bluuebunny/crossref_metadata_2025 huggingface dataset:
Interplay between diet and gut microbiome, and circulating concentrations of trimethylamine N-oxide: findings from a longitudinal cohort of US men
Authors: Li Jun , Li Yanping , Ivey Kerry L , Wang Dong D , Wilkinson Jeremy E , Franke Adrian , Lee Kyu Ha , Chan Andrew , Huttenhower Curtis , Hu Frank B , Rimm Eric B , Sun Qi
Published: April 2021

Objectives

Gut-produced trimethylamine N-oxide (TMAO) is postulated as a possible link between red meat intake and poor cardiometabolic health. We investigated whether gut microbiome could modify associations of dietary precursors with TMAO concentrations and cardiometabolic risk markers among free-living individuals.

Design

We collected up to two pairs of faecal samples (n=925) and two blood samples (n=473), 6 months apart, from 307 healthy men in the Men’s Lifestyle Validation Study. Diet was assessed repeatedly using food-frequency questionnaires and diet records. We profiled faecal metagenome and metatranscriptome using shotgun sequencing and identified microbial taxonomic and functional features.

Results

TMAO concentrations were associated with the overall microbial compositions (permutational analysis of variance (PERMANOVA) test p=0.001). Multivariable taxa-wide association analysis identified 10 bacterial species whose abundance was significantly associated with plasma TMAO concentrations (false discovery rate <0.05). Higher habitual intake of red meat and choline was significantly associated with higher TMAO concentrations among participants who were microbial TMAO-producers (p<0.05), as characterised based on four abundant TMAO-predicting species, but not among other participants (for red meat, P-interaction=0.003; for choline, P-interaction=0.03). Among abundant TMAO-predicting species, Alistipes shahii significantly strengthened the positive association between red meat intake and HbA1c levels (P-interaction=0.01). Secondary analyses revealed that some functional features, including choline trimethylamine-lyase activating enzymes, were associated with TMAO concentrations.

Conclusion

We identified microbial taxa that were associated with TMAO concentrations and modified the associations of red meat intake with TMAO concentrations and cardiometabolic risk markers. Our data underscore the interplay between diet and gut microbiome in producing potentially bioactive metabolites that may modulate cardiometabolic health.
Sex Differences in the Induction of Angiotensin Converting Enzyme 2 (Ace-2) in Mouse Lungs after E-Cigarette Vapor Exposure and Its Relevance to Covid-19
Authors: Naidu Vegi , Zeki Amir A , Sharma Pawan
Published: April 2021

The COVID-19 pandemic has affected over 114 million people and has resulted in >2.5 million deaths so far. Some people have greater susceptibility which influences both SARS-CoV-2 infectivity and COVID-19 severity. Smoking is associated with increased ACE-2, the receptor for SARS-CoV-2, which facilitates its entry through the lung. However, despite the widespread use of e-cigarettes, also known as ‘vaping’, little is known regarding the effects of vaping on ACE-2 expression and how this affects SARS-CoV-2 infection. In addition, the added effect of nicotine in the vapor is also unknown. Thus, we tested whether vaping induces ACE-2 expression in the mouse lung. BALB/c mice exposed to e-cigarette vapor (±nicotine) resulted in a significant increase in peribronchiolar inflammation and influx of immune cells into the airways. Vapor increased monocyte chemoattractant protein-1, interleukin 1β, and KC levels in bronchoalveolar lavage fluid in both sexes, which were further enhanced by nicotine (whereas increase in interleukin 6 was sex and nicotine independent). The reduction in basal inspiratory capacity with vapor exposure occurred independent of sex or nicotine. The increase in methacholine-induced airway hyper-responsiveness was independent of sex; however, in female mice it was only significant in the nicotine-exposed group. Lung ACE-2 expression was increased in male mice in a nicotine-dependent manner as compared with female mice. Collectively, while vaping (±nicotine) induced airway inflammation and impaired lung function, the induction of lung ACE-2 occurred to a significantly greater degree in males exposed to vapor containing nicotine as compared with females. Thus, via these effects on ACE-2 expression in the lungs and airways, vaping itself may facilitate SARS-CoV-2 entry into the airways.
Going beyond ‘regular and casual’: development of a classification of sexual partner types to enhance partner notification for STIs
Authors: Estcourt Claudia S , Flowers Paul , Cassell Jackie A , Pothoulaki Maria , Vojt Gabriele , Mapp Fiona , Woode-Owusu Melvina , Low Nicola , Saunders John , Symonds Merle , Howarth Alison , Wayal Sonali , Nandwani Rak , Brice Susie , Comer Alex , Johnson Anne M , Mercer Catherine H
Published: April 2021

Objectives

To develop a classification of sexual partner types for use in partner notification (PN) for STIs.

Methods

A four-step process: (1) an iterative synthesis of five sources of evidence: scoping review of social and health sciences literature on partner types; analysis of relationship types in dating apps; systematic review of PN intervention content; and review of PN guidelines; qualitative interviews with public, patients and health professionals to generate an initial comprehensive classification; (2) multidisciplinary clinical expert consultation to revise the classification; (3) piloting of the revised classification in sexual health clinics during a randomised controlled trial of PN; (4) application of the Theoretical Domains Framework (TDF) to identify index patients’ willingness to engage in PN for each partner type.

Results

Five main partner types emerged from the evidence synthesis and consultation: ‘established partner’, ‘new partner’, ‘occasional partner’, ‘one-off partner’ and ‘sex worker’. The types differed across several dimensions, including likely perceptions of sexual exclusivity, likelihood of sex reoccurring between index patient and sex partner. Sexual health professionals found the classification easy to operationalise. During the trial, they assigned all 3288 partners described by 2223 index patients to a category. The TDF analysis suggested that the partner types might be associated with different risks of STI reinfection, onward transmission and index patients’ engagement with PN.

Conclusions

We developed an evidence-informed, useable classification of five sexual partner types to underpin PN practice and other STI prevention interventions. Analysis of biomedical, psychological and social factors that distinguish different partner types shows how each could warrant a tailored PN approach. This classification could facilitate the use of partner-centred outcomes. Additional studies are needed to determine the utility of the classification to improve measurement of the impact of PN strategies and help focus resources.
Nocturnal hypoxaemia in interstitial lung disease: a systematic review
Authors: Khor Yet Hong , Ng Yvonne , Sweeney Duncan , Ryerson Christopher J
Published: April 2021

Background

Patients with interstitial lung disease (ILD) are at risk of developing nocturnal hypoxaemia due to ventilatory restriction and impaired gas exchange that worsen with supine posture and reduced ventilatory drive during sleep. This systematic review synthesised literature on the diagnostic evaluation, epidemiology, associations, management and prognosis of nocturnal hypoxaemia in ILD.

Methods

Ovid MEDLINE, Embase and CENTRAL databases were searched for eligible studies. Meta-analyses with subgroup analyses were conducted, where possible.

Results

Fifty-three studies were included (total participant number=2590). The most common definition for clinically significant nocturnal hypoxaemia was ≥10% of total sleep time with oxyhaemoglobin saturation <90%, with pooled prevalence of 37%. There were no significant differences in pooled prevalence according to ILD subtype and comorbid obstructive sleep apnoea status. Study heterogeneity precluded meta-analysis of associations and prognosis. Diffusing capacity for carbon monoxide (DLCO) and echocardiographic features for pulmonary hypertension were consistently associated with nocturnal hypoxaemia. There were inconsistent associations between nocturnal hypoxaemia with ILD subtype and severity. Multivariable analyses in most studies demonstrated significant associations of nocturnal hypoxaemia with survival. Two small short-term intervention studies demonstrated that supplemental oxygen of 1–3 L/min corrected nocturnal hypoxaemia, with improved heart rate control during in-laboratory observation and increased serum antioxidant levels after 1 month of therapy.

Conclusion

Nocturnal hypoxaemia is common, associated with DLCO impairment and markers suggestive of pulmonary hypertension, and a potential prognostic factor in patients in ILD. There is a need to establish a consensus definition of nocturnal hypoxaemia and evaluate long-term effects of nocturnal supplemental oxygen in ILD.
Pulmonary fibrosis 4 months after COVID-19 is associated with severity of illness and blood leucocyte telomere length
Authors: McGroder Claire F , Zhang David , Choudhury Mohammad A , Salvatore Mary M , D'Souza Belinda M , Hoffman Eric A , Wei Ying , Baldwin Matthew R , Garcia Christine Kim
Published: April 2021

The risk factors for development of fibrotic-like radiographic abnormalities after severe COVID-19 are incompletely described and the extent to which CT findings correlate with symptoms and physical function after hospitalisation remains unclear. At 4 months after hospitalisation, fibrotic-like patterns were more common in those who underwent mechanical ventilation (72%) than in those who did not (20%). We demonstrate that severity of initial illness, duration of mechanical ventilation, lactate dehydrogenase on admission and leucocyte telomere length are independent risk factors for fibrotic-like radiographic abnormalities. These fibrotic-like changes correlate with lung function, cough and measures of frailty, but not with dyspnoea.
From participatory engagement to co-production: modelling climate-sensitive processes in the Arctic
Authors: Davis Katy , Ford James D. , Quinn Claire , IHACC Research Team  , Harper Sherilee L.
Published: April 2021

Participation is increasingly being used in the modelling of climate-sensitive systems to improve usability. Bottom-up, place-based approaches to modelling can challenge the dominantly positivist approaches used until recently. We examined how participation is reported within modelling research that uses participatory approaches, focusing on the Arctic. Our systematic scoping review identified 26 articles that used participatory approaches in modelling research to explore a climate-sensitive process in an Arctic setting and analysed the degree of participation at each stage of the process for each article. A diversity of topics, modelling approaches, and participant groups were identified. Most studies (71%) occurred in Arctic North America, and all studies engaged with non-Western knowledge types to some degree. Participation was most commonly reported at the model generation and participant identification stages, and least commonly reported in the choice of modelling type. Participatory scores — based on the number and degree of participatory stages of a study — were higher where authors gave instrumental or transformative rationales for the use of participation, and among studies that described prioritising non-Western knowledge types. Detailed reporting of participatory processes was frequently absent, suggesting a need for clearer discussions of these issues in the descriptions of the process.
Non-comoving cold dark matter in a $$\varLambda $$CDM background
Authors: Nájera Sebastián , Sussman Roberto A.
Published: April 2021

We examine the evolution of peculiar velocities of cold dark matter (CDM) in localized arrays of inhomogeneous cosmic structures in a$$\varLambda $$ΛCDM background that can be identified as a frame comoving with the Cosmic Microwave (CMB). These arrays are constructed by smoothly matching to this cosmological background regions of Szekeres-II models whose source is an imperfect fluid reinterpreted as non-comoving dust, keeping only first order terms inv/c. Considering a single Szekeres-II region matched along two comoving interfaces to a$$\varLambda $$ΛCDM background, the magnitudes of peculiar velocities within this region are compatible with values reported in the literature, while the present day Hubble expansion scalar differs from that of the$$\varLambda $$ΛCDM background value by a 10% factor, a result that might provide useful information to the ongoing debate on the$$H_0$$H0tension. While the models cannot describe the virialization process, we show through a representative example that structures of galactic cluster mass reach the onset of this process at redshifts around$$z\sim 3$$z∼3.
Gravitational resonances on f(T)-branes
Authors: Tan Qin , Guo Wen-Di , Zhang Yu-Peng , Liu Yu-Xiao
Published: April 2021

In this work, we investigate the gravitational resonances in various f(T)-brane models with the warp factor $$\text {e}^{A(y)}=\tanh \big (k(y+b)\big )-\tanh \big (k(y-b)\big )$$

e

A
(
y
)

=
tanh

(

k

(
y
+
b
)

)

-
tanh

(

k

(
y
-
b
)

)

, where f(T) is an arbitrary function of the torsion scalar T. For three kinds of f(T), we give the solutions to the system. Besides, we consider the tensor perturbation of the vielbein and obtain the effective potentials by the Kaluza–Klein (KK) decomposition. Then we analyze what kind of effective potential can produce the gravitational resonances. The effects of different parameters on the gravitational resonances are analyzed. The lifetimes of the resonances could be long enough as regards the age of our universe in some ranges of the parameters. This indicates that the gravitational resonances might be considered as one of the candidates for dark matter. Combining the current experimental observations, we constrain the parameters for these brane models.
The Use of the Telegram Application as an Information-Sharing Tool
Authors: AlAwadhi Suha , Dashti Maryam
Published: April 2021

This study explored the use and acceptance by sixth-grade Kuwaiti English language teachers of the Telegram application as an information source and a knowledge-sharing tool that enables users to easily find, store and share useful learning information and enhances their teaching–learning practices. A mixed method approach was employed that included data triangulation: observation, a survey and a focus group to empirically reveal the results. The findings revealed that Telegram application was an effective source of textual and non-textual information as well as an information-sharing tool that saved time, effort and costs and overcame time and place limitations. Telegram’s various information sets allowed for the generation of innovative ideas, which improved the effectiveness of the teaching methods and accelerated language learning. The results of this study can assist information specialists to work collaboratively with teachers to plan and design information content for Telegram to support schools’ curriculum, complement teaching practices and develop learner’s information literacy skills.
Virtual Reality Sickness Mitigation Methods
Authors: Shi Rongkai , Liang Hai-Ning , Wu Yu , Yu Difeng , Xu Wenge
Published: April 2021

Using virtual reality (VR) head-mounted displays (HMDs) can induce VR sickness. VR sickness can cause strong discomfort, decrease users' presence and enjoyment, especially in games, shorten the duration of the VR experience, and can even pose health risks. Previous research has explored different VR sickness mitigation methods by adding visual effects or elements. Field of View (FOV) reduction, Depth of Field (DOF) blurring, and adding a rest frame into the virtual environment are examples of such methods. Although useful in some cases, they might result in information loss. This research is the first to compare VR sickness, presence, workload to complete a search task, and information loss of these three VR sickness mitigation methods in a racing game with two levels of control. To do this, we conducted a mixed factorial user study (N = 32) with degree of control as the between-subjects factor and the VR sickness mitigation techniques as the within-subjects factor. Participants were required to find targets with three difficulty levels while steering or not steering a car in a virtual environment. Our results show that there are no significant differences in VR sickness, presence and workload among these techniques under two levels of control in our VR racing game. We also found that changing FOV dynamically or using DOF blur effects would result in information loss while adding a target reticule as a rest frame would not.
Interaction Based Redirected Walking
Authors: Schmelter Thereza , Hernadi Levente , Störmer Marc Aurel , Steinicke Frank , Hildebrand Kristian
Published: April 2021

With a significant improvement in virtual reality (VR) devices, the number of interaction-based applications for consumers and industrial products is naturally increasing. As a result, many people can use VR in their homes or offices where they are limited by the physical tracking space. One way to overcome this limitation of natural walking is to use perception-inspired locomotion techniques such as redirected walking (RDW). RDW utilizes imperfections of human perception to introduce small changes like rotations or translations to steer the user away from the tracking boundaries. In this work we evaluate the detection threshold for discrete manipulation rotations to reorient the users in the scene during interactions. We show the thresholds of five most common interactions (Looking, Picking Up, Throwing, Shooting and Sword Fighting) that can be used as a distraction for RDW, which was confirmed in a user study. Based on the findings we propose a novel steer-to-action technique that helps game developers to improve VR games experiences.
Am I Playing Better Now?
Authors: Riahi Maryam , Watson Benjamin Allen
Published: April 2021

G-SYNC technology matches formerly regular display refreshes to irregular frame updates, improving frame rates and interactive latency. In a previous study of gaming at the 30Hz frame rates common on consoles, players of Battlefield 4 were unable to discern when G-SYNC was in use, but scored higher with G-SYNC and were affected emotionally. We build on that study with the first examination of G-SYNC's effects at the 60Hz frame rate more common in PC gaming and on emerging consoles. Though G-SYNC's effects are less at 60Hz than they were at 30Hz, G-SYNC can still improve the performance of veteran players, particularly when games are challenging. G-SYNC's effects on emotion and experience were limited.
Additives for Superconformal Gold Feature Filling
Authors: Josell D. , Moffat T. P.
Published: April 2021

An overview of the effect of additives on Au electrodeposition from Na3Au(SO3)2 based electrolytes is presented with an emphasis on filling of fully metallized recessed surface features such as trenches and vias. The impact of heavy metal additives Tl+, Pb2+, and Bi3+ is reviewed and accompanied by a brief survey of the effects of Sb3+, Te4+, SeCN−, 3-mercapto-1-propanesulfonic acid (MPS) and polyethyleneimine (PEI) additions. The addition of Tl+, Pb2+, Bi3+ or Sb3+ accelerates the kinetics of Au(SO3)2
3− reduction to Au, as manifest in hysteretic voltammetry and rising chronoamperometric transients, and yields bright specular deposits. Gold deposition with Pb2+ addition exhibits superconformal filling in sub-micrometer trenches while Bi3+ addition induces a more extreme bottom-up filling, but Tl+ and Sb3+ additions yield essentially conformal deposition for the conditions examined. Modest acceleration and hysteresis observed with Te4+ addition reflect roughening due to limited nucleation, 3D growth and delayed coalescence, rather than catalysis, and are associated with conformal feature filling. Unlike the other additives, SeCN−, MPS and PEI inhibit the deposition kinetics. Breakdown of suppression during deposition in micrometer size trenches is biased toward recessed surfaces where the flux of suppressor is constrained, yielding localized deposition and superconformal filling.
3D Anode Microbial Fuel Cell Characterization and Monitoring Coupling X-Ray Tomography and Electrochemical Impedance Spectroscopy
Authors: Papillon Justine , Ter-Ovanessian Benoît , Ondel Olivier , Adrien Jérôme , Maire Éric
Published: April 2021

Entangled stainless steel single wire was used as a promising 3D anode for Microbial Fuel Cells (MFCs). Two complementary techniques were coupled to precisely characterize the anode structure and activity: X-Ray Computed Tomography (XRCT) and Electrochemical Impedance Spectroscopy (EIS). XRCT provides an acurate estimation of the pore distribution and size while EIS allows to check and monitor the electrochemical activity. Electrochemical measurements were performed with activated sludges and synthetic medium at an imposed potential of −0.2 V vs Ag/AgCl in a single chamber MFC. Modified Transmission Line Model was used to follow the evolution of the anode in both media including the formation and the growth on the biofilm.
The effect of long-acting dual bronchodilator therapy on exercise tolerance, dynamic hyperinflation, and dead space during constant work rate exercise in COPD
Authors: Stringer William W. , Porszasz Janos , Cao Min , Rossiter Harry B. , Siddiqui Shahid , Rennard Stephen , Casaburi Richard
Published: April 2021

This study was a randomized clinical trial (NCT03081156) that collected detailed physiology data to investigate the effect of dual bronchodilator therapy on exercise tolerance in COPD, and additionally to determine the relative contributions of changes in dead space ventilation (VD/VT) and dynamic hyperinflation to alterations in exercise limitation. We utilized a unique noninvasive method to assess VD/VT (transcutaneous carbon dioxide, Tc[Formula: see text]) and found that dual bronchodilators yielded a moderate improvement in exercise tolerance. Importantly, attenuation of dynamic hyperinflation rather than change in dead space ventilation was the most important contributor to exercise tolerance improvement.
Application of Multimedia Networks in Business English Teaching in Vocational College
Authors: Cheng Xuexia , Liu Kuifen
Published: April 2021

To better meet the needs of economic restructuring and industrial development in China, educators in vocational colleges have to find new approaches to narrow the gaps between the updated requirements from the employers for business English majors and the vocational college education reality. Under this circumstance, a tentative study was carried out with the aids of multimedia to help the educators remove obstacles blocking achieving their educational aim, which is cultivating the graduates who are qualified for the social requirement. This study mainly discussed how effective the multimedia networks can help the business English majors in vocational colleges to enrich their work experience and enhance their practical English ability, computer skills, communication skills, and cooperation skills comprehensively. It aimed at exploring the ways of helping the business English majors in vocational colleges to gain work experience and improve their practical English skills, computer skills, communication skills, and cooperation skills with the aid of multimedia networks. An experimental teaching program was designed under the guidelines of a task-based teaching approach and constructive learning theory. The program includes four teaching models, which are in-class learning and field preparation, mock practice, in-field learning and field education, and learning reflection. All learning and field practices are delivered online facilitated by multimedia networks. One hundred and forty sophomores majoring in business English are selected as participants of the program. Data of students’ confidence in all five monitored essential abilities are collected before and after the learning procedure through questionnaires, and students’ feedbacks are collected through interviews. The statistical results show that multimedia networks can help students improve their overall competence, especially in gaining work experience and practical English skills. Moreover, adopting multimedia networks in teaching can provide more internship opportunities, enrich teaching scenarios, and prolong net teaching hours, which forms a preferred learning environment and provides better learning outcomes. It could also be used to assist communication and cooperation trainings.
Numerical Simulation of Helicopter Rotor Performance Degradation in Natural Rain Encounter
Authors: Li Guozhi , Cao Yihua
Published: April 2021

Sustained flight operation in the rain conditions is still a challenge to a pilot. This problem can be mainly attributed to the aerodynamic performance degradation of aircraft. In this article, in order to quickly understand the influence of rainfall aiming at the engineering application, an approach to predict helicopter rotor performance degradation in heavy rain encounters is presented. Firstly, we develop a computational fluid dynamics- (CFD-) based method of simulation of the blade airfoil under natural rain scenario and different angles of attack in order to obtain a data-driven basis relating to multiple working conditions of the rotating blades for further analysis. Then, these data are studied using a discretization analysis method of rotor aerodynamics. CFD simulations are conducted, including the case of NACA 0012 airfoil with 10 m chord length, and the case of SC1095 airfoil used in a full-scale rotor of UH-60A helicopter. Prediction of helicopter rotor performance degradation is carried out in a thunderstorm heavy rain with the rain rate of 1500 mm/h using this full-scale rotor. The quantitative results indicate that heavy rain dramatically degrades the rotor performance. The maximum percentage decrease in lift coefficient of this full-scale rotor blade airfoil is reached by 12.75%. The maximum percentage increase in drag coefficient of this full-scale rotor blade airfoil is reached by 26.51%. The maximum percentage decrease in averaging lift-to-drag ratio of this full-scale rotor disk is reached by 26.39%.
[Retracted] Urinary Angiogenin as a Marker for Bladder Cancer: A Meta‐Analysis
Authors: Aalami Amir Hossein , Abdeahad Hossein , Mesgari Mohammad , Sathyapalan Thozhukat , Sahebkar Amirhossein
Published: April 2021

Aims. Bladder cancer (BCa) is a common cancer in North America and Europe that carries considerable morbidity and mortality. A reliable biomarker for early detection of the bladder is crucial for improving the prognosis of BCA. In this meta‐analysis, we examine the diagnostic role of the angiogenin (ANG) protein in patients’ urine with bladder neoplasm. Methods. We performed a systematic literature search using ScienceDirect, Web of Science, PubMed/MEDLINE, Scopus, Google Scholar, and Embase, up to 10th October 2020 databases. Meta‐Disc V.1.4 and Comprehensive Meta‐Analysis V.2.2 software calculated the pooled specificity, sensitivity, area under the curve (AUC), diagnostic odds ratio (DOR), positive likelihood ratio (LR+), negative likelihood ratio (LR-), Q∗ index, and summary receiver‐operating characteristic (SROC) for the role of ANG as a urinary biomarker for BCa patients. Results. Four case‐control studies were included with 656 participants (417 cases and 239 controls) in this meta‐analysis. The pooled sensitivity of 0.71 (95% CI: 0.66–0.75), specificity of 0.78 (95% CI: 0.73–0.81), LR+ of 3.34 (95% CI: 2.02–5.53), LR- of 0.37 (95% CI: 0.32–0.44), DOR of 9.99 (95% CI: 4.69–21.28), and AUC of 0.789 and Q∗ index of 0.726 demonstrate acceptable diagnostic precision of ANG in identifying BCa. Conclusion. This meta‐analysis showed that ANG could be a fair biomarker for the diagnosis of BCa patients.
COVID-19 Mortality in a Pediatric Patient with Hemoglobin SC Disease and Alpha-Thalassemia Trait
Authors: Motelow Joshua E. , Kahn Stacie , Wilson Patrick T.
Published: April 2021

As the pandemic continues to evolve, more cases of COVID-19 in pediatric patients are being detected. A 12-year-old boy with HbSC disease alpha-thalassemia trait presented to a pediatric emergency room with fever and weakness. His vital signs were notable for fever, tachypnea, and tachycardia. His physical exam was concerning for increased work of breathing. He tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by PCR although his hemoglobin level remained near his baseline. His chest radiograph showed a retrocardiac opacity concerning for evolving acute chest syndrome. He decompensated quickly requiring invasive mechanical ventilation and exchange transfusion. He received hydroxychloroquine, broad-spectrum antibiotics, and enoxaparin for DVT prophylaxis. Despite showing clinical signs of improvement, he became acutely hypoxemic and suffered a cardiac arrest. We believe this to be an unusual case of a pediatric patient with HbSC disease and COVID-19. We outline clearly the course of illness and treatments trialed, which can prove beneficial to providers facing similar challenges as this virus continues to strike areas around the world. Although children have significantly better outcomes than adults, providers must remain vigilant while treating any patient with a hemoglobinopathy in the setting of severe COVID-19.
MRC2 Promotes Proliferation and Inhibits Apoptosis of Diabetic Nephropathy
Authors: Li Lanlan , Chen Xin , Zhang Henglu , Wang Min , Lu Weiping
Published: April 2021

Diabetic nephropathy (DN) is an important microvascular complication of diabetes and is the main cause of end-stage renal disease. Type 2 mannose receptor C (MRC2) is a member of the mannose receptor protein family, which has been confirmed to have the ability to promote the cell migration signaling pathway and invasion. By complementary DNA chip screening and analysis, we found that the expression of MRC2 was upregulated in the kidneys of mice with diabetic nephropathy. However, the role of MRC2 in diabetic nephropathy is still unclear. This work studied the effect of MRC2 on diabetic nephropathy. After verifying the results of the chip by quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting, we used small interfering RNAs (siRNAs) to knock down the expression of MRC2 in mouse mesangial cells (MMCs) and analyzed the level of cell proliferation and apoptosis using western blotting, Cell Counting Kit-8, and flow cytometry. The results showed that the MRC2 knockdown inhibited MMC proliferation and induced cell apoptosis. These results suggest that MRC2 may be a molecular marker and a therapeutic target for diabetic nephropathy.
Synthesis of Iron Oxide Nanoparticle Functionalized Activated Carbon and Its Applications in Arsenic Adsorption
Authors: Ha Hoang Thu , Phong Pham Tuan , Minh Tran Dinh
Published: April 2021

This work reveals the As(V) adsorption behaviors onto iron oxide (Fe3O4) nanoparticles modified activated carbon (AC), originally developed from biochar (BC), as a green adsorbent denoted by FAC. Since FAC has abundant surface functional groups and a desired porous structure that is favorable for the removal of As(V) in contaminated water, FAC has greatly enhanced the As(V) adsorption capacity of the original BC. Various methods were employed to characterize the FAC characteristics and adsorption mechanism, including pHpzc determination, BET specific surface area, elemental analysis (EA), and scanning electron microscopy (SEM). Results show that the AC surface was successfully modified by iron oxide nanoparticles, enhancing the porosity and specific surface area of original adsorbent. Batch adsorption tests indicated a well-fitted Langmuir model and pseudo-second-order model for As(V) adsorption. Additionally, the highest adsorption capacity (Qmax = 32.57 mg/g) by FAC was higher than previously reported literature reviews. Until now, no article was conducted to research the effect of carbon surface chemistry and texture on As removal from waters. It is required to obtain a rational view of optimal conditions to remove As from contaminated water.
Solar Hybrid System Component Study in Low Concentrated Sunlight
Authors: Cotfas Petru A. , Cotfas Daniel T.
Published: April 2021

The solar energy is increasingly used as a renewable energy source. Raising the efficiency of energy conversion from solar to useful energy (electric and thermal) represents an important research direction in the renewable energy domain. Using hybrid systems for electric and thermal energy cogeneration can be a solution. In this study, a hybrid system (HS) is designed, manufactured, implemented, and experimentally tested under concentrated sunlight with a concentration ratio of 25 suns, obtained using a Fresnel lens as a sunlight concentrator. The HS comprises of four concentrated photovoltaic cells (CPVs), four thermoelectric generators (TEGs), and a solar thermal collector (STC). The HS is studied in three configurations of the exposed surface: only the CPV active area, the CPV active area with ceramic support, and the CPV active area with ceramic support covered with graphite sheet. Results reveal that the efficiency of each system component is affected by the exposed surface. If the efficiencies of the CPVs decrease from 32.3% to 30.8% from the first configuration to the last one, the efficiencies of TEGs and STC increase from 0.12% to 0.44 and from 26.3% to 52.0%, respectively. Increasing the concentration ratio from 25 to 33 suns, the power of the CPVs increases with almost 31%, but the efficiency decreases slightly, instead the efficiencies of the TEGs and STC increase.
Evaluation of Hookworm Diagnosis Techniques from Patients in Debre Elias and Sanja Districts of the Amhara Region, Ethiopia
Authors: Zeleke Ayalew Jejaw , Addisu Ayenew , Derso Adane , Tegegne Yalewayker , Birhanie Meseret , Sisay Tekeba , Aemero Mulugeta
Published: April 2021

Background. Inappropriate diagnosis could intimidate the prevention and control of hookworm infection. Thus, this study was aimed at evaluating the performance of hookworm diagnosis methods. Methods. An institution-based cross-sectional study was conducted from patients in Debre Elias and Sanja districts of the Amhara region, Ethiopia, from November 2019 to January 2020. The study subjects were selected conveniently. After the data was entered into Statistical Package for the Social Sciences (SPSS), sensitivity, specificity, predictive values, test accuracy, and agreement of the different hookworm diagnosis methods, namely, test tube flotation technique (TFT), McMaster (MM), formol-ether concentration (FEC), Kato-Katz (KK), and direct wet mount microscopy (DWMM), were calculated by using SPSS software. The composite reference standard (CRS) was used as the gold standard method. The kappa (

κ

) test was used to measure the level of agreement between diagnosis tests. Result. A total of 389 stool samples were collected from patients in the study. The overall prevalence of hookworm was 63.24%. The test tube flotation technique (TFT) was found to be the highest both in terms of sensitivity and diagnostic accuracy (100%). McMaster (MM) was the second most sensitive test (68.7%), followed by FEC (44.3%) and KK (38.2%). On the other hand, DWMM had the lowest sensitivity (37.4%), and its diagnostic accuracy was also the least (60%). Only TFT had a perfect agreement (

agreement
=
100
%

,

kappa
=
1

) with the CRS. The sensitivity of DWMM, KK, and FEC showed a kind of linear function with the intensity of infection, but TFT and MM methods were not affected by the infection intensity. Conclusion. Hookworm is still a public health problem in the study area. TFT is by far more sensitive than MM, FEC, KK, and DWMM techniques.
Production, Optimization, and Characterization of an Acid Protease from a Filamentous Fungus by Solid-State Fermentation
Authors: Usman Abdilbar , Mohammed Said , Mamo Jermen
Published: April 2021

Acid proteases represent an important group of enzymes, extensively used in food and beverage industries. There is an increased demand for acid proteases adapting to the industrial extreme environment, especially lower pH. Thus, this necessitates the search for a better acid protease from fungi that best performs in industrial conditions. The fungal isolates were isolated from grape and dairy farm soil using potato dextrose agar and further screened for protease production based on the hydrolysis of clear zone on skim milk agar. The potential fungi were then subjected to secondary screening under solid-state fermentation (SSF). After the secondary screening, the potential fungus was identified to the genus level by the macroscopic and microscopic methods. The growth conditions and media composition for the potential fungus were further optimized under SSF. The crude enzyme produced by the potential isolate was characterized after partial purification by acetone and ammonium sulfate precipitation. A total of 9 fungal isolates showed protease production in primary and secondary screening; however, one potential isolate (Z1BL1) was selected for further study based on its protease activity. The isolate was identified to the genus Aspergillus based on their morphological features. The maximum acid protease from the isolate Z1BL1 was obtained using fermentation media containing wheat bran as a solid substrate, 1 mL of 3.2

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106 inoculum size, 50% moisture content, and pH 4.5 upon 120-h incubation at 30°C. The acetone-precipitated enzyme exhibited the maximum activity at 50°C and pH 5 with stability at pH 4–6 and temperature 40–60°C. Thus, the acid protease produced from Aspergillus showed suitable enzyme characteristics required in the industry and could be a candidate for application in the food industry after further purification.
Resin Composite Materials for Chairside CAD/CAM Restorations: A Comparison of Selected Mechanical Properties
Authors: Grzebieluch Wojciech , Mikulewicz Marcin , Kaczmarek Urszula
Published: April 2021

Objective. The aim was to evaluate the flexural strength, flexural modulus, microhardness, Weibull modulus, and characteristic strength of six resin composite blocks (Grandio Blocs-GR, Tetric CAD-TE, Brilliant Crios-CR, Katana Avencia-AV, Cerasmart-CS, and Shofu Block HC-HC). Methods. Flexural strength and flexural modulus were measured using a three-point bending test and microhardness using the Vickers method. Weibull analysis was also performed. Results. The materials showed flexural strength ranging from 120.38 (HC) to 186.02 MPa (GR), flexural modulus from 8.26 (HC) to 16.95 GPa (GR), and microhardness from 70.85 (AV) to 140.43 (GR). Weibull modulus and characteristic strength ranged from 16.35 (CS) to 34.98 (TE) and from 123.45 MPa (HC) to 190.3 MPa (GR), respectively. Conclusions. GR, TE, and CR presented significantly higher flexural strength, modulus, Weibull modulus, and characteristic strength than the others.
Computed Tomography Image Processing Analysis in COVID-19 Patient Follow-Up Assessment
Authors: Tello-Mijares Santiago , Woo Luisa
Published: April 2021

The rapid worldwide spread of the COVID-19 pandemic has infected patients around the world in a short space of time. Chest computed tomography (CT) images of patients who are infected with COVID-19 can offer early diagnosis and efficient forecast monitoring at a low cost. The diagnosis of COVID-19 on CT in an automated way can speed up many tasks and the application of medical treatments. This can help complement reverse transcription-polymerase chain reaction (RT-PCR) diagnosis. The aim of this work is to develop a system that automatically identifies ground-glass opacity (GGO) and pulmonary infiltrates (PIs) on CT images from patients with COVID-19. The purpose is to assess the disease progression during the patient’s follow-up assessment and evaluation. We propose an efficient methodology that incorporates oversegmentation mean shift followed by superpixel-SLIC (simple linear iterative clustering) algorithm on CT images with COVID-19 for pulmonary parenchyma segmentation. To identify the pulmonary parenchyma, we described each superpixel cluster according to its position, grey intensity, second-order texture, and spatial-context-saliency features to classify by a tree random forest (TRF). Second, by applying the watershed segmentation to the mean-shift clusters, only pulmonary parenchyma segmentation-identified zones showed GGO and PI based on the description of each watershed cluster of its position, grey intensity, gradient entropy, second-order texture, Euclidean position to the border region of the PI zone, and global saliency features, after using TRF. Our classification results for pulmonary parenchyma identification on CT images with COVID-19 had a precision of over 92% and recall of over 92% on twofold cross validation. For GGO, the PI identification showed 96% precision and 96% recall on twofold cross validation.
Porosity Characterization of Thermal Barrier Coatings by Ultrasound with Genetic Algorithm Backpropagation Neural Network
Authors: Zhang Shuxiao , Lv Gaolong , Guo Shifeng , Zhang Yanhui , Feng Wei
Published: April 2021

Porosity is considered as one of the most important indicators for the characterization of the comprehensive performance of thermal barrier coatings (TBCs). In this study, the ultrasonic technique and the artificial neural network optimized with the genetic algorithm (GA_BPNN) are combined to develop an intelligent method for automatic detection and accurate prediction of TBCs’s porosity. A series of physical models of plasma‐sprayed ZrO2 coating are established with a thickness of 288 μm and porosity varying from 5.71% to 26.59%, and the ultrasonic reflection coefficient amplitude spectrum (URCAS) is constructed based on the time‐domain numerical simulation signal. The characteristic features (f1, f2, Amax, ΔA) of the URCAS, which are highly dependent on porosity, are extracted as input data to train the GA_BPNN model for predicting the unknown porosity. The average error of the prediction results is 1.45%, which suggests that the proposed method can achieve accurate detection and quantitative characterization of the porosity of TBCs with complex pore morphology.
Positive and Negative Regulation of Ferroptosis and Its Role in Maintaining Metabolic and Redox Homeostasis
Authors: Sharma Ankita , Flora Swaran Jeet Singh
Published: April 2021

Ferroptosis is a recently recognized regulated form of cell death characterized by accumulation of lipid‐based reactive oxygen species (ROS), particularly lipid hydroperoxides and loss of activity of the lipid repair enzyme glutathione peroxidase 4 (GPX4). This iron‐dependent form of cell death is morphologically, biochemically, and also genetically discrete from other regulated cell death processes, which include autophagy, apoptosis, necrosis, and necroptosis. Ferroptosis is defined by three hallmarks, defined as the loss of lipid peroxide repair capacity by GPX4, the bioavailability of redox‐active iron, and oxidation of polyunsaturated fatty acid‐ (PUFA‐) containing phospholipids. Experimentally, it can be induced by many compounds (e.g., erastin, Ras‐selective lethal small‐molecule 3, and buthionine sulfoximine) and also can be pharmacologically inhibited by iron chelators (e.g., deferoxamine and deferoxamine mesylate) and lipid peroxidation inhibitors (e.g., ferrostatin and liproxstatin). The sensitivity of a cell towards ferroptotic cell death is tightly associated with the metabolism of amino acid, iron, and polyunsaturated fatty acid metabolism, and also with the biosynthesis of glutathione, phospholipids, NADPH, and coenzyme Q10. Ferroptosis sensitivity is also governed by many regulatory proteins, which also link ferroptosis to the function of key tumour suppressor pathways. In this review, we highlight the discovery of ferroptosis, the mechanism of ferroptosis regulation, and its association with other cellular metabolic processes.
Progressive Transmission of Medical Images via a Bank of Generative Adversarial Networks
Authors: Chang Ching-Chun , Wang Xu , Horng Ji-Hwei , Echizen Isao
Published: April 2021

The healthcare sector is currently undergoing a major transformation due to the recent advances in deep learning and artificial intelligence. Despite a significant breakthrough in medical imaging and diagnosis, there are still many open issues and undeveloped applications in the healthcare domain. In particular, transmission of a large volume of medical images proves to be a challenging and time-consuming problem, and yet no prior studies have investigated the use of deep neural networks towards this task. The purpose of this paper is to introduce and develop a deep-learning approach for the efficient transmission of medical images, with a particular interest in the progressive coding of bit-planes. We establish a connection between bit-plane synthesis and image-to-image translation and propose a two-step pipeline for progressive image transmission. First, a bank of generative adversarial networks is trained for predicting bit-planes in a top-down manner, and then prediction residuals are encoded with a tailored adaptive lossless compression algorithm. Experimental results validate the effectiveness of the network bank for generating an accurate low-order bit-plane from high-order bit-planes and demonstrate an advantage of the tailored compression algorithm over conventional arithmetic coding for this special type of prediction residuals in terms of compression ratio.
Application of 64-Slice Spiral CT Imaging Technology Based on Smart Medical Augmented Reality in the Diagnosis of Foreign Bodies in the Respiratory Tract in Children
Authors: Liu Jiewei , Wang Ying , Zhao Tana , Li Chunyu , Nie Lei
Published: April 2021

A foreign body in the respiratory tract is one of the common accidental injuries of children in our country, and is usually an important and serious event. Injuries caused by foreign substances in the respiratory tract seriously threaten the health and life of children in Korea and are a great challenge for parents as well. In the process of diagnosis of foreign bodies in the respiratory tract, there is often missed diagnosis or serious complications. Therefore, this article proposes the application of 64-slice spiral CT imaging technology based on smart medical augmented reality in the diagnosis of foreign bodies in the respiratory tract in order to improve the diagnosis of foreign bodies in the respiratory tract, provide help with treatment to improve the prognosis of foreign bodies in the respiratory tract, and reduce the incidence of foreign bodies in the respiratory tract. In this paper, 36 children underwent a 64-slice spiral CT scan of their lungs, and images were transferred to a workstation for multiplanar reconstruction, minimal density projection, three-dimensional volume reconstruction imaging, and CT virtual endoscopic reconstruction, the location, shape, size, and size of the foreign body in contrast with adjacent structural lesions and lesions seen during surgery. Experiments have shown that the left bronchial granulation accounted for 27.3%, the right bronchial granulation 18.75%, the main tracheal granulation 28.6%; there was no significant difference between the left and right bronchial granulation (P > 0.05), while the main tracheal granulation and bilateral bronchial granulation there are significant differences between the shape distributions (P < 0.05). This shows that CT imaging technology has enabled more patients to avoid surgical operations and ensure that the spiral computer can bring the greatest benefits to children. A 64-slice spiral CT scan can diagnose foreign bodies in the child’s respiratory tract. The detection rate is high and the diagnostic failure rate is low. The diagnostic rationale provides a reference for early clinical treatment.