bluuebunny/crossref_metadata_2025 huggingface dataset:
Perceived self‐efficacy of students and its influence on attitudes and knowledge about HIV/AIDS in Ghana
Authors: Opoku Maxwell Peprah , Agyei‐Okyere Elvis , Nketsia William , Torgbenu Eric Lawer , Kumi Emmanuel Opoku
Published: October 2021

Globally, human immunodeficiency syndrome (HIV) and its accompanying acquired immune deficiency syndrome (AIDS) have long been a public health threat due to the high death toll and the various effects on individuals and societies. Unfortunately, in developing countries such as Ghana, persons living with HIV/AIDS are victims of discrimination and rejection and are often excluded from social activities. Consequently, there is a need for mitigation strategies aimed at reducing the spread of the disease. Indeed, in human society, beliefs are fundamental to understanding people's intentions towards a given phenomenon. The purpose of this study was to assess students' perceived self‐efficacy, attitude towards and knowledge about HIV/AIDS. In this study, Bandura's self‐efficacy theory was used as a framework to assess the relationship between students' perceived self‐efficacy, attitude towards and knowledge about HIV/AIDS. A total of 342 students of at least 15 years old were recruited from junior and senior high schools and a public university to complete two scales: the general self‐efficacy and attitude and knowledge about HIV/AIDS scales. While there was a positive correlation among self‐efficacy, attitude and knowledge, attitude and knowledge combined to predict self‐efficacy. The limitations of the study, recommendations for future research and policy implications are discussed herein.
Two‐phase fluid motion through porous medium with volume fraction: An application of MATLAB bvp4c solver technique
Authors: Dey Debasish , Chutia Barbie
Published: October 2021

In this paper, we have attempted to study the steady two‐dimensional hydromagnetic convective flow through porous medium and heat transfer effects. Fluid is containing dust particles and is moving under the influence of Lorentz, buoyancy, Darcy, and viscous forces. Motion is considered to be governed by the volume fraction of the dust grains and the increment of shear stress and rate of heat transfer at the surface has been analyzed. Governing equations of the problem are converted into ordinary differential equations utilizing similarity transformations. The converted differential equations are figured numerically using the MATLAB built‐in technique bvp4c. The results are depicted in graphical forms for different values of the flow parameters. The findings are obtained considering the volume fraction and compared with the results of the previous paper. It is observed that the shear stress enhances with diminishing resistance and decreases for the higher values of the Hartmann number, permeability parameter, and volume fraction of the dust phase. Also, improving the Nusselt number gives a boost to thermal diffusivity.
Using micro‐catchment experiments for multi‐local scale modelling of nature‐based solutions
Authors: Hankin Barry , Page Trevor J. C. , Chappell Nick A. , Beven Keith J. , Smith Paul J. , Kretzschmar Ann , Lamb Rob
Published: October 2021

The Q‐natural flood management project has co‐developed with the Environment Agency 18 monitored micro‐catchments (~1 km2) in Cumbria, UK installing calibrated flumes aimed at quantifying the potential shift in observed flows resulting from a range of nature‐based‐solutions installed by local organizations. The small‐scale reduces the influence of variability characterizing larger catchments that would otherwise mask any such shifts, which we attempt to relate to a shift in model parameters. This paper demonstrates an approach to applying donor‐parameter‐shifts obtained from modelling two of the paired micro‐catchments to a much larger scale, in order to understand the potential for improved distributed modelling of nature‐based solutions in the form of additional tree‐planting. The models include a rainfall‐runoff model, Dynamic Topmodel, and a 2D hydrodynamic model, JFlow, permitting analysis of changes in hillslope processes and channel hydrodynamics resulting from a range of distributed measures designed to emulate natural hydrological processes that evaporate, store or infiltrate flows. We report on attempts to detect shift in hydrological response using one of the paired‐micro‐catchment moorland versus forestry sites in Lorton using Dynamic Topmodel. A donor‐parameter‐shift approach is used in a hypothetical experiment to represent new woodland in a much larger catchment, although testing all combinations of spatial planting strategies, responses to multiple‐extremes, failure‐modes and changes to synchronization becomes intractable to support good decision making. We argue that the problem can be re‐framed to use donor‐parameter‐shifts at multi‐local‐scale catchments above communities known to be at risk, commensurate with most of the evidence of NbS impacts being effective at the small scale (ca. 10 km2). This might lead to more effective modelling to help catchment managers prioritize those communities‐at‐risk where there is more evidence that NbS might be effective.
Accuracy and precision of the cosmic‐ray neutron sensor for soil moisture estimation at humid environments
Authors: Iwema Joost , Schrön Martin , Koltermann Da Silva Juliana , Schweiser De Paiva Lopes Rodolfo , Rosolem Rafael
Published: October 2021

The accuracy and precision of the cosmic‐ray neutron sensor (CRNS) neutron count and soil moisture estimate are affected differently by distinct neutron moderating factors. Moreover, whereas the accuracy can be improved by correcting for different hydrogen pools, the precision can only be improved by increasing the surface area of the CRNS sensors or by increasing the integration time. To date, the effects of different neutron moderating factors on CRNS accuracy and precision are not completely understood. We used data from three agricultural and low biomass sites located within a few kilometres distance from each other in South England. We developed an extended version of the COsmic‐ray Soil Moisture Interaction Code (COSMIC), which included the effects of relevant neutron moderating factors on the neutron counts. With sensitivity analysis, we found atmospheric pressure and soil moisture content to be most influential on neutron count accuracy and precision. These two factors were, respectively, seven and four times more important than soil bulk density, lattice water and soil organic matter. Above ground biomass was substantially less influential compared to these variables. However, because the three sites had similar soil organic matter and meteorology, calibration results showed that differences between sites could be mostly explained by differences in above ground biomass and to a lesser extent intercepted water. The neutron count differences due to above ground biomass corresponded with substantial soil moisture estimate differences up to ; a significant effect on soil moisture accuracy. The precision of the soil moisture estimate was 10 times more sensitive to soil moisture than other factors and was therefore mostly a function of soil moisture content itself. The neutron count integration times required to obtain a soil moisture precision were typically less than a day. Our results are indicative for other humid, temperate, agricultural sites.
Critically Reading the Canon: Culturally Sustaining Approaches to a Prescribed Literature Curriculum
Authors: Ervin Jennifer
Published: October 2021

Culturally sustaining pedagogy (Paris, 2012) has emerged as an essential way to value the evolution of culture among diverse learners. Discussions around teaching in a culturally sustaining manner in the English language arts classroom, specifically when teaching literary analysis, often address the need to incorporate multicultural literature so that students are exposed to stories told from diverse perspectives. However, the reality in many schools is that teachers do not have ownership over their curriculum in a way that allows them to choose which texts they read and study with students. In this context, culturally sustaining teaching presents a difficult challenge. In this literature review, the author presents classroom strategies that apply a critical literacy lens to analysis of canonical literature as a way to create a place for culturally sustaining teaching within a prescribed curriculum.
CEO ownership and firm performance: Evidence from the 2003 dividend tax cut
Authors: Duong Hong Kim
Published: October 2021

This study investigates the performance consequences of changes in the optimality of chief executive officer (CEO) ownership by using the 2003 dividend tax cut (DTC) as an exogenous shock. I find that CEO ownership of dividend payers significantly increased after the DTC in the form of higher annual restricted stock grants and more option exercises. I also document that more optimal ownership is associated with performance improvement and more efficient R&D investment. Overall, findings from my study provide insights into the role of managerial equity incentives for firm performance.
STING‐mediated inflammation contributes to Gao binge ethanol feeding model
Authors: Wang Ling , You Hong‐Mei , Meng Hong‐Wu , Pan Xue‐Yin , Chen Xin , Bi Yi‐Hui , Zhang Ya‐Fei , Li Juan‐Juan , Yin Na‐Na , Zhang Zheng‐Wei , Huang Cheng , Li Jun
Published: October 2021

Alcohol metabolism causes hepatocytes to release damage‐associated molecular patterns (DAMPs). This includes mitochondrial DNA (mtDNA), which is generated and released from damaged hepatocytes and contributes to liver injury by producing proinflammatory cytokines. STING is a pattern recognition receptor of DAMPs known to control the induction of innate immunity in various pathological processes. However, the expression profile and functions of STING in the Gao binge ethanol model remain poorly understood. We demonstrated that STING is upregulated in the Gao binge ethanol model. STING functions as an mtDNA sensor in the Kupffer cells of the liver and induces STING‐signaling pathway‐dependent inflammation and further aggravates hepatocyte apoptosis in the Gao binge ethanol model. This study provides novel insights into predicting disease progression and developing targeted therapies for alcoholic liver injury.
Role of miR‐185‐5p as modulator of periostin synthesis and smooth muscle contraction in asthma
Authors: Rodrigo‐Muñoz José M. , Cañas José A. , Sastre Beatriz , Gil‐Martínez Marta , García Latorre Raquel , Sastre Joaquín , del Pozo Victoria
Published: October 2021

Asthma is a chronic respiratory disease produced by an aberrant immune response that originates with breathing difficulties and cough, through airway remodeling. The above pathophysiological events of asthma emerge the regulators of effectors, like epigenetics, which include microRNAs (miRNAs) who perform post‐transcriptional regulation, controlling diverse pathways in respiratory diseases. The objective of the study was to determine how miR‐185‐5p regulates the secretion of periostin by airway structural cells, and smooth muscle cells contraction, both related to airway remodeling in asthma. We used miR‐185‐5p mimic and inhibitors in bronchial smooth muscle cells (BSMCs) and small airway epithelial cells (SAECs) from healthy subjects. Gene expression and protein levels of periostin (POSTN), CDC42, and RHOA were analyzed by RT‐PCR and ELISA/Western blot, respectively. BSMC contractility was analyzed using cell‐embedded collagen gels and measurement of intracellular calcium was performed using Fura‐2. Additionally, miR‐185‐5p and periostin expression were evaluated in sputum from healthy and asthmatics. From these experiments, we observed that miR‐185‐5p modulation regulates periostin mRNA and protein in BSMCs and SAECs. A tendency for diminished miR‐185‐5p expression and higher periostin levels was seen in sputum cells from asthmatics compared to healthy, with an inverse correlation observed between POSTN and miR‐185‐5p. Inhibition of miR‐185‐5p produced higher BSMCs contraction induced by histamine. Calcium mobilization was not modified by miR‐185‐5p, showing that miR‐185‐5p role in BSMC contractility is performed by regulating CDC42 and RhoA pro‐contractile factors instead. In conclusion, miR‐185‐5p is a modulator of periostin secretion by airway structural cells and of smooth muscle contraction, which can be related to asthma pathophysiology, and thus, might be a promising therapeutic target.
Population Pharmacokinetics of Ponatinib in Healthy Adult Volunteers and Patients With Hematologic Malignancies and Model‐Informed Dose Selection for Pediatric Development
Authors: Hanley Michael J. , Diderichsen Paul M. , Narasimhan Narayana , Srivastava Shouryadeep , Gupta Neeraj , Venkatakrishnan Karthik
Published: October 2021

The BCR‐ABL1 inhibitor ponatinib is approved for the treatment of adults with chronic myeloid leukemia or Philadelphia chromosome–positive acute lymphoblastic leukemia, including those with the T315I mutation. We report a population pharmacokinetic model‐based analysis for ponatinib and its application to inform dose selection for pediatric development. Plasma concentration–time data were collected from 260 participants (86 healthy volunteers; 174 patients with hematologic malignancies) enrolled across 7 clinical trials. Data were analyzed using nonlinear mixed‐effects modeling. Ponatinib pharmacokinetics were described by a 2‐compartment model with first‐order elimination from the central compartment. The final model included body weight and age as covariates on the apparent central volume of distribution; however, exposure variability explained by these covariates was small compared with overall variability in the population. None of the covariates evaluated, including sex, age (19‐85 years), race, body weight (40.7‐152.0 kg), total bilirubin (0.1‐3.16 mg/dL), alanine aminotransferase (6‐188 U/L), albumin (23.0‐52.5 g/L), and creatinine clearance (≥28 mL/min) had clinically meaningful effects on apparent oral clearance. Simulations based on the final model predicted that daily doses of 15 to 45 mg result in steady‐state average concentrations that are in the pharmacological range for BCR‐ABL1 inhibition and approximate or exceed concentrations associated with suppression of T315I mutant clones. The final model was adapted using allometric scaling to inform dose selection for pediatric development. Clinicaltrials.gov identifier: NCT00660920; NCT01667133; NCT01650805
Caplacizumab Model‐Based Dosing Recommendations in Pediatric Patients With Acquired Thrombotic Thrombocytopenic Purpura
Authors: Bergstrand Martin , Hansson Emma , Delaey Bernard , Callewaert Filip , De Passos Sousa Rui , Sargentini‐Maier Maria Laura
Published: October 2021

Acquired thrombotic thrombocytopenic purpura (aTTP) is a rare and life‐threatening autoimmune thrombotic microangiopathy. Caplacizumab, evaluated in phase II and III studies in adults, shortens the time to platelet count response and reduces aTTP exacerbations, has a favorable safety profile, and can potentially reduce refractoriness and mortality associated with aTTP. Since no children with aTTP were enrolled in these clinical trials, caplacizumab has been initially approved for use only in adult patients with aTTP (10 mg). Pediatric dosing recommendations were developed using model‐based simulations. A semimechanistic pharmacokinetic/pharmacodynamic population model has been developed describing the interaction between caplacizumab and von Willebrand factor antigen (vWF:Ag) following intravenous and subcutaneous administration of caplacizumab in different adult populations, at various dose levels, using nonlinear mixed‐effects modeling. Based on the allometrically scaled pharmacokinetic/pharmacodynamic model, different dosing regimens were simulated in 8000 children (aged 2‐18 years). Simulated caplacizumab exposures and vWF:Ag levels across different age categories were compared to an adult reference group. A simulated daily dose of 5 mg in children weighing <40 kg and of 10 mg in children weighing ≥40 kg resulted in similar exposures and vWF:Ag suppression across age and weight groups. Despite the lack of pediatric clinical data, the results of this modeling and simulation analysis constituted the basis for the European extension of indication for caplacizumab (10 mg) to adolescents aged >12 years and with a body weight ≥40 kg. This represents a rare case in which regulatory authorities have deemed a modeling and simulation study robust enough to approve a variation of indication.
Investigation of polyacrylamide hydrogel‐based molecularly imprinted polymers using protein gel electrophoresis
Authors: EL Sharif Hazim F. , Giosia Flavio , Reddy Subrayal M.
Published: October 2021

In conjunction with polyacrylamide gel electrophoresis (PAGE), molecular imprinting methods have been applied to produce a multilayer mini‐slab in order to evaluate how selectively and specifically a hydrogel‐based molecularly imprinted polymer (MIP) binds bovine haemoglobin (BHb, ~64.5 kDa). A three‐layer mini‐slab comprising an upper and lower layer and a MIP, or a non‐imprinted control polymer dispersion middle layer has been investigated. The discriminating MIP layer, also based on polyacrylamide, was able to specifically bind BHb molecules in preference to a protein similar in molecular weight such as bovine serum albumin (BSA, ~66 kDa). Protein staining allowed us to visualise the protein retention strength of the MIP layer under the influence of an electric field. This method could be applied to other proteins with implications in effective protein capture, disease diagnostics, and protein analysis.
SARS‐CoV‐2 variant with mutations in N gene affecting detection by widely used PCR primers
Authors: Laine Pia , Nihtilä Hanna , Mustanoja Ella , Lyyski Annina , Ylinen Anne , Hurme Jukka , Paulin Lars , Jokiranta Sakari , Auvinen Petri , Meri Taru
Published: October 2021

While most of the spontaneous mutations in the viral genome have no functional, diagnostic, or clinical consequences, some have. In February 2021, we noticed in Southern Finland coronavirus disease 2019 cases where two commercial polymerase chain reaction (PCR) analyses failed to recognize the used N gene target but recognized the other target gene of severe acute respiratory syndrome coronavirus 2. Complete viral genome sequence analysis of the strains revealed several mutations that were not found at that time in public databases. A short 3 bp deletion and three subsequent single nucleotide polymorphisms in the N gene were found exactly at the site where an early published and widely used N gene‐based PCR primer is located, explaining the negative results in the N gene PCR. Later the variant strain was identified as a member of the B.1.1.318 Pango lineage that had first been found from Nigerian samples collected in January 2021. This strain shares with the Beta variant the S gene E484K mutation linked to impaired vaccine protection, but differs from this variant in several other ways, for example by deletions in the N gene region. Mutations in the N gene causing diagnostic resistance and on the other hand E484K mutation in the causing altered infectivity warrants careful inspection on virus variants that might get underdiagnosed.
The seasonal predictability of the wet season over Peninsular Florida
Authors: Narotsky Carly D. , Misra Vasubandhu
Published: October 2021

In this study, we examine the seasonal predictability of Peninsular Florida (PF)'s boreal summer season, which is also known as the PF wet season (PFWS) due to the coinciding peak of the robust seasonal cycle of rainfall. The seasonal predictability is examined in the Community Climate System Model, version 4 (CCSM4), which is one of the models of the North American Multi‐Model Ensemble used for routine, operational seasonal forecasts by the National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center (CPC). An objective definition of the onset and the demise of the PFWS are then implemented, and the predictability of the onset, the demise and the seasonal rainfall anomaly is assessed from the CCSM4 seasonal hindcasts. Our study shows that the 33 years (1983–2015) of the CCSM4 seasonal hindcasts display very poor deterministic and probabilistic skill in predicting the onset and the demise of the PFWS and its seasonal rainfall anomalies for all lead times. It is shown that the seasonal hindcasts display poor skill for both the fixed calendar month and varying seasonal length of the PFWS. In many of these instances, the skills deteriorate with the lead time of the CCSM4 hindcasts, although, in some cases, they bear no relation (e.g., demise date of the PFWS). Our analysis reveals that the interannual variability of the location of the western ridge of the North Atlantic subtropical high is poorly rendered in the seasonal hindcast of CCSM4 with respect to reanalysis. This could explain the origins of some of the potential issues of the CCSM4 seasonal hindcasts with the variability of the PFWS.
The role of the timing of sudden stratospheric warmings for precipitation and temperature anomalies in Europe
Authors: Monnin Erika , Kretschmer Marlene , Polichtchouk Inna
Published: October 2021

The Northern Hemisphere stratospheric polar vortex (SPV), a band of fast westerly winds over the Pole extending from approximately 10 to 50 km altitude, is a key driver of European winter weather. Extremely weak polar vortex states, so called sudden stratospheric warmings (SSWs), are on average followed by dry and cold weather in Northern Europe, as well as wetter weather in Southern Europe. However, the surface response of SSWs varies greatly between events, and it is not well understood which factors modulate this difference. Here, we address the role of the timing of SSWs within the cold season (December–March) for the temperature and precipitation response in Europe. Given the limited sample size of SSWs in the observations, hindcasts of the seasonal forecasting model SEAS5 from the European Centre for Medium‐Range Weather Forecasts are analysed. First, we evaluate key characteristics of stratosphere–troposphere coupling in SEAS5 against reanalysis data and find them to be reasonably well captured by the model, justifying our approach. We then show that in SEAS5, early winter (December and January) SSWs are followed by more pronounced surface impacts compared to late winter (February and March) SSWs. For example, in Scotland, the low precipitation anomalies are roughly twice as severe after early winter SSWs than after late winter SSWs. The difference in the response cannot be explained by more downward propagating SSWs in early winter, or by different monthly precipitation climatologies. Instead, we demonstrate that the differences result from stronger SPV anomalies associated with early winter SSWs. This is a statistical artefact introduced through the commonly used SSW event definition, which involves an absolute threshold, and, therefore, leads to stronger SPV anomalies during early winter SSWs when the stratospheric mean state is stronger. Our study highlights the sensitivity of surface impacts to SSW event definition.
Predictors of anatomical and functional outcomes following tympanoplasty: A retrospective study of 413 procedures
Authors: Zhu Xiao‐Hui , Zhang Yong‐Li , Xue Ruo‐Yan , Xie Meng‐Yao , Tang Qi , Yang Hua
Published: October 2021

Objectives

To identify the predictors of anatomical and functional outcomes following tympanoplasty.

Study Design

A retrospective cohort study.

Methods

Patients with chronic suppurative otitis media (CSOM) who underwent a tympanoplasty at Peking Union Medical College Hospital from January 1, 2015 to December 31, 2019 were retrospectively included. Outcome measures included graft success and postoperative pure tone audiometry air‐bone gap (PTA‐ABG) at last follow‐up (≥6 months). PTA‐ABG and MERI were calculated. Descriptive, univariable, and multivariable logistic regression analyses were conducted to evaluate the predictors of the graft and hearing outcomes.

Results

During the study, 385 patients (167 male, 218 female, median age 44 years) undergoing 413 procedures were studied. Out of this, 219 ears underwent tympanoplasty, 45 ears had tympanoplasty with canal wall up mastoidectomy, and 149 ears had tympanoplasty with canal wall down mastoidectomy. At the last follow‐up, the overall graft success rate was 91.3% (377/413) and the overall hearing success rate was 40% (165/413). Multivariable analysis results showed that the obstructed aditus ad antrum (OR 2.67, 95%CI 1.13‐6.30; P = .025) was an independent prognostic factor for graft failures. Moreover, the obstructed aditus ad antrum (OR 2.18, 95%CI 1.16‐4.08; P = .015) and MERI >3 (OR 6.53, 95%CI 3.55‐12.02; P < .001) were independent predictors of hearing failures (PTA‐ABG > 20 dB).

Conclusions

Aditus ad antrum patency was an independent predictor of both graft and hearing success among patients following tympanoplasty. MERI score greater than three was found to be a significant predictor of postoperative hearing and could serve as a useful tool for assisting clinicians in perioperative risk assessment.

Level of Evidence

4.
Plankton community composition and productivity near the Subantarctic Prince Edward Islands archipelago in autumn
Authors: Stirnimann Luca , Bornman Thomas G. , Verheye Hans M. , Bachèlery Marie‐Lou , van der Poel Janine , Fawcett Sarah E.
Published: October 2021

The Subantarctic Ocean is a sink for atmospheric CO2, largely due to its biological pump, which is enhanced by the influence of the Subantarctic islands on the plankton ecosystem (the so‐called “island mass effect”). The influence of the Prince Edward Islands archipelago in the Indian Subantarctic on the surrounding hydrography and benthos has been well studied; however, over the last two decades, little attention has been paid to the functioning and productivity of its plankton ecosystem. Here, we present the first measurements of primary production at the archipelago in over 20 years and the first‐ever rates of secondary production, interpreted in the context of hydrographic, biogeochemical, and plankton community composition data. In autumn 2017, after the late‐summer bloom, nanophytoplankton dominated the near‐island waters and regenerated nutrients fuelled 76% of phytoplankton growth. Primary production and carbon export potential (inferred from nitrate uptake) reached a local maximum in the inter‐island region, which we attribute to water‐mass retention and stratification over the inter‐island plateau (a manifestation of the island mass effect). We observed a diverse mesozooplankton community, likely a remnant of the late‐summer bloom rather than representing the consumers feeding on the in situ (nano)phytoplankton. We estimate that even after the decay of the late‐summer bloom, roughly a quarter of the planktonic carbon was potentially exportable. This finding implies that the archipelago's upper‐ocean ecosystem sequesters atmospheric CO2 at least through autumn despite high rates of recycling and inefficient trophic transfer, thereby contributing to the island mass effect‐associated strengthening of the Subantarctic Ocean's biological pump.
Seasonality of dissolved organic matter in lagoon ecosystems along the Alaska Beaufort Sea coast
Authors: Connolly Craig T. , Crump Byron C. , Dunton Kenneth H. , McClelland James W.
Published: October 2021

Seasonal variations in dissolved organic matter (DOM) fluxes from land to sea have been well documented in the Arctic, yet remarkably little is known about how DOM varies seasonally within Arctic coastal waters. This is particularly true for shallow inshore environments. Here we document seasonality of DOM in lagoons along the eastern Alaska Beaufort Sea coast during the spring ice break‐up (June), summer open‐water (August), and late winter ice‐covered (April) periods. We measured dissolved organic carbon (DOC) concentrations, C:N ratios, and chromophoric DOM (CDOM) characteristics (SUVA254 and S275–295). On average, lagoon DOC was highest during spring (~200 μM) and lowest during winter (~120 μM). C:N and SUVA254 also differed markedly between spring (C:N ~ 28; SUVA254 ~ 3.5 L mg C−1 m−1) and winter (C:N ~ 16; SUVA254 ~ 2.2 L mg C−1 m−1). Average S275–295 values (~14–17 × 10−3 nm−1) were not significantly different among seasons, but variability in S275–295 was much lower in spring. This was attributed to terrestrial runoff based on its relatively uniform composition during the spring freshet. Seasonal variations in lagoon DOM were broadly correlated with variations in salinity (i.e., lagoon water transitioned from largely fresh in spring to hypersaline in winter), but a mixing analysis revealed strong evidence of processing and net DOC generation in summer. We also found evidence of DOC processing and build‐up under the ice over the winter. This baseline understanding of DOM seasonality in Arctic lagoons is essential for evaluating climate‐linked impacts on Arctic coastal ecosystems and broader feedbacks associated with carbon cycling.
Sunlight‐Mediated Degradation of Polyethylene under the Synergy of Photothermal CH Activation and Modification
Authors: Kong Shengnan , He Congze , Dong Jin , Li Ning , Xu Chaoran , Pan Xiangcheng
Published: October 2021

The reuse of waste plastic has always been one of the challenges in the field of macromolecular science. The authors report that the degradation of polyethylene (PE) plastics can be achieved by a photothermal reaction using tetrabutylammonium decatungstate (TBADT) as photocatalysts, and the grafting of diisopropyl azodicarboxylate (DIAD) onto PE concurrently occurs under sunlight irradiation. Through adjusting the amount of DIAD or TBADT used in the reaction, low molecular weight PE waxes with tunable polarity can be prepared. This method can be applied to different sorts of PE plastics including films, gloves, and bags. Subsequently, synthesized low molecular weight PE‐graft‐DIAD waxes are used as compatibilizers to successfully realize the compatibilized blending of polyolefin plastics and starch, which paved a viable way to reuse waste plastics to reduce environmental pollution.
Characterization of endogenous promoters of GapC1 and GS for recombinant protein expression in Phaeodactylum tricornutum
Authors: Erdene‐Ochir Erdenedolgor , Shin Bok‐Kyu , Huda Md Nazmul , Lee Eun Ha , Song Dae‐Geun , Jung Choonkyun , Pan Cheol‐Ho
Published: October 2021

Although diatoms have been utilized as a cellular factory to produce biopharmaceuticals, recombinant proteins, and biofuels, only a few numbers of gene promoters are available. Therefore, the development of novel endogenous promoters is essential for the production of a range of bioactive substances. Here, we characterized the activities of endogenous promoters glyceraldehyde‐3‐phosphate dehydrogenase (GapC1) and glutamine synthetase (GS) of Phaeodactylum tricornutum using green fluorescent protein (GFP) under different culture conditions. Compared with the widely used fucoxanthin chlorophyll‐binding protein A (fcpA) promoter, the GS promoter constitutively drove the expression of GFP throughout all growth phases of P. tricornutum, regardless of culture conditions. Additionally, the GFP level driven by the GapC1 promoter was the highest at the log phase, similar to the fcpA promoter, and increased light and nitrogen‐starvation conditions reduced GFP levels by inhibiting promoter activity. These results suggested that the GS promoter could be utilized as a strong endogenous promoter for the genetic engineering of P. tricornutum.
Insights into ground response during underground coal gasification through thermo‐mechanical modeling
Authors: Gao Wu , Zagorščak Renato , Thomas Hywel Rhys
Published: October 2021

This paper presents a coupled thermo‐mechanical model to investigate the ground response during underground coal gasification (UCG). The model incorporated the temporal and spatial development of temperature, the gradual growth of the cavity, and temperature‐dependent material properties. Model verification was made against two benchmarks to acquire the confidence for the predictive purpose. The first exercise demonstrated the correctness of the model implemented in COMPASS. The second exercise showed that using the ash‐filled cavity to represent null or empty zones is a good option in the numerical modeling and provided highly comparable results to other models. Based on the Hanna UCG trial, different cases were simulated to investigate the effects of the cavity size in the coal seam and the thermal expansion coefficient of the caprock and base rock on key features that take place during the process of UCG. A maximum temperature in the range of 1200–1500 ℃ was induced by the gasification of coal, and a cavity with a maximum length of 13.5 m was formed after 30 days of simulation. Meanwhile, small vertical displacement in the range of ‐5–12 mm took place near the cavity because of the thermal expansion of the geologic materials and the reduction of the overall weight with the creation of the cavity. In addition, it was found the thermal expansion coefficients can influence the thermo‐mechanical response of geologic materials, but the effects were insignificant when its order of magnitude was smaller than 10‐6 K‐1.
Symmetric and asymmetric effects of exchange rate: Evidence from capital market and financial sector in Nigeria
Authors: Mesagan Ekundayo Peter , Vo Xuan Vinh , Amadi Idimmachi Pius
Published: October 2021

The study analyses the symmetric and asymmetric impacts of exchange rate volatility and fluctuations, respectively on the capital market and financial sector in Nigeria. This analysis entails using monthly data from January 2010 to April 2018 and the autoregressive distributed lag (ARDL) bounds testing framework. The linear ARDL result shows that exchange rate volatility negatively but significantly impacts financial development and capital market in the short‐run and long‐run. Results of the asymmetric effect show that exchange rate depreciation negatively and insignificantly affects the capital market while exerting a significant positive impact on the financial market in both short‐run and long‐run at about 0.06 and 0.04% respectively for both sectors. However, currency appreciation positively influences the capital market at 1.23 and 0.66%, but negatively affects the financial sector at 0.09 and 0.02% in the short‐ and long‐run respectively. Thus, the study calls for effective public policy management since exchange rate volatility and currency depreciation pose a bad omen to the capital market. This entails public regulation of the key macroeconomic indicators by encouraging the central bank to maintain interest rates that are favorable toward expanding the productive capacity of private investors. Such policy can also be supported by providing affordable access to investment funds.
Intestinal mycobiota composition and changes in children with thalassemia who underwent allogeneic hematopoietic stem cell transplantation
Authors: Yalcin Siddika Songul , Aksu Tekin , Kuskonmaz Baris , Ozbek Namık Yasar , Pérez‐Brocal Vicente , Celik Melda , Uckan Cetinkaya Duygu , Moya Andrés , Dinleyici Ener Cagri
Published: October 2021

Background: Allogeneic hematopoietic stem cell transplantation (HSCT) alters the diversity of the intestinal bacterial microbiota. This study aimed to evaluate human mycobiota composition pre‐HSCT and post‐HSCT in children with thalassemia.

Method: Ten children with thalassemia undergoing allogeneic HSCT were enrolled. The stool samples were collected before the transplantation regimen, before the transplant day, and +15, +30 days, and three months after transplantation. Stool samples were also collected from the donor and the patient's caregivers. Gut mycobiota composition was evaluated with metagenomic analysis.

Results: Pretransplant mycobiota of children with thalassemia (the predominant genus was Saccharomyces, 64.1%) has been shown to approximate the diverse mycobiota compositions of healthy adult donors but becomes altered (lower diversity) following transplant procedures. Three months after HSCT, phyla Ascomycota and Basidiomycota were 83.4% and 15.6%, respectively. The predominant species were Saccaharomyces_uc and Saccharomyces cerevisiae (phylum Ascomycota); we also observed Malassezia restricta and Malassezia globosa (phylum Basidiomycota) (∼13%). On day 90 after HSCT, we observed 65.3% M. restricta and 18.4% M. globosa predominance at the species level in a four‐year‐old boy with acute graft‐versus‐host disease (GVHD) (skin and gut involvement) 19 days after transplantation included.

Conclusion: The mycobiota composition of children with thalassemia altered after HSCT. We observed Malassezia predominance in a child with GVHD. Further studies in children with GVHD will identify this situation.
Post‐extrusion process for the robust preparation of highly uniform multiphase polymeric 3D printing filaments
Authors: Gancheva Teodora , Li Youjian , Pilon Daniel , Gauthier Matthieu , Akbarzadeh Abdolhamid , Favis Basil D.
Published: October 2021

Fused filament fabrication 3D printing demands the preparation of polymeric filaments of highly uniform dimensions in order to achieve the best possible mechanical performance. This stringent requirement is a challenging task and becomes even more difficult when multiphase hybrid polymers are used. In this work, a post‐extrusion setup is presented, allowing for the preparation of immiscible quaternary polymeric blend filaments of highly stable dimensions. The polymer blend used is bio‐based and is comprised of poly(L‐lactide), poly(ethylene oxide), poly(ether‐b‐amide), and polyamide‐11. The setup is connected to an extruder die. By incorporating a precisely localized temperature control over a pathway of 66 mm, the extrudate melt is initially transformed into a stable semisolid state. Forced convection cooling, imposed at a distance of 4–5 mm from the last static cooling zone, allows thereafter the complete solidification of the profile. Filaments with a uniform diameter of 1.75 and 2.85 mm are manufactured. The developed approach can be used to manufacture, otherwise non‐processable, complex quaternary polymer blend filaments with a highly controlled diameter in the range of 0.1–4.5 mm with no restriction regarding the filament length. The produced filaments were used to 3D print dogbone samples with very high elongation at break.
Microstructured biphasic hydrogels for highly sensitive and asymmetric sensors with temperature‐dependent sensitivity
Authors: Gao Tenglong , Gao Xin , Li Tuoqi , Zhang Jiuyang
Published: October 2021

Microfabrication of advanced architectures in flexible polymers has been a prevalent strategy to achieve high‐performance stretchable sensors. However, such microfabrication is usually challenging, requiring delicate synthesis with expensive instruments. This work utilizes the microphase separation in biphasic hydrogels (BHs) to conveniently achieve microstructured high‐performance sensors. Different microphase separated structures were observed in BH sensors depending on the oil/water ratios and temperature, resulting in many unexpected features. The BH sensors show excellent extensibility (1000%) and phenomenal mechanical durability (>1000 compressive cycles). The microphase separated non‐conductive phase (oil phase) and conductive phase (water phase) lead to structured conductive microchannels of water phase, providing the high resistive sensitivity (gauge factor > 50), superior than many reported flexible sensors. Interestingly, the sensory behaviors of BHs are drastically varied around body temperature due to the melting point of oil phases (eicosane, 36.8°C), making BH sensors highly suitable to monitor human bodily motions. The BH sensors are able to discern a series of subtle writings via resistive change attributed by the asymmetric deformation in soft microchannels from microphase separation. In this work, the BH sensors are successfully utilized to discern bodily motions, voice and writings around body temperature.
Growth of InPBi on InP(311)B Substrate by Molecular Beam Epitaxy
Authors: Akahane Kouichi , Matsumoto Atsushi , Umezawa Toshimasa , Tominaga Yoriko , Yamamoto Naokatsu
Published: October 2021

The growth of InPBi by molecular beam epitaxy on an InP(311)B substrate is investigated. Bi atoms are incorporated into the samples grown at or below 350 °C. A Bi concentration of up to 5% is estimated by X‐ray diffraction and secondary mass spectroscopy measurements. Although the surface roughness increased with decreasing growth temperature and at a high Bi flux, Bi atoms are found to have surfactant effects on the surface flatness of the samples grown at a low Bi flux.
An Enhanced Charge Carrier Separation in a Heterojunction Solar Cell with a Metal Oxide
Authors: Danilyuk A. L. , Sidorova T. N. , Borisenko V. E. , Wang Hong , Rusli Rusli , Lu Chenjin
Published: October 2021

A model of charge carrier transport in heterojunction solar cells composed of a solar light‐absorbing semiconductor and a wide‐bandgap semiconducting metal oxide is proposed. It describes an electric field in the semiconductor originating from the difference in the electron work functions between the two contacting materials, an enhanced hole separation by this field, and subsequent trap‐assisted tunneling of holes through the semiconducting oxide. The model predicts a dramatic influence of the donor concentration in the semiconductor, trap parameters in the oxide, and ideality factor of the semiconductor/oxide heterojunction on the performance of the cell. The efficiency of the solar energy harvesting by MoOx/n‐Si solar cells is calculated to reach 23% of the donor concentration in Si of 1018 cm−3at a limited hole current density. It is predicted to be reduced to 16−18% when donor concentration is in the range of 1015−1016 cm−3. The numerical predictions agree well with experimental data, at least for donor concentrations in Si below 1018 cm−3, confirming suitability of the model for heterojunction solar cells composed of other semiconductors and semiconducting metal oxides.
The Effect of Pull Speed and Heat Treatment on Thermal Donors in Czhocralski Silicon
Authors: Olsen Espen , Mehl Torbjørn , Stalheim Helene Eikaas , Juel Mari , Søndenå Rune , Burud Ingunn
Published: October 2021

In silicon crystals manufactured by the Czochralski method, oxygen is incorporated as a contaminant originating primarily from dissolution of the quartz crucible used to contain the molten silicon feedstock. The oxygen can be found either as interstitials, agglomerates, or as oxide particles. Particular kinds of agglomerates are known to lead to the formation of thermal donors—electronic states in the bandgap of the silicon base material. These can act as sites for recombination of excited charge carriers and are called thermal donors due to their ability to inject two electrons into the conduction band of silicon by thermal excitation, leading to enhanced electrical conductivity. Neither of these features are desirable in Cz‐Si manufacture. Herein, the behavior of thermal donors as a function of the pull speed, and the position in the ingot, is investigated. Thermal treatment is provided, first for the formation of thermal donors and then for their removal. The aim is to investigate methods for minimalizing their incorporation in the crystal in the first place and then how they can be removed. Hyperspectral imaging and spectroscopy combined with Fourier‐transform infrared spectroscopy are used.
Ballistic Injection Terahertz Plasma Instability in Graphene n+–i–n–n+ Field‐Effect Transistors and Lateral Diodes
Authors: Ryzhii Victor , Ryzhii Maxim , Satou Akira , Mitin Vladimir , Shur Michael S. , Otsuji Taiichi
Published: October 2021

The operation of the graphene n+–i–n–n+ field‐effect transistors (GFETs) and lateral diodes (GLDs) with the injection of ballistic electrons into the n‐region is analyzed. The momentum transfer of the injected ballistic electrons can lead to an effective Coulomb drag of the quasiequilibrium electrons in the n‐region and the plasma instability in the GFETs and GLDs. The instability enables the generation of terahertz radiation. The obtained results can be used for the optimization of the structures under consideration for different devices, in particular, terahertz emitters.
Preparation and performance of (Co, Mn)3O4 spinel coating on Crofer alloy by composite electrodeposition and step‐heating thermal conversion
Authors: Ma Zhang‐Bo , Zhang Yuan‐Shuo , Zhang Hao , Zhang Min‐Gang , Li Yong‐Tang , Yang Wen
Published: October 2021

The preparation and performance improvement of the spinel coating on the surface of ferritic alloy is of wide interest for its application in the metallic interconnects of the solid oxide fuel cells (SOFCs). The CoMn2O3 composite coating is prepared on the surface of the Crofer alloy by the composite electrodeposition method. A step‐heating thermal conversion process is subsequently used to convert the composite coating into a spinel coating, while a direct‐heating process is implemented as the control experiment. Isothermal oxidation tests are then carried out for the prepared samples in order to present the high temperature performance. Scanning electron microscopy (SEM), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), and area‐specific resistance (ASR) are used to analyze the properties of the matrix and coatings. The experimental results reveal that the coatings by step‐heating thermal conversion exhibit better performance of electrical conductivity and oxidation resistance than the coatings by direct‐heating process. Furthermore, with the increase of oxidation time, the atomic proportion of Cr element diffusing to the surface of the matrix is maintained at about 3%–4% for the samples with spinel coatings by step heating, which effectively prevent the Cr volatilization in the matrix. The preparation of spinel coatings on the ferritic alloy by composite electrodeposition and step‐heating thermal conversion is helpful to stimulate new ideas for the development of reliable and cost‐effective metallic interconnect.
Muscle Fatigue Sensor Based on Ti3C2Tx MXene Hydrogel
Authors: Lee Kang Hyuck , Zhang Yi‐Zhou , Kim Hyunho , Lei Yongjiu , Hong Seunghyun , Wustoni Shofarul , Hama Adel , Inal Sahika , Alshareef Husam N.
Published: October 2021

MXene‐based hydrogels have received significant attention due to several promising properties that distinguish them from conventional hydrogels. In this study, it is shown that both strain and pH level can be exploited to tune the electronic and ionic transport in MXene‐based hydrogel (M‐hydrogel), which consists of MXene (Ti3C2Tx)‐polyacrylic acid/polyvinyl alcohol hydrogel. In particular, the strain applied to the M‐hydrogel changes MXene sheet orientation which leads to modulation of ionic transport within the M‐hydrogel, due to strain‐induced orientation of the surface charge‐guided ionic pathway. Simultaneously, the reorientation of MXene sheets under the axial strain increases the electronic resistance of the M‐hydrogel due to the loss of the percolative network of conductive MXene sheets during the stretching process. The iontronic characteristics of the M‐hydrogel can thus be tuned by strain and pH, which allows using the M‐hydrogel as a muscle fatigue sensor during exercise. A fully functional M‐hydrogel is developed for real‐time measurement of muscle fatigue during exercise and coupled it to a smartphone to provide a portable or wearable digital readout. This concept can be extended to other fields that require accurate analysis of constantly changing physical and chemical conditions, such as physiological changes in the human body.