bluuebunny/crossref_metadata_2025 huggingface dataset:
Taking the Guess Work Out of the Initial Guess: A Solution Interval Method for Least-Squares Parameter Estimation in Nonlinear Models
Authors: Zhang Guanglu , Allaire Douglas , Cagan Jonathan
Published: October 2020

Fitting a specified model to data is critical in many science and engineering fields. A major task in fitting a specified model to data is to estimate the value of each parameter in the model. Iterative local methods, such as the Gauss–Newton method and the Levenberg–Marquardt method, are often employed for parameter estimation in nonlinear models. However, practitioners must guess the initial value for each parameter to initialize these iterative local methods. A poor initial guess can contribute to non-convergence of these methods or lead these methods to converge to a wrong or inferior solution. In this paper, a solution interval method is introduced to find the optimal estimator for each parameter in a nonlinear model that minimizes the squared error of the fit. To initialize this method, it is not necessary for practitioners to guess the initial value of each parameter in a nonlinear model. The method includes three algorithms that require different levels of computational power to find the optimal parameter estimators. The method constructs a solution interval for each parameter in the model. These solution intervals significantly reduce the search space for optimal parameter estimators. The method also provides an empirical probability distribution for each parameter, which is valuable for parameter uncertainty assessment. The solution interval method is validated through two case studies in which the Michaelis–Menten model and Fick’s second law are fit to experimental data sets, respectively. These case studies show that the solution interval method can find optimal parameter estimators efficiently. A four-step procedure for implementing the solution interval method in practice is also outlined.
Enhancement of Flow Boiling at Very High Initial Surface Temperature by Using Various Additives
Authors: Swain B. , Pati A. R. , Mohapatra S. S. , Behera A.
Published: October 2020

In the current work, for the simultaneous attainment of enhancement and uniformity in temperature distribution in case of quenching performed in transition and nucleate boiling regimes, the heat treatment is performed by adopting thin coolant flow boiling methodology which depicts high replacement rate of vapor and low coolant consumption rate in comparison with the other cooling methodology such as jet and spray cooling. In addition to the above, the simultaneous flow over the entire plate reduces the intensity of nonuniformity in cooling. The analysis of experimental results in case of thin-film flow boiling clearly indicates significant improvement in initial heat flux (IHF) and critical heat flux (CHF) in comparison with low mass flux jet and spray coolings. The comparative study also ensures that better enhancement and uniformity in cooling are achieved in the current case in comparison with the process such as low mass flux spray and jet coolings. Furthermore, the calculation indicates very low coolant consumption characteristic in comparison with the others, the abovementioned parameters (CHF and IHF) alter due to the change in surface tension, viscosity, specific heat, and thermal conductivity of the coolant and therefore, the role of abovementioned coolant properties in case of thin-film boiling is monitored. For this, various additives such as sodium dodecyl sulfate (SDS), polyethylene glycol (PEG), Polyoxyethylene 20 Sorbitan Monolaurate (Tween 20), and ethanol were used. In the present work, the analysis discloses that for the better Nusselt number the optimum Reynolds number is 1953 and Ohensorge number and Prandtl number are 0.0032 and 5.85, respectively.
Opto-Electro-Thermal Modeling of Thin-Film Hydrogenated Amorphous Silicon (a-Si:H) Photovoltaic Cell
Authors: Lai Jia-Jiun , Wong Basil T. , Chai Jasman Y.-H.
Published: October 2020

A one-dimensional opto-electro-thermal simulator for an a-Si:H-based thin-film solar cell is developed. The simulator includes optical, electrical, and thermal modeling for a complete modeling of energy conversion in a-Si:based solar cells. Particularly, the thermal impact on the performance of the cell has been studied. Cell performance is worse when thermal simulation is included compared to simulations where the temperature is kept constant. This implication suggests that cell performance is typically overestimated in simulations where the thermal effect is ignored. A simplified optical model was used, reducing the computational resources required in the study. The electrical model proposed in this study extends the classical drift-diffusion model to include the effects of temperature. The proposed thermal model considers the energy conservation in a non-thermal equilibrium condition between electron, optical phonons, and acoustic phonons. While simplifications have been used to reduce the complexity of the simulations, the program captures the essential behavior of the cell with reasonable accuracy. Hence, the developed program is useful for a-Si:H-based thin-film solar cell design and optimization.
Numerical Method for Direct Solution to Form-Finding Problem in Convex Gridshell
Authors: Huang Weicheng , Qin Longhui , Khalid Jawed Mohammad
Published: October 2020

Elastic gridshell is a class of net-like structure formed by an ensemble of elastically deforming rods coupled through joints, such that the structure can cover large areas with low self-weight and allow for a variety of aesthetic configurations. Gridshells, also known as X-shells or Cosserat Nets, are a planar grid of elastic rods in its undeformed configuration. The end points of the rods are constrained and positioned on a closed curve—the final boundary—to actuate the structure into a 3D shape. Here, we report a discrete differential geometry-based numerical framework to study the geometrically nonlinear deformation of gridshell structures, accounting for non-trivial bending-twisting coupling at the joints. The form-finding problem of obtaining the undeformed planar configuration given the target convex 3D topology is then investigated. For the forward (2D to 3D) physically based simulation, we decompose the gridshell structure into multiple one-dimensional elastic rods and simulate their deformation by the well-established discrete elastic rods (DER) algorithm. A simple penalty energy between rods and linkages is used to simulate the coupling between two rods at the joints. For the inverse problem associated with form-finding (3D to 2D), we introduce a contact-based algorithm between the elastic gridshell and a rigid 3D surface, where the rigid surface describes the target shape of the gridshell upon actuation. This technique removes the need of several forward simulations associated with conventional optimization algorithms and provides a direct solution to the inverse problem. Several examples—hemispherical cap, paraboloid, and hemi-ellipsoid—are used to show the effectiveness of the inverse design process.
Fluid Convection Models for Low-Temperature Grinding and Effect of Fluid Warming
Authors: Zhang Lei , Brian Rowe W.
Published: October 2020

The paper considers fluid convection in low-temperature grinding. Fluid cooling often predominates over all other forms of heat dispersion in the grinding zone particularly in low-temperature grinding. Experimental values of convection heat transfer coefficient (CHTC) up to and in excess of 200,000 W/m2K have been found by various researchers both for water-based emulsions and in one case for mineral oils employed in high wheel-speed grinding. Several convection models have been developed in recent years for the prediction of CHTCs in low-temperature grinding. This paper reviews advances in convection modeling and reconsiders the basic assumptions implied. A proposal is made for improved estimation for highly churned flow assuming a degree of fluid warming. Predicted coefficients are compared with measured values.
Modeling the Dynamics of Five-Axis Machine Tool Using the Multibody Approach
Authors: Huynh Hoai Nam , Altintas Yusuf
Published: October 2020

A systematic modeling of multibody dynamics of five-axis machine tools is presented in this article. The machine is divided into major subassemblies such as spindle, column, bed, tool changer, and longitudinal and rotary drives. The inertias and mass center of each subassembly are calculated from the design model. The subassemblies are connected with elastic springs and damping elements at contact joints to form the complete multibody dynamic model of the machine that considers the rigid body kinematics and structural vibrations of the machine at any point. The unknown elastic joint parameters are estimated from the experimental modal analysis of the machine tool. The resulting position-dependent multibody dynamic model has the minimal number of degrees-of-freedom that is equivalent to the number of measured modes, as opposed to thousands used in finite element models. The frequency response functions of the machine can be predicted at any posture of the five-axis machine, which are compared against the directly measured values to assess the validity of model. The proposed model can predict the combined rigid body motion and vibrations of the machine with computational efficiency, and hence, it can be used as a digital twin to simulate its dynamic performance in machining operations and tracking control tests of the servo drives.
The diagnostic accuracy of ultrasound in the detection of foot and ankle fractures: a systematic review and meta-analysis
Authors: Wu Jiangfeng , Wang Yunlai , Wang Zhengping
Published: October 2020

Aims: Foot and ankle injuries are a common presenting complaint in the emergency department. The diagnosis of foot and ankle fractures is conventionally accomplished through X-rays. Whether ultrasound (US) can be considered as a primary scanning modality is still a controversial issue; therefore, we did a meta-analysis to synthesize the diagnostic performance ofultrasound for foot and ankle fractures.Material and methods: A comprehensive search was carried out to identify studies in which patients with clinically suspected foot and ankle fractures were assessed by US. Two investigators independently screened the literature and extracted the data. Any discrepancies were resolved via discussion. Study quality was assessed by the Quality Assessment of Diagnostic Accuracy Studies 2 tool, and pooled sensitivity and specificity of various US findings were determined.Results: Ten studies with a total of 1065 patients were included. There was significant heterogeneity across the included studies. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio for the diagnosis of foot and ankle fractures by US were 0.96 (95% confidence interval [CI], 0.90-0.99), 0.94 (95% CI, 0.88-0.97), 15.0 (95% CI, 7.9-28.6), 0.04 (95% CI, 0.02-0.11), and 367 (95% CI, 101-1338), respectively. Furthermore, the summary receiver operating characteristic area under the curve was calculated to be 0.99.Conclusions: Ultrasound has an excellent diagnostic performance for foot and ankle fractures and should be considered as a primary and radiation-free scanning modality in the diagnosis of foot and ankle fractures.
Global work index by non-invasive pressure-strain loops: a novel parameter to assess left ventricular performance in the early stages of heart failure with preserved or mid-range ejection fraction after acute myocardial infarction
Authors: Tomoaia Raluca , Beyer Ruxandra Stefana , Zdrenghea Dumitru , Dadarlat-Pop Alexandra , Cismaru Gabriel , Gusetu Gabriel , Rosu Radu , Serban Adela , Pop Dana
Published: October 2020

Aim: To determine the relationship between myocardial work (MW) indices derived from non-invasive pressure-strain loops (PSL) and established parameters of left ventricular (LV) performance in patients with acute myocardial infarction (AMI) and heart failure (HF) with preserved or mid-range ejection fraction (HFpEF/HFmrEF).Material and methods: Speckle-tracking echocardiography (STE) was used to determine MW indices and global longitudinal strain (GLS) in the first 24-48 hours after admission in patients with AMI, HF symptoms, NT-proBNP >300 pg/mL and left ventricular ejection fraction (LVEF) >40%. MW was calculated by using PSL, which combine strain and non-invasive blood pressure  measurement. Global MW index (GWI) was defined as the work inside the area of the PSL.Results: Forty-nine patients (mean age 68±13 years) fulfilled the inclusion criteria. Both GWI (1057±338 mmHg%) and GLS (-10.4±3.3%) were reduced in the majority of the patients. However, a proportion of patients with abnormal GLS showed normal GWI. There was a strong inverse relationship between GWI and GLS (r=-0.81). GWI demonstrated a strong relationship with LVEF (r=0.69) and a moderate correlation to NT-proBNP (n=-0.29). NT-proBNP showed a tendency to higher values in patients with more reduced GWI (820 [590-2550] vs 707 [460-1335], p=0.17). Out of the diastolic dysfunction parameters, GWI showed moderate correlations to LA volume index (r-0.29), E/A (r=-0.23) and E/e’ (r=-0.39), which were also significantly more impaired in patients with more reduced GWI.Conclusion: Non-invasive PSL might bring further information to LVEF and GLS in patients AMI at the early stages of HFpEF/HFmrEF, since LV performance depends on both contractile properties and variations in load in the ischemic segments.
Ultrasonic atomization of titanium isopropoxide at room temperature for TiO2 atomic layer deposition
Authors: Jang Moon-Hyung , Lei Yu
Published: October 2020

Room temperature evaporation of titanium isopropoxide [Ti[OCH(CH3)2]4, TTIP] precursor was performed using ultrasonic atomization for TiO2 atomic layer deposition (ALD). Quartz crystal microbalance data show comparable results between room temperature TTIP ultrasonic atomization and conventional thermal evaporation. The TiO2 ALD saturation window is established for room temperature atomized TTIP exposure time and reactor temperatures. Room temperature atomized TTIP grown TiO2 films show smooth surface morphology before/after the annealing treatment. Two-dimensional TiO2 film thickness mappings on a 150 mm diameter Si(100) wafer were performed by spectroscopic ellipsometry. The thickness variation of TiO2 films by the room temperature atomized TTIP is less uniform than that of TiO2 films by thermally evaporated TTIP, probably due to the incomplete evaporation of the TTIP liquid droplets, which is more difficult to transport than its vapor.
Use of Numerically Blinded Ratings of Perceived Exertion in Soccer: Assessing Concurrent and Construct Validity
Authors: Lovell Ric , Halley Sam , Siegler Jason , Wignell Tony , Coutts Aaron J. , Massard Tim
Published: October 2020

Purpose: To examine the concurrent and construct validity of numerically blinded ratings of perceived exertion (RPEs). Methods: A total of 30 elite male youth soccer players (age 16.7 [0.5] y) were monitored during training and matches over a 17-wk in-season period. The players’ external loads were determined via raw 10-Hz global positioning system. Heart rate (HR) was collected continuously and expressed as Bannister and Edwards training impulses, and minutes >80% of the players predetermined the maximum HR by the Yo-Yo Intermittent Recovery Test Level 1. RPE was collected confidentially 10 to 15 min after training/matches using 2 methods: (1) a traditional verbal response to the 0 to 100 category-ratio “centiMax” scale (RPE) and (2) numerically blinded RPE centiMax scale (RPEblind) with the response selected manually via a 5 × 7-in tablet “slider.” The RPE and RPEblind were divided by 10 and multiplied by the duration to derive the sessional RPE. Linear mixed models compared ratings, and within-subject repeated-measures correlations assessed the sessional RPE versus HR and external load associations. Results: There were no differences between the RPE and RPEblind (0.19; 95% confidence intervals, −0.59 to 0.20 au, P = .326) or their session values (13.5; 95% confidence intervals, −17.0 to 44.0 au, P = .386), and the ratings were nearly perfectly correlated (r = .96). The associations between the sessional RPE versus HR and external load metrics were large to very large (r = .65–.81), with no differences between the RPE methods (P ≥ .50). The RPEblind also reduced verbal anchor clustering and integer bias by 11% and 50%, respectively. Conclusions: RPEblind demonstrated concurrent and construct validity versus the traditional method, and may be used in situations where practitioners have concerns regarding the authenticity of athlete ratings.
Neuropilin-1 facilitates SARS-CoV-2 cell entry and infectivity
Authors: Cantuti-Castelvetri Ludovico , Ojha Ravi , Pedro Liliana D. , Djannatian Minou , Franz Jonas , Kuivanen Suvi , van der Meer Franziska , Kallio Katri , Kaya Tuğberk , Anastasina Maria , Smura Teemu , Levanov Lev , Szirovicza Leonora , Tobi Allan , Kallio-Kokko Hannimari , Österlund Pamela , Joensuu Merja , Meunier Frédéric A. , Butcher Sarah J. , Winkler Martin Sebastian , Mollenhauer Brit , Helenius Ari , Gokce Ozgun , Teesalu Tambet , Hepojoki Jussi , Vapalahti Olli , Stadelmann Christine , Balistreri Giuseppe , Simons Mikael
Published: October 2020

Another host factor for SARS-CoV-2

Virus-host interactions determine cellular entry and spreading in tissues. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the earlier SARS-CoV use angiotensin-converting enzyme 2 (ACE2) as a receptor; however, their tissue tropism differs, raising the possibility that additional host factors are involved. The spike protein of SARS-CoV-2 contains a cleavage site for the protease furin that is absent from SARS-CoV (see the Perspective by Kielian). Cantuti-Castelvetri
et al.
now show that neuropilin-1 (NRP1), which is known to bind furin-cleaved substrates, potentiates SARS-CoV-2 infectivity. NRP1 is abundantly expressed in the respiratory and olfactory epithelium, with highest expression in endothelial and epithelial cells. Daly
et al.
found that the furin-cleaved S1 fragment of the spike protein binds directly to cell surface NRP1 and blocking this interaction with a small-molecule inhibitor or monoclonal antibodies reduced viral infection in cell culture. Understanding the role of NRP1 in SARS-CoV-2 infection may suggest potential targets for future antiviral therapeutics.

Science
, this issue p.
856
, p.
861
; see also p.
765
Structural analysis of full-length SARS-CoV-2 spike protein from an advanced vaccine candidate
Authors: Bangaru Sandhya , Ozorowski Gabriel , Turner Hannah L. , Antanasijevic Aleksandar , Huang Deli , Wang Xiaoning , Torres Jonathan L. , Diedrich Jolene K. , Tian Jing-Hui , Portnoff Alyse D. , Patel Nita , Massare Michael J. , Yates John R. , Nemazee David , Paulson James C. , Glenn Greg , Smith Gale , Ward Andrew B.
Published: October 2020

Structure of a vaccine candidate

Much effort is being targeted at developing vaccines that will provide protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A trimeric spike protein that decorates the virus is a primary target of the host immune system and the focus of vaccine development. Bangaru
et al.
present the structure of a leading vaccine candidate: a full-length spike protein with some modifications aimed at enhancing stability that is formulated in polysorbate 80 detergent. The study confirms that the full-length immunogen is in a stable prefusion conformation and provides a basis for understanding immune responses to the vaccine.

Science
, this issue p.
1089
Dimerization regulates the human APC/C-associated ubiquitin-conjugating enzyme UBE2S
Authors: Liess Anna K. L. , Kucerova Alena , Schweimer Kristian , Schlesinger Dörte , Dybkov Olexandr , Urlaub Henning , Mansfeld Jörg , Lorenz Sonja
Published: October 2020

The E2 enzyme UBE2S may be stored as a dimer to prevent its degradation between mitotic cycles.
Hug and hold tight: Dimerization controls the turnover of the ubiquitin-conjugating enzyme UBE2S
Authors: Bremm Anja
Published: October 2020

Dimerization limits the autoubiquitination-driven breakdown of the E2 UBE2S (Liesset al., in 20 October 2020 issue).
Intrapulmonary Pharmacokinetics of Cefepime and Enmetazobactam in Healthy Volunteers: Towards New Treatments for Nosocomial Pneumonia
Authors: Das Shampa , Fitzgerald Richard , Ullah Asad , Bula Marcin , Collins Andrea M. , Mitsi Elena , Reine Jesus , Hill Helen , Rylance Jamie , Ferreira Daniela M. , Tripp Karen , Bertasini Andrea , Franzoni Samantha , Massimiliano Mameli , Lahlou Omar , Motta Paola , Barth Philip , Velicitat Patrick , Knechtle Philipp , Hope William
Published: October 2020

Cefepime-enmetazobactam is a novel β-lactam–β-lactamase inhibitor combination with broad-spectrum antimicrobial activity against a range of multidrug-resistant
Enterobacteriaceae
. This agent is being developed for a range of serious hospital infections. An understanding of the extent of partitioning of β-lactam–β-lactamase inhibitor combinations into the human lung is required to better understand the potential role of cefepime-enmetazobactam for the treatment of nosocomial pneumonia.
Hexachlorobenzene Monooxygenase Substrate Selectivity and Catalysis: Structural and Biochemical Insights
Authors: Guo Yuan , Li De-Feng , Ji Huining , Zheng Jianting , Zhou Ning-Yi
Published: October 2020

As an endocrine disrupter and possible carcinogen to human beings, hexachlorobenzene (HCB) is especially resistant to biodegradation, largely due to difficulty in its dechlorination. The lack of knowledge of HCB dechlorinases limits their application in bioremediation. Recently, an HCB monooxygenase, HcbA1A3, representing the only naturally occurring aerobic HCB dechlorinase known so far, was reported. Here, we report its biochemical and structural characterization, providing new insights into its substrate selectivity and catalytic mechanism. This research also increases our understanding of HCB dechlorinases and flavin-N5-peroxide-utilizing enzymes.
Nonsynonymous Polymorphism Counts in Bacterial Genomes: a Comparative Examination
Authors: Loo Sara L. , Ong Anna , Kyaw Wunna , Thibaut Loïc M. , Lan Ruiting , Tanaka Mark M.
Published: October 2020

Identifying selection from SNP data obtained from whole-genome sequencing studies is challenging. Some current measures used to identify and quantify selection acting on genomes rely on fixed diﬀerences; thus, these are inappropriate for SNP data where variants are not fixed. With the increase in whole-genome sequencing studies, it is important to consider SNP data in the context of evolutionary processes. How SNPs are counted and analyzed can help in understanding mutation accumulation and trajectories of strains. We developed a tool for identifying possible evidence of selection and for comparative analysis with other SNP data. We propose a model that provides a rule-of-thumb guideline and two new visualization techniques that can be used to interpret and compare SNP data. We quantify the expected proportion of nonsynonymous SNPs in coding regions under neutrality and demonstrate its use in identifying evidence of positive and negative selection from simulations and empirical data.
Carbamate C-N Hydrolase Gene
ameH
Responsible for the Detoxification Step of Methomyl Degradation in Aminobacter aminovorans Strain MDW-2
Authors: Jiang Wankui , Zhang Chenfei , Gao Qinqin , Zhang Mingliang , Qiu Jiguo , Yan Xin , Hong Qing
Published: October 2020

Based on the structural characteristic, carbamate insecticides can be classified into oxime carbamates (methomyl, aldicarb, oxamyl, etc.) and
N
-methyl carbamates (carbaryl, carbofuran, isoprocarb, etc.). So far, research on the degradation of carbamate pesticides has mainly focused on the detoxification step and hydrolysis of their carbamate bond. Several genes, such as
cehA
,
mcbA
,
cahA
, and
mcd
, and their encoding enzymes have also been reported to be involved in the detoxification step. However, none of these enzymes can hydrolyze methomyl. In this study, a carbamate C-N hydrolase gene,
ameH
, responsible for the detoxification step of methomyl in strain MDW-2 was cloned and the key amino acid sites of AmeH were investigated. These findings provide insight into the microbial degradation mechanism of methomyl.
Digital Image Analysis for the Detection of Group B
Streptococcus
from ChromID Strepto B Medium Using PhenoMatrix Algorithms
Authors: Baker Justin , Timm Karen , Faron Matthew , Ledeboer Nathan , Culbreath Karissa
Published: October 2020

Group B
Streptococcus
(GBS) can be found to colonize about 25% of all healthy, adult women and is the leading infectious cause of early neonatal morbidity and mortality in the United States. This study evaluated the clinical performance of PhenoMatrix (PM) chromogenic detection module (CDM) digital imaging software in detection of GBS from LIM broth plated on ChromID Strepto B chromogenic medium (ChromID) using the WASP automated processor. The performance of the PM CDM was compared to manual culture review of the digital images and molecular detection of GBS.
Evaluation of Pneumococcal Serotyping of Nasopharyngeal-Carriage Isolates by Latex Agglutination, Whole-Genome Sequencing (PneumoCaT), and DNA Microarray in a High-Pneumococcal-Carriage-Prevalence Population in Malawi
Authors: Swarthout Todd D. , Gori Andrea , Bar-Zeev Naor , Kamng’ona Arox W. , Mwalukomo Thandie S. , Bonomali Farouck , Nyirenda Roseline , Brown Comfort , Msefula Jacquline , Everett Dean , Mwansambo Charles , Gould Katherine , Hinds Jason , Heyderman Robert S. , French Neil
Published: October 2020

Accurate assessment of the serotype distribution associated with pneumococcal colonization and disease is essential for evaluating and formulating pneumococcal vaccines and for informing vaccine policy. For this reason, we evaluated the concordance between pneumococcal serotyping results by latex agglutination, whole-genome sequencing (WGS) with PneumoCaT, and DNA microarray for samples from community carriage surveillance in Blantyre, Malawi. Nasopharyngeal swabs were collected according to WHO recommendations between 2015 and 2017 by using stratified random sampling among study populations.
Molecular and Epidemiological Characteristics of Carbapenemase-Producing Klebsiella pneumoniae Clinical Isolates in Japan
Authors: Yonekawa Shinsuke , Mizuno Tomoki , Nakano Ryuichi , Nakano Akiyo , Suzuki Yuki , Asada Tomoko , Ishii Ayako , Kakuta Naoki , Tsubaki Kosuke , Mizuno Sayaka , Ogawa Miho , Yano Hisakazu , Kasahara Kei , Mikasa Keiichi
Published: October 2020

Carbapenems serve as a last resort for the clinical treatment of multidrug-resistant infections. Therefore, the rapid spread of carbapenemase-producing strains represents a serious public health threat, further limiting antibiotic choices. The current findings of hypervirulent carbapenemase-producing
Klebsiella pneumoniae
clinical isolates in Japan demonstrate the potential broad spread and transfer of these genes, necessitating close surveillance.
Effectiveness of Face Masks in Preventing Airborne Transmission of SARS-CoV-2
Authors: Ueki Hiroshi , Furusawa Yuri , Iwatsuki-Horimoto Kiyoko , Imai Masaki , Kabata Hiroki , Nishimura Hidekazu , Kawaoka Yoshihiro
Published: October 2020

Airborne simulation experiments showed that cotton masks, surgical masks, and N95 masks provide some protection from the transmission of infective SARS-CoV-2 droplets/aerosols; however, medical masks (surgical masks and even N95 masks) could not completely block the transmission of virus droplets/aerosols even when sealed.
Observational study to define reference ranges for the 3% oxygen desaturation index during sleep in healthy children under 12 years using oximetry motion-resistant technology
Authors: Ong Jonathan Wen Yi , Williams Daniel , Gavlak Johanna C , Liddle Natasha , Lowe Paula , Evans Hazel J
Published: October 2020

Objective

To define reference ranges for the 3% oxygen desaturation index (DI3) in healthy children under 12 years old during sleep.

Design

Observational.

Setting

Home.

Subjects

Healthy children aged 6 months to 12 years of age.

Intervention

Nocturnal pulse oximetry at home. Parents documented sleep times. Visi-Download software (Stowood Scientific) analysed data with artefact and wake periods removed.

Main outcome measures

The following oximetry parameters used in the assessment of sleep-disordered breathing conditions were measured: 3% (DI3) and 4% (DI4) oxygen desaturation indices—the number of times per hour where the oxygen saturation falls by at least 3% or 4% from baseline, mean saturations (SAT50), minimum saturations (SATmin), delta index 12 s (DI12s), and percentage time with saturations below 92% and 90%.

Results

Seventy-nine children underwent nocturnal home pulse oximetry, from which there were 66 studies suitable for analysis. The median values for DI3 and DI4 were 2.58 (95% CI 1.96 to 3.10) and 0.92 (95% CI 0.73 to 1.15), respectively. The 95th and 97.5th centiles for DI3 were 6.43 and 7.06, respectively, which inform our cut-off value for normality. The mean values for SAT50 and SATmin were 97.57% (95% CI 97.38% to 97.76%) and 91.09% (95% CI 90.32% to 91.86%), respectively.

Conclusion

In children aged 6 months to 12 years, we define normality of the 3% oxygen desaturation index as <7 using standalone, motion-resistant pulse oximeters with short averaging times.
Nodding syndrome: bridging the gap—a scoping review protocol
Authors: De Castro Ana Cristina , Ortega-Deballon Ivan
Published: October 2020

Introduction

Nodding syndrome (NS) is an encephalopathy of unknown origin that affects children aged between 3 and 15 years old. Cases have been reported since the 1950 in Tanzania and South Sudan, the most heavily affected population is the Acholi community in Uganda. In response to the high incidence of the disease, the Ugandan Government has developed a management algorithm, but access to such measures in affected communities is limited. There is little funding for research on the disease, consequently, few studies have been conducted to date. Nevertheless, the number of scientific publications on NS has increased since 2013, reporting several aetiological hypotheses, management algorithms and cases of stigmatisation; however, none has obtained conclusive results.

This document describes a protocol for a scoping review of NS to date aimed at obtaining a broad overview of the disease. The results will identify gaps in knowledge in order to better guide future research, intervention strategies, health policies in areas at risk and cooperation and development programmes.

Methods and analysis

To identify the relevant data, we will conduct a literature search using the electronic databases PubMed/Medline, Embase, Social Science Citation Index Scopus, Scientific Electronic Library Online (SciELO), Literatura Latinoamericana y del Caribe en Ciencias de la Salud (LILACS), Social Science Citation Index Expanded and The Cochrane Library. We will also include grey literature. The search strategy will be designed by a librarian.

Two members of the team will work independently to identify studies for inclusion and perform data extraction. The search results will be assessed by two independent reviewers and data from the included studies will be charted and summarised in duplicate. The data will be summarised in tables and figures to present the research landscape and describe and map gaps.

Ethics and dissemination

Ethical approval is not required. The scoping review will adhere to the Preferred Reporting Items for Systematic Reviews andMeta-Analyses-ScR guidelines. The results will be disseminated at scientific congresses and meetings.
Promoting early treatment for mild traumatic brain injury in primary care with a guideline implementation tool: a pilot cluster randomised trial
Authors: Silverberg Noah D , Panenka William J , Lizotte Pierre-Paul , Bayley Mark T , Dance Derry , Li Linda C
Published: October 2020

Objectives

New clinical practice guidelines for the management of mild traumatic brain injury (mTBI) emphasise that family physicians should proactively screen and initiate treatment for depression/anxiety, insomnia and headaches. This study aimed to evaluate the feasibility of delivering an implementation intervention to family physicians.

Design

Pilot cluster randomised controlled trial.

Setting

Specialty outpatient clinic (recruitment) and primary care (implementation).

Participants

114 primary care clinics were randomised. These clinics were associated with 137 unique family physicians caring for 148 adult patients who sustained an mTBI within the previous 3 months and were seeking care for persistent symptoms.

Interventions

Patients completed self-report screening measures for depression/anxiety, insomnia and headaches. A tailored letter that incorporates the patient’s screening test results and associated treatment algorithms was sent to their family physician (or walk-in clinic). Physicians at clinics assigned to the control condition received a generic letter, without the screening test results.

Primary outcome measures

Feasibility outcomes included the frequency of primary care follow-up, retention rates and reliability of patient recall of their physicians’ actions (primary mechanistic outcome). The primary efficacy outcome was the Rivermead Post-Concussion Symptom Questionnaire (RPQ).

Results

Most patients (97.8%; 128 of 131) followed up at the primary care clinic they planned to. Retention rates were 88% (131 of 148) and 78% (116 of 148) at the 1-month and 3-month assessments, respectively. Agreement between patient recall of their physicians’ actions and medical chart audits was moderate (intraclass correlation coefficient=0.48–0.65). Patients in the experimental group reported fewer symptoms on the RPQ compared with those in the control group, whose physician received a general letter (B=−4.0, 95% CI: −7.3 to −0.7).

Conclusions

A larger trial will need to address minor feasibility challenges to evaluate the effectiveness of this guideline implementation tool for improving mTBI clinical outcomes and confirm the mechanism(s) of intervention benefit.

Trial registration number

NCT03221218.
Developing core economic parameter sets for asthma studies: a realist review and an analytical framework
Authors: Roukas Chris , Quayyum Zahidul , Patel Anita , Fitzsimmons Deborah , Phillips Ceri , Hounsome Natalia
Published: October 2020

Objective

To develop a standardised set of economic parameters (core economic parameter set) for economic evaluations in asthma studies.

Design

A systematic literature review and an analytical framework.

Outcome measures

Economic parameters used to evaluate costs and cost-effectiveness of healthcare interventions for people with asthma.

Data sources

PubMed, the Cochrane Database of Systematic Reviews, the National Health Service Economic Evaluation Database, the Database of Abstracts of Reviews of Effects and the Health Technology Aaaessment Library starting from 1990.

Review methods

Research methods were based on the realist review methodology and included a number of non-sequential, iterative and overlapping components, such as developing an analytical framework for the realist review; systematic literature review of economic parameters; identifying and categorising economic parameters; producing preliminary list of core economic parameters.

Results

Database searches found 2531 publications of which 224 were included in the systematic review. We identified 65 economic parameters that were categorised into 11 groups to enable the realist synthesis. Parameters related to secondary care, primary care, medication use, emergency care and work productivity comprised 84% of all economic parameters. An analytical framework was used to investigate the rationale behind the choices of economic parameters in these studies. The main framework domains included type of intervention, research population, study design, study setting and a stakeholder’s perspective.

Conclusion

Past research thus suggests that in asthma study parameters depicting the use of secondary care, primary care, medication, emergency care and work productivity can be considered as core economic parameters, since they apply to different types of studies. Parameters including diagnostics, healthcare delivery, school activity, informal care, medical devices and health utility apply to a particular type of study (or research question), and thus can be recommended as supplemental parameters.

PROSPERO registration number

CRD42017067867.
Variation in the design of Do Not Resuscitate orders and other code status options: a multi-institutional qualitative study
Authors: Batten Jason N , Blythe Jacob A , Wieten Sarah , Cotler Miriam Piven , Kayser Joshua B , Porter-Williamson Karin , Harman Stephanie , Dzeng Elizabeth , Magnus David
Published: October 2020

Background

US hospitals typically provide a set of code status options that includes Full Code and Do Not Resuscitate (DNR) but often includes additional options. Although US hospitals differ in the design of code status options, this variation and its impacts have not been empirically studied.

Design and methods

Multi-institutional qualitative study at 7 US hospitals selected for variability in geographical location, type of institution and design of code status options. We triangulated across three data sources (policy documents, code status ordering menus and in-depth physician interviews) to characterise the code status options available at each hospital. Using inductive qualitative methods, we investigated design differences in hospital code status options and the perceived impacts of these differences.

Results

The code status options at each hospital varied widely with regard to the number of code status options, the names and definitions of code status options, and the formatting and capabilities of code status ordering menus. DNR orders were named and defined differently at each hospital studied. We identified five key design characteristics that impact the function of a code status order. Each hospital’s code status options were unique with respect to these characteristics, indicating that code status plays differing roles in each hospital. Physician participants perceived that the design of code status options shapes communication and decision-making practices about resuscitation and life-sustaining treatments, especially at the end of life. We identified four potential mechanisms through which this may occur: framing conversations, prompting decisions, shaping inferences and creating categories.

Conclusions

There are substantive differences in the design of hospital code status options that may contribute to known variability in end-of-life care and treatment intensity among US hospitals. Our framework can be used to design hospital code status options or evaluate their function.
SAFER brief community intervention: a primary suicide prevention strategy to improve firearm and medication storage behaviour
Authors: Stuber Jennifer Paige , Massey Anne , Meadows Morgan , Bass Brett , Rowhani-Rahbar Ali
Published: October 2020

Objective

To determine if a brief intervention, called Signpost, Assess, Facts, Emotion, Recommend (SAFER), designed to motivate changes in behaviour to secure firearms and medications to prevent future suicide is feasible to implement in community-based settings such as gun shows, acceptable to participants at higher risk for suicide including veterans and men in the middles years (35–64) and improves firearm and medication locking behaviours.

Methods

1175 people received SAFER over a 12-month period at 18 gun shows and community events in 2019 and completed a preassessment measuring firearms ownership, storage practices, knowledge about suicide as the leading type of firearm fatality and attitudes about suicide prevention. 372 responded to a brief postassessment using comparable measures.

Results

85% of participants reported keeping firearms at home. 43.7% reported current or prior military service. 53.2% were males between the ages of 35 and 64. Among those who responded to the postassessment, 61% of participants reported SAFER to be highly valuable. Safe firearms storage improved among participants who completed the preassessment and postassessment (51.2% pre, 66.0% post; p<0.01) as did safe medication storage (14.8% pre, 21.6% post; p=0.01). Knowledge that most firearm fatalities are suicides (33.4% pre, 45.8% post; p<0.01) also improved.

Conclusions

It is feasible, acceptable and effective to reach groups at elevated risk for suicide using a brief intervention strategy in unconventional settings. Community-based interventions to improve safe storage motivated by suicide prevention messaging should be prioritised because men in the middle years are less likely to use mental health services.
SARS-CoV-2 detection in formalin-fixed paraffin-embedded tissue specimens from surgical resection of tongue squamous cell carcinoma
Authors: Guerini-Rocco Elena , Taormina Sergio Vincenzo , Vacirca Davide , Ranghiero Alberto , Rappa Alessandra , Fumagalli Caterina , Maffini Fausto , Rampinelli Cristiano , Galetta Domenico , Tagliabue Marta , Ansarin Mohssen , Barberis Massimo
Published: October 2020

In the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, pathologists can be exposed to infection handling surgical specimens. Guidelines related to safety procedures in the laboratory have been released. However, there is a lack of studies performed on biopsy and surgical resection specimens. Here we report the detection of SARS-CoV-2 in formalin-fixed paraffin-embedded samples from surgical resection of tongue squamous cell carcinoma of a patient who developed COVID-19 postsurgery. RNA of SARS-CoV-2 strain was detected in the tumour and the normal submandibular gland samples using real-time PCR-based assay. No viral RNA was found in metastatic and reactive lymph nodes. We demonstrated that SARS-CoV-2 RNA can be detected in routine histopathological samples even before COVID-19 disease development. These findings may give important information on the possible sites of infection or virus reservoir, and highlight the necessity of proper handling and fixation before sample processing.
Using the realist approach to unravel the complexity of health programmes: the evaluation of smoke-free school policies as a case study
Authors: Schreuders Michael , Stronks Karien , Kunst Anton E
Published: October 2020

Numerous commentaries plea for the use of methods that take into account complexity when evaluating health programmes. These commentaries provide compelling arguments on why evaluations of health programmes should not rely exclusively on methods that were designed for making universal claims about whether and to what extent a policy is effective. However, there exist only few concrete examples showing how to take this complexity into account during the evaluation of health programmes. One increasingly popular approach to do so is the realist approach. In this paper, we explain the realist approach for taking into account complexity, discuss how we applied this approach to study the impact of smoke-free school policies and reflect on the practical value of the resultant insights. We hope this case study may inspire fellow scholars to use the realist approach for evaluating health programmes.
Women in surgery: a systematic review of 25 years
Authors: Singh Charleen , Loseth Caitlin , Shoqirat Noordeen
Published: October 2020

The number of women entering medicine significantly increased over the last decades. Currently, over half of the medical students are women but less than half are applying to surgery and even less go on to surgical specialties. Even fewer women are seen in leadership roles throughout the profession of surgery and surgical residency. Our purpose of the literature review is to identify any themes, which would provide insight to the current phenomenon. We used the Preferred Reporting Items for Systemic Reviews and Meta-Analyses method for a systematic review of the literature over a 20-year period (1998–2018). Five broad themes were identified: education and recruitment, career development, impact of/on life around the globe and surgical subspecialties as areas of barriers for women entering or considering surgery. The systematic review suggests there are opportunities to improve and encourage women entering the profession of surgery as well as the quality of life for surgeons. Creating systems for mentorship across programmes, having policies to support work–life balance and recognising surgical training overlaps with childbearing years are key opportunities for improvement. Improving the current status in surgery will require direction from leadership.
Factors associated with reporting antibiotic use as STI prophylaxis among HIV PrEP users: findings from a cross-sectional online community survey, May–July 2019, UK
Authors: O'Halloran Charlotte , Croxford Sara , Mohammed Hamish , Gill Owen Noel , Hughes Gwenda , Fifer Helen , Allen Hester , Owen Greg , Nutland Will , Delpech Valerie , Saunders John Michael
Published: October 2020

Objectives

The use of antibiotics as pre-exposure or postexposure prophylaxis for sexually transmitted infection (STI) prevention (STI prophylaxis) is not currently recommended in the UK, but there is evidence that self-prescribing occurs among those at greatest risk. We present the prevalence and factors associated with STI prophylaxis among a community sample of HIV pre-exposure prophylaxis (PrEP) users.

Methods

The 2019 online PrEP User Survey ran between 17 May and 1 July. Eligible participants included UK residents reporting HIV PrEP use or having tried to obtain HIV PrEP since January 2017. STI prophylaxis use was defined as reporting buying antibiotics to prevent STIs, either privately or through the internet; this question was only asked to HIV PrEP users. Factors associated with STI prophylaxis use were assessed using univariable and multivariable logistic regression.

Results

Overall, 9% (167/1856) of HIV PrEP users reported STI prophylaxis use; 97% were gay or bisexual men, 84% reported white ethnicity, 55% resided in London and 69% were aged ≥35 years. Factors associated with STI prophylaxis included: reporting ≥5 compared with 1–4 condomless sex partners in the past 6 months (12% vs 5.6%, adjusted odds ratio (aOR)=1.80; 95% CI 1.22 to 2.64), reporting chemsex drug use compared with no sexualised drug use in the past 12 months (13% vs 6.0%, aOR=1.88; 95% CI 1.20 to 2.93) and reporting an STI diagnosis in the past 12 months (12% vs 6.6%, aOR=1.54; 95% CI 1.08 to 2.18). Variables not significant in multivariable analyses included: ethnicity, age, residence and HIV PrEP sourcing.

Conclusions

Approximately 1 in 10 HIV PrEP users from this community sample reported self-prescribed STI prophylaxis. STI prophylaxis was associated with sexual behaviour known to facilitate STI transmission and with a history of recent STIs acquisition. Given the potential risk of antimicrobial resistance, sexual health clinicians should consider asking attendees, especially HIV PrEP users, about the use of antibiotics as STI prophylaxis, to inform appropriate counselling, testing and management.