bluuebunny/crossref_metadata_2025 huggingface dataset:
School-based research agenda on healthcare simulation for nursing education in Hong Kong
Authors: Wong Suet Lai , Gill Baljit Kaur , Chan Jacky Hoi Man , Cheung Alison Pui Han , Charm Caroline Yee Chong , Fung Carmen Ka Man , Lam Ching Yee , Tong Mavis Ying Ting , Lo Cora Ka Yee , Tsang Alan Yat Kwan , Nestel Debra
Published: February 2021

Background

Healthcare simulation has been used as a pedagogical strategy in nursing education. Evidence has shown one of the positive impacts that simulations replace clinical placement. These wide-ranging initiatives are essential, and they can guide a nursing school’s simulation training. However, researching each innovation in the nursing field is beyond the scope.

Methods

To focus our research and develop the capacity and capability to incorporate healthcare simulation in nursing education, we used a consensus building process to establish a school’s research agenda. A modified Delphi process was adopted to reach a consensus among 10 nursing faculty members in one university with a visiting professor’s support.

Results

The three themes were identified as (1) embedding simulation into the baccalaureate in nursing curriculum, (2) designing effective simulation-based education and (3) simulating education in the broader world (adolescents). These themes were further categorised into two areas that used simulation in the educational and community settings. Sixty per cent of the faculty members agreed that the question, ‘How can simulation be incorporated into clinical placements to enhance students’ learning?' should be the highest research priority.

Conclusion

This study adds understanding to incorporate simulation-based education in the nursing curriculum and community provides insights into future research.
Implementing a crèche-based community drowning programme in rural Bangladesh: a process evaluation
Authors: Gupta Medhavi , Rahman Aminur , Dutta Notan C , Saha Ashim K , Zwi Anthony , Ivers Rebecca Q , Jagnoor Jagnoor
Published: February 2021

Background

Living and environmental conditions in rural Bangladesh expose children to drowning. The Anchal programme protects children through crèche-based supervision in an enclosed space run by locally recruited carers. It is unclear under what conditions the programme best operates to maximise protection. We conducted a process evaluation of Anchal to determine enabling factors and challenges to implementation.

Methods

Quantitative programme data were analysed to calculate metrics including child participation and fidelity of implementation to defined processes. Qualitative data collection with programme participants and implementers provided insights into barriers and enablers of implementation. Analysis was guided by the UK Medical Research Council’s process evaluation framework.

Results

Anchal operated 400 centres with an average of 22.2 children enrolled, as per target. However, daily attendance averaged lower than the 80% target. Children aged 1–2 years old, who are most at risk of drowning, were least likely to enrol and attend regularly due to low engagement with activities and parental concerns for safety. Greater distances and lower educational attainment in some regions reduced attendance and increased carer attrition.

Conclusions

The Anchal programme met most programme delivery targets. However, programme success could be improved through increasing supervision, providing communication training for implementing staff, designing programmes for children aged 1–2 years old, encouraging community ownership and providing child pick-up services. These contextual solutions can be adapted to similar programmes operating through grassroots-level engagement and recruitment of community health workers, to maximise their effectiveness and sustainability.
Drowning in Uganda: examining data from administrative sources
Authors: Clemens Tessa , Oporia Frederick , Parker Erin M , Yellman Merissa A , Ballesteros Michael F , Kobusingye Olive
Published: February 2021

Background

Drowning death rates in the African region are estimated to be the highest in the world. Data collection and surveillance for drowning in African countries are limited. We aimed to establish the availability of drowning data in multiple existing administrative data sources in Uganda and to describe the characteristics of drowning based on available data.

Methods

We conducted a retrospective descriptive study in 60 districts in Uganda using existing administrative records on drowning cases from January 2016 to June 2018 in district police offices, marine police detachments, fire/rescue brigade detachments, and the largest mortuary in those districts. Data were systematically deduplicated to determine and quantify unique drowning cases.

Results

A total of 1435 fatal and non-fatal drowning cases were recorded; 1009 (70%) in lakeside districts and 426 (30%) in non-lakeside districts. Of 1292 fatal cases, 1041 (81%) were identified in only one source. After deduplication, 1283 (89% of recorded cases; 1160 fatal, 123 non-fatal) unique drowning cases remained. Data completeness varied by source and variable. When demographic characteristics were known, fatal victims were predominantly male (n=876, 85%), and the average age was 24 years. In lakeside districts, 81% of fatal cases with a known activity at the time of drowning involved boating.

Conclusion

Drowning cases are recorded in administrative sources in Uganda; however, opportunities to improve data coverage and completeness exist. An improved understanding of circumstances of drowning in both lakeside and non-lakeside districts in Uganda is required to plan drowning prevention strategies.
Post-transplantation cyclophosphamide reduces the incidence of acute graft-versus-host disease in patients with acute myeloid leukemia/myelodysplastic syndromes who receive immune checkpoint inhibitors after allogeneic hematopoietic stem cell transplantation
Authors: Saberian Chantal , Abdel-Wahab Noha , Abudayyeh Ala , Rafei Hind , Joseph Jacinth , Rondon Gabriela , Whited Laura , Gruschkus Stephen , Fa'ak Faisal , Daher May , Knape Cristina , Safa Houssein , Shoukier Mahran , Suarez-Almazor Maria E , Marcotulli Megan , Ludford Kaysia , Gulbis Alison M , Konopleva Marina , Ohanian Maro , Ravandi Farhad , Garcia-Manero Guillermo , Oran Betul , Popat Uday R , Mehta Rotesh , Alousi Amin M , Daver Naval , Champlin Richard , Diab Adi , Al-Atrash Gheath
Published: February 2021

Background

Immune checkpoint inhibitors (ICIs) are being used after allogeneic hematopoietic stem cell transplantation (alloHCT) to reverse immune dysfunction. However, a major concern for the use of ICIs after alloHCT is the increased risk of graft-versus-host disease (GVHD). We analyzed the association between GVHD prophylaxis and frequency of GVHD in patients who had received ICI therapy after alloHCT.

Methods

A retrospective study was performed in 21 patients with acute myeloid leukemia (n=16) or myelodysplastic syndromes (n=5) who were treated with antiprogrammed cell death protein 1 (16 patients) or anticytotoxic T lymphocyte-associated antigen 4 (5 patients) therapy for disease relapse after alloHCT. Associations between the type of GVHD prophylaxis and incidence of GVHD were analyzed.

Results

Four patients (19%) developed acute GVHD. The incidence of acute GVHD was associated only with the type of post-transplantation GVHD prophylaxis; none of the other variables included (stem cell source, donor type, age at alloHCT, conditioning regimen and prior history of GVHD) were associated with the frequency of acute GVHD. Twelve patients received post-transplantation cyclophosphamide (PTCy) for GVHD prophylaxis. Patients who received PTCy had a significantly shorter median time to initiation of ICI therapy after alloHCT compared with patients who did not receive PTCy (median 5.1 months compared with 26.6 months). Despite early ICI therapy initiation, patients who received PTCy had a lower observed cumulative incidence of grades 2–4 acute GVHD compared with patients who did not receive PTCy (16% compared with 22%; p=0.7). After controlling for comorbidities and time from alloHCT to ICI therapy initiation, the analysis showed that PTCy was associated with a 90% reduced risk of acute GVHD (HR 0.1, 95% CI 0.02 to 0.6, p=0.01).

Conclusions

ICI therapy for relapsed acute myeloid leukemia/myelodysplastic syndromes after alloHCT may be a safe and feasible option. PTCy appears to decrease the incidence of acute GVHD in this cohort of patients.
Association of fine particulate matter with glucose and lipid metabolism: a longitudinal study in young adults
Authors: Qin Jingyi , Xia Wei , Liang Gaodao , Xu Shunqing , Zhao Xiuge , Wang Danlu , Sun Xiaojie , Li Yuanyuan , Liu Hongxiu
Published: February 2021

Objectives

This study aimed to evaluate whether PM2.5exposure in a highly polluted area (>100 µg/m3) affects glucose and lipid metabolism in healthy adults.

Methods

We recruited 110 healthy adults in Baoding city, Hebei, China, and followed them up between 2017 and 2018. Personal air samplers were used to monitor personal PM2.5levels. Eight glucose and lipid metabolism parameters were quantified. We performed the linear mixed-effect models to investigate the relationships between PM2.5and glucose and lipid metabolism parameters. Stratified analyses were further performed according to sex and body mass index (BMI).

Results

The concentration of PM2.5was the highest in spring, with a median of 232 μg/m3and the lowest in autumn (139 μg/m3). After adjusting for potential confounders, we found that for each twofold increase in PM2.5, the median of insulin concentration decreased by 5.89% (95% CI −10.91% to −0.58%; p<0.05), and ox-LDL increased by 6.43% (95% CI 2.21% to 10.82%; p<0.05). Stratified analyses indicated that the associations were more pronounced in females, overweight and obese participants.

Conclusions

Exposure to high PM2.5may have deleterious effects on glucose and lipid metabolism. Females, overweight and obese participants are more vulnerable.
Scoping review of COVID-19-related systematic reviews and meta-analyses: can we really have confidence in their results?
Authors: Wurth Rachel , Hajdenberg Michelle , Barrera Francisco J , Shekhar Skand , Copacino Caroline E , Moreno-Peña Pablo J , Gharib Omar A M , Porter Forbes , Hiremath Swapnil , Hall Janet E , Schiffrin Ernesto L , Eisenhofer Graeme , Bornstein Stefan R , Brito Juan P , González-González José Gerardo , Stratakis Constantine A , Rodríguez-Gutiérrez René , Hannah-Shmouni Fady
Published: February 2021

Aim

The aim of this study was to systematically appraise the quality of a sample of COVID-19-related systematic reviews (SRs) and discuss internal validity threats affecting the COVID-19 body of evidence.

Design

We conducted a scoping review of the literature. SRs with or without meta-analysis (MA) that evaluated clinical data, outcomes or treatments for patients with COVID-19 were included.

Main outcome measures

We extracted quality characteristics guided by A Measurement Tool to Assess Systematic Reviews-2 to calculate a qualitative score. Complementary evaluation of the most prominent published limitations affecting the COVID-19 body of evidence was performed.

Results

A total of 63 SRs were included. The majority were judged as a critically low methodological quality. Most of the studies were not guided by a pre-established protocol (39, 62%). More than half (39, 62%) failed to address risk of bias when interpreting their results. A comprehensive literature search strategy was reported in most SRs (54, 86%). Appropriate use of statistical methods was evident in nearly all SRs with MAs (39, 95%). Only 16 (33%) studies recognised heterogeneity in the definition of severe COVID-19 as a limitation of the study, and 15 (24%) recognised repeated patient populations as a limitation.

Conclusion

The methodological and reporting quality of current COVID-19 SR is far from optimal. In addition, most of the current SRs fail to address relevant threats to their internal validity, including repeated patients and heterogeneity in the definition of severe COVID-19. Adherence to proper study design and peer-review practices must remain to mitigate current limitations.
Associations between haemodynamics and wall enhancement of intracranial aneurysm
Authors: Zhang Miaoqi , Peng Fei , Tong Xin , Feng Xin , Li Yunduo , Chen Huijun , Niu Hao , Zhang Baorui , Song Guangrong , Li Youxiang , Liu Peng , Liu Aihua , Li Rui
Published: February 2021

Background and purpose

Previous studies have reported about inflammation processes (IPs) that play important roles in aneurysm formation and rupture, which could be driven by blood flow. IPs can be identified using aneurysmal wall enhancement (AWE) on high-resolution black-blood MRI (BB-MRI) and blood flow haemodynamics can be demonstrated by four-dimensional-flow MRI (4D-flow MRI). Thus, this study investigated the associations between AWE and haemodynamics in unruptured intracranial aneurysms (IA) by combining 4D-flow MRI and high-resolution BB-MRI.

Materials and methods

Between April 2014 and October 2017, 48 patients with 49 unruptured IA who underwent both 4D-flow MRI and high-resolution BB-MRI were retrospectively included in this study. The haemodynamic parameters demonstrated using 4D-flow MRI were compared between different AWE patterns using the Kruskal-Wallis test and ordinal regression.

Results

The results of Kruskal-Wallis test showed that the average wall shear stress in the IA (WSSavg-IA), maximum through-plane velocity in the adjacent parent artery, inflow jet patterns and the average vorticity in IA (vorticityavg-IA) were significantly associated with the AWE patterns. Ordinal regression analysis identified WSSavg-IA(p=0.002) and vorticityavg-IA(p=0.033) as independent predictors of AWE patterns.

Conclusion

A low WSS and low average vorticity were independently associated with a high AWE grade for IAs larger than 4 mm. Therefore, WSS and average vorticity could predict AWE and circumferential AWE.
Cessation rates from a national collective social network smoking cessation programme: results from the ‘I quit smoking with Facebook on March 21’ Swiss programme
Authors: Desrichard Olivier , Moussaoui Lisa S , Blondé Jérôme , Felder Max , Riedo Gisana , Folly Laura , Falomir-Pichastor Juan M
Published: February 2021

BackgroundProgrammes for collective smoking cessation, based on the British model Stoptober, are proposed by public health units in many countries. There is a need for data estimating the rate at which participants in these programmes are successful in quitting smoking. We report a prospective study carried out as part of a large-scale collective cessation programme conducted in Switzerland in 2017.

Methods1112 participants among the 7008 smokers enrolled in the collective cessation programme were recruited before the start of the attempt. Continuous abstinence was measured 10 days, 3 months and 6 months after the start of the attempt. Participants who dropped out at follow-up were considered to have failed the attempt (worst-case scenario).

ResultsThe continuous abstinence rate was at least 37.9% at 10-day follow-up, 18.8% at 3-month follow-up and 13.1% at 6-month follow-up. Similar levels of continuous abstinence as the worst-case scenario were found in sensitivity analyses including those whose quit attempt started before the beginning of the programme and where multiple imputation was used to replace dropouts. Sensitivity analyses using complete cases or an indicator of abstinence which allows occasional lapses found around double the abstinence rates.

ConclusionsOur results support the potential usefulness of large-scale collective cessation campaigns and suggest that such programmes based on social networks are promising areas for future smoking cessation programme activity.
Functional differentiation among 12 dipterocarp species under contrasting water availabilities in Northeast Thailand
Authors: Kawai Kiyosada , Waengsothorn Surachit , Leksungnoen Nisa , Okada Naoki
Published: February 2021

Species composition varies greatly dependent on water availability gradients. In Northeast Thailand, dry deciduous forests (DDF) and dry evergreen forests (DEF) show contrasting species composition due to differences in soil structure and moisture. Although plant traits (physiological and morphological characteristics) are known to be involved in species distributions, which traits underpin these distinct distributions (either dry DDF or less-dry DEF) remain unclear. Here, we examined the differentiation of 21 leaf and stem traits between DDF and DEF using 12 dipterocarp species. We found that DDF species showed higher water use efficiency and higher water storage capacity in the lamina and petiole, higher leaf nitrogen content, higher stomatal density, larger leaves, thicker mesophyll layers, and a higher rate of water loss under severe dehydration than DEF species. Leaf osmotic potential at full turgor, wood density, and wood water content were not significantly different between DDF and DEF. We also observed a negative relationship between the potential photosynthetic capacity and the water loss rate during severe dehydration across species. Our results suggest that the differences in leaf traits related to photosynthesis and dehydration avoidance among the tree species produce niche differences along the soil water availability in tropical dry forests.
Fermion spectrum and $$g-2$$ anomalies in a low scale 3-3-1 model
Authors: Hernández A. E. Cárcamo , Velásquez Yocelyne Hidalgo , Kovalenko Sergey , Long H. N. , Pérez-Julve Nicolás A. , Vien V. V.
Published: February 2021

We propose a renormalizable theory based on the $$SU(3)_C\times SU(3)_L\times U(1)_X$$

S
U

(
3
)

C

×
S
U

(
3
)

L

×
U

(
1
)

X

gauge symmetry, supplemented by the spontaneously broken $$U(1)_{L_g}$$

U

(
1
)

L
g

global lepton number symmetry and the $$S_3 \times Z_2 $$

S
3

×

Z
2

discrete group, which successfully describes the observed SM fermion mass and mixing hierarchy. In our model the top and exotic quarks get tree level masses, whereas the bottom, charm and strange quarks as well as the tau and muon leptons obtain their masses from a tree level Universal seesaw mechanism thanks to their mixing with charged exotic vector like fermions. The masses for the first generation SM charged fermions are generated from a radiative seesaw mechanism at one loop level. The light active neutrino masses are produced from a loop level radiative seesaw mechanism. Our model successfully accommodates the experimental values for electron and muon anomalous magnetic dipole moments.
Global Analysis of an Asymmetric Continuous Piecewise Linear Differential System with Three Linear Zones
Authors: Pu Jiao , Chen Xiaofeng , Chen Hebai , Xia Yong-Hui
Published: February 2021

In [Chen et al., 2020], the third author and other coauthors studied global dynamics of the following system: [Formula: see text] in the parameter region [Formula: see text]. To study completely the piecewise linear system, we consider the parameter region [Formula: see text] in this paper. Firstly, we study the local dynamics, such as the bifurcations of equilibria (including the equilibrium at infinity). Secondly, the number and stability of limit cycles are studied completely. Then, we analyze the existence of upper and lower saddle connections and homoclinic loops. Moreover, we show that there are no heteroclinic loops in this parameter region. Finally, we give the bifurcation diagram and all global phase portraits on the Poincaré disc are given as well as some numerical examples.
Transient Dynamics of the Lorenz System with a Parameter Drift
Authors: Cantisán Julia , Seoane Jesús M. , Sanjuán Miguel A. F.
Published: February 2021

Nonautonomous dynamical systems help us to understand the implications of real systems which are in contact with their environment as it actually occurs in nature. Here, we focus on systems where a parameter changes with time at small but non-negligible rates before settling at a stable value, by using the Lorenz system for illustration. This kind of systems commonly show a long-term transient dynamics previous to a sudden transition to a steady state. This can be explained by the crossing of a bifurcation in the associated frozen-in system. We surprisingly uncover a scaling law relating the duration of the transient to the rate of change of the parameter for a case where a chaotic attractor is involved. Additionally, we analyze the viability of recovering the transient dynamics by reversing the parameter to its original value, as an alternative to the control theory for systems with parameter drifts. We obtain the relationship between the paramater change rate and the number of trajectories that tip back to the initial attractor corresponding to the transient state.
Topological Equivalence Classification of Balanced Linearly Separable Boolean Functions on n-Dimensional Hypercube
Authors: He Qinbin , Chen Fangyue , Jin Wei
Published: February 2021

The concept of conformal transformation is proposed through the study of the spatial structure of [Formula: see text]-dimensional hypercubes. Based on conformal transformation, a novel algorithm, called topological equivalence classification algorithm, is proposed for classifying balanced linearly separable Boolean functions. By the proposed algorithm, the topological equivalence classes of all balanced linearly separable Boolean functions and the number of Boolean functions in each of the topological equivalence classes are obtained. In addition, the properties of conformal transformation also show an application prospect for decomposing nonlinearly separable Boolean functions.
Investigation of particle production in h–A collisions using statistical distributions
Authors: Kaur A. , Kaur M. , Aggarwal R.
Published: February 2021

Study of the characteristic properties of charged particle production in hadron–nucleus collisions at high energies by utilizing the approaches from different statistical models is performed. Predictions from different approaches using the negative binomial distribution, shifted Gompertz distribution, Weibull distribution and the Krasznovszky–Wagner distribution are considered for a comparative study of the relative success of these models. These distributions derived from a variety of functional forms are based on either phenomenological parameterizations or some model of the underlying dynamics. Some of these have also been used to study the data at the Large Hadron Collider (LHC) for both proton–proton and nucleus–nucleus collisions. Various physical and derived observables have been used for the analysis.
A NOVEL 3D MICROMIXER WITH QUARTIC KOCH CURVE FRACTAL
Authors: XIONG SIYUE , CHEN XUEYE
Published: February 2021

In this paper, we mainly study the mixing performance of the micromixer with quartic Koch curve fractal (MQKCF) by numerical simulation. Changing the structure of the microchannel based on the fractal principle can significantly improve the fluid flow state in the microchannel and improve the mixing efficiency of the micromixer. This paper discussed the effects of different fractal deflection angles, microchannel heights and different fractal times on the mixing efficiency under four different Reynolds numbers (Re). It is found that changing the deflection angle of the fractal can bring extremely high benefits, which makes the fluid deflect and fold in the microchannel, enhancing the chaotic convection in the microchannel, and improve the mixing efficiency of the fluid. Under the reasonable arrangement of the quartic Koch curve fractal principle, it can give the micro-mixture more than 99% mixing efficiency. Based on the excellent mixing performance of MQKCF, it also has extremely high application value in the biochemical neighborhood.
PORTFOLIO ALLOCATION IN A LEVY-TYPE JUMP-DIFFUSION MODEL WITH NONLIFE INSURANCE RISK
Authors: SERRANO RAFAEL
Published: February 2021

We propose a model that integrates investment, underwriting, and consumption/dividend policy decisions for a nonlife insurer by using a risk control variable related to the wealth-income ratio of the firm. This facilitates the efficient transfer of insurance risk to capital markets since it allows to select simultaneously investments and underwriting volume. The model is particularly valuable for business lines with significant exposure to extreme events and disaster risk, as it accounts for features usually depicted during negative economic shocks and catastrophic events, such as Levy-type jump-diffusion dynamics for the financial log-returns that are in turn correlated with insurance premiums and liabilities, as well as worst-case scenarios in which policyholders in the insurance portfolio report claims with the same severity simultaneously. Using the martingale method, we determine an optimal solvency threshold or wealth-income ratio, and investment strategy that maximizes the expected utility from dividend payouts that follows a (possibly stochastic) consumption clock. We illustrate the main results with numerical examples for log- and power-utility functions, and (bounded variation) tempered stable Levy jumps.
Analysis of the Bi-Stable Hybrid Laminate under Thermal Load
Authors: Fazli M. , Sadr M. H. , Ghashochi-Bargh H.
Published: February 2021

Adaptive structures have the ability to modify their shapes in different operational conditions. Multi-stable structures are one of the methods of making adaptive structures. In the bi-stable square laminates, due to geometric symmetry and equality of strain energy between stable states, it is possible to continue actuating between stable states, specially when using dynamic or thermal load. The bi-stability of the hybrid square laminated structure with the stacking sequence of [0/90/Al] is asymmetric. This leads to inequality of strain energy in stable states and therefore, development of an effective method to control and avoid automatic actuating. In this paper, the deformation and strain energy of the bi-stable hybrid square laminated structure is investigated. To show the effect of elastic boundary condition, a similar section with the stacking sequence of [0/0/Al] is connected to the mentioned hybrid laminate. The effects of the temperature, the presence of an aluminum layer and its thickness on the potential multiple shapes are also studied. To check the accuracy, the bi-stability behavior is investigated using finite element analysis and the results are compared with the experimental data.
Gorenstein flat modules relative to injectively resolving subcategories
Authors: Gao Zenghui , Wu Wan
Published: February 2021

Let [Formula: see text] be an injectively resolving subcategory of left [Formula: see text]-modules. We introduce and study [Formula: see text]-Gorenstein flat modules as a common generalization of some known modules such as Gorenstein flat modules (Enochs, Jenda and Torrecillas, 1993), Gorenstein AC-flat modules (Bravo, Estrada and Iacob, 2018). Then we define a resolution dimension relative to the [Formula: see text]-Gorensteinflat modules, investigate the properties of the homological dimension and unify some important properties possessed by some known homological dimensions. In addition, stability of the category of [Formula: see text]-Gorensteinflat modules is discussed, and some known results are obtained as applications.
On solutions of second-order matrix polynomial equation of high degree
Authors: Tan Lu , Cheng Xue-Han , Jiang Tong-Song , Ling Si-Tao
Published: February 2021

In this paper, we focus on discussing diagonal solutions and general solutions of second-order matrix polynomial equation of high degree in complex field. By characterizing some algebraic properties of the mentioned two types of the solutions, we present sufficient conditions that a general second-order matrix polynomial equation has diagonal solutions or general solutions. Analytic expressions of the solutions, as well as the corresponding algorithms for finding the solutions are provided. An example is given so as to verify the theoretical results we have derived.
An uncertainty principle for the basic wavelet transform
Authors: Ganie Javid Ahmad , Jain Renu
Published: February 2021

The aim of this paper is to derive the uncertainty principle which has implications in signal analysis and in quantum mechanics. First, we derive the definition of the wavelet transform in [Formula: see text]-calculus by using some weight function. Certain properties like linearity, scaling, translation, etc. were discussed. Later on, to illustrate this integral transform several results were derived for the effectiveness and performance of the proposed method. Also, this paper surveys recent applications to establish generalized uncertainty principle.
Rational design of catalysts towards energy-saving formaldehyde oxidation: A review
Authors: Chen Gongxuan , Huang Qing , Zheng Ping , Wu Tian
Published: February 2021

Volatile organic compounds are the major concern with formaldehyde being the dominant indoor air pollutant. Exploring advanced catalysts towards energy-saving formaldehyde oxidation catalysts is the key to mitigate the risks from indoor air. This review summarizes the recent progress on enhancing oxidation of formaldehyde by tailoring the structure, morphology, surface, interface and external field of catalysts. The modification strategy of various catalysts is discussed with focus on mass transfer enhancement, surface manipulation, interface engineering and environment regulation. Future researches to address the remaining challenges on formaldehyde oxidation are also proposed, which are expected to inspire further sparkling ideas for development of energy-saving systems toward efficient removal of formaldehyde.
Wiener index via wirelength of an embedding
Authors: Nandini G. Kirithiga , Rajan R. Sundara , Rajalaxmi T. M. , Shantrinal A. Arul , Husain Sharifah Kartini Said , Hasni Roslan
Published: February 2021

Embeddings are often viewed as a high-level representation of systematic methods to simulate an algorithm designed for one kind of parallel machine on a different network structure and/or techniques to distribute data/program variables to achieve optimum use of all available processors. A topological index is a numeric quantity of a molecule that is mathematically derived in an unambiguous way from the structural graph of a molecule. In theoretical chemistry, distance-based molecular structure descriptors are used for modeling physical, pharmacologic, biological and other properties of chemical compounds. Arguably, the best known of these indices is the Wiener index, defined as the sum of all distances between distinct vertices. In this paper, we have obtained the exact wirelength of embedding Cartesian products of complete graphs into a Cartesian product of paths and cycles, and generalized book. In addition to that, we have found the Wiener index of generalized book and the relation between the Wiener index and wirelength of an embedding, which solves (partially) an open problem proposed in Kumar et al. [K. J. Kumar, S. Klavžar, R. S. Rajan, I. Rajasingh and T. M. Rajalaxmi, An asymptotic relation between the wirelength of an embedding and the Wiener index, submitted to the journal].
On the spectral radius, energy and Estrada index of the arithmetic–geometric matrix of a graph
Authors: Lin Zhen , Deng Bo , Miao Lianying , Li He
Published: February 2021

Let [Formula: see text] be a simple undirected graph with vertex set [Formula: see text]. The arithmetic–geometric matrix [Formula: see text] of a graph [Formula: see text] is defined so that its [Formula: see text]-entry is equal to [Formula: see text] if the vertices [Formula: see text] and [Formula: see text] are adjacent, and zero otherwise, where [Formula: see text] denotes the degree of vertex [Formula: see text] in [Formula: see text]. In this paper, some bounds on the arithmetic–geometric spectral radius and arithmetic–geometric energy are obtained, and the respective extremal graphs are characterized. Moreover, some bounds for the arithmetic–geometric Estrada index involving arithmetic–geometric energy of graphs are determined. Finally, a class of arithmetic–geometric equienergetic graphs is constructed by graph operations.
Effects of melt-percolation, refertilization and deformation on upper mantle seismic anisotropy: constraints from peridotite xenoliths, Marie Byrd Land, West Antarctica
Authors: Chatzaras Vasileios , Kruckenberg Seth C.
Published: February 2021

We report on the petrology, microstructure and seismic properties of 44 peridotite xenoliths extracted from the upper mantle beneath Marie Byrd Land (MBL), West Antarctica. The aim of this work is to understand how melt-rock reaction, refertilization, and deformation affected the seismic properties (velocities, anisotropy) of the West Antarctic upper mantle, in the context of MBL tectonic evolution and West Antarctic Rift System formation. Modal compositions, mineral major element compositions, microstructures, and crystallographic preferred orientations (CPOs) provide evidence for diachronous reactive melt percolation and refertilization. Olivine shows three main CPO patterns, the A-type, axial-[010], and axial-[100] texture types. Average seismic properties of the MBL mantle lithosphere are mainly controlled by the strength of olivine crystallographic texture. Reactive melt percolation and refertilization likely modified seismic velocities and anisotropy, as is suggested by a systematic decrease in maximum P-wave and S-wave anisotropies with increasing modal abundance of pyroxene. At larger spatial scales, the seismic properties of the MBL mantle xenoliths are dominated by the anisotropy resulting from the A-type olivine CPO. Variations between individual volcanic centres, however, attest to spatial variations in the mantle structure, potentially related to 3D deformation and the prolonged tectonic history of MBL.
Combining process-based models and multiple-point geostatistics for improved reservoir modelling
Authors: Mullins James , van Der Vegt Helena , Howell John
Published: February 2021

The construction of subsurface reservoir models is typically aided by the use of outcrops and modern analogue systems. We show how process-based models of depositional systems help to develop and substantiate reservoir architectural concepts. Process-based models can simulate assumptions relating to the physical processes influencing sedimentary deposition, accumulation and erosion on the resultant 3D sediment distribution. In this manner, a complete suite of analogue geometries can be produced by implementing different sets of boundary conditions based on hypotheses of depositional controls. Simulations are therefore not driven by a desired/defined outcome in the depositional patterns, but their application to date in reservoir modelling workflows has been limited because they cannot be conditioned to data such as well logs or seismic information.

In this study a reservoir modelling methodology is presented that addresses this problem using a two-step approach: process-based models producing 3D sediment distributions that are subsequently used to generate training images for multi-point geostatistics.

The approach has been tested on a dataset derived from a well-exposed outcrop from central Utah. The Ferron Sandstone Member includes a shallow-marine deltaic interval that has been digitally mapped using a high-resolution unmanned aerial vehicle (UAV) survey in 3D to produce a virtual outcrop (VO). The VO was used as the basis to build a semi-deterministic outcrop reference model (ORM) against which to compare the results of the combined process/multiple-point statistics (MPS) geostatistical realizations. Models were compared statically and dynamically through flow simulation.

When used with a dense well dataset, the MPS realizations struggle to account for the high levels of non-stationarity inherent in the depositional system that are captured in the process-based training image. When trends are extracted from the outcrop analogue and used to condition the simulation, the geologically realistic geometries and spatial relationships from the process-based models are directly imparted onto the modelling domain, whilst simultaneously allowing the facies models to be conditioned to subsurface data.

When sense-checked against preserved analogues, this approach reproduces more realistic architectures than traditional, more stochastic techniques.
Moderate aerobic exercise prevents matrix degradation and death in a mouse model of aortic dissection and aneurysm
Authors: Aicher Brittany O. , Zhang Jackie , Muratoglu Selen C. , Galisteo Rebeca , Arai Allison L. , Gray Vicki L. , Lal Brajesh K. , Strickland Dudley K. , Ucuzian Areck A.
Published: February 2021

Moderate aerobic exercise was shown to significantly reduce mortality, extracellular matrix degradation, and thoracic aortic aneurysm and dissection formation associated with lysyl oxidase inhibition in a mouse model. Gene expression suggested a reversal of TGF-β, inflammation, and extracellular matrix remodeling pathway dysregulation, along with augmented elastogenesis with exercise.
A Systematic Literature Review on Traumatic Optic Neuropathy
Authors: Karimi Saeed , Arabi Amir , Ansari Iman , Shahraki Toktam , Safi Sare
Published: February 2021

Traumatic optic neuropathy (TON) is an uncommon vision-threatening disorder that can be caused by ocular or head trauma and is categorized into direct and indirect TON. The overall incidence of TON is 0.7–2.5%, and indirect TON has a higher prevalence than direct TON. Detection of an afferent pupillary defect in the presence of an intact globe in a patient with ocular or head trauma with decreased visual acuity strongly suggests TON. However, afferent pupillary defects may be difficult to detect in patients who have received narcotics that cause pupillary constriction and in those with bilateral TON. Mechanical shearing of the optic nerve axons and contusion necrosis due to immediate ischemia from damage to the optic nerve microcirculation and apoptosis of neurons is a probable mechanism. The proper management of TON is controversial. High-dose corticosteroid therapy and decompression of the optic nerve provide no additional benefit over observation alone. Intravenous erythropoietin may be a safe and efficient treatment for patients with TON.
α
,
BK

-Contractions in Bipolar Metric Spaces
Authors: Gaba Yaé Ulrich , Aphane Maggie , Aydi Hassen
Published: February 2021

In this paper, we introduce the concept of

α
,
BK

-contractions and prove the existence of fixed points for contravariant mappings on bipolar metric spaces.
The Acceptability, Feasibility, and Effectiveness of Breast Massage Combined with Acupoint Stimulation to Promote the Volume of Human Milk in Mothers with Preterm Infants: A Pilot Study
Authors: Sheng Jia , Ding Yan , Wang Jing , Zhang Junping , Qi Xingling , Xia Haiou
Published: February 2021

Background. Preterm infant mothers have always encountered difficulties in human milk production. For this reason, an intervention of breast massage combined with acupoint stimulation was designed to increase the production. Purpose. Through a pilot randomized trial, we assessed the acceptability, feasibility, and effectiveness of breast massage combined with acupoint stimulation and the study procedures. Methods. 40 participants of preterm infants born at less than 34 weeks of gestation were randomly allocated to the CG (control group) or the EG (group with breast massage combined with acupoint stimulation). Data related to the acceptability, feasibility, and effectiveness of the intervention and research procedures were collected and analysed. Results. The daily volume progressively increased each day in the first 7 days in both groups and a significant difference was observed between the groups (

P

 < 0.001). The initiation time of lactogenesis stage II was 50.06 ± 6.78 (40.00–64.00) hours in the EG and 66.18 ± 14.64 (48.00–96.00) hours in the CG, where a significant difference was detected (

P

 < 0.05). The mean score of satisfaction with the intervention in the EG was 4.56 ± 0.32 (4.0–5.0), while the retention rates were 82.5% and 85.5% (17/20) in the CG, and 80% (16/20) in the EG. Conclusion. This pilot study was oriented towards the effectiveness of breast massage combined with acupuncture stimulation for the increase of human milk production in the participants. The intervention was accepted well and the study process was reasonable. A large-scale RCT will be able to determine the beneficial effects of this intervention on human milk production.
A LiDAR-Aided Inertial Positioning Approach for a Longwall Shearer in Underground Coal Mining
Authors: Zheng Jiangtao , Li Sihai , Li Nan , Fu Qiangwen , Liu Shiming , Yan Gongmin
Published: February 2021

The absolute three-dimensional position of a longwall shearer is fundamental to longwall mining automation. The positioning of the longwall shearer is usually realized by the inertial navigation system (INS) and odometer (OD). However, the position accuracy of this positioning approach gradually decreases over time due to the gyro drift. To further increase the positioning accuracy of the shearer, this paper proposes a positioning approach based on the INS and light detection and ranging (LiDAR). A Kalman filter (KF) model based on the observation provided by detecting hydraulic supports which are part of the longwall face, using the LiDAR, is established. The selection scheme of the point features is studied through a set of simulations. In addition, compared with that of the approach based on the INS and OD, the shearer positioning accuracy obtained using the proposed approach is higher. When the shearer moves along a 350 m track for 6 cutting cycles and lasts about 7.1 h, both east and north position errors can be maintained within 0.2 m and the height error within 0.1 m.
Flexible Temporary Shield in Soft and Sensitive Clay: 3D FE Modelling of Experimental Field Test
Authors: Alam Miah , Chaallal Omar , Galy Bertrand
Published: February 2021

A finite-element (FE) numerical study using PLAXIS-3D software was carried out to reproduce and validate a full-scale experimental in situ test and to investigate the earth pressure on a flexible temporary trench box shield in soft and sensitive clay soil. The excavation trench model was 6 m (20 ft) deep and was considered as nonlinear and anisotropic clay. A 45 kPa (0.94 ksf) surface overload on top of the soil near the trench box was also simulated to produce a maximum load case on the flexible wall of the shield. Both Mohr-Coulomb (MC) and hardening soil (HS) constitutive soil models were considered for FE analysis. Different values of the modulus reduction factor (MRF) and the coefficient of earth pressure at rest (

K

0

) were considered to validate the model. For a specific shear strength profile, FE analysis with a linear elastoplastic soil model showed relatively small differences in soil pressure with the field test results along the depth of the trench. Results were also compared with the predictions of well-established analytical formulae.
Investigation on the Influence of Design Parameters of Streamline Flow Tubes on Pump Performance
Authors: Bian Kan , Huang Zhi , Dai Jietao , Zhang Fan , Chen Xiaosheng , Chen Zhenlin , Lai Liyi , Zhang Jianhui
Published: February 2021

Studies have shown that the valveless piezoelectric pump with streamline flow tubes (VPPSFTs) can increase the flow rate while reducing the vortex, which has a broad application prospect and conforms to the huge potential demand in the fields of medical treatment, sanitation, and health care. The flow runner of the VPPSFT was designed as two segments with a smooth transition between the hyperbola segment and the arc segment. However, the effect of the radius of the arc segment on pump performance is not clear. Therefore, three groups of VPPSFT with arc segments of different curvature radii were designed in this study, and the influence of curvature radius of arc segment on the pump performance was explored. On the basis of the theoretical analysis of fluid continuity and conservation of energy, the structure of VPPSFT was designed, the experimental test was carried out, and the finite element simulation software was used for numerical analysis. The results show that the output performance increases with the increase in the radius of the arc segment, and the maximum flow rate was 116.78 mL/min. The amplitude and the flow rate are almost the same trend as the frequency. This study improves the performance of the valveless piezoelectric pump and provides reference for the structure design of VPPSFT.
The Relation between Body Mass Index and Retinal Photoreceptor Morphology and Microvascular Changes Measured with Adaptive Optics (rtx1) High-Resolution Imaging
Authors: Zaleska-Żmijewska Anna , Wawrzyniak Zbigniew , Kupis Magdalena , Szaflik Jacek P.
Published: February 2021

Background. Overweight and obese patients are at risk for diabetes, cardiovascular disorders, and microvascular complications. The rtx1TM (Imagine Eyes, France) is a microscope that allows near histological visualizations of cones and retinal microcirculation. Objective. This study analysed the cones and retinal microvascular changes in a group of 47 healthy women with different BMI values. Participants were divided into 2 groups: the BMI group (28 women with BMI >/25) and the control group (19 lean women with BMI <25). Results. The lumen and diameter of retinal arteries were not significantly different between groups. There were significant differences in the thickness of arteriole walls. The WLR and WCSA values differed significantly between the control and BMI groups (for WLR 0.25 ± 0.03 vs. 0.29 ± 0.03,

p
<
0.001

; for WCSA 4136.7 ± 1140.0 vs. 5217.3 ± 944.0, respectively,

p
<
0.001

). In healthy eyes, cone density and morphology were not affected by weight. Conclusions. Retinal image analysis with rtx1 offers a novel noninvasive measurement of early changes in retinal vasculature that are not detectable during routine clinical examination. Abnormalities of retinal arterioles found by rtx1™examination should be considered as a strong risk factor for cardiovascular changes resulting from overweight and obesity.
Analytical Hierarchy Process Applied to Pedagogical Method Selection Problems
Authors: Chaibate Hind , Hadek Amine , Ajana Souad , Bakkali Soumia
Published: February 2021

The purpose of this study is to apply multicriteria decision-making (MCDM) methods, namely, analytic hierarchy process (AHP) for selecting the best pedagogical method able to develop the soft skills required by the job market with respect to the preference level assigned by employers to each soft skill. The evaluated pedagogical strategies are experiential pedagogy (EP), project-based learning (PjBL), problem-based learning (PBL), serious games (SG), Harvard case method (HCM), and lecture course (LC). Ten criteria (soft skills) were identified from a previous quantitative content analysis of engineering job ads in Morocco in order to identify the extent to which soft skills are required by employers. These skills include communication, efficiency, adaptability, decision-making, innovation, problem resolution, team working, project management, professional responsibility, and using technology in engineering practice. After pairwise comparisons between all the evaluated alternatives with respect to each criterion, results show that experiential pedagogy is the optimal solution to develop the soft skills demanded by the job market.