajisegiri Whenayon S. , Narasimhan Padmanesan , Joshi Rohina , Peiris David
Published: October 2021

Background

Non-communicable diseases (NCDs) now account for about 71% and 32% of all the deaths globally and in Ethiopia. Primary health care (PHC) is a vital instrument to address the ever-increasing burden of NCDs and is the best strategy for delivering integrated and equitable NCD care. We explored the capacity and readiness of Ethiopia’s PHC system to deliver integrated, people-centred NCD services.

Methods

A qualitative study was conducted in two regions and Federal Ministry of Health, Addis Ababa, Ethiopia. We carried out twenty-two key informant interviews with national and regional policymakers, officials from a partner organisation, woreda/district health office managers and coordinators, and PHC workers. Data were coded and thematically analysed using the World Health Organization (WHO) Operational Framework for PHC.

Results

Although the rising NCD burden is well recognised in Ethiopia, and the country has NCD-specific strategies and some interventions in place, we identified critical gaps in several levers of the WHO Operational Framework. Many compared the under-investment in NCDs contrasted with Ethiopia’s successful PHC models established for maternal and child health and communicable disease programs. Insufficient political commitment and leadership required to integrate NCD services at the PHC level and weaknesses in governance structures, inter-sectoral coordination, and funding for NCDs were identified as significant barriers to strengthening PHC capacity to address NCDs. Among the operational-focussed levers, fragmented information management systems and inadequate equipment and medicines were identified as critical bottlenecks. The PHC workforce was also considered insufficiently skilled and supported to provide NCD services in PHC facilities.

Conclusion

Strengthening NCD prevention and control through PHC in Ethiopia requires greater political commitment and investment at all health system levels. Prior success strategies with other PHC programs could be adapted and applied to NCD policies and practice, giving due consideration for the unique nature of the NCD program.
Rationalizing the design of a broad coverage Shigella vaccine based on evaluation of immunological cross-reactivity among S. flexneri serotypes
Authors: Citiulo Francesco , Necchi Francesca , Mancini Francesca , Rossi Omar , Aruta Maria Grazia , Gasperini Gianmarco , Alfini Renzo , Rondini Simona , Micoli Francesca , Rappuoli Rino , Saul Allan , Martin Laura B.
Published: October 2021

No vaccine to protect against an estimated 238,000 shigellosis deaths per year is widely available. S. sonnei is the most prevalent Shigella, and multiple serotypes of S. flexneri, which change regionally and globally, also cause significant disease. The leading Shigella vaccine strategies are based on the delivery of serotype specific O-antigens. A strategy to minimize the complexity of a broadly-protective Shigella vaccine is to combine components from S. sonnei with S. flexneri serotypes that induce antibodies with maximum cross-reactivity between different serotypes. We used the GMMA-technology to immunize animal models and generate antisera against 14 S. flexneri subtypes from 8 different serotypes that were tested for binding to and bactericidal activity against a panel of 11 S. flexneri bacteria lines. Some immunogens induced broadly cross-reactive antibodies that interacted with most of the S. flexneri in the panel, while others induced antibodies with narrower specificity. Most cross-reactivity could not be assigned to modifications of the O-antigen, by glucose, acetate or phosphoethanolamine, common to several of the S. flexneri serotypes. This allowed us to revisit the current dogma of cross-reactivity among S. flexneri serotypes suggesting that a broadly protective vaccine is feasible with limited number of appropriately selected components. Thus, we rationally designed a 4-component vaccine selecting GMMA from S. sonnei and S. flexneri 1b, 2a and 3a. The resulting formulation was broadly cross-reactive in mice and rabbits, inducing antibodies that killed all S. flexneri serotypes tested. This study provides the framework for a broadly-protective Shigella vaccine which needs to be verified in human trials.
Combined assessment of tuberculosis case notification rate and infection control at health facilities of Dale districts, Sidama Zone, Southern Ethiopia
Authors: Ali Makka Adam , Balcha Ermias Sissay , Woldesemayat Adugna Abdi , Tirore Lopisso Dessalegn
Published: October 2021

Background

Mycobacterium tuberculosis (TB) is the deadliest disease that claims millions of deaths globally. Ethiopia is among the countries heavily hit by the disaster. Despite the effective directly observed treatment and TB infection control (TBIC) measures provided by the world health organization (WHO), the rate of new cases increased daily throughout the country. Healthcare workers (HCWs) are at highest risk serving without having the necessary facility in place while overcrowding of patients exacerbated TB transmission. The study aimed to assess TBIC implementation and analyze case notification rate (CNR) of smear-positive pulmonary TB in the selected health facilities at Dale district, Sidama Zone, Southern Ethiopia.

Methods

Seven health care facilities have been visited in the study area and smear-positive pulmonary TB notification rate was determined retrospectively during the years 2012 to 2014. Data on smear positive test results and demographic characteristics were collected from the TB unit registries. A structured questionnaire, facility survey, and observation checklists were used to assess the presence of TBIC plans at the health care facilities.

Results

The overall case notification rate of smear-positive pulmonary tuberculosis was 5.3% among all 7696 TB suspected patients. The odds of being diagnosed with smear-positive TB were 24% more in males than in females (adj OR = 1.24, 95% CI: (1.22, 1.55). Moreover, in the study area, only 28% of the facilities have been practiced TB infection control and 71% of the facilities assigned a focal person for the TBIC plan. The implementation of environmental control measures in the facilities was ranged between 16–83%. N95 particulate respirators were found only in 14% of the facilities.

Conclusion

TB CNR in Dale district was low. Moreover, implementations of TBIC in Dale district health facilities were poor when the survey was done. Hence, urgent measures should be taken to reverse the burden of TB.
The needs and opportunities of older laypeople to acquire first aid skills
Authors: Dolenc Eva , Slabe Damjan , Kovačič Uroš
Published: October 2021

We aimed to determine the needs and opportunities of older lay people to obtain first aid skills. We determined the level of theoretical knowledge of performing first aid with a structured questionnaire, performed on the sample of 842 adult inhabitants of Slovenia. The method of sampling was balanced by using a system of sampling weights in order to correct deviations in the structure of the sample to the level of the population structure. We also checked their attitude regarding the renewal of first aid knowledge. The level of self-assessment of first aid knowledge and actual theoretical knowledge of proper first aid measures typically decreased with age. The percentage of those who had attended first aid courses at any time was statistically significantly lower among respondents over the age of 60; 38% of elderly respondents thought they needed to renew their first aid knowledge, and 44% would attend a suitable first aid course. None of the 29 European Red Cross and Red Crescent Societies member states that responded have a developed a formally adopted first aid program to train the elderly. A tailored first aid training program for the elderly could be one of the many steps that should be taken to ensure adequate health care for the elderly population.
Regional effects of the renewable energy components on CO2 emissions of Asia-Pacific countries
Authors: Tian Man-Wen , Yan Shu-Rong , Khezri Mohsen , Karimi Muhaamad Sharif , Mamghaderi Mahnaz , Khan Yousaf Ali
Published: October 2021

This paper utilizes spatial econometric reenactments to examine the geographic effects of different types of environmentally friendly power on corban discharges. The example covers 31 nations in the Asia-Pacific district during the time frame 2000 to 2018. The spatial connection in the model was affirmed by symptomatic testing, and the spatial Durbin model was picked as the last model. Results show that Gross domestic product per capita, receptiveness to business sectors, unfamiliar direct venture, energy force, and urbanization critically affect CO2emanations. In correlation, just wind and sunlight-based energy have added to a generous abatement in ozone harming substance emanations in nations over the long run. In contrast, hydropower, bioenergy, and geothermal energy discoveries have been irrelevant. A cross-sectional examination worldview delineated that nations with more elevated sunlight-based energy yield have higher CO2outflows, while nations with lower levels have lower CO2emanations. The presence of spatial impacts in the model gave off an impression of the negative consequences for homegrown CO2outflows of Gross domestic product per capita and exchange transparency of adjoining nations. Furthermore, energy power and higher creation of sustainable power in adjoining nations will prompt lower homegrown CO2outflows.
Description of a new halophilic tiger beetle in the genus Eunota (Coleoptera, Cicindelidae, Cicindelini) identified using morphology, phylogenetics and biogeography
Authors: Duran Daniel P. , Roman Stephen J.
Published: October 2021

Tiger beetles are a popular group of insects amongst amateur naturalists, and are well-represented in museum and private collections. New species descriptions plateaued in the 19th century, but there is a recent resurgence of discoveries as integrative taxonomy methods, guided by molecular systematics, uncover “cryptic” tiger beetle diversity. In this paper, we describe a new species using multiple data types. This new species, Eunota mecocheila Duran and Roman n. sp., is in the tribe Cicindelini, and is described from specimens collected in saline muddy ditches in northern Mexico. This species is closely related to E. circumpicta (LaFerté-Sénectère, 1841), but is separated based on morphological differences, geographic range, and genetic differentiation. Little is known about the biology or distribution of this species and it has only been collected from two sites in the state of Coahuila. Given the location of this new species, and its genetic divergence from its closest relative, E. circumpicta, we discuss the historical biogeography that may have led to isolation and speciation. The male and female dorsal, lateral and frontal habitus and the male aedeagus are shown.
These boots are made for burnin’: Inferring the position of the corpse and the presence of leather footwears during cremation through isotope (δ13C, δ18O) and infrared (FTIR) analyses of experimentally burnt skeletal remains
Authors: Salesse Kevin , Stamataki Elisavet , Kontopoulos Ioannis , Verly Georges , Annaert Rica , Boudin Mathieu , Capuzzo Giacomo , Claeys Philippe , Dalle Sarah , Hlad Marta , de Mulder Guy , Sabaux Charlotte , Sengeløv Amanda , Veselka Barbara , Warmenbol Eugène , Vercauteren Martine , Snoeck Christophe
Published: October 2021

Cremation is a complex mortuary practice, involving a number of activities of the living towards the dead before, during, and after the destruction of the bodily soft tissues by fire. The limiting information concerning these behavioral patterns obtained from the pyre remains and/or cremation deposits prevents the reconstruction of the handling of the corpse during the burning process. This pioneering study tries to determine the initial positioning of the corpse in the pyre and assess whether the deceased was wearing closed leather shoes during cremation through isotopic (δ13C, δ18O) and infrared (ATR-FTIR) analyses of experimentally burnt pig remains, used as a proxy for humans. The results obtained show that both the position of feet on or within the pyre and the presence of footwears may moderately-to-highly influence the oxygen isotope ratios of bone apatite carbonates and the cyanamide content of calcined bone in certain situations. By forming a protective layer, shoes appear to temporarily delay the burning of the underlying pig tissues and to increase the heat-shielding effect of the soft tissues protecting the bone mineral fraction. In such case, bioapatite bone carbonates exchange oxygen with a relatively more18O-depleted atmosphere (due to the influence of lignin-derived oxygen rather than cellulose-derived oxygen), resulting in more pronounced decrease in the δ18Ocarbvalues during burning of the shoed feet vs. unshoed feet. The shift observed here was as high as 2.5‰. A concomitant isotopic effect of the initial location of the feet in the pyres was also observed, resulting in a top-to-bottom decrease difference in the δ18Ocarbvalues of shoed feet of about 1.4‰ between each deposition level tested. Finally, the presence of cyanamide (CN/P ≥ 0.02) seems to be indicative of closed footwear since the latter creates favorable conditions for its incorporation into bone apatite.
Short-term outcomes of cochlear implantation for single-sided deafness compared to bone conduction devices and contralateral routing of sound hearing aids—Results of a Randomised controlled trial (CINGLE-trial)
Authors: Peters Jeroen P. M. , van Heteren Jan A. A. , Wendrich Anne W. , van Zanten Gijsbert A. , Grolman Wilko , Stokroos Robert J. , Smit Adriana L.
Published: October 2021

Single-sided deafness (SSD) leads to difficulties with speech perception in noise, sound localisation, and sometimes tinnitus. Current treatments (Contralateral Routing of Sound hearing aids (CROS) and Bone Conduction Devices (BCD)) do not sufficiently overcome these problems. Cochlear implants (CIs) may help. Our aim was to evaluate these treatments in a Randomised Controlled Trial (RCT). Adult SSD patients were randomised using a web-based randomisation tool into one of three groups: CI; trial period of ‘first BCD, then CROS’; trial period of ‘first CROS, then BCD’. After these trial periods, patients opted for BCD, CROS, or No treatment. The primary outcome was speech perception in noise (directed from the front (S0N0)). Secondary outcomes were speech perception in noise with speech directed to the poor ear and noise to the better ear (SpeNbe) and vice versa (SbeNpe), sound localisation, tinnitus burden, and disease-specific quality of life (QoL). We described results at baseline (unaided situation) and 3 and 6 months after device activation. 120 patients were randomised. Seven patients did not receive the allocated intervention. The number of patients per group after allocation was: CI (n = 28), BCD (n = 25), CROS (n = 34), and No treatment (n = 26). In S0N0, the CI group performed significantly better when compared to baseline, and when compared to the other groups. In SpeNbe, there was an advantage for all treatment groups compared to baseline. However, in SbeNpe, BCD and CROS groups performed worse compared to baseline, whereas the CI group improved. Only in the CI group sound localisation improved and tinnitus burden decreased. In general, all treatment groups improved on disease-specific QoL compared to baseline. This RCT demonstrates that cochlear implantation for SSD leads to improved speech perception in noise, sound localisation, tinnitus burden, and QoL after 3 and 6 months of follow-up. For most outcome measures, CI outperformed BCD and CROS.

Trial registration: Netherlands Trial Register (www.trialregister.nl): NTR4580, CINGLE-trial.
Connection, constraint, and coping: A qualitative study of experiences of loneliness during the COVID-19 lockdown in the UK
Authors: McKenna-Plumley Phoebe E. , Graham-Wisener Lisa , Berry Emma , Groarke Jenny M.
Published: October 2021

The COVID-19 pandemic has necessitated physical distancing which is expected to continue in some form for the foreseeable future. Physical distancing policies have increased reliance on digital forms of social connection and there are widespread concerns about social isolation and mental health in this context. This qualitative study sought to understand how loneliness was experienced during physical distancing in the initial national UK COVID-19 lockdown. Eight individuals who reported feeling lonely during the initial lockdown were interviewed in May 2020. Interviews were analysed using reflexive thematic analysis. Four main themes were identified: (1) Loss of in-person interaction causing loneliness, (2) Constrained freedom, (3) Challenging emotions, and (4) Coping with loneliness. The loss of in-person interaction contributed to feelings of loneliness and digital interaction was viewed as an insufficient alternative. Social freedom could be constrained by distancing policies and by social contacts, contributing to strained personal relationships and feelings of frustration as part of loneliness. Fluctuations in mood and difficult emotions were experienced alongside loneliness, and distraction and seeking reconnection were commonly reported methods of coping, although they were less accessible. These findings indicate that physical distancing measures can impact loneliness due to the limitations they impose on in-person social contact and the perceived insufficiency of digital contact as a substitute.
Comparative sphingolipidomic analysis reveals significant differences between doxorubicin-sensitive and -resistance MCF-7 cells
Authors: Shammout Ola D. A. , Ashmawy Naglaa S. , Shakartalla Sarra B. , Altaie Alaa M. , Semreen Mohammad H. , Omar Hany A. , Soliman Sameh S. M.
Published: October 2021

Drug resistance is responsible for the failure of many available anticancer drugs. Several studies have demonstrated the association between the alteration in sphingolipids (SPLs) and the development of drug resistance. To investigate the association between SPLs metabolism and doxorubicin (dox)-resistance in MCF-7 cells, a comparative sphingolipidomics analysis between dox-sensitive (parental) and -resistant MCF-7 cell lines along with validation by gene expression analysis were conducted. A total of 31 SPLs representing 5 subcategories were identified. The data obtained revealed that SPLs were clustered into two groups differentiating parental from dox-resistant cells. Eight SPLs were significantly altered in response to dox-resistance including SM (d18:1/16), SM (d18:1/24:2), SM (d18:1/24:0), SM (d18:1/20:0), SM (d18:1/23:1), HexCer (d18:1/24:0), SM (d18:1/15:0), DHSM (d18:0/20:0). The current study is the first to conclusively ascertain the potential involvement of dysregulated SPLs in dox-resistance in MCF-7 cells. SPLs metabolism in dox-resistant MCF-7 cells is oriented toward the downregulation of ceramides (Cer) and the concomitant increase in sphingomyelin (SM). Gene expression analysis has revealed that dox-resistant cells tend to escape from the Cer-related apoptosis by the activation of SM-Cer and GluCer-LacCer-ganglioside pathways. The enzymes that were correlated to the alteration in SPLs metabolism of dox-resistant MCF-7 cells and significantly altered in gene expression can represent potential targets that can represent a winning strategy for the future development of promising anticancer drugs.
Myopia-correcting lenses decrease eye fatigue in a visual search task for both adolescents and adults
Authors: Ryu Hyeongsuk , Ju Uijong , Wallraven Christian
Published: October 2021

The steady, world-wide increase in myopia prevalence in children over the past decades has raised concerns. As an early intervention for axial-length-related myopia, correcting lenses have been developed (such as Defocus Incorporated Multiple Segment (DIMS) lenses), which have been shown to be effective in slowing myopia progression. Beyond this direct effect, however, it is not known whether such lenses also affect other aspects important to the wearer, such as eye fatigue, and how such effects may differ across age, as these lenses so far are typically only tested with adolescents. In the present work, we therefore investigated perceived fatigue levels according to lens type (normal vs DIMS) and age (adolescents vs adults) in a demanding visual search task (“Finding Wally”) at two difficulty levels (easy vs difficult). Whereas age and difficulty did not result in significant differences in eye fatigue, we found a clear reduction of fatigue levels in both age groups when wearing the correcting lenses. Hence, the additional accommodation of these lens types may result in less strain in a task requiring sustained eye movements at near viewing distances.
Development of algorithms for identifying patients with Crohn’s disease in the Japanese health insurance claims database
Authors: Morikubo Hiromu , Kobayashi Taku , Fukuda Tomohiro , Nagahama Takayoshi , Hisamatsu Tadakazu , Hibi Toshifumi
Published: October 2021

Background

Real-world big data studies using health insurance claims databases require extraction algorithms to accurately identify target population and outcome. However, no algorithm for Crohn’s disease (CD) has yet been validated. In this study we aim to develop an algorithm for identifying CD using the claims data of the insurance system.

Methods

A single-center retrospective study to develop a CD extraction algorithm from insurance claims data was conducted. Patients visiting the Kitasato University Kitasato Institute Hospital between January 2015–February 2019 were enrolled, and data were extracted according to inclusion criteria combining the Tenth Revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) diagnosis codes with or without prescription or surgical codes. Hundred cases that met each inclusion criterion were randomly sampled and positive predictive values (PPVs) were calculated according to the diagnosis in the medical chart. Of all cases, 20% were reviewed in duplicate, and the inter-observer agreement (Kappa) was also calculated.

Results

From the 82,898 enrolled, 255 cases were extracted by diagnosis code alone, 197 by the combination of diagnosis and prescription codes, and 197 by the combination of diagnosis codes and prescription or surgical codes. The PPV for confirmed CD cases was 83% by diagnosis codes alone, but improved to 97% by combining with prescription codes. The inter-observer agreement was 0.9903.

Conclusions

Single ICD-code alone was insufficient to define CD; however, the algorithm that combined diagnosis codes with prescription codes indicated a sufficiently high PPV and will enable outcome-based research on CD using the Japanese claims database.