bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical studies of turbulent premixed flame interaction with repeated solid obstacles
Authors: Elshimy M , Ibrahim S , Malalasekera W
Published: November 2020

This paper presents numerical simulations of hydrogen and propane turbulent premixed flames interaction with repeated solid obstructions. The laboratory-scale combustion chamber used in this study is equipped with three solid baffles which promote the generation of turbulence and a square obstacle located downstream from the ignition source. The test cases considered have two different area blockage ratios (ABR) of 24% and 50%, respectively. The large eddy simulation (LES) turbulence modelling technique is used. The numerical simulations are carried out using an in-house computational fluid dynamics (CFD) model. Two different flow configurations are examined, both using three consecutive baffles to identify the subsequent effects and the sensitivity of each fuel to increasing the ABR. These effects are studied using the nature of the flame-obstacles interaction, generated combustion overpressure and resultant flame speed. The modelling capability is confirmed by validating the numerical results against published experimental data. Conclusions are drawn that increasing the ABR increases the combustion overpressure, rate of pressure rise and flame speed. It is also concluded that the larger obstacle has a significant effect on the propagating flame structure and that hydrogen flames are more sensitive to an increased ABR and produce a significantly higher peak overpressure.
Pre-Cracking techniques of polymeric materials: an overview
Authors: Kamal A , Elsheikh AH , Showaib E
Published: November 2020

In fracture toughness tests, a number of notched specimens with identical artificial pre-cracks are essential to obtain accurate fracture parameters. The test results are critically depending on the initiation stage quality. Any slight variance in pre-cracks front shape, length and orientation could significantly affects the test results; therefore, producing identical pre-cracks is a critical issue to obtain accurate results. The pre-cracking technique should be selected carefully to fulfil controllably and repeatability requirements of the standard pre-cracks for a certain material while preserving the induced residual stresses at the crack tip at a minimal value. The notching and pre-cracking standards for metallic material have been well specified in ASTM E399. However, the case is more cumbersome for polymeric materials due their viscoelastic nature. ASTM D5045, ISO 13586:2000 and ASTM D6068 specified different procedures to prepare a sharp pre-crack for polymeric materials. Many pre-cracking techniques have been proposed in literature. The present work introduces an overview of the pre-cracking techniques for polymeric materials.
Effect of applying lean maintenance in oil and gas fields
Authors: Hassan M Nasr , Barakat A F , Sobh A S
Published: November 2020

Oil and Gas Sector are facing a huge increase and delay in Operations & Maintenance tasks for all facilities beside continuous demand from management to improve the productivity of wells and the efficiency of facilities. The top management decides to use Lean Maintenance as a new tool, technique and methodology to improve and modify the current operations, production and maintenance systems as done before by many researchers in the oil and gas sector. This improvement will be done through three real case studies by integrating Building Information Modelling with lean concepts, monitoring Key Performance Indicators within a modern Computerized Maintenance Management Software and finally using some LM tools such as Total Productive Maintenance, Value Stream Mapping and 5S Methodology to increase productivity, efficiency, and quality of the output production and services. The results of implementation since July 2017 till June 2018 show average increase in crude oil production by 6.72% per day in addition to overcome natural decline of oil wells, reduced Technician’s total Preventive Maintenance tasks by 52.63% and transfer the less difficult inspections to Operator to be responsible for making checks to all parameters of all equipment and to enable Technicians to perform other maintenance tasks, Saving about $724,770 in Water Injection Pumps Operation’s Expense. Last but not least, accelerate the workflow of production and maintenance processes by 28% compared with the previous financial year.
A new integrated product and process development model
Authors: Ayman A , Alhamaki A B , Abdellatif M H
Published: November 2020

Currently, the demand for more robust, economic, and quality products has increased the complexity in the integrated process development and product design model. In the knowledge economy century, all nations are competing to innovate new technologies to develop a new system that produces goods in less time and cost with compatible quality. Hence, a new IPPD model is needed to offer support and information/technology sharing during the entire product life cycle. The new IPPD model proposed that integrate all domains shall affect the product development. The model has a friendly computerized interface supported with internet enablers that offer support to the user to collect and share data easily. This model contains 6 domains. The Business Environment is the first domain, which analyzing the pre-feasibility of the product creation. The second domain is the market analysis and segmentation taking into consideration customer needs and competition. Managerial readiness of the product developing company is the third domain, including all managerial functions and the necessity of implementing the organizational change techniques if necessary. The fourth domain is Technological creation and deals with product concepts and robust quality design. Production/Launch is the fifth domain which consists of production processes and quality techniques to assure producing with the required quality and price levels. Finally, the sixth domain deals with the vital information of product distribution, maintenance and after-market service. The model is easily adapted to the industry need.
Degradable calcium deficient hydroxyapatite/poly(lactic-glycolic acid copolymer) bilayer scaffold through integral molding 3D printing for bone defect repair
Authors: Wu Ning , Liu Jia , Ma Weibo , Dong Xian , Wang Feng , Yang Dicheng , Xu Yan
Published: November 2020

A novel method was developed for calcium deficient hydroxyapatite (CDHA) scaffold 3D printing, through which a bilayer scaffold was fabricated by the integral molding of individual CDHA and poly(lactic-glycolic acid copolymer) (PLGA). The hydration reaction of α-tricalcium phosphate (TCP) was utilized to form CDHA, and a mixed solution of gelatin, glycerine and glutaraldehyde was applied as the dispersant and adhesive. The concentration of the glutaraldehyde (1‰(v/v)) and the mixing ratio of α-TCP (0.6, 0.8, 1.0 and 1.2 g ml−1) were studied with regard to the effect on the forming ability of the CDHA ink. The influence of α-TCP proportion (0.6, 0.8, 1.0 and 1.2 g ml−1) on the formation of CDHA was also researched in phase analysis, morphology and compressive strength measurements. The CDHA/PLGA bilayer scaffold was fabricated with a good combination of the two components by 3D printing. The
in vitro
degradation, cytotoxicity and cell proliferation behavior were studied. Meanwhile, the
in-vivo
performances in terms of surgical safety, biodegradation and osteogenic capacity were investigated with a cortical bone defect model in a rabbit femur. The results showed that the CDHA/PLGA bilayer scaffold had excellent biocompatibility and no cytotoxicity. The scaffolds were successfully implanted and presented remarkable osteogenic capacity within 6 months through analyses in radiography and histology. In conclusion, the method has a potential clinical application in diverse bone repair practices by varied 3D-printing fabrication.
Effect of electric-double layer on the blood flow in glycocalyx layered tubes: applications to drug delivery in microvessels
Authors: Shaw Sachin
Published: November 2020

Role of endothelium glycocalyx integraty is important for targeted intravenous nanoparticle drug delivery. It plays a vital role in many physical functions in microvessel including protection of the vessel wall with harmful levels of fluid shear. Hence, understanding the impact of the glycocalyx layer is important to develop of human medicine for the treatment of cardiovascular disorders. By experiment it observed that the glycocalyx layer embraces negative charges in the electric-double layer which interacting with plasma phase (treated as an electrolyte) adjoin to the microvessel wall and induces various mechanical and electrochemical phenomena at the interfacial layer. A two fluid model is considered to define the nature of the blood flow. The electrochemical characteristics of the glycocalyx layer are defined by Gouy–Chapman theory. The Navier–Stokes equation related to the blood flow and Poisson equation related to the charge density are solve analytically and represent in the form of Bessel function and hyper-geometric function. The charge effect of glycocalyx layer on the blood flow due to permeability of the wall, conditions at the interface of the clear and peripheral region, boundary condition at the wall mainly slip or no-slip condition and the rheology of blood are discussed and displays through graphs. The behavior of the glycocalyx layer which plays a vital role in the cardiovascular disorders such as atherosclerosis, are discussed under the influence of different parameters. It will give more brief idea on the electrochemical nature and electrokinetic effect of the glycocalyx layer.
Analytical optimization of piezoelectric acoustic power transfer systems
Authors: Freychet O , Frassati F , Boisseau S , Garraud N , Gasnier P , Despesse G
Published: November 2020

Acoustic power transfer and communication through metal layers is of great interest in many applications where the integrity of metal boxes, tanks, pipes or walls must be preserved by avoiding through-hole electrical connections. While acoustic power transfer has been widely studied last decades, the optimization of such systems has not been assessed comprehensively regarding the choice of transducers’ dimensions and materials and the impact of the wall characteristic acoustic impedance. This paper stands at answering these optimization issues, using a new implementation of an analytical model and two figures of merit to evaluate performances: the power transfer efficiency and a new figure of merit, the normalized transmitted power, a crucial characteristic for electronics implementation. Among other results, we disprove the commonly used design rule stating that equalizing the characteristic acoustic impedance of wall and transducers is the best option. We propose a method to quantify the impact of acoustic impedance mismatches on performances and show that intermediary layers sized with our optimization process can solve these acoustic impedance issues, resulting in an important gain in the transmitted power (multiplied by 40 in our example) and opening up great opportunities for the acoustic power transfer technology.
Endemic Population Response to Increasingly Severe Fire: A Cascade of Endangerment for the Mt. Graham Red Squirrel
Authors: Merrick Melissa J , Morandini Marina , Greer Vicki L , Koprowski John L
Published: November 2020

Drought, past fire suppression, insect invasion, and high-severity fire represent a disturbance cascade characteristic of forests in the western United States. The result is altered forest ecosystems diminished in their function and capacity to support biodiversity. Small habitat specialists are particularly vulnerable to the impacts of disturbances because of their limited movement capacity and high site fidelity. Research suggests that small mammals suffer limited direct mortality from fire but are increasingly vulnerable to local extirpation because of secondary impacts that include habitat loss and reduced food availability, survival, and reproduction. We examine the direct and secondary impacts of increasingly severe fire events on the endangered Mt. Graham red squirrel—a model system to demonstrate how disturbances can threaten the persistence of range-limited species. We document survival, space use, and displacement prior to and following fires and discuss implications for conservation. We suggest that management plans address future threats, including disturbance-related habitat loss.
Deploying authentication in the wild: towards greater ecological validity in security usability studies
Authors: Aebischer Seb , Dettoni Claudio , Jenkinson Graeme , Krol Kat , Llewellyn-Jones David , Masui Toshiyuki , Stajano Frank
Published: November 2020

Pico is a token-based login method that claims to be simultaneously more usable and more secure than passwords. It does not ask users to remember any secrets, nor to type one-time passwords. We evaluate Pico’s claim with two deployments and user studies, one on a web-based service and another within an organization. Our main aim is to collect actionable intelligence on how to improve the usability and deployability of Pico. In our first study we team up with an established website, Gyazo, to offer this alternative login mechanism to users intent on performing a real task of image sharing. From the lessons of this first study, we retarget Pico’s focus from replacing web passwords to replacing desktop login passwords; and thus in our second study we engage with a government organization, Innovate UK, to offer employees the ability to lock and unlock their computer automatically based on proximity. We focus particularly on the ecological validity of the trials and we thereby gain valuable insights into the viability of Pico, not only through the actual responses from the participants but also through the many practical challenges we had to face and overcome. Reflecting on the bigger picture, from our experience we believe the security usability community would greatly benefit from pushing towards greater ecological validity in published work, despite the considerable difficulties and costs involved.
Acute coronary syndrome with spontaneous coronary artery dissection: which therapeutic option for a different pathophysiology?
Authors: Calderone Dario , Capodanno Davide
Published: November 2020

Spontaneous coronary artery dissection (SCAD) has been recognized as an emergent cause of acute coronary syndrome (ACS), myocardial infarction, and sudden death. Patients mostly affected by SCAD are individuals without or with few cardiovascular risk factors, particularly young women, thus suggesting a clearly different pathophysiology than the more common atherosclerosis. Present research efforts outlined an improved characterization of the prevalence, natural history, and clinical outcome of SCAD. Intracoronary imaging has been an important asset in this condition, providing an improved diagnostic and therapeutic understanding. Current evidences suggest not only that this condition is more common than previously thought but also that the clinical management could be distinctly different from ACS secondary to atherosclerosis. Both medical and interventional treatment should consider the different cause of ACS, as well as the clinical stability of the patient, taking into account that the risk of recurrence is particularly high, predominantly during the first few days after the acute event. Stemming from new scientific evidences in terms of pathophysiology, clinical approach, therapy strategies, and follow-up of SCAD, it is important to identify spontaneous coronary dissection in the differential diagnosis of ACS.
Stroke and mortality risk after atrial fibrillation ablation: lesson from the CABANA trial
Authors: Balla Cristina , Cappato Riccardo
Published: November 2020

The CABANA trial is a randomized controlled study comparing catheter ablation vs. conventional medical therapy in atrial fibrillation (AF) patients. The results of the study showed that catheter ablation did not have a significant reduction of strokes, deaths, serious bleeding, or cardiac arrest compared to medical therapy. However, a significant improvement in AF recurrences, quality of life, and symptom relief has been shown after catheter ablation compared to drug therapy. The mixed results of the study emphasized an active controversy in the cardiology community on the interpretation of the data and their use in current clinical practice. In this review, we summarized the principal controversy points of the trial describing the strengths and weaknesses of the study design and analysis.
The uraemic hypertensive patient: a therapeutic challenge—right you are (if you think so)
Authors: Cice Gennaro , Monzo Luca , Calo Leonardo
Published: November 2020

High blood pressure (BP) is a leading cause of chronic kidney disease (CKD) and at the same time represents its most frequent complication. High BP is an independent risk factor for advanced CKD; on the other hand, at least 40% of patients with normal glomerular filtration rate (GFR) and virtually all patients with GFR <30 mL/min are hypertensive. CKD and microalbuminuria are powerful risk factors for cardiovascular morbidity and mortality. Consequently, in uraemic hypertension, it is of utmost importance to carefully manage both high BP and microalbuminuria, in order to slow down the progression of kidney damage and to reduce the incidence of cardiovascular events. The first purpose of the medical treatment in hypertensive patients is to normalize BP, regardless of the drug used. Nevertheless, some drugs have an ‘additional’ nephroprotective effect at the same BP target achieved. In this regard, first-line drugs are definitely renin–angiotensin–aldosterone inhibitors, mainly for their proved efficacy in reducing hypertension-related kidney damage and proteinuria. Anyway, a combined approach (two or more drugs) is usually needed to achieve the optimal BP target and reduce the worsening of CKD.
How far should guidelines be followed?
Authors: Rapezzi Claudio , Lorenzini Massimiliano
Published: November 2020

Clinical guidelines irreparably characterize contemporary medicine. Referring to guidelines has become routine in both medical literature and daily clinical activity, with the risk of becoming the only—or at least the main—inspiring element of the physician's behaviour. This would lead to the mortification of clinical reasoning, a term that is synonymous with an individualized approach, focused on the single patient, and not on a population.
Summer school: a warm journey through teaching microbiology to undergraduate students
Authors: Gonçalves Osiel Silva , Nogueira Jéssica Rosa , da Silva Leandro Lopes , da Silva Giarlã Cunha , Martin José Guilherme Prado , Santana Mateus Ferreira , Bazzolli Denise Mara Soares , de Queiroz Marisa Vieira , Kasuya Maria Catarina Megumi
Published: November 2020

The Núcleo de Estudos em Microbiologia Agrícola (NEMA) is an academic-scientific group created by graduate students in the Post Graduate in Agricultural Microbiology in the Department of Microbiology at Universidade Federal de Viçosa, Brazil. NEMA's purposes include promoting and sharing research and knowledge on microbiology in different fields of application. Here, we will comment on our experience in organizing the Summer School on Microbiology and teaching microbiology to undergraduate students during the program. NEMA offers this annual event to disseminate and stimulate knowledge about microbiology for undergraduate students in a participatory, collaborative and interactive way.
ECG Restitution Analysis and Machine Learning to Detect Paroxysmal Atrial Fibrillation: Insight from the Equine Athlete as a Model for Human Athletes
Authors: Huang Ying H , Alexeenko Vadim , Tse Gary , Huang Christopher L-H , Marr Celia M , Jeevaratnam Kamalan
Published: November 2020

Atrial fibrillation is the most frequent arrhythmia in both equine and human athletes. Currently, this condition is diagnosed via electrocardiogram (ECG) monitoring which lacks sensitivity in about half of cases when it presents in paroxysmal form. We investigated whether the arrhythmogenic substrate present between the episodes of paroxysmal atrial fibrillation (PAF) can be detected using restitution analysis of normal sinus-rhythm ECGs. In this work, ECG recordings were obtained during routine clinical work from control and horses with PAF. The extracted QT, TQ, and RR intervals were used for ECG restitution analysis. The restitution data were trained and tested using k-nearest neighbor (k-NN) algorithm with various values of neighbors k to derive a discrimination tool. A combination of QT, RR, and TQ intervals was used to analyze the relationship between these intervals and their effects on PAF. A simple majority vote on individual record (one beat) classifications was used to determine the final classification. The k-NN classifiers using two-interval measures were able to predict the diagnosis of PAF with area under the receiving operating characteristic curve close to 0.8 (RR, TQ with k ≥ 9) and 0.9 (RR, QT with k ≥ 21 or TQ, QT with k ≥ 25). By simultaneously using all three intervals for each beat and a majority vote, mean area under the curves of 0.9 were obtained for all tested k-values (3–41). We concluded that 3D ECG restitution analysis can potentially be used as a metric of an automated method for screening of PAF.
Phylogenomics Identifies a New Major Subgroup of Apicomplexans, Marosporida class nov., with Extreme Apicoplast Genome Reduction
Authors: Mathur Varsha , Kwong Waldan K , Husnik Filip , Irwin Nicholas A T , Kristmundsson Árni , Gestal Camino , Freeman Mark , Keeling Patrick J
Published: November 2020

The phylum Apicomplexa consists largely of obligate animal parasites that include the causative agents of human diseases such as malaria. Apicomplexans have also emerged as models to study the evolution of nonphotosynthetic plastids, as they contain a relict chloroplast known as the apicoplast. The apicoplast offers important clues into how apicomplexan parasites evolved from free-living ancestors and can provide insights into reductive organelle evolution. Here, we sequenced the transcriptomes and apicoplast genomes of three deep-branching apicomplexans, Margolisiella islandica, Aggregata octopiana, and Merocystis kathae. Phylogenomic analyses show that these taxa, together with Rhytidocystis, form a new lineage of apicomplexans that is sister to the Coccidia and Hematozoa (the lineages including most medically significant taxa). Members of this clade retain plastid genomes and the canonical apicomplexan plastid metabolism. However, the apicoplast genomes of Margolisiella and Rhytidocystis are the most reduced of any apicoplast, are extremely GC-poor, and have even lost genes for the canonical plastidial RNA polymerase. This new lineage of apicomplexans, for which we propose the class Marosporida class nov., occupies a key intermediate position in the apicomplexan phylogeny, and adds a new complexity to the models of stepwise reductive evolution of genome structure and organelle function in these parasites.
Azimuthal anisotropy in Bayesian surface wave tomography: application to northern Cascadia and Haida Gwaii, British Columbia
Authors: Gosselin Jeremy M , Audet Pascal , Schaeffer Andrew J , Darbyshire Fiona A , Estève Clément
Published: November 2020

Surface wave tomography is a valuable tool for constraining azimuthal anisotropy at regional scales. However, sparse and uneven coverage of dispersion measurements make meaningful uncertainty estimation challenging, especially when applying subjective model regularization. This paper considers azimuthal anisotropy constrained by measurements of surface wave dispersion data within a Bayesian trans-dimensional (trans-d) tomographic inversion. A recently proposed alternative model parametrization for trans-d inversion is implemented in order to produce more realistic models than previous studies considering trans-d surface wave tomography. The reversible-jump Markov chain Monte Carlo sampling technique is used to numerically estimate the posterior probability density of the model parameters. Isotropic and azimuthally anisotropic components of surface wave group velocity maps (and their associated uncertainties) are estimated while avoiding model regularization and allowing model complexity to be determined by the data information content. Furthermore, data errors are treated as unknown, and solved for within the inversion. The inversion method is applied to measurements of surface wave dispersion from regional earthquakes recorded over northern Cascadia and Haida Gwaii, a region of complex active tectonics but highly heterogeneous station coverage. Results for isotropic group velocity are consistent with previous studies that considered the southern part of the study region over Cascadia. Azimuthal anisotropic fast-axis directions are generally margin-parallel between Vancouver Island and Haida Gwaii, with a small change in direction and magnitude along the margin which may be attributed to the changing tectonic regime (from subduction to transform tectonics). Estimated errors on the dispersion data (solved for within the inversion) reveal a correlation between surface wave period and the dependence of data errors on travel path length. This paper demonstrates the value of considering azimuthal anisotropy within Bayesian tomographic inversions. Furthermore, this work provides structural context for future studies of tectonic structure and dynamics of northern Cascadia and Haida Gwaii, with the aim of improving our understanding of seismic and tsunami hazards.
A skipping rope translocation mechanism in a widespread family of DNA repair helicases
Authors: Roske Johann J , Liu Sunbin , Loll Bernhard , Neu Ursula , Wahl Markus C
Published: November 2020

Mitomycin repair factor A represents a family of DNA helicases that harbor a domain of unknown function (DUF1998) and support repair of mitomycin C-induced DNA damage by presently unknown molecular mechanisms. We determined crystal structures of Bacillus subtilis Mitomycin repair factor A alone and in complex with an ATP analog and/or DNA and conducted structure-informed functional analyses. Our results reveal a unique set of auxiliary domains appended to a dual-RecA domain core. Upon DNA binding, a Zn2+-binding domain, encompassing the domain of unknown function, acts like a drum that rolls out a canopy of helicase-associated domains, entrapping the substrate and tautening an inter-domain linker across the loading strand. Quantification of DNA binding, stimulated ATPase and helicase activities in the wild type and mutant enzyme variants in conjunction with the mode of coordination of the ATP analog suggest that Mitomycin repair factor A employs similar ATPase-driven conformational changes to translocate on DNA, with the linker ratcheting through the nucleotides like a ‘skipping rope’. The electrostatic surface topology outlines a likely path for the displaced DNA strand. Our results reveal unique molecular mechanisms in a widespread family of DNA repair helicases linked to bacterial antibiotics resistance.
Circulating Biomarkers for Glioma: A Review
Authors: Jones Jordan , Nguyen Hong , Drummond Katharine , Morokoff Andrew
Published: November 2020

Accurate circulating biomarkers have potential clinical applications in population screening, tumor subclassification, monitoring tumor status, and the delivery of individualized treatments resulting from tumor genotyping. Recently, significant progress has been made within this field in several cancer types, but despite the many potential benefits, currently there is no validated circulating biomarker test for patients with glioma. A number of circulating factors have been examined, including circulating tumor cells, cell-free DNA, microRNA, exosomes, and proteins from both peripheral blood and cerebrospinal fluid with variable results. In the following article, we provide a narrative review of the current evidence pertaining to circulating biomarkers in patients with glioma, including discussion of the advantages and challenges encountered with the current methods used for discovery. Additionally, the potential clinical applications are described with reference to the literature.
Time well spent versus a life considered: changing subjective Well-Being in China
Authors: Cai Shu , Park Albert , Yip Winnie
Published: November 2020

Using unique longitudinal survey data that employed the Day Reconstruction Method to measure experienced utility (EU) in rural China, this study reveals striking differences in the trends for life satisfaction and EU. We find that reported life satisfaction changed little over the period from 2006 to 2009. However, EU increased significantly during the same period. The improvement in EU is mainly due to more positive feelings about specific activities rather than changes in the time spent on different activities. These findings are consistent with the predictions of aspiration adaptation theory.
COVID-19 infection among first responders in Broward County, Florida, March–April 2020
Authors: Niu Jianli , Rodriguez Jose A , Sareli Candice , Goldman Jennifer , Puga Monica , Eckardt Paula A
Published: November 2020

Background

First responders (FRs) may have a significant risk of coronavirus 19 (COVID-19) infection than the general population due to job-related exposures. We aimed to determine the prevalence and exposure patterns of COVID-19 among FRs.

Methods

Between March and April 2020, FRs in Broward County, Florida, were screened for COVID-19 infection by real-time reverse transcription polymerase chain reaction assay using nasopharyngeal swabs. Demographics and COVID-19 positive rate of the FRs were summarized.

Results

A total of 3375 FRs were screened for COVID-19 infection. The median age of FRs tested was 42 years (IQR 33–52 years), and 1464 (43.4%) were men. A total of 2902 (85.9%) were asymptomatic, and 473 (14.1%) reported symptoms associated with COVID-19. Overall, 289 (8.6%) were positive, with the highest rates among the age between 25 and 49 years. Of those testing positive, 235 (81.3%) were asymptomatic. Fourteen days after their first positive test, 81 (69.8%) of the 116 asymptomatically infected FRs were negative, and 35 (30.2%) remained positive and asymptomatic.

Conclusions

The FRs in Broward County, FL, had an overall infection rate of 8.6% at the time of COVID-19 testing, and asymptomatic FRs accounted for 81.3% of infection. Active surveillance should be focused on the asymptomatic FRs with COVID-19.
The number of risk factors for persistent disease determines the clinical course of early arthritis
Authors: Luurssen-Masurel N , Weel A E A M , Koc G H , Hazes J M W , de Jong P H P ,   for the tREACH group investigators
Published: November 2020

Objectives

Management of early arthritis is based upon early recognition of individuals at high risk of developing persistent arthritis. Therefore, this study investigates whether the number of risk factors for persistent disease or treatment determines the clinical course of early arthritis by comparing the chance at (sustained) DMARD-free remission ((S)DFR) after 2 years follow-up.

Methods

Data from the tREACH trial, a stratified single-blinded multicentre strategy trial with a treat-to-target approach were used. We selected all patients with ≥1 swollen joint who did not fulfil 1987 and/or 2010 criteria for RA. The number of risk factors present; autoantibody-positivity, polyarthritis (>4), erosive disease and elevated acute phase reactants, determined risk group stratification. Multivariate logistic regression analyses were performed with (S)DFR as dependent variables and baseline disease activity score (DAS), treatment, symptom duration and number of risk factors present as independent variables.

Results

In total, 130 early arthritis patients were included and respectively 31, 66 and 33 had 0, 1 and ≥2 risk factors present. DFR rates were respectively 74%, 48% and 45% for early arthritis patients with 0, 1 and ≥2 risk factors present. In accordance SDFR rates were 61%, 32% and 30%. In our logistic model (S)DFR was not influenced by the initial treatment strategies when stratified for risk groups.

Conclusion

The chance at (S)DFR in early arthritis diminishes when more risk factors are present, which is irrespective of the given initial treatment. Our data point out to a stratified management approach in early arthritis based on their risk profile, but validation is needed.

Trial registration

ISRCTN registry: ISRCTN26791028 (http://www.isrctn.com/ISRCTN26791028).
Differential Toxicological Outcome of Corn Oil Exposure in Rats and Mice as Assessed by Microbial Composition, Epithelial Permeability, and Ileal Mucosa-Associated Immune Status
Authors: Gokulan Kuppan , Kumar Amit , Lahiani Mohamed H , Sutherland Vicki L , Cerniglia Carl E , Khare Sangeeta
Published: November 2020

Studies to evaluate the toxicity of xenobiotics on the human gut microbiome and related health effects require a diligent selection of (1) an appropriate animal model to facilitate toxicity assessment in predicting human exposure, and (2) an appropriate non-interfering vehicle for the administration of water insoluble compounds. In biomedical studies with water insoluble xenobiotics, corn oil is one of the most commonly used nonaqueous vehicles. This study evaluated the suitability of corn oil as a vehicle in adult female Sprague Dawley rats and adult CD-1 mice; the rodent models that are often utilized in toxicological studies. We studied the host response in terms of change in the intestinal microbiome and mRNA expression of intestinal permeability and immune response-related genes when water (control) and corn oil (2 ml/kg) were administered as a vehicle through oral gavage. The results showed that the use of corn oil as a vehicle has no adverse impact in rats for either the immune response or the intestinal microbial population. On the other hand, mice treated with corn oil showed changes in bacterial community adhered to the ileum, as well as changes in the mRNA expression of intestinal permeability-related and ileal mucosa-associated immune response genes. Overall, results of this study suggest that the type of rodent species and vehicle used in toxicological risk assessments of xenobiotics studies should be taken into consideration in the experimental setup and study design.
Longitudinal sampling is required to maximize detection of intrahost A/H3N2 virus variants
Authors: Koel B F , Vigeveno R M , Pater M , Koekkoek S M , Han A X , Tuan H M , Anh T T N , Hung N T , Thinh L Q , Hai L T , Ngoc H T B , Chau N V V , Ngoc N M , Chokephaibulkit K , Puthavathana P , Kinh N V , Trinh T , Lee R T C , Maurer-Stroh S , Eggink D , Thanh T T , Tan L V , van Doorn H R , de Jong M D
Published: November 2020

Seasonal human influenza viruses continually change antigenically to escape from neutralizing antibodies. It remains unclear how genetic variation in the intrahost virus population and selection at the level of individual hosts translates to the fast-paced evolution observed at the global level because emerging intrahost antigenic variants are rarely detected. We tracked intrahost variants in the hemagglutinin and neuraminidase surface proteins using longitudinally collected samples from 52 patients infected by A/H3N2 influenza virus, mostly young children, who received oseltamivir treatment. We identified emerging putative antigenic variants and oseltamivir-resistant variants, most of which remained detectable in samples collected at subsequent days, and identified variants that emerged intrahost immediately prior to increases in global rates. In contrast to most putative antigenic variants, oseltamivir-resistant variants rapidly increased to high frequencies in the virus population. Importantly, the majority of putative antigenic variants and oseltamivir-resistant variants were first detectable four or more days after onset of symptoms or start of treatment, respectively. Our observations demonstrate that de novo variants emerge, and may be positively selected, during the course of infection. Additionally, based on the 4–7 days post-treatment delay in emergence of oseltamivir-resistant variants in six out of the eight individuals with such variants, we find that limiting sample collection for routine surveillance and diagnostic testing to early timepoints after onset of symptoms can potentially preclude detection of emerging, positively selected variants.
Impact of Preconditioning Temperature and Duration Period on Carpogenic Germination of Diverse Sclerotinia sclerotiorum Populations in Southwestern Australia
Authors: Michael Pippa J. , Lui King Yin , Thomson Linda L. , Lamichhane Ashmita Rijal , Bennett Sarita J.
Published: November 2020

The soilborne pathogen Sclerotinia sclerotiorum (Lib.) de Bary is the causal agent of Sclerotinia stem rot, a severe disease of broad-leaf crops including canola/rapeseed (Brassica napus) that can result in significant yield losses. Sclerotia, the hard melanized resting structure of the pathogen, requires preconditioning before carpogenic germination can occur. We investigated the effect of preconditioning temperature (4, 20, 35, 50°C, and field conditions) and duration (0, 30, 60, 120, 179, 240, and 301 days) on germination of S. sclerotiorum sclerotia collected from five canola fields in the southwestern Australia grain belt. The ecological diversity of each population was characterized using mycelial compatibility group (MCG) typing. No response was observed for isolates conditioned at 4°C at any time period, indicating that chilling is not a preconditioning requirement for these isolates. Sclerotia required preconditioning for a minimum of 60 days before any significant increase in germination occurred, with no further increases in germination recorded in response to longer conditioning after 60 days. The highest germination was observed in sclerotia conditioned at 50°C. The MCG results indicated significant diversity within and between populations, suggesting local adaptation to different environments as well as ensuring the ability to respond to seasonal variation between years.
Bacterial Panicle Blight and Burkholderia glumae: From Pathogen Biology to Disease Control
Authors: Ortega Laura , Rojas Clemencia M.
Published: November 2020

Bacterial panicle blight (BPB), caused by the bacterium Burkholderia glumae, has affected rice production worldwide. Despite its importance, neither the disease nor the causal agent are well understood. Moreover, methods to manage BPB are still lacking. Nevertheless, the emerging importance of this pathogen has stimulated research to identify the mechanisms of pathogenicity, to gain insight into plant disease resistance, and to develop strategies to manage the disease. In this review, we consolidate current information regarding the virulence factors that have been identified in B. glumae and present a model of the disease and the pathogen. We also provide an update on the current research status to develop methods to control the disease especially through biological control approaches and through the development of resistant cultivars.
Confidence Intervals in Clinical Research
Authors: Schober P. , Vetter T.R.
Published: November 2020

(Anesth Analg. 2020;130:1303)

A recent issue of Anesthesia & Analgesia published an article wherein Reale and colleagues reported an increase in the risk of postpartum hemorrhage (PPH) from 2010 with 2.9% [95% confidence interval (CI), 2.7%-3.1%] of deliveries affected to 2014 with 3.2% with PPH (95% CI, 3.1%-3.3%). The CIs recorded in these circumstances are critical to the results of the study, as varying samples are affected by the randomness of their selections. CIs, to combat this, provide a range of values of the plausible true parameter value in the underlying population (assuming a representative sample). A 95% CI indicates that 95% of the repeated random samples contain a true population parameter.
Does Fentanyl Epidural Analgesia Affect Breastfeeding: A Prospective Cohort Study
Authors: Mahomed K. , Wild K. , Brown C. , Green A.
Published: November 2020

(Aust N Z J Obstet Gynaecol. 2019;59:819–824)

Breastfeeding has clear short-term and long-term benefits and is widely recommended. The majority of mothers in Australia (77%) request epidural analgesia for labor. As a result, concerns have been voiced about the possible effects of epidural fentanyl on success with breastfeeding. Fentanyl is often used with bupivacaine for epidural labor analgesia to decrease the dose of local anesthetic needed and minimize motor block. However, it may depress neonatal reflexes associated with swallowing or sucking and could thus negatively affect breastfeeding success. In 2016, a systematic review assessed the effects of epidural labor analgesia on breastfeeding. Mixed results were found, and the investigators had difficulty comparing studies due to varied study designs. This current study aimed to clarify the association between epidural fentanyl and breastfeeding, including any dose effects, in a well-defined population of nulliparous women who had just delivered vaginally and planned to breastfeed.
Postoperative Analgesic Effectiveness of Quadratus Lumborum Block for Cesarean Delivery under Spinal Anesthesia
Authors: Hussain Nasir , Brull Richard , Weaver Tristan , Zhou Meiqin , Essandoh Michael , Abdallah Faraj W.
Published: November 2020

Background

Spinal morphine is the mainstay of postcesarean analgesia. Quadratus lumborum block has recently been proposed as an adjunct or alternative to spinal morphine. The authors evaluated the analgesic effectiveness of quadratus lumborum block in cesarean delivery with and without spinal morphine.

Methods

Randomized trials evaluating quadratus lumborum block benefits in elective cesarean delivery under spinal anesthesia were sought. Three comparisons were considered: spinal morphine versus spinal morphine and quadratus lumborum block; spinal morphine versus quadratus lumborum block; and no block or spinal morphine versus quadratus lumborum block. The two coprimary outcomes were postoperative (1) 24-h cumulative oral morphine equivalent consumption and (2) pain at 4 to 6 h. Secondary outcomes included area under the curve pain, time to analgesic request, block complications, and opioid-related side effects.

Results

Twelve trials (924 patients) were analyzed. The mean differences (95% CIs) in 24-h morphine consumption and pain at 4 to 6 h for spinal morphine versus spinal morphine and quadratus lumborum block comparison were 0 mg (−2 to 1) and −0.1 cm (−0.7 to 0.4), respectively, indicating no benefit. For spinal morphine versus quadratus lumborum block, these differences were 7 mg (−2 to 15) and 0.6 cm (−0.7 to 1.8), respectively, also indicating no benefit. In contrast, for no block or spinal morphine versus quadratus lumborum block, improvements of −18 mg (−28 to −7) and −1.5 cm (−2.4 to −0.6) were observed, respectively, with quadratus lumborum block. Finally, for no block or spinal morphine versus quadratus lumborum block, quadratus lumborum block improved area under the 48-h pain curve by −4.4 cm · h (−5.0 to −3.8), exceeding the clinically important threshold (3.96 cm · h), but no differences were observed in the other comparisons.

Conclusions

Moderate quality evidence suggests that quadratus lumborum block does not enhance analgesic outcomes when combined with or compared with spinal morphine. However, the block improves postcesarean analgesia in the absence of spinal morphine. The clinical utility of this block seems limited to situations in which spinal morphine is not used.

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Cutaneous Cephalic Neurocristic Hamartoma on the Head With Melanocytic, Cartilage, Blood Vessel, Neural, and Bony Tissue
Authors: Stieler Karola Maria , Röwert-Huber Joachim , Vogt Annika , Meyer Lutz , Ulrike Blume-Peytavi
Published: November 2020

We report on a congenital tumor of the face and scalp in a male newborn, histologically proven to contain melanocytes, cartilage, and bone, vascular, and neural tissue as part of a pigmented congenital tumor. Thus, this tumor was classified as a cutaneous cephalic neurocristic hamartoma.
Dysregulated Hepatic Expression of Glucose Transporter Type-1, Toll-Like Receptor 4, and Nuclear Factor Kappa B in Estrogen-Induced Cholestasis Pregnant Rats with Placental Ischemia-Reperfusion Stress
Authors: Zhou Fan , Chen Huafang , Shan Dan , Wu Yuxia , Chen Qian , Hu Yayi
Published: November 2020

Objective:

This study aimed at investigating the expression of nuclear factor kappa B (NF-κB) and mammalian target of rapamycin (mTOR) related signal pathways in liver tissues of intrahepatic cholestasis of pregnancy animal models.

Methods:

Estrogen (EE)-induced cholestasis and a placental ischemia-reperfusion (IR) model were established in pregnant rats. All pregnant rats were divided into four groups by random number table: EE-IR group (n = 6), EE-sham group (n = 6), control-IR group (n = 6) and control-sham group (n 
= 6). Liver expression of mTOR, its upstream regulator DNA damage response-1 (REDD1), and downstream factor glucose transporter type-1 (GLUT1), accompanied by NF-κB (p65 is the most important component), its activator toll-like receptor 4 (TLR4), and inhibitor IκBα, were detected by western blot analysis and real-time polymerase chain reaction. The intergroup comparisons were performed with a one-way analysis of variance, the comparisons among groups were analyzed with the nonparametric Kruskal-Wallis test.

Results:

Giving pregnant rats EE alone reduced the hepatic expression of IκBα (0.72 ± 0.20 vs. 1.01 ± 0.07, P = 0.008). Meanwhile, giving pregnant rats placental IR alone increased liver levels of REDD1 (3.24 ± 0.98 vs. 1.06 ± 0.24, P = 0.025), GLUT1 (2.37 ± 0.82 vs. 1.09 ± 0.10, P = 0.039), TLR4 (2.12 ± 0.29 vs. 1.20 ± 0.28, P = 0.010), and p65 (2.09 ± 0.85 vs. 1.04 ± 0.06, P = 0.023), and decreased hepatic mTOR (0.50 ± 0.07 vs. 1.01 ± 0.03, P = 0.001) and IκBα (0.61 ± 0.08 vs. 1.01 ± 0.07, P = 0.014) expression. Subjecting EE-treated rats to placental IR did not further alter liver levels of GLUT1 (2.02 ± 0.45 vs. 1.79 ± 0.39, P = 0.240), TLR4 (2.10 ± 0.74 vs. 1.60 ± 0.36, P = 0.129), or p65 (2.41 ± 0.83 vs. 1.65 ± 0.46, P = 0.145), whereas it did decrease hepatic mTOR (0.42 ± 0.09 vs. 0.90 ± 0.14, P = 0.008) and IκBα (0.43 ± 0.09 vs. 0.72 ± 0.20, P = 0.004) expression and enhance REDD1 expression (4.46 ± 0.65 vs. 2.05 ± 0.47, P = 0.009). Placental IR stress did impact the hepatic expression of REDD1-mTOR-GLUT1 and TLR4/NF-κB/IκBα in pregnant rats.

Conclusion:

Placental IR-induced hepatic GLUT1, TLR4, and p65 alternation, which responded efficiently in control rats, were impaired in EE-induced ICP rats.