bluuebunny/crossref_metadata_2025 huggingface dataset:
Mothers' Movements: Shifts in Calving Area Selection by Partially Migratory Elk
Authors: Berg Jodi E. , Reimer Jody , Smolko Peter , Bohm Holger , Hebblewhite Mark , Merrill Evelyn H.
Published: July 2021

Loss of migratory behavior or shifts in migratory ranges are growing concerns to wildlife managers. How ungulates prioritize safety from predators at the expense of high‐quality foraging opportunities during calving may be key to understanding these shifts and long‐term reproductive success. We compared trade‐offs in selection for forage and predation risk by elk (Cervus canadensis) following 3 migratory tactics (western and eastern migration and resident) during 2 time periods in a declining (by almost 70% from 2002–2016), partially migratory elk population adjacent to Banff National Park in Alberta, Canada. We hypothesized that regardless of migratory tactic, maternal elk would show stronger trade‐offs between high‐quality foraging associated with higher predation risk and forage resources of lower‐quality yet lower risk on calving ranges than on ranges used during summer because of vulnerability of their offspring. Additionally, we hypothesized these trade‐offs would occur at high (2002–2006) and low (2013–2016) elk population sizes. We used a machine‐learning algorithm to predict dates of parturition based on global positioning system (GPS) movements of elk equipped with vaginal implants (n = 60) and predictions were within 1.43 ± 0.85 (SE) days of the known date. We applied the model to an additional 58 GPS‐collared elk without vaginal implants. Based on changes in localized movements, we defined calving areas as the 26 days post‐parturition and compared habitat characteristics of calving areas to 10 similar‐sized areas centered on random locations during summer for the same individual in a latent selection framework. Across the 2 time periods, parturition occurred from 8 May–11 July with median parturition dates differing among migratory tactics and residents shifting towards an earlier parturition date in the later period. All elk, regardless of migratory tactic and time period, selected calving areas with greater forage resources than were available on areas used during summer, with no evidence for greater selection of areas that reduced predation risk at the expense of higher‐quality foraging. Calving season selection for areas with abundant forage exposed western migrants to high risk of bear (Ursusspp.) predation, residents to high risk of wolf (Canis lupus) predation, and eastern migrants to low risk of bear and wolf predation. Patterns in exposure to predation risk during calving between migratory tactics were consistent with the recent decline in western migrants and increase in eastern migrants, implying that conditions on calving areas contributed to observed changes in the number of elk following these tactics. © 2021 The Wildlife Society.
Silicon accumulation by Phragmites australis positively responds to rise in groundwater depth in the desert oasis areas of the HeXi Corridor, China
Authors: Kang Jianjun , Zhao Wen Zhi , Zhang Cai Xia , Wang Zhiwei , Li Hong
Published: July 2021

Our study investigated the characteristics of Phragmites australis (Gramineae) silicon (Si) accumulation, and the response relationship between P. australis Si accumulation and groundwater depth changes. Plants were dug out and taken back to the laboratory for Si accumulation analysis, and a supplementary survey of P. australis Si accumulation was conducted among different groundwater depths. Result showed that Si absorbed and accumulated by P. australis mainly came from the soil and the Si accumulation differed significantly in tissues and growth stages, and the total Si accumulations (withering stage) of P. australis in sand dune (SD), desert steppe (DT), interdune lowland (IL), saline meadow (SM), and wetland (W) habitats were 7.09%, 6.77%, 5.72%, 7.73%, and 8.12%, respectively. More importantly, P. australis Si accumulation was almost equal to the total accumulation of nitrogen, phosphorus, and potassium, and even higher than of the total accumulation of calcium, magnesium, and sulfur. P. australis Si accumulation (withering stage) reduced first from SD to DT habitat, and then increased remarkably from DT to W habitat with a significant increase of −23.95% and 41.96%, respectively. P. australis Si accumulation positively responds to the groundwater depths, and the relationship was an increasing linear function of one variable. Our findings suggested that accumulating Si might be one of the effective strategies for P. australis to adapt to adverse habitats, and the Si‐rich characteristic of P. australis was likely to lay a solid theoretical foundation for exploring effective measures to restore and reconstruct the degraded ecosystems in desert oasis areas.
Effects of percutaneous injection laryngoplasty on voice and swallowing problems in cancer‐related unilateral vocal cord paralysis
Authors: Kang Min‐Gu , Seo Han Gil , Chung Eun‐Jae , Lee Hyun Haeng , Yun Seo Jung , Keam Bhumsuk , Kim Tae Min , Kwon Seong Keun , Oh Byung‐Mo
Published: July 2021

Background

Unilateral vocal cord paralysis may result from nerve compression by tumors or direct nerve injuries during tumor resections, which can cause dysphonia or dysphagia, and reduced quality of life.

Objectives

This prospective, single‐group study aimed to investigate the effect of percutaneous injection laryngoplasty on voice and swallowing function in patients with cancer‐related unilateral vocal cord paralysis.

Methods

Patients underwent percutaneous injection laryngoplasty with hyaluronic acid under local anesthesia. Stroboscopy and videofluoroscopic swallowing study were conducted to evaluate the voice‐ and swallowing‐related outcome measures, respectively. The participants were evaluated before injection laryngoplasty, as well as after two weeks and three months.

Results

Injection laryngoplasty significantly improved the glottal gap, vocal fold position, Maximum Phonation Time, and Voice Handicap Index‐10. Post‐hoc analysis using Bonferroni correction showed that the improvements occurred within two post‐treatment weeks and remained at three post‐treatment months. In the subgroup analysis, the patients who underwent injection laryngoplasty within 8 weeks from onset showed significantly higher improvements in the videofluoroscopic dysphagia scale and swallowing function than the patients who received the procedure after 8 weeks or more.

Conclusion

Percutaneous injection laryngoplasty improves glottal closure and voice in patients with cancer‐related unilateral vocal cord paralysis. Early injection laryngoplasty may lead to greater benefits on swallowing function.

Level of Evidence

4.
Light Confinement by Local Index Tailoring in Inhomogeneous Dielectrics
Authors: Krešić I. , Makris K. G. , Rotter S.
Published: July 2021

The engineering of light confinement is a topic with a long history in optics and with significant implications for the control of light‐matter interaction. In inhomogeneous and disordered media, however, multiple scattering prevents the application of conventional approaches for the design of light fields with desired properties. This is because any local change to such a medium typically affects these fields in a non‐local and complicated fashion. Here, we present a theoretical methodology for tailoring an inhomogeneous 1D Hermitian dielectric index distribution that allows us to control the intensity profile of an incoming light field purely locally, that is, with little or no influence on the field profile outside of a designated region of interest. Strongly increasing or decreasing the light's intensity at arbitrary positions inside the medium thereby becomes possible without, in fact, changing the external reflectance or transmittance. These local modifications of the medium can thus be made undetectable to far field measurements. We apply this approach to locally control the confinement of light inside 1D materials with inhomogeneous continuous refractive index profiles and extend it to multilayer films as well as to chains of coupled micro‐resonators.
PVA‐Based Hydrogels: Promising Candidates for Articular Cartilage Repair
Authors: Chen Yuru , Song Jian , Wang Song , Liu Weiqiang
Published: July 2021

The complex, gradient physiological structure of articular cartilage is a severe hindrance of its self‐repair, leaving the clinical treatment of cartilage defects a demanding issue to be addressed. Currently applied tissue engineering treatments and traditional non‐tissue engineering treatments have different limitations, for example, cell dedifferentiation, immune rejection, and prosthesis‐related complications. Thus, studies have been focusing on seeking promising candidates for novel cartilage repair methods. Polyvinyl alcohol (PVA) hydrogels with excellent biocompatibility and tunable material properties have become the alternatives. For pure PVA hydrogels, the mechanical strength and lubricity are not capable of replacing articular cartilage until proper modifications are done. This paper summarizes the research progress in PVA hydrogels, including the preparation, modification, and cartilage‐repair‐aimed biomimetic improvements. Design guidance of PVA hydrogels is put forward as assistance to functional hydrogel preparation. Finally, the prospects and main obstacles of PVA hydrogels are discussed.
Emerging economies openness and efficiency
Authors: Bai Min , Bai Feng , Qin Yafeng
Published: July 2021

The objective of this study is to examine the impact of economic openness on the efficiency of 25 emerging stock markets. By employing two measures of market efficiency, variance ratios with different time lags and short‐run reversal returns, we find that in majority of the emerging markets in our sample, there is strong evidence to show that the market efficiency improves with market openness. This effect is robust and stronger when we measure variance ratio with longer horizons. When using the reversal returns to measure efficiency, the results are weaker. However, there is no evidence showing that liberalization of the market would impede the market efficiency. The overall results suggest that market openness reduces a stock price's departure from a random walk.
Effects of Hesperidin Consumption on the Cardiovascular System in Pre‐ and Stage 1 Hypertensive Subjects: Targeted and Non‐Targeted Metabolomic Approaches (CITRUS Study)
Authors: Pla‐Pagà L. , Pedret A. , Valls R. M. , Calderón‐Pérez L. , Llauradó E. , Companys J. , Martín‐Luján F. , Moragas A. , Canela N. , Puiggròs F. , Caimari A. , del Bas J. M. , Arola L. , Solà R. , Mayneris‐Perxachs J.
Published: July 2021

Scope

The aim of the present work is to determine new biomarkers of the biological effects of hesperidin in orange juice (OJ) applying a non‐targeted metabolomics approach validated by targeted metabolomics analyses of compliance biomarkers.

Methods and Results

Plasma/serum and urine targeted (HPLC‐MS/MS) and untargeted (1H‐NMR) metabolomics signatures are explored in a subsample with pre‐ and stage‐1 hypertension subjects of the CITRUS study (N = 159). Volunteers received 500 mL day−1 of control drink, OJ, or hesperidin‐enriched OJ (EOJ) for 12‐weeks. A 6‐h postprandrial study is performed at baseline. Targeted analyses reveals plasma and urine hesperetin 7‐O‐β‐d‐glucuronide as the only metabolite differing between OJ and EOJ groups after 12‐weeks consumption, and in urine is correlated with a decreased systolic blood pressure level. The non‐targeted approach shows that after single dose and 12‐weeks consumption of OJ and EOJ change several metabolites related with an anti‐inflammatory and antioxidant actions, lower blood pressure levels and uremic toxins.

Conclusions

Hesperetin 7‐O‐β‐d‐glucuronide can be a candidate marker for distinguishing between the consumption of different hesperidin doses at 12‐weeks consumption as well as a potential agent mediating blood pressure reduction. Moreover, changes in different endogenous metabolites can explain the mechanisms of action and the biological effects of hesperidin consumption.
Rectangular‐cavity‐like feed for radiation of phase gradient metasurface
Authors: Yu Xinhua , Sun Guiyu , Wan Jianfeng , Wu Xianxi , Mo Jinjun , Jiang Yannan , Wang Yiying
Published: July 2021

In this letter, a rectangular‐cavity‐like structure is proposed to feed the phase gradient metasurface (PGM), where two symmetrical long slots are cut on side walls along wave propagation direction of the rectangular waveguide cavity resonator. It consists of rectangular waveguide, transition section, slotted‐waveguide feed section, and shorted end of the cavity. The PGMs are placed in the slotted‐waveguide section and the slot is wide enough to accommodate PGMs. The antenna prototype is fabricated and measured whose measurements agree well with simulations in 7.8–11.0GHz.
Quantification of airway dimensions using a high‐resolution CT scanner: A phantom study
Authors: Zhao Yixiao , Hernandez Andrew M. , Boone John M. , Molloi Sabee
Published: July 2021

Purpose

Small airways with inner diameters less than 2 mm are sites of major airflow limitations in patients with chronic obstructive pulmonary disease (COPD) and asthma. The purpose of this study is to investigate the limitations for accurate assessment of small airway dimensions using both high‐resolution CT (HRCT) and conventional normal‐resolution CT at low dose levels.

Methods

To model the normal human airways from the 3rd to 20th generations, a cylindrical polyurethane phantom with 14 airway tubes of inner diameters (ID) ranging from 0.3 to 3.4 mm and wall thicknesses (WT) ranging from 0.15 to 1.6 mm was placed within an Anthropomorphic QRM‐Thorax phantom. The Aquilion Precision (Canon Medical Systems Corporation) HRCT scanner was used to acquire images at 80, 100, and 120 kV using high resolution mode (HR, 0.25 mm × 160 detector configuration) and normal‐resolution (NR) mode (0.5 mm × 80 detector configuration). The HR data were reconstructed using a 1024 × 1024 matrix (0.22 × 0.22 × 0.25 mm voxel size) and the NR data were reconstructed using a 512 × 512 matrix (0.43 × 0.43 × 0.50 mm). Two reconstruction algorithms (filtered back projection; FBP and an adaptive iterative dose reduction 3D algorithm; AIDR 3D) and three reconstruction kernels (FC30, FC52, and FC56) were investigated. Thedose values ranged from 0.2 to 6.2 mGy. A refined automated full‐width half‐maximum (FWHM) method was used for the measurement of airway dimensions, where the density profiles were computed by radial oversampling using a polar coordinate system. Both ID and WT were compared to the known dimensions using a regression model, and the root‐mean‐square error (RMSE) and average error were computed across all 14 airway tubes.

Results

The results indicate that the ID can be measured within a 15% error down to approximately 0.8 and 2.0 mm using the HR and NR modes, respectively. The overall RMSE (and average error) of ID measurements for HR and NR were 0.10 mm (−0.70%) and 0.31 mm (−2.63%), respectively. The RMSE (and average error) of WT measurements using HR and NR were 0.10 mm (23.27%) and 0.27 mm (53.56%), respectively. The WT measurement using HR yielded a factor of two improvement in accuracy as compared to NR.

Conclusions

High‐resolution CT can provide more accurate measurements of airway dimensions as compared with NR CT, potentially improving quantitative assessment of pathologies such as COPD and asthma. The HR mode acquired and reconstructed with AIDR3D and the FC52 kernel provides most accurate measurement of airway dimensions. Low‐dose HR measurements at dose level above 0.9 mGy can provide improved accuracy on both inner diameters and wall thicknesses compared to full dose NR airway phantom measurements.
Selenate—An internal chemical shift standard for aqueous 77Se NMR spectroscopy
Authors: Pálla Tamás , Herbath Laura , Mazák Károly , Mirzahosseini Arash , Noszál Béla
Published: July 2021

The 77Se NMR spectra of selenate were studied under various circumstances, such as concentration, pH, temperature, ionic strength, and D2O:H2O ratio, in order to examine its potential as a water‐soluble internal chemical shift standard. The performance of selenate as a chemical shift reference and that of other attempted ones from the literature (dimethyl selenide, tetramethylsilane/TMS, and 3‐(trimethylsilyl)propane‐1‐sulfonate/DSS) was also explored. The uncertainty in the resulting chemical shift relative to the effective spectral width is comparable to that of DSS. Compared to the currently prevalent water‐soluble external chemical shift reference, selenic acid solution, the properties of internal selenate are much more favorable in terms of ease of use. We have also demonstrated that selenate can be used in reducing media, which is inevitable for the analysis of selenol compounds. Thus, it can be stated that sodium selenate is a robust internal chemical shift reference in aqueous media for 77Se NMR measurements; the chemical shift of this reference in a solution containing 5 V/V% D2O at 25°C and 0.15 mol·dm−3 ionic strength is 1048.65 ppm relative to 60 V/V% dimethyl selenide in CDCl3 and 1046.40 ppm relative to the 1H signal of 0.03 V/V% TMS in CDCl3. In summary, a water‐soluble, selenium‐containing internal chemical shift reference compound was introduced for 77Se NMR measurements for the first time in the literature, and with the aforementioned results all previous 77Se measurements can be converted to a unified scale defined by the International Union of Pure and Applied Chemistry.
Displacement current distribution on a high dielectric constant helmet and its effect on RF field at 10.5 T (447 MHz)
Authors: Gandji Navid P. , Sica Christopher T. , Lanagan Michael T. , Woo Myung‐Kyun , DelaBarre Lance , Radder Jerahmie , Zhang Bei , Lattanzi Riccardo , Adriany Gregor , Ugurbil Kamil , Yang Qing X.
Published: July 2021

Purpose

Investigating the designs and effects of high dielectric constant (HDC) materials in the shape of a conformal helmet on the enhancement of RF field and reduction of specific absorption rate at 10.5 T for human brain studies.

Methods

A continuous and a segmented four‐piece HDC helmet fit to a human head inside an eight‐channel fractionated‐dipole array were constructed and studied with a phantom and a human head model using computer electromagnetic simulations. The simulated transmit efficiency and receive sensitivity were experimentally validated using a phantom with identical electric properties and helmet‐coil configurations of the computer model. The temporal and spatial distributions of displacement currents on the HDC helmets were analyzed.

Results

Using the continuous HDC helmet, simulation results in the human head model demonstrated an average transmit efficiency enhancement of 66%. A propagating displacement current was induced on the continuous helmet, leading to an inhomogeneous RF field enhancement in the brain. Using the segmented four‐piece helmet design to reduce this effect, an average 55% and 57% enhancement in the transmit efficiency and SNR was achieved in human head, respectively, along with 8% and 28% reductions in average and maximum local specific absorption rate.

Conclusion

The HDC helmets enhanced the transmit efficiency and SNR of the dipole array coil in the human head at 10.5 T. The segmentation of the helmet to disrupt the continuity of circumscribing displacement currents in the helmet produced a more uniform distribution of the transmit field and lower specific absorption rate in the human head compared with the continuous helmet design.
The PHU‐NET: A robust phase unwrapping method for MRI based on deep learning
Authors: Zhou Hongyu , Cheng Chuanli , Peng Hao , Liang Dong , Liu Xin , Zheng Hairong , Zou Chao
Published: July 2021

Purpose

This work was aimed at designing a deep‐learning‐based approach for MR image phase unwrapping to improve the robustness and efficiency of traditional methods.

Methods

A deep learning network called PHU‐NET was designed for MR phase unwrapping. In this network, a novel training data generation method was proposed to simulate the wrapping patterns in MR phase images. The wrapping boundary and wrapping counts were explicitly estimated and used for network training. The proposed method was quantitatively evaluated and compared to other methods using a number of simulated datasets with varying signal‐to‐noise ratio (SNR) and MR phase images from various parts of the human body.

Results

The results showed that our method performed better in the simulated data even under an extremely low SNR. The proposed method had less residual wrapping in the images from various parts of human body and worked well in the presence of severe anatomical discontinuity. Our method was also advantageous in terms of computational efficiency compared to the traditional methods.

Conclusion

This work proposed a robust and computationally efficient MR phase unwrapping method based on a deep learning network, which has promising performance in applications using MR phase information.
Hyperpolarized 129Xe multi‐slice imaging of the human brain using a 3D gradient echo pulse sequence
Authors: Grynko Vira , Shepelytskyi Yurii , Li Tao , Hassan Ayman , Granberg Karl , Albert Mitchell S.
Published: July 2021

Purpose

To demonstrate the possibility of performing multi‐slice in‐vivo human brain MRI using hyperpolarized (HP) xenon‐129 (129Xe) in two different orientations and to calculate the signal‐to‐noise ratio (SNR).

Methods

Two healthy female participants were imaged during a single breath‐hold of HP 129Xe using a Philips Achieva 3.0T MRI scanner (Philips, Andover, MA). Each HP 129Xe multi‐slice brain image was acquired during separate HP 129Xe breath‐holds using 3D gradient echo (GRE) imaging. The acquisition started 10 s after the inhalation of 1 L of HP 129Xe. Overall, four sagittal and three axial images were acquired (seven imaging sessions per participant). The SNR was calculated for each slice in both orientations.

Results

The first ever HP 129Xe multi‐slice images of the brain were acquired in axial and sagittal orientations. The HP 129Xe signal distribution correlated well with the gray matter distribution. The highest SNR values were close in the axial and sagittal orientations (19.46 ± 3.25 and 18.76 ± 4.94, respectively). Additionally, anatomical features, such as the ventricles, were observed in both orientations.

Conclusion

The possibility of using multi‐slice HP 129Xe human brain magnetic resonance imaging was demonstrated for the first time. HP 129Xe multi‐slice MRI can be implemented for brain imaging to improve current diagnostic methods.
Development of a spiral spin‐ and gradient‐echo (spiral‐SAGE) approach for improved multi‐parametric dynamic contrast neuroimaging
Authors: Stokes Ashley M. , Ragunathan Sudarshan , Robison Ryan K. , Fuentes Alberto , Bell Laura C. , Karis John P. , Pipe James G. , Quarles C. Chad
Published: July 2021

Purpose

The purpose of this study was to develop a spiral‐based combined spin‐ and gradient‐echo (spiral‐SAGE) method for simultaneous dynamic contrast‐enhanced (DCE‐MRI) and dynamic susceptibility contrast MRI (DSC‐MRI).

Methods

Using this sequence, we obtained gradient‐echo TEs of 1.69 and 26 ms, a SE TE of 87.72 ms, with a TR of 1663 ms. Using an iterative SENSE reconstruction followed by deblurring, spiral‐induced image artifacts were minimized. Healthy volunteer images are shown to demonstrate image quality using the optimized reconstruction, as well as for comparison with EPI‐based SAGE. A bioreactor phantom was used to compare dynamic‐contrast time courses with both spiral‐SAGE and EPI‐SAGE. A proof‐of‐concept cohort of patients with brain tumors shows the range of hemodynamic maps available using spiral‐SAGE.

Results

Comparison of spiral‐SAGE images with conventional EPI‐SAGE images illustrates substantial reductions of image distortion and artifactual image intensity variations. Bioreactor phantom data show similar dynamic contrast time courses between standard EPI‐SAGE and spiral‐SAGE for the second and third echoes, whereas first‐echo data show improvements in quantifying T1 changes with shorter echo times. In a cohort of patients with brain tumors, spiral‐SAGE–based perfusion and permeability maps are shown with comparison with the standard single‐echo EPI perfusion map.

Conclusion

Spiral‐SAGE provides a substantial improvement for the assessment of perfusion and permeability by mitigating artifacts typically encountered with EPI and by providing a shorter echo time for improved characterization of permeability. Spiral‐SAGE enables quantification of perfusion, permeability, and vessel architectural parameters, as demonstrated in brain tumors.
First Evidence of the Efficacy of Extensive Culture of Longfin Dace as a Replacement for Nonnative Baitfish in the Southwestern United States
Authors: Oliver Devon C. , Loubere Alexander D. , Mann Ryan D.
Published: July 2021

The production, distribution, and sale of live baitfish represent a multimillion dollar industry in the United States. However, production is often limited by the feasibility of culture and few species are profitable. In turn, distribution often occurs well outside of a profitable species’ natural range. Beyond the concern of nonnative species introductions, live baitfish can introduce or spread diseases, resulting in negative ecological consequences. As a result, Arizona Game and Fish Department (AZGFD) wanted to evaluate the feasibility of using a species native to Arizona and southwestern North America that is abundant with a wide regional distribution to meet current commercial needs for small-bodied baitfish in Arizona. An internal AZGFD team had identified Longfin Dace Agosia chrysogaster as a potential candidate baitfish species due to its low conservation threat, wide distribution in Arizona, and optimal body size (i.e., similar to that of current nonnative baitfish). The goal of this study was to provide a proof-of-concept of Longfin Dace culture to meet current small-bodied baitfish needs in Arizona. To meet this goal, we investigated the efficacy of extensive pond culture of Longfin Dace during 2017–2019 as an option for the replacement of nonnative baitfish. Extensive culture of Longfin Dace resulted in a 21–23-fold population increase over the course of a year in 2018. Additionally, based on length-frequency distributions, multiple generations were produced in one year. We conclude that the propagation of Longfin Dace via pond culture to replace nonnative, small-bodied baitfish is potentially viable. However, the lack of information on carrying capacity and optimized pond characteristics for the pond culture of Longfin Dace should be addressed in the future.
Spherical cavity expansion in porous rock considering plasticity and damage
Authors: Huang Linchong , Liang Jiguan , Ma Jianjun , Yang Hongwei , Gui Yilin
Published: July 2021

In rock engineering, damage evolution upon loading imposes significant impacts on the stiffness of rock mass and its deformation characteristics. In order to investigate the influence of both damage and plasticity on cavity expansion, a plastic damage solution is derived for undrained spherical cavity expansion in rock medium. For the consideration of plasticity‐damage, Modified Cam‐Clay (MCC) model is selected as the plasticity driver, a damage evolution criterion is adopted and coupled with MCC. The coupled damage MCC model is validated against experimental data in the literature. The proposed cavity expansion solution with the consideration of plasticity damage is verified through a classic solution in literature. The role of damage in undrained spherical cavity expansion is investigated by studying the spatial variations of effective stress, pore pressure and damage for cases with different stress ratios. Distribution of cavity expansion induced plastic and damage zones for cases with different stress ratios are also reproduced and discussed. Cavity expansion results show that, the damage zone should be considered for engineering application as the plastic zone is affected due to the damage evolution. In addition, the stability (e.g., radial stress) of rock mass is overestimated in classical solution without the consideration of damage zone.
Investigation of aminolysis routes on PET fabrics using different amine‐based materials
Authors: Lorusso Emanuela , Feng Ying , Schneider Jessica , Kamps Leonie , Parasothy Nirtharsan , Mayer‐Gall Thomas , Gutmann Jochen S. , Ali Wael
Published: July 2021

In this study, functionalization of PET fabrics with amino groups was achieved by aminolysis. Aminolysis routes were explored using different amine‐based materials including ethylenediamine (EDA), triaminotriethylamine (TAEA) and (3‐aminopropyl)trimethoxysilane (APTMS), (3‐trimethoxy‐silylpropyl)diethylentriamine (TRIAMO) in addition to amino‐functionalized silica nanoparticles as amino‐silane based reagents. The samples were deeply characterized by SEM, AFM, and XPS. Abrasion and tensile tests were carried out to evaluate the mechanical properties of the modified fabrics. Results showed that aminolysis conducted with EDA and TAEA as amino based reagents lower the performances of PET, while dense coatings can be deposited on the fibres by amino silane‐based reagents that act as protective layers. APTMS modified PET presented improved abrasion resistance compared to the native PET. The antibacterial activity of the PET surfaces functionalized with the different amino groups was also evaluated using the gram‐negative bacterium A. fischeri antibacterial assay. The results showed improved antibacterial performances of the native textile treated with APTMS and TAEA based reagents.
Preparation of electrosprayed composite coated microporous filter for particulate matter capture
Authors: Peng Qingyan , Yang Kai , Venkataraman Mohanapriya , Tan Xiaodong , Xiong Xiaoman , Novotna Jana , Karpiskova Jana , Hruza Jakub , Stuchlík Martin , Militky Jiri
Published: July 2021

Particulate matter 2.5 (PM 2.5.) pollution is a serious threat to human health. In this paper, we firstly used electrospraying technology to fabricate composite polytetrafluoroethylene (PTFE)/expanded graphite (EG) coated spun‐bond polypropylene (PP) microporous filters that show tremendous potential for its use as an effective PM 2.5. capture medium. The surface morphology, the surface area, the surficial chemical structure, the hydrophobicity, the antifouling ability, the mechanical property, the air permeability, and the filtration efficiency (FE) of the prepared composite PTFE/EG coated microporous filters were investigated. It is found that with the increase of EG content, the surface area of the filter tended to increase, and the pore size decreased correspondingly. Physical adhesion between the PTFE or PTFE/EG and the PP fabric is found. The composite PTFE/EG coated spun‐bond PP microporous filter exhibits an excellent hydrophobicity and antifouling ability. Compared with the original spun bond PP, the FE of the composite PTFE/EG coated spun bond PP microporous filter for PM 2.5. is significantly increased from 52.18% to 85.00%, and the quality factor (QF) increases from 0.0238 to 0.0431. These results indicate that the composite PTFE/EG coated spun‐bond PP microporous filter is an excellent material for PM 2.5. capture.
Additive ram material extrusion and diddling of fully compounded thermoset nitrile rubber
Authors: Kazmer David O. , Kodra Stiven , Mubasshir Abdullah A. , Keaney Erin E. , Mead Joey L.
Published: July 2021

A ram extruder is described for high‐pressure extrusion of fully compounded thermoset rubber to achieve additive manufacturing. The extruder uses a piston driven by a geared stepper motor to provide volumetric displacement of the rubber charge residing in a temperature‐controlled barrel. Along with activators, accelerators, and a vulcanizing agent, the rubber compound is a formulation of 30 parts carbon black per hundred parts nitrile rubber. Sets of serpentine patterns are printed in parallel and transverse orientations relative to the load direction. From printing to post‐cure, the printed specimens exhibited linear shrinkage of 65% in the print direction. Although printed samples had relatively low void content compared with typical additively manufactured parts by material extrusion, significant decreases in the tensile properties were observed relative to compression‐molded specimens of the same rubber compound. The mean strain to failure was observed as 462% for compression‐molded samples, compared with 347% and 183% for printed specimens with parallel and transverse orientations. To reduce the shrinkage and increase the interfacial area between extruded roads, backstitch and sinewave diddling patterns were implemented to superimpose oscillatory motions along the print path with a periodicity of 1 mm. The specimens printed with the diddling patterns were observed to provide less shrinkage and improved properties compared to the regular serpentine patterns. The mean strain to failure in the transverse orientation, respectively, increased to 218% and 265% for the backstitch and sinewave patterns. Suggested future research is discussed, and the diddling program is provided in the appendix.
Crashworthiness analysis and multi‐objective optimization of Al/CFRP tubes with induced holes
Authors: Shun Wang , Qi‐hua Ma , Xue‐hui Gan , Tian‐jun Zhou
Published: July 2021

Reasonable design of induced holes on thin‐walled structure is beneficial to enhance the crashworthy performance of the structure. In order to improve the crashworthiness of Al/carbon fiber‐reinforced polymer (CFRP) tube, the effect of induced holes on the Al/CFRP thin‐walled structure was studied, and the Al/CFRP tube configuration with better overall crashworthiness was obtained by multi‐objective optimization design method. First, the quasi‐static axial compression tests were carried out on the intact Al/CFRP tube and the Al/CFRP tube with induced holes, and a numerical model validated by the experiment was established. Second, the parameters of the induced hole were studied numerically to explore the influence of the induced holes on the crashworthiness of the Al/CFRP tube. It was found that the diameter and number of the induced hole had a great influence on the crashworthiness and energy absorption (EA) capacity. Finally, the multi‐objective optimization was performed to optimize the parameters of the induced holes by integrating the Kriging model technique and the nondominated sorting genetic algorithm (NSGA‐II). Compared the optimal design with the intact Al/CFRP tube, the first peak load is reduced by 24.32% and the specific EA is slightly improved by 0.68%.
Effect of pendant groups on the blood compatibility and hydration states of poly(2‐oxazoline)s
Authors: Liu Shichen , Kobayashi Shingo , Nishimura Shin‐nosuke , Ueda Tomoya , Tanaka Masaru
Published: July 2021

Poly(2‐methyl‐2‐oxazoline) (PMeOx), poly(2‐ethyl‐2‐oxazoline) (PEtOx), poly(2‐n‐butyl‐2‐oxazoline) (PBuOx), and poly(2‐phenyl‐2‐oxazoline) (PPhOx) are selected as poly(2‐oxazoline) (POX) models to study the effect of pendant groups on their blood compatibility and hydration states. A comprehension of this can provide a perspective for understanding the biocompatibility of PMeOx and PEtOx in water‐polymer interactions and may inspire the development of novel blood‐compatible POX derivatives. The aforementioned four POXs are grafted onto glass substrates via photo‐grafting, and their blood compatibility is estimated via platelet adhesion and the degree of denaturation of the adsorbed fibrinogen. The hydration states of the POXs are investigated using differential scanning calorimetry and attenuated total reflection infrared spectroscopy. Intermediate water is found to be present in hydrated PMeOx and PEtOx, but is observed to be scarce in hydrated PBuOx and PPhOx. This could be the reason for the biocompatibility of PMeOx and PEtOx. The carbonyl groups in PMeOx and PEtOx can be fully hydrated. However, in PBuOx and PPhOx, water mainly exists as bulk water. The hydration of the carbonyl groups is hindered by the bulky side chains, and IW cannot be generated.
Geographical barriers to timely diagnosis of cystic fibrosis and anxiety level of parents during newborn screening in Turkey
Authors: Gokdemir Yasemin , Eyuboglu Tuğba Sismanlar , Emiralioglu Nagehan , Er Berrin , Sen Velat , Pekcan Sevgi , Ergenekon Almala Pınar , Hizal Mina Gharibzadeh , Eryilmaz Sanem , Kose Mehmet , Hangul Melih , Cakir Erkan , Cokugras Haluk , Kılınc Ayse Ayzıt , Sasıhuseyinoglu Ayse Senay , Altintas Derya Ufuk , Gulen Figen , Eski Aykut , Bingol Aysen , Ozdemir Ali , Topal Erdem , Gursoy Tugba Ramaslı , Girit Saniye , Ay Pınar , Yılmaz Ozge
Published: July 2021

Background

Despite the availability of cystic fibrosis (CF) screening countrywide, diagnostic delay is still a crucial issue. The objectives of this study were to explore the stages of the NBS process, determine the risk factors associated with diagnostic delay and evaluate parent anxiety and experience throughout the process.

Methods

This is a multicenter cross‐sectional study. A questionnaire was completed by parents of newborns diagnosed with CF via NBS in 17 centers. Socio‐demographic characteristics, parent knowledge and experiences related to NBS, sweat test availability in the region of residence, and time to the definitive CF diagnosis were assessed through this questionnaire. Parents' anxiety levels were evaluated through the State‐Trait Anxiety Inventory scales 1 and 2. Delayed diagnosis (DD) was defined as a definite CF diagnosis beyond the 8th week of life. Predictors of delayed CF diagnosis were evaluated by univariate and multivariate analysis.

Results

A total of 220 CF patients diagnosed via NBS were enrolled; 82 (37.3%) babies had DD. Multivariable analysis indicated that residence in the Southeast Anatolia region of Turkey (OR = 10.79, 95% CI = 2.37–49.2) was associated with a higher incidence of DD compared with other regions in Turkey. Of the total, 216 (98.1%) of the caregivers regarded the NBS program as useful and 180 (82%) reported high anxiety levels.

Conclusion

The organization of newborn screening should take into account regional and socio‐cultural characteristics to improve the early diagnosis of CF and also reduce the anxiety level of parents.
Inhibitory effect of Zn2+ on the chain‐initiation process of cumene oxidation
Authors: Chen Zhicheng , Li Yuhang , Cao Yonghai , Zhang Qiao , Yu Hao , Peng Feng
Published: July 2021

Carbon nanotubes (CNTs) have excellent catalytic activity in liquid phase reaction, especially in aerobic oxidation of cumene. In previous work, the conversion of cumene was 41.8% and the selectivity of cumene hydroperoxide was 71.5%, which was catalyzed by CNTs. But a small amount of impurity Zn2+ totally blocked up the aerobic oxidation of cumene that catalyzed by CNTs, which is an unexpected discovery. By analyzing the catalytic mechanism of CNTs, the inhibition effect of Zn2+ is locked on the abstraction of H atom from cumene. The inhibition of Zn2+ is confirmed in two effects by density functional theory calculations. First, due to the strongly coordination of active oxygen species (ROS) by Zn2+, the energy barrier of initial reaction increases to 1.90 eV, which is nearly 4 times higher than that of the only ROS promoted‐process. Second, the interaction of Zn2+ and RO· or ROO· to inhibits the chain propagation reaction of free radicals. This work precisely demonstrates that the inhibition effect of Zn2+ on initial reaction of cumene. The most significant thing is that the effect of metallic heteroatoms is not negligible in organic oxidation reaction.
Finitary codings for gradient models and a new graphical representation for the six‐vertex model
Authors: Ray Gourab , Spinka Yinon
Published: July 2021

It is known that the Ising model on at a given temperature is a finitary factor of an i.i.d. process if and only if the temperature is at least the critical temperature. Below the critical temperature, the plus and minus states of the Ising model are distinct and differ from one another by a global flip of the spins. We show that it is only this global information which poses an obstruction to being finitary by showing that the gradient of the Ising model is a finitary factor of i.i.d. at all temperatures. As a consequence, we deduce a volume‐order large deviation estimate for the energy. Results in the same spirit are shown for the Potts model, the so‐called beach model, and the six‐vertex model. We also introduce a coupling between the six‐vertex model with and a new Edwards–Sokal type graphical representation of it, which we believe is of independent interest.
Algebraic and combinatorial expansion in random simplicial complexes
Authors: Fountoulakis Nikolaos , Przykucki Michał
Published: July 2021

In this paper we consider the expansion properties and the spectrum of the combinatorial Laplace operator of a d‐dimensional Linial–Meshulam random simplicial complex, above the cohomological connectivity threshold. We consider the spectral gap of the Laplace operator and the Cheeger constant as this was introduced by Parzanchevski, Rosenthal, and Tessler. We show that with high probability the spectral gap of the random simplicial complex as well as the Cheeger constant are both concentrated around the minimum co‐degree of among all ‐faces. Furthermore, we consider a random walk on such a complex, which generalizes the standard random walk on a graph. We show that the associated conductance is with high probability bounded away from 0, resulting in a bound on the mixing time that is logarithmic in the number of vertices of the complex.
Beyond individual job insecurity: A multilevel examination of job insecurity climate on work engagement and job satisfaction
Authors: Hsieh Hui‐Hsien , Kao Kuo‐Yang
Published: July 2021

To address the recent call for investigations of job insecurity as a collective construct—namely, job insecurity climate—this study developed and tested a multilevel model of consequences of job insecurity climate. Specifically, we examined the association of job insecurity climate with employees' perceived organizational obstruction, which, in turn, relates to their work engagement and job satisfaction. In the current study, cross‐sectional data were collected from a sample of 357 full‐time Taiwanese employees in 42 work units. Using multilevel structural equation modeling analyses to test our hypotheses, we found that job insecurity climate was positively related to employees' perceived organizational obstruction. We also found that job insecurity climate had a negative indirect association with employees' work engagement and job satisfaction through the perceived organizational obstruction. Our results shed light on the relationship between job insecurity climate and employee outcomes beyond individual job insecurity and the psychological mechanism through which job insecurity climate relates to employee work engagement and job satisfaction. Theoretical and practical implications are discussed.
Embedding of Ti3C2TxNanocrystals in MAPbI3Microwires for Improved Responsivity and Detectivity of Photodetector
Authors: Guo Hang , Wang Hongyue , Fan Haibo , Ye Qian , Zhang Jin , Cao Fengren , Li Liang , Tong Yu , Wang Hongqiang
Published: July 2021

Organic–inorganic hybrid MAPbI3microwires show unique optoelectronic properties for high performances of photodetectors (PDs). However, the defects‐assisted nonradiative recombination is harmful for carrier transport, which limits the performances improvement of MAPbI3microwires PDs. Traditional organic passivation agents effectively combine the surface defects of microwires and also reduce the mobility of overall film based on the perovskite microwires. Therefore, the improvement of internal carrier transport of microwires and the mobility of integrated film simultaneously is a particular challenge for fabrication of performances enhanced perovskite microwires PDs. Here, the Ti3C2TxNCs are fabricated by nonfocus laser irradiation in liquid environment, and hybrids the high conductive NCs in the MAPbI3microwires. The presence of Ti3C2TxNCs renders defects passivation, enhancement of crystalline orientation, charge transport, and carrier extraction for MAPbI3microwires, and boots the mobility of microwires based film, leading to about tenfolds enhancement of performances of PDs than that of the control. The maximum responsivity and the detectivity of the Ti3C2TxNCs embedded MAPbI3microwires PDs reach to 1.70 A W−1and 7.0 × 1011Jones in visible window, respectively. The findings suggest that the laser generated high conductive Ti3C2TxNCs is an effective additive for perovskite microwires to fabricate performances enhanced optoelectronics.
Heterogeneous Degradation in Thick Nickel‐Rich Cathodes During High‐Temperature Storage and Mitigation of Thermal Instability by Regulating Cationic Disordering
Authors: Zhang Lihan , Zhao Chenglong , Qin Xianying , Wang Shuwei , He Lunhua , Qian Kun , Han Ting , Yang Zhangping , Kang Feiyu , Li Baohua
Published: July 2021

The thermal instability is a major problem in high‐energy nickel‐rich layered cathode materials for large‐scale battery application. Due to the scarce investigation of thick electrodes at the practical full‐cell level, the understanding of thermal failure mechanism is still insufficient. Herein, an intrinsic origin of thermal instability in fully charged industrial pouch cells during high‐temperature storage is discovered. Through the investigation from crystals to particles, and from electrodes to cells, it is shown that serious top‐down heterogeneous degradation occurs along the depth direction of the thick electrode, including phase transition, cationic disordering, intergranular/intragranular cracks, and side reactions. Such degradation originates from the abundant oxygen vacancies and reduced catalytic Ni2+ at cathode surface, causing microstructural defects and directly leading to the thermal instability. Nonmagnetic elements doping and surface modification are suggested to be effective in mitigating the thermal instability through modulating cationic disordering.
Stochastic actor‐oriented modelling of the impact of COVID‐19 on financial network evolution
Authors: Chu Amanda M.Y. , Chan Lupe S.H. , So Mike K.P.
Published: July 2021

The coronavirus disease 2019 (COVID‐19) pandemic has led to tremendous loss of human life and has severe social and economic impacts worldwide. The spread of the disease has also caused dramatic uncertainty in financial markets, especially in the early stages of the pandemic. In this paper, we adopt the stochastic actor‐oriented model (SAOM) to model dynamic/longitudinal financial networks with the covariates constructed from the network statistics of COVID‐19 dynamic pandemic networks. Our findings provide evidence that the transmission risk of the COVID‐19, measured in the transformed pandemic risk scores, is a main explanatory factor of financial network connectedness from March to May 2020. The pandemic statistics and transformed pandemic risk scores can give early signs of the intense connectedness of the financial markets in mid‐March 2020. We can make use of the SAOM approach to predict possible financial contagion using pandemic network statistics and transformed pandemic risk scores of the COVID‐19 and other pandemics.
Matrix‐variate time series modelling with hidden Markov models
Authors: Asilkalkan Abdullah , Zhu Xuwen
Published: July 2021

In this paper, a hidden Markov model for modelling matrix‐variate time series data is developed. It relies on matrix‐variate distribution and presents a promising alternative to the existing methods. Simulation study is carefully conducted and uses benchmark tests with pre‐specified overlapping values. Compared with the existing methods, the proposed model demonstrates rather high accuracy in state classification. Results suggest that such an approach is indeed competitive. Interesting applications are presented for real‐life data illustration.