bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling of sediment supply from torrent catchments in the Western Alps using the sediment contributing area (SCA) approach
Authors: Altmann Moritz , Haas Florian , Heckmann Tobias , Liébault Frédéric , Becht Michael
Published: December 2020

The production of coarse sediment in mountain landscapes depends mainly on the type and activity of geomorphic processes and topographic and natural conditions (e.g. vegetation cover) of these catchments. The supply of sediment from these slopes to mountain streams and its subsequent transport lead to sediment connectivity, which describes the integrated coupled state of these systems. Studies from the Northern Calcareous Alps show that the size of the sediment contributing area (SCA), a subset of the drainage area that effectively delivers sediment to the channel network, can be used as a predictor of sediment delivery to mountain streams. The SCA concept is delineated on a digital elevation model (DEM) using a set of rules related to the steepness and length of slopes directly adjacent to the channel network, the gradient of the latter and the vegetation cover. The present study investigates the applicability of this concept to the Western Alps to identify geomorphologically active areas and to estimate mean annual sediment yield (SY) in mainly debris‐flow‐prone catchments. We use a statistical approach that shows a parameter optimisation and a linear regression of SY on SCA extent. We use a dataset of ~25 years of assessed coarse sediment accumulation in 35 sediment retention basins. In the investigated catchments, sediment transport is governed by several factors, mainly by the extent of vegetation‐free areas with a minimum slope of 23° that is coupled to the channel network with a very low gradient of the latter. With our improved framework, we can show that the SCA approach can be applied to catchments that are widely distributed, in a large spatial scale (hectare area) and very heterogeneous in their properties. In general, the investigated catchments show high connectivity, resulting in significant correlations between long‐term average yield and the size of the SCA.
A performance‐aware routing mechanism for flying ad hoc networks
Authors: Ali Hannan , Islam Saif ul , Song Houbing , Munir Kashif
Published: December 2020

Flying ad hoc networks (FANETs) are visioned to unlock the potential of the Internet of Drones in various application scenarios like surveillance, agriculture, health care, disaster management, and rescue operations. As the unmanned aerial vehicles possess fast movements and frequent topological variations, selection of the next hop, self‐adaptation, and avoidance of dissemination loops have proven to be the challenging issues that have a considerable impact on the performance of a FANET. We propose a performance‐aware routing mechanism, G‐OLSR, for efficient communication and collaboration among the unmanned aerial vehicles in a FANET environment. The self‐adaptation of the network in case of any topological changes is considered in the proposed mechanism. Moreover, the proposed mechanism avoids the dissemination loops and it, consequently, improves the performance of the network. The simulation results show that the proposed mechanism performs better in terms of delay, message overhead, packet delivery ratio, and throughput than Optimized Link State Routing.
A fully coupled high‐order discontinuous Galerkin solver for viscoelastic fluid flow
Authors: Kikker Anne , Kummer Florian , Oberlack Martin
Published: December 2020

A fully coupled high order discontinuous Galerkin (DG) solver for viscoelastic Oldroyd B fluid flow problems is presented. Contrary to known methods combining DG for the discretization of the convective terms of the material model with standard finite element methods (FEM) and using elastic viscous stress splitting (EVSS) and its derivatives, a local discontinuous Galerkin (LDG) formulation first described for hyperbolic convection‐diffusion problems is used. The overall scheme is described, including temporal and spatial discretization as well as solution strategies for the nonlinear system, based on incremental increase of the Weissenberg number. The solvers suitability is demonstrated for the two‐dimensional confined cylinder benchmark problem. The cylinder is immersed in a narrow channel with a blocking ratio of 1:2 and the drag force of is compared to results from the literature. Furthermore, steady and unsteady calculations give a brief insight into the characteristics of instabilities due to boundary layer phenomena caused by viscoelasticity arising in the narrowing between channel and cylinder.
Association of cerebral microbleeds with cerebrospinal fluid Alzheimer‐biomarkers and clinical symptoms in early dementia with Lewy bodies
Authors: Mendes Aline , Noblet Vincent , Mondino Mary , Loureiro de Sousa Paulo , Manji Sumayya , Archenault Anne , Casanovas Michel , Bousiges Olivier , Philippi Nathalie , Baloglu Seyyid , Rauch Lucie , Cretin Benjamin , Demuynck Catherine , Martin‐Hunyadi Catherine , Blanc Frederic
Published: December 2020

Objectives

To determine the prevalence, localization and associations of cerebral microbleeds (CMB) in dementia with Lewy bodies (DLB) with its core clinical symptoms and cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD). We hypothesize DLB patients with CMB have increased amyloid burden compared to those without CMB, which could also translate into clinical differences.

Methods

Retrospective cross‐sectional analysis from the AlphaLewyMA study (https://clinicaltrials.gov/ct2/show/NCT01876459). Patients underwent a standardized protocol of brain MRI including 3D T1, 3D FLAIR and T2* sequences, and CSF analysis of AD biomarkers. CMB and white matter hyperintensities (WMHs) were visually assessed in prodromal and mild demented (DLB, N = 91) and AD (AD, N = 67) patients.

Results

CMB prevalence did not differ among DLB and AD (24.2% vs. 37.3%; p = 0.081). CMB were mainly distributed in lobar topographies in both DLB (74%) and AD (89%). CMB in DLB was not associated with global cognitive performance, executive functioning, speed of information processing, or AD CSF biomarkers. Similarly, there was no difference regarding specific clinical symptoms: fluctuations, psychotic phenomena, sleep behavior disorder and Parkinsonism between DLB patients with and without CMB. AD patients with CMB had increased burden of WMH compared to those without (2.1 ± 0.86 vs. 1.4 ± 0.89; p = 0.005), according to Fazekas scale, whereas no significant difference was observed in DLB patients (1.68 ± 0.95 vs. 1.42 ± 0.91; p = 0.25).

Conclusion

CMB were equally prevalent with similar topographic distribution in both DLB and AD patients. CMB was not associated with CSF AD biomarkers or core clinical symptoms in DLB.
Metastatic thyroid carcinoma to the parapharyngeal and retropharyngeal spaces: Systematic review with seven newly reported cases describing an uncommon presentation of a common disease
Authors: Sandler Mykayla L. , Xing Monica H. , Levy Juliana C. , Chai Raymond L. , Khorsandi Azita S. , Gonzalez‐Velazquez Camilo , Urken Mark L.
Published: December 2020

Background

Metastatic thyroid carcinoma to retropharyngeal and parapharyngeal (RP/PP) lymph nodes is rare. Literature suggests previous lateral neck dissection (LND) may alter patterns of lymphatic drainage in the neck, predisposing to these less common sites of spread.

Methods

PRISMA‐guided systematic search for all published cases detailing RP/PP metastases of well‐differentiated thyroid carcinoma from 1970 to 2019.

Results

Seventy articles were identified and 44 were included, along with seven cases treated at our institution, totaling 239 cases. Cases represented both retropharyngeal (60.7%) and parapharyngeal (39.3%) metastases identified in the initial (27.6%) and recurrent (72.4%) setting.

Conclusion

RP/PP metastases generally present in the recurrent setting. RP/PP metastases often represent high‐risk disease, and surgical treatment is recommended.
Government and private sectors' electronic transfer practices and financial inclusion in the economic community of the West African States
Authors: Niankara Ibrahim
Published: December 2020

Relying on a pooled‐cross‐sectional panel of the 2014 and 2017 Global Findex data, and a random utility theoretic model for revealed financial preferences data analysis, this paper examines the impact of government and private sectors' electronic transfer practices on financial inclusion, in terms of individuals' ability to save and borrow within the Economic Community of the West African States (ECOWAS). For sensitivity analysis, we adopt a sequential empirical strategy, in which we estimate and contrast four specifications of the saving and borrowing processes. Overall, our findings are stable across all specifications and show that along with socio‐economic factors such as age and income, public welfare transfers and employment‐based salary transfers foster financial inclusion by significantly raising individuals' marginal propensity to save (MPS) (by 11.6% and 12.9% respectively) and marginal propensity to borrow (MPB) (by 12.6% and 8.2% respectively) within ECOWAS. We found however that, within ECOWAS, both MPS and MPB have decreased by 21.4% and 7.2%, respectively, between 2014 and 2017. Therefore, in addition to other economic growth promoting fiscal tools in national governments' toolkits, mandates on public (governments to citizens) and private (Business to citizens) electronic financial transfers are significant policy leverages for improving financial inclusion and growth within ECOWAS.
Outflow hydrology of tailwater recovery systems with comparisons to a control catchment*
Authors: Omer A.R. , Aldridge C. , Baker B.H.
Published: December 2020

Conservation practices termed tailwater recovery (TWR) systems are being installed throughout the Lower Mississippi River basin to mitigate damage from agricultural production. Many of the costs and benefits of these systems have yet to be documented; therefore, the objective of this study is to assess whether TWR systems have the potential to impact on the hydrology of downstream systems. In this study, we compare hydrologic parameters of two TWR systems—one with an on‐farm storage reservoir (TWR‐OFS) and one without (TWR‐D)—and a control ditch (CTRL). Systems were monitored at one outflow location each using flow meters. Estimated percentage differences between TWR‐D and CTRL sites were determined, in which the CTRL site was found to have greater values reflected in the parameters, including length of event median 94% and mean 60%; time to peak median 80% and mean 70%; time to base median 88% and mean 60%; peak flow median 86% and mean 67% and discharge median 134% and mean 101%. The TWR‐D and TWR‐OFS sites differed in peak flow, with TWR‐OFS being 40% greater. Evidence from this investigation shows that TWR systems have the potential to influence downstream hydrology by retaining water.
Collagen type XVIII alpha 1 chain (COL18A1) variants affect the risk of anti‐tuberculosis drug‐induced hepatotoxicity: A prospective study
Authors: Cheng Yuhui , Jiao Lin , Li Weixiu , Wang Jialing , Lin Zhangyu , Lai Hongli , Ying Binwu
Published: December 2020

Background

The role of collagen type XVIII alpha 1 chain (COL18A1) in anti‐tuberculosis drug‐induced hepatotoxicity (ATDH) has not been reported. This study aimed to explore the association between of COL18A1 variants and ATDH susceptibility.

Methods

A total of 746 patients were enrolled in our study from December 2016 to April 2018, and all subjects in the study signed an informed consent form. The custom‐by‐design 2x48‐Plex SNPscanTM kit was used to genotype all selected 11 SNPs. Categorical variables were compared by chi‐square (χ2) or Fisher's exact test, while continuous variables were compared by Mann‐Whitney's U test. Plink was utilized to analyze allelic and genotypic frequencies, and genetic models. Multivariate logistic regression analyses were used to adjust potential factors. The odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were also calculated.

Results

Among patients with successfully genotyping, there were 114 cases and 612 controls. The mutant A allele of rs12483377 conferred the decreased risk of ATDH (OR = 0.13, 95%CI: 0.02–0.98, P = 0.020), and this significance still existed after adjusting age and gender (P = 0.024). The mutant homozygote AA genotype of rs12483377 was associated with decreased total protein levels (P = 0.018).

Conclusion

Our study first revealed that the A allele of COL18A1 rs12483377 was associated with the decreased risk of ATDH in the Western Chinese Han population, providing new perspective for the molecular prediction, precise diagnosis, and individual treatment of ATDH.
Expansion of Sidman's theory: The inclusion of prompt stimuli in equivalence classes
Authors: Palmer Simone K. , Maguire R. W. , Lionello‐DeNolf Karen M. , Braga‐Kenyon Paula
Published: December 2020

Stimulus equivalence is defined as the ability to relate stimuli in novel ways after training in which not all of the stimuli had been directly linked to one another. Sidman (2000) suggested all elements of conditional discrimination training contingencies that result in equivalence potentially become class members. Research has demonstrated the inclusion of samples, comparisons, responses, and reinforcers in equivalence classes. Given the evidence that all elements of a conditional discrimination become part of the class, the purpose of this study was to determine if class‐specific prompts would also enter into their relevant equivalence classes. Experiment 1 investigated the inclusion of prompts in an equivalence class using abstract stimuli with neurotypical students enrolled in higher education courses. Experiment 2 systematically replicated Experiment 1 using meaningful stimuli and individuals diagnosed with autism spectrum disorder. The results of both experiments demonstrated that class‐specific prompts became part of equivalence classes with the other positive elements of the contingency. The results are discussed in terms of class expansion and the potential impact on equivalence‐based instruction.
Associations between common genetic variants in microRNAs and Hirschsprung disease susceptibility in Southern Chinese children
Authors: Wu Qi , Zhao Jinglu , Zheng Yi , Xie Xiaoli , He Qiuming , Zhu Yun , Wang Ning , Huang Lihua , Lu Lifeng , Hu Tuqun , Zeng Jixiao , Xia Huimin , Zhang Yan , Zhong Wei
Published: December 2020

Introduction

Hirschsprung disease (HSCR), characterized by the defective migration of enteric neural crest cells, is a severe congenital tract disease in infants. Its etiology is not clear at present, although a genetic component plays an important role in its etiology. Many studies focused on the polymorphisms of microRNA (miRNA) in several disease progressions have been reported, including HSCR. However, the findings remain inconclusive. The present study aimed to explore the association of genetic variants in miRNAs and HSCR susceptibility in Southern Chinese children.

Methods

Five single nucleotide polymorphisms (SNPs) (miR‐146A rs2910164, miR‐4318 rs8096901, miR‐3142 rs2431697, miR‐3142 rs2431097 and miR‐3142 rs5705329) were included to be genotyped in the stratified analysis through the Mass ARRAY iPLEX Gold system (Sequenom, San Diego, CA, USA) conducted on all the samples, comprising 1470 cases and 1473 controls. After quality control, the minor allele frequency was compared in cases and controls to analyze the association between SNPs and HSCR using PLINK 1.9 (https://www.cog‐genomics.org/plink) and multiple heritability models were tested (additive, recessive and dominant models).

Results

Our results indicated that miR‐4318 rs8096901 polymorphisms were associated with HSCR susceptibility in Southern Chinese children, especially in short‐segment HSCR (S‐HSCR) patients after stratified analysis.

Conclusions

In summary, we report that miR‐4318 rs8096901 was associated with HSCR, especially in SHSCR patients.
Straightforward synthesis, antiproliferative screening, and density functional theory study of some pyrazolylpyrimidine derivatives
Authors: Halim Karema N. M. , Rizk Sameh A. , El‐Hashash Maher A. , Ramadan Sayed K.
Published: December 2020

Tetrahydropyrimidinone derivative was synthesized through one‐pot three components condensation of 1,3‐diphenylpyrazole‐4‐carbaldehyde with pentan‐2,4‐dione and urea under Biginelli reaction conditions. The corresponding chloro‐ and hydrazino derivatives were synthesized and utilized for the construction of some valuable N‐heterocycles encompassing both pyrazole and pyrimidine cores, such as triazolopyrimidine, tetrazolopyrimidine, pyrazole, and pyrazolone derivatives through condensation with nitrogen nucleophiles and carbon electrophiles. The antiproliferative activity evaluation of the synthesized compounds against four human carcinoma cell lines namely, liver carcinoma (HepG2), breast adenocarcinoma (MCF7), prostate cancer (PC3), and colon cancer (HCT‐116) cell lines revealed that some of them provided significant potency, as well as the density‐functional theory (DFT) was studied. The permeability of various hydrophilic and hydrophobic synthesized compounds across both normal and cancer cells is confirmed via DFT simulation in which the much higher permeability through aquaporin channels revealed the selective cytotoxicity toward cancer cells.
Real‐Time Magnetic Resonance Imaging
Authors: Nayak Krishna S. , Lim Yongwan , Campbell‐Washburn Adrienne E. , Steeden Jennifer
Published: December 2020

Real‐time magnetic resonance imaging (RT‐MRI) allows for imaging dynamic processes as they occur, without relying on any repetition or synchronization. This is made possible by modern MRI technology such as fast‐switching gradients and parallel imaging. It is compatible with many (but not all) MRI sequences, including spoiled gradient echo, balanced steady‐state free precession, and single‐shot rapid acquisition with relaxation enhancement. RT‐MRI has earned an important role in both diagnostic imaging and image guidance of invasive procedures. Its unique diagnostic value is prominent in areas of the body that undergo substantial and often irregular motion, such as the heart, gastrointestinal system, upper airway vocal tract, and joints. Its value in interventional procedure guidance is prominent for procedures that require multiple forms of soft‐tissue contrast, as well as flow information. In this review, we discuss the history of RT‐MRI, fundamental tradeoffs, enabling technology, established applications, and current trends.

Level of Evidence

5

Technical Efficacy Stage

1
Saliva for diagnosis of SARS‐CoV‐2: First report from India
Authors: Bhattacharya Debdutta , Parai Debaprasad , Rout Usha K. , Dash Pujarini , Nanda Rashmi R. , Dash Girish C. , Kanungo Srikanta , Palo Subrata K. , Giri Sidhartha , Choudhary Hari R. , Kshatri Jaya S. , Turuk Jyotirmayee , Mishra Bijay K. , Lenka Rajesh K. , Dash Saroj , Pati Sanghamitra
Published: December 2020

There are very few studies in search of an alternate and convenient diagnostic tool which can substitute nasopharyngeal swab (NPS) specimen for detection of SARS‐CoV‐2. In the study we analyzed, the comparison and agreement between the feasibility of using the saliva in comparison to NPS for diagnosis of SARS‐CoV‐2. A total number of 74 patients were enrolled for this study. We analyzed and compared the NPS and saliva specimen collected within 48 h after the symptom onset. We carried out real‐time quantitative polymerase chain reaction, gene sequencing for the detection and determination SARS‐CoV‐2 specific genes. Phylogenetic tree was constructed to establish the isolation of viral RNA from saliva. We used the Bland–Altman model to identify the agreement between two specimens. This study showed a lower cycle threshold (CT) mean value for the detection of SARS‐CoV‐2 ORF1 gene (mean, 27.07; 95% confidence interval [CI], 25.62 to 28.52) in saliva methods than that of NPS (mean 28.24; 95% CI, 26.62 to 29.85) specimen although the difference is statistically nonsignificant (p > .05). Bland–Altman analysis produced relatively smaller bias and high agreement between these two clinical specimens. Phylogenetic analysis with the RdRp and S gene confirmed the presence of SARS‐CoV‐2 in the saliva samples. Saliva represented a promising tool in COVID‐19 diagnosis and the collection method would reduce the exposure risk of frontline health workers which is one of the major concerns in primary healthcare settings.
Reply to the letter by Kondo et al: Mechanisms for new‐onset atrial fibrillation in patients with acute coronary syndrome
Authors: Nagai Mizuyoshi , Itoh Tomonori , Morino Yoshihiro
Published: December 2020

See articles in Journal Of Arhythmia

DOI: doi.org/10.1002/joa3.12233

Letter to the Editor: New‐onset atrial fibrillation after atrial ischemia
Cell‐Free Culture Broth of Pseudomonas aeruginosa—An Alternative Source of Biodispersant to Synthetic Surfactants for Dyeing the Polyester Fabric
Authors: Khubaib Muhammad Anam , Raza Zulfiqar Ali , Abid Sharjeel , Nazir Ahsan , Tariq Muhammad Rizwan
Published: December 2020

Conventional synthetic dispersants have extensively been used in various textile processes due to their easy availability and cost effectiveness. Nonetheless, due to environmental concerns, researchers are trying to explore ecofriendly dispersants such as biosurfactants as substituents to synthetic surfactants. Currently, biosurfactants are not economical due to the cost of their downstream processing and laborious purification steps. Herein, we employed as‐collected cell‐free culture broth (CFCB) of a Pseudomonas aeruginosa strain being an indigenous source of rhamnolipid surfactants (as biodispersant) for disperse‐dyeing of polyester fabric in comparison with some commercially available synthetic surfactants (such as Triton X‐100, cetyltrimethylammonium bromide “CTAB” and sodium dodecyl sulfate ‘SDS’). The efficiency of biosurfactant‐enriched culture broth was compared with that of synthetic surfactants for the said purpose. In addition to conventional testing, dyed fabrics were characterized using scanning electron microscopy (SEM), x‐ray diffraction, and surface resistivity analyses. It was observed that the fabric specimen dyed at 1.5% dye concentration on the weight of the fabric (o.w.f.) in the presence of CFCB (containing biosurfactant above‐CMC) resulted in excellent tensile and colorfastness properties. The SEM analysis indicated that the dyeing done in the presence of biosurfactant was safer as it did not damage the fabric surface as observed in synthetic dispersants; moreover, the mechanical and color characteristics of dyed fabric were also in the acceptable range.
Trace metals as indicators of tree rooting in bituminous soils
Authors: La Flèche Marc , Cuss Chad W. , Noernberg Tommy , Shotyk William , Karst Justine
Published: December 2020

In some reclamation practices, following bitumen mining in the Canadian Boreal forest, overburden containing low concentrations of hydrocarbons (<8% of bulk soil volume) is buried under suitable soils. Residual hydrocarbons may influence the growth of trees used in afforestation of reclaimed sites, thus determining whether roots interact with buried bitumen is a key to predicting reclamation success. As the organic fraction of bitumen is enriched in vanadium, nickel, molybdenum, and rhenium, dendrochemistry may be a method to determine whether tree roots are interacting with bitumen without disturbing soils. We analyzed trace concentrations of these metals in soil, soil pore water, and tree cores of Pinus banksiana growing on natural bitumen deposits and sites free of bitumen. If roots are present within bitumen and passively uptake trace metals during water transport and wood growth, metals enriched in bitumen should be present in higher concentrations in the woody tissue of trees growing in bituminous soils compared to trees growing in bitumen‐free soils. Concentrations of nickel in trees growing on shallow bitumen deposits were approximately 3× higher than those growing in bitumen‐free soils. The concentration of vanadium (1.33 μg kg−1 in younger wood and 3.21 μg kg−1 in older wood) was also elevated in trees on bituminous sites, though not significantly. Molybdenum concentrations decreased by ~25% in trees growing on bituminous sites, likely an outcome of soil pH. This research supports the use of dendrochemistry to investigate, and potentially monitor, tree rooting at depth in substrates with signature metals.
Functional properties of Australian blue lupin (Lupinus angustifolius) protein and biological activities of protein hydrolysates
Authors: Kamran Fozia , Phillips Michael , Reddy Narsimha
Published: December 2020

Lupin is an undervalued legume despite its high protein content with known health benefits. In this research, Australian blue lupin protein was isolated and hydrolysed enzymatically to produce bioactive peptides with a view to assess their potential for nutraceutical and therapeutic applications. Pepsin, pancreatin and flavourzyme were used to enzymatically hydrolyse blue lupin protein, and the hydrolysates were subjected to molecular weight cut‐off (MWCO) fractionation. Measurement of biological activities led to the identification of angiotensin converting enzyme (ACE) inhibitory fractions in the molecular weight range of 2–3 and 3–5 kDa. For the most active fractions in this range, the ACE inhibitory activities were very significant with IC50 values from 450 to 600 μg/ml. Blue lupin protein‐derived MWCO fractions were significantly active against Gram‐positive bacteria and only a little inhibition was observed against Gram‐negative bacteria. Pancreatin hydrolysed fractions showed the best antimicrobial activities with several fractions exhibiting ≥85% inhibition against Bacillus cereus and Staphylococcus aureus. These properties reveal the potential of lupin protein hydrolysates for developing antihypertensive and host defence agents. In order to demonstrate the potential of isolated blue lupin protein in food industry, functional properties including water and oil absorption capacity, gelling properties, solubility and emulsifying properties were evaluated and found to be extremely suitable for developing functional foods with enhanced health benefits.
SnS2 nanosheets as an excellent lubricant additive in polyalphaolefin oil
Authors: Li Jinna , Cao Lei , Su Huijuan , Wan Yong , Wang Yanshuang
Published: December 2020

This paper is devoted to investigate the friction‐reducing and wear protection of SnS2 nanosheets as lubricant additive in poly‐α‐olefin oil (PAO). SnS2 nanosheets, synthesised by a hydrothermal process, were characterised by Raman and X‐ray photoelectron spectroscopy (XPS). A ball‐on‐disk tribometer was used to compare the friction coefficient and wear when lubricated by PAO oil in absence and presence of SnS2 nanosheets. The worn surfaces were observed by SEM. The chemical compositions of tribofilm are analysed by XPS. The experiments showed that addition of SnS2 nanosheets are effective in reducing both friction and wear when lubricated by using base oil. XPS results shows that the enhanced tribological performance is due to a SnS2‐rich boundary film which is formed by deposit of SnS2 nanosheets on the contact area during the sliding process.
Investigation of the Porosity of Poly(sodium methacrylate) Hydrogels by 1H‐NMR T2‐Relaxation and Inverse Size‐Exclusion Chromatography
Authors: Pfeifer Christoph , Cavalli Federica , Huber Birgit , Theato Patrick , Barner Leonie , Wilhelm Manfred
Published: December 2020

A series of poly(sodium methacrylate) hydrogels, also called superabsorbents, having a theoretical degree of neutralization of 100 mol%, and degree of crosslinking varying from 0.6 to 20 mol%, are synthesized via conventional free radical polymerization. The networks are characterized in detail by inverse size‐exclusion chromatography and 1H‐NMR relaxometry in order to place particular emphasis on the investigation of the pore size distribution (PSD) and the chain mobility, respectively. The two previously mentioned parameters are compared to understand the correlation between the elastic chain mobilities and the average pore size of the hydrogel. From the resulting data, a new empirical equation is proposed, which is valid under the given experimental conditions and permits a rough estimation of the average PSD from the relaxation data. Thus, the equation permits to reduce the number of analytical techniques needed for the characterization of complex systems such as polymer networks.
Selectively Depolymerizable Polyurethanes from Unsaturated Polyols Cleavable by Olefin Metathesis
Authors: Jones Brad H. , Staiger Chad , Powers Jackson , Herman Jeremy A. , Román‐Kustas Jessica
Published: December 2020

This communication describes a novel series of linear and crosslinked polyurethanes (PUs) and their selective depolymerization under mild conditions. Two unique polyols are synthesized bearing unsaturated units in a configuration designed to favor ring‐closing metathesis (RCM) to five‐ and six‐membered cycloalkenes. These polyols are co‐polymerized with toluene diisocyanate to generate linear PUs and trifunctional hexamethylene‐ and diphenylmethane‐based isocyanates to generate crosslinked PUs. The polyol design is such that the RCM reaction cleaves the backbone of the polymer chain. Upon exposure to dilute solutions of Grubbs’ catalyst under ambient conditions, the PUs are rapidly depolymerized to low molecular weight, soluble products bearing vinyl and cycloalkene functionalities. These functionalities enable further re‐polymerization by traditional strategies for polymerization of double bonds. It is anticipated that this general approach can be expanded to develop a range of chemically recyclable condensation polymers that are readily depolymerized by orthogonal metathesis chemistry.
Hybrid fully spectral linearized scheme for time‐fractional evolutionary equations
Authors: Hamid Muhammad , Usman Muhammad , Wang Wei , Tian Zhenfu
Published: December 2020

In the current study, we proposed an operational matrix‐based spectral computational method coupled with the Picard technique and successfully employed to seek the solutions to a family of nonlinear evolution differential equations. However, the operational matrices are constructed assisted by monomials, and relevant theorems are available to authenticate the approach mathematically. The iterative form of residual vector for the problems understudy has been presented to seek some new results of a nonlinear family of evolutionary fractional problems. The coupling of spectral technique with the Picard method can easily tackle the high nonlinearities including quadratic, cubic, exponential, and hyperbolic, while it brings more accurate and efficient results than the published results. A worthy comparative study with exact solutions and existing techniques including numerical and analytical is being made, which shows an excellent level of accuracy for the problems under study. The authenticity of the proposed method is validated via convergence, error‐bound, and norms, while the set of graphs is illustrated for integer and noninteger orders. Hence, this unlocks the opportunities to deal with solutions of the weakly singular integral and lattice Toda equations and other complex nonlinear problems arising in applied sciences and may provide a better observation of physical mechanism.
Safety, feasibility, and efficacy of strengthening exercise in Duchenne muscular dystrophy
Authors: Lott Donovan J. , Taivassalo Tanja , Cooke Korey D. , Park Hyunjun , Moslemi Zahra , Batra Abhinandan , Forbes Sean C. , Byrne Barry J. , Walter Glenn A. , Vandenborne Krista
Published: December 2020

Background

This two‐part study explored the safety, feasibility, and efficacy of a mild–moderate resistance isometric leg exercise program in ambulatory boys with Duchenne muscular dystrophy (DMD).

Methods

First, we used a dose escalation paradigm with varying intensity and frequency of leg isometric exercise to determine the dose response and safety in 10 boys. Second, we examined safety and feasibility of a 12‐wk in‐home, remotely supervised, mild–moderate intensity strengthening program in eight boys. Safety measures included T2 MRI, creatine kinase levels, and pain. Peak strength and function (time to ascend/descend four stairs) were also measured.

Results

Dose‐escalation revealed no signs of muscle damage. Seven of the eight boys completed the 12‐wk in‐home program with a compliance of 84.9%, no signs of muscle damage, and improvements in strength (knee extensors P < .01; knee flexors P < .05) and function (descending steps P < .05).

Conclusions

An in‐home, mild–moderate intensity leg exercise program is safe with potential to positively impact both strength and function in ambulatory boys with DMD.
The impact of activity on pelvic age‐at‐death estimation
Authors: Bertsatos Andreas , Chovalopoulou Maria‐Eleni , Boskovits Nikoletta‐Maria , Garoufi Nefeli , Nikita Efthymia
Published: December 2020

This study assesses whether greater levels of physical activity result in increased rates of degenerative change in the pubic symphysis and the iliac auricular surface. The sample comprises 131 skeletons from the Athens Collection. Skeletal age‐at‐death was estimated from the pubic symphysis and the iliac auricular surface. Skeletal activity was assessed using femoral cross‐sectional geometric (CSG) properties and fibrocartilaginous entheses. The association between skeletal age stages, CSG properties and entheseal changes (EC) was tested using Spearman correlation followed with partial Spearman correlation controlling for the effect of documented age‐at‐death and estimated body mass, as well as generalised linear models. Moreover, Kruskal–Wallis tests were used to compare the EC and CSG values among individuals who were underaged, correctly aged and overaged using the pubic symphysis and the iliac auricular surface. Our results show a negative correlation of skeletal age stages with particular CSG properties, implying a decrease in skeletal rigidity as age increases, and a positive correlation with EC scores, suggesting that older individuals exhibit more pronounced EC. Controlling for documented age‐at‐death and body mass produced low correlation coefficients and very few statistically significant results. The difference in EC and CSG values among underaged, correctly aged and overaged individuals was significant only for ECs in individuals over 50 years old. The present study highlights that the effect of activity on pelvic age markers is not pronounced, because a limited association between activity and skeletal degeneration in the pubic symphysis and iliac auricular surface was found. Considering the difficulty in identifying past occupations skeletally, our study supports that this often missing parameter in past osteobiographies does not affect skeletal age estimation. Moreover, our results suggest that taking into account the EC scores when evaluating skeletal age can provide further insights in age‐at‐death estimation in older individuals.
Benefits of Goods and Services Tax implementation in India: An analytical hierarchy process approach
Authors: Maheshwari Taru , Mani Mukta
Published: December 2020

The purpose of this study is to empirically analyze the benefits of Goods and Services Tax (GST) implementation in India from the perspective of various stakeholders. The study has reviewed the existent literature to find out various benefits of GST implementation in India. Thirteen benefits identified are then analyzed through analytical hierarchy process (AHP) technique. The respondents compared and ranked pairwise parameters on a 9‐point scale. The responses collected from 30 stakeholders and have been analyzed to calculate the relative importance of each parameter. The findings provide major, intermediate, and minor benefits of GST implementation which can be utilized by various researchers and policymakers for academic and administrative purposes. The outcome of the study reveals that “elimination of cascading effect” and “enhancement of threshold limit” have utmost importance and GST once fully implemented will benefit the economy in the long run.
Fatigue performance of carbon fiber reinforced epoxy resin: A molecular simulation
Authors: Bowen Li , Yong Lv , Jianzhong Chen , Li Huang , Xiaoyu Zhang
Published: December 2020

In this work, mechanical behavior of multilayer graphene reinforced epoxy resin during fatigue was studied by molecular dynamic method. Transversely isotropic atom based model was established to simulate the carbon fiber reinforced plastics. The reinforced phase was multilayer graphene, and the matrix phase was epoxy resin. Performance degradation in the fiber direction (axial fatigue) and the vertical fiber direction (transversal fatigue) was studied, respectively. Mean stress was considered as the performance per cycle and the power function was employed to describe the tendency of performance degradation. Evolution of energy and structure in atomic scale was used to characterize the cause of performance degradation. The results showed that performance degraded slower in the fiber direction than that in the vertical fiber direction and faster in atomic scale than that in macroscopic experiment. Transformation of molecular structure, which could be represented by the radius of gyration (Rg) of molecular fragments, was one of the reasons that caused performance degradation. Besides, it could cause a change in microscopic energy. Both bond stretch energy and non‐bond interactional energy decrease obviously in the fiber direction while only non‐bond interactional energy decrease in the vertical fiber direction. This phenomenon indicates that existence of carbon fiber effectively slows down the rate of performance degradation in the fiber direction.
Metabolomic analysis reveals the valuable bioactive compounds of Ardisia elliptica
Authors: Wong Pei Lou , Ramli Nurul Shazini , Tan Chin Ping , Azlan Azrina , Abas Faridah
Published: December 2020

Introduction

Ardisia elliptica Thunb. (Primulaceae) is a medicinal herb that is traditionally used for the treatment of fever, diarrhoea, measles and herpes. However, there is limited information regarding the correlation of its phytoconstituents with the bioactivity. Optimisation of solvent extraction is vital for maximising retention of bioactive molecules.

Objective

This study investigated the metabolite variations in A. elliptica leaves and the correlation with antioxidant activities.

Methodology

Total phenolic content (TPC), 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and nitric oxide (NO) radicals scavenging assays were performed on A. elliptica leaves extracted with four different ethanol ratios (0%, 50%, 70% and absolute ethanol). The correlation of metabolites with antioxidant activities was evaluated using a nuclear magnetic resonance (NMR)‐based metabolomics approach.

Results

The results showed that the 50% and 70% ethanolic extracts retained the highest TPC, and the 70% ethanolic extract was the most active, exhibiting half maximal inhibitory concentration (IC50) values of 10.18 ± 0.83 and 43.05 ± 1.69 μg/mL, respectively, in both radical scavenging assays. A total of 46 metabolites were tentatively identified, including flavonoids, benzoquinones, triterpenes and phenolic derivatives. The 50% and 70% ethanolic extracts showed similarities in metabolites content and were well discriminated from water and absolute ethanol extracts in a principal component analysis (PCA) model. Moreover, 31 metabolites were found to contribute significantly to the differentiation and antioxidant activity.

Conclusion

This study provides information on bioactive compounds in A. elliptica leaves, which is promising as a functional ingredient for food production or for the development of phytomedicinal products.
Theoretical research of second generation molecular motor with unidirectional rotary motion
Authors: Guan Qiuping , Wang Hailong , Wang Xueye
Published: December 2020

The rotational process and conformation inversion of the second generation molecular motor (9‐(5‐methoxy‐2‐methyl‐2, 3‐dihydro‐1H‐cyclopentyl[a]naphthalene‐1‐subunit)‐9H‐fluorene) are calculated and analyzed by potential energy surface scanning at the level of density functional theory, the M06‐2X functional combined with the def‐TZVP basis set. The effects of four different donor–acceptor substituents on the molecular stability are mainly explored. The fully optimized geometries of molecular motors 1–5 are discussed at the M06‐2X/def‐TZVP theoretical level. The energy barrier analysis of molecular motors shows that the nature of the substituents will not have a significant impact on the thermal isomerization barrier of the motor. Theoretical analysis of frontier molecular orbital (FMO) shows that after replacing the methyl group with phenyl, methoxy, fluorine, and cyano, the stability of the molecule is reduced. It can be seen from the absorption spectrum that the substituent makes the molecular motor absorption peak significantly red shifted from the absorption spectrum. The study of nuclear magnetic resonance (NMR) shows that it may be affected by deshielding effects, and the substitution of the methyl substituent causes most of the chemical shift (δ) of the molecular motor to a downfield. Finally, it is verified that the conformation of the motors changed from a stable state to unstable state during the photoisomerization process. The calculated results have explained the rotation of molecular motor well and can be used in the design of molecular motor.
Lung transplant referrals for individuals with cystic fibrosis: A pediatric perspective on the cystic fibrosis foundation consensus guidelines
Authors: Solomon Melinda , Mallory George B.
Published: December 2020

Lung transplant referral guidelines for individuals with cystic fibrosis (CF) were published recently. Most of the recommendations focus on the specific indications and barriers to transplantation in adults with CF. Although the number of children with CF and end‐stage lung disease continues to decrease, the specific issues related to pediatric patients merit further elucidation. We address each recommendation from the recent publication with a pediatric perspective. Furthermore, we note some significant differences between the practice and policy related to lung transplantation between Canada and the United States.
Identification and mechanism of insecticidal periplocosides from the root bark of Periploca sepium Bunge
Authors: Li Tian , Zhang Jiwen , Ma Shichuang , Gao Lvtong , Chen Cuicui , Ji Zhiqin , Hu Zhaonong , Shi Baojun , Wu Wenjun
Published: December 2020

BACKGROUND

The Periploca sepium bark root (PSBR) has been regarded as a potential botanical insecticide because of its significant insecticidal activity of secondary metabolites. Several periplocosides were isolated from it as promising pesticides to control crop pests in agriculture.

RESULTS

In our research, two new periplocosides, along with four known periplocosides were isolated from PSBR. The names of new periplocosides were periplocoside T (PST) and periplocoside U (PSU) while another four periplocosides were known as follows: periplocoside A (PSA), periplocoside F (PSF), periplocoside E (PSE) and periplocoside D (PSD). All periplocosides were evalulated for insecticidal activity against 3rd Mythimna separata (Walker) and Plutella xylostella. The biometric data showed that periplocoside T, PSD and PSF had remarkable insecticidal activity against tested insects. Its values of LD50 were 1.31, 3.94 and 3.42 μg·lavare−1 against 3rd M. separata respectively, while the activity of those compounds against 3rd P. xylostella were 5.45, 12.17 and 13.95 μg·lavare−1, respectively. It was apparent after further study of the mechanism of action against M. separata was conducted that PST possessed the most significant insecticidal activity. The results of enzymatic activity displayed that powerful activation of tryptase, especially weak alkaline tryptase might be a dominant factor causing death of M. separata in vivo.

CONCLUSION

We herein report isolation and the mechanisms of action of insecticidal periplocosides, which established the fundamental development of natural agents to prevent pest damage to crops. © 2020 Society of Chemical Industry
Gentiopicroside prevents alcoholic liver damage by improving mitochondrial dysfunction in the rat model
Authors: Zhang Yan , Yang Xiaomei , Wang Shuang , Song Shuang , Yang Xiudong
Published: December 2020

Gentianae Radix et Rhizoma is a medical plant that is widely cultivated in China, North Korea, Japan, and Russia, and gentiopicroside is one of its major active compounds. In this study, the hepatoprotective activity of gentiopicroside on rats with alcoholic liver damage (ALD) was evaluated using the transaminase and blood lipid levels and antioxidant capacity. The potential mechanism of hepatoprotective effect of gentiopicroside was evaluated by mitochondrial function detection, gas chromatography–mass spectrometry (GC–MS) metabolomic analysis, and anti‐apoptosis analysis. Results showed that the gentiopicroside exhibited good hepatoprotective activity on rats with ALD by decreasing the transaminase levels, regulating the blood lipid levels, and increasing the antioxidant capacity. The potential mechanisms were related to regulating mitochondrial dysfunction by recovering mitochondrial membrane potential level, adenosine triphosphate concentration, activities of key enzymes in tricarboxylic acid cycle, and activities of complex I‐V, regulating micromolecular metabolism and anti‐apoptosis. These findings supported the further exploration of Gentianae Radix et Rhizoma as effective phytotherapy to prevent and treat ALD.
Reviving the Orchard: Visions of reclaiming science education for Nicaragua
Authors: Fowler Kelsie N.
Published: December 2020

Educators involved in the improvement of science instruction need to explore how science education could better align with the needs and interests of specific communities, especially in areas of Central America where local knowledge has been expunged from schools. In this paper, I draw upon Culturally Sustaining and Revitalizing Pedagogies to explore a single community's visions for science education and how these visions may be used as pathways for restoring relevant science education practices. To do this study, a case study approach was used to collect 150 h of science lesson observations at three schools in a small Nicaraguan community and interview 18 science teachers and community members. Many of these teachers and community members provided detailed accounts of local science knowledge or methods of teaching science that had been replaced with Westernized curriculum and pedagogies to the detriment of learning and their community. Results indicate two overarching visions: (1) a vision for reviving Scholar Orchards and (2) a vision for learning science with community resources. These findings highlight the need to partner with local teachers and community members when designing, implementing, and evaluating science education because they possess sophisticated visions for making science more relevant, sustaining, and revitalizing within their community context.