bluuebunny/crossref_metadata_2025 huggingface dataset:
Time‐varying effects and structural change of oil price shocks on industrial output: Evidence from China's oil industrial chain
Authors: Chen Jin‐Yu , Zhu Xue‐Hong , Zhong Mei‐Rui
Published: August 2020

Based on the output data of the oil industry chain from February 2006 to June 2017, we construct a time‐varying parameter structural vector auto‐regression with stochastic volatility (TVP‐SVAR‐SV) model and specifically analyse the time‐varying effects and structural change of oil price shocks on China's output at each stage of the oil industrial chain. The results show that the effects of oil price shocks on output from upstream to downstream in the oil industrial chain are time‐varying, and the dynamic impacts vary under different lag lengths. The increase in oil price driven by oil demand shocks is the major factor affecting output at each stage of the oil industrial chain. In addition, there is a structural change in the impacts of oil price shocks before and after the international financial crisis. With the decline in external demand and the implementation of policies to expand domestic demand, the responses of China's output at each stage of the oil industrial chain to oil price shocks have decreased significantly since the international financial crisis.
Three‐dimensionally printed polycaprolactone/beta‐tricalcium phosphate scaffold was more effective as an rhBMP‐2 carrier for new bone formation than polycaprolactone alone
Authors: Park Su A , Lee Hyo‐Jung , Kim Sung‐Yeol , Kim Keun‐Suh , Jo Deuk‐Won , Park Shin‐Young
Published: August 2020

Recombinant human bone morphogenetic protein 2 (rhBMP‐2) has been widely used in bone tissue engineering to enhance bone regeneration because of its osteogenic inductivity. However, clinical outcomes can vary depending on the scaffold materials used to deliver rhBMP‐2. In this study, 3D‐printed scaffolds with a ratio of 1:1 polycaprolactone and beta‐tricalcium phosphate (PCL/T50) were applied as carriers for rhBMP‐2 in mandibular bone defect models in dog models. Before in vivo application, in vitro experiments were conducted. Preosteoblast proliferation was not significantly different between scaffolds made of PCL/T50 and polycaprolactone alone (PCL/T0) regardless of rhBMP‐2 delivery. However, PCL/T50 showed an increased level of the alkaline phosphatase activity and mineralization assay when rhBMP‐2 was delivered. In in vivo, the newly formed bone volume of the PCL/T50 group was significantly increased compared with that of the PCL/T0 scaffolds regardless of rhBMP‐2 delivery. Histological examination showed that PCL/T50 with rhBMP‐2 produced significantly greater amounts of newly bone formation than PCL/T0 with rhBMP‐2. The quantities of scaffold remaining were lower in the PCL/T50 group than in the PCL/T0 group, although it was not significantly different. In conclusion, PCL/T50 scaffolds were advantageous for rhBMP‐2 delivery as well as for maintaining space for bone formation in mandibular bone defects.
Sickle cell disease‐associated arrhythmias and in‐hospital outcomes: Insights from the National Inpatient Sample
Authors: Patel Upenkumar , Desai Rupak , Hanna Bishoy , Patel Dhruval , Akbar Shahzad , Zubair Mohammed , Kumar Gautam , Sachdeva Rajesh
Published: August 2020

Background

The frequency and temporal trend in the prevalence of arrhythmias and associated in‐hospital outcomes in patients with sickle cell disease (SCD) have never been quantified.

Methods

Our study cohort of SCD patients and sub‐types of arrhythmias were derived from the 2010‐2014 National Inpatient Sample using relevant diagnostic codes. The frequency and trends of arrhythmia and odds of inpatient mortality were measured.

Results

A total of 891 450 hospitalized SCD patients were identified, of which, 55 616 (6.2%) patients experienced arrhythmias. The SCD cohort with arrhythmia demonstrated higher all‐cause mortality (2.7% vs 0.4%; adjusted OR 2.53, 95% CI 2.15‐2.97, P < .001), prolonged hospital stays (6.9 vs 5.0 days) and higher hospital charges ($53 871 vs $30 905) relative to those without arrhythmias (P < .001).The frequency of supraventricular arrhythmia (AFib, SVT, and AF) and ventricular arrhythmia (VFib and VT) were 1893 and 362 per 100 000 SCD‐related admissions, respectively. Unspecified arrhythmias (4126) were seen most frequently followed by AFib (1622) per 100 000 SCD‐related admissions. From 2010 to 2014, the frequency of any arrhythmias and atrial fibrillation in hospitalized SCD patients relatively increased by 29.6% and 38.5%, respectively. There was nearly a twofold (2.4% in 2010 to 5.0% in 2014) increase in the frequency of arrhythmia among patients aged <18 years. The frequency of arrhythmias in hospitalized male and female SCD patients relatively increased by 28.8% and 31.4%, respectively (Ptrend < .001).

Conclusions

The frequency of arrhythmias among SCD patients is on the rise with worse hospitalization outcomes, including higher in‐hospital mortality and higher resource utilization as compared to those without arrhythmias.
Reduction of Central Line–Associated Bloodstream Infections and Line Occlusions in Pediatric Intestinal Failure Patients Receiving Long‐Term Parenteral Nutrition Using an Alternative Locking Solution, 4% Tetrasodium Ethylenediaminetetraacetic Acid
Authors: Quirt Jill , Belza Christina , Pai Nikhil , Clause Rose‐Frances , Markovic Filip , Wong‐Sterling Sylvia , Avitzur Yaron , Wales Paul W.
Published: August 2020

Background

Patients with intestinal failure (IF) are dependent on parenteral nutrition (PN), however, they are at risk of central line–associated bloodstream infections (CLABSIs) and line complications. Four‐percent tetrasodium ethylenediaminetetraacetic acid (EDTA) solution is an effective nonantibiotic, antimicrobial, antibiofilm, and anticoagulant agent. Our objective was to determine 4% tetrasodium EDTA efficacy in preventing CLABSIs and reducing line occlusions in pediatric IF patients.

Methods

We conducted a retrospective cohort study of patients managed at 2 tertiary Canadian pediatric centers between April 2016 and December 2018 who received 4% tetrasodium EDTA solution under the brand name Kitelock. Data were collected for 12 months pre and post‐Kitelock. CLABSIs and alteplase administration were compared using a Wilcoxon matched‐pairs signed‐rank test. Data were reported as medians and frequencies.

Results

Twenty patients were included (10 boys; median age, 83 months [range, 8–232 months]). The rate of CLABSIs before 4% tetrasodium EDTA was 2.7+4 per 1000 catheter days. Patients received 4% tetrasodium EDTA for a median of 365 (278–365) days, with no infections in the 12 months post‐therapy (P = .002). Median rates of occlusive episodes for the entire cohort before 4% tetrasodium EDTA were 0 (0–5.0) and 0 (0–2.0) after starting therapy (P = .018). In patients with previous occlusions (n = 9), the median episodes of alteplase use previously was 5.5 (2.7–19.2) compared with 2.7 (0–2.7) (P = .018).

Conclusions

Our preliminary findings suggest 4% tetrasodium EDTA solution is effective in reducing CLABSIs and catheter occlusions in pediatric patients with long‐term central‐access.
Effects of peri‐implant infection on serum biochemical analysis
Authors: Chaushu Liat , Tal Haim , Sculean Anton , Fernández‐Tomé Blanca , Chaushu Gavriel
Published: August 2020

Background

Peri‐implant disease (PID) has not been directly linked to pathological organ changes. The present study assessed the dynamics of serum biochemical parameters in a model of experimental peri‐implantitis in dogs, followed by open flap debridement.

Methods

Seven male beagle dogs comprised the study group. Procedures were performed as follows—extractions of two premolars and one molar on each mandibular quadrant (Day 0); bone healing time (week14); placement of four rough‐surface endoosseous implants, two on each mandibular side; implant uncovering (week 28); induction of experimental peri‐implantitis by the use of three ligatures (weeks 31, 34, 37) followed by open flap debridement (week 42). Serum biochemical analysis following each procedure was compared to baseline. Biochemical parameters were assigned into four subsets of variables—inflammation, renal function, liver function, and blood glucose. Wilcoxon paired tests were conducted in order to identify statistically significant differences between baseline data and values obtained after each procedure

Results

Following experimental peri‐implantitis, the dynamics of renal parameters and blood glucose were minimal whereas statistically significant (P < 0.05) increases were noted for inflammatory (total protein and albumin concentrations) and hepatic (ALT, AST) parameters. A statistically significant (P < 0.05) decrease was only noted for total bilirubin. After open flap debridement, inflammatory (total protein and albumin concentrations) and hepatic (AST) parameters returned to baseline.

Conclusions

Within their limits, the present results indicate that: (a) PID affects inflammatory and hepatic serum biochemical parameters, and (b) following open flap debridement most of the values returned to baseline.
Estimation of the number of Anisakis larvae in commercial fish using a descriptive model based on real‐time PCR
Authors: Godínez‐González Carla , Roca‐Geronès Xavier , Montoliu Isabel , Fisa Roser
Published: August 2020

BACKGROUND

Seafood parasitation by Anisakis (Anisakidae) larvae has been reported in most of the oceans and seas worldwide. The presence of these nematodes in commonly consumed fish represents a potential hazard for consumers as they can provoke gastrointestinal symptoms and allergic reactions. In the present work, the capacity of a SYBR Green qPCR protocol to quantify Anisakis larvae in commercial fish was evaluated using experimentally spiked samples with different numbers (0–50) of A. simplex third‐stage larvae (L3). To verify the agreement of the obtained results, 25 naturally infected fish specimens of Atlantic blue whiting underwent a parallel visual inspection.

RESULTS

The logarithmic behavior of the Cq data obtained from the experimentally spiked samples allowed the development of a descriptive mathematical model that correlates the Cq value with the number of Anisakis larvae (R2 = 0.9908, CV = 2.37%). In the commercial blue whiting specimens there was a high correlation between the results of the molecular technique and the visual inspection (R2 = 0.9912); the Bland–Altman analysis showed that 94% of the differences were within the limits of agreement (−4.98 and 6.68), indicating the reliability of the descriptive mathematical model based on the SYBR Green qPCR technique.

CONCLUSION

The descriptive function presented based on the SYBR Green qPCR assay is promising as a sensitive and accurate tool for measuring the Anisakis larval load in commercial fish, with a potential application not only in the food industry but also in prevention programs for public health. © 2020 Society of Chemical Industry
Prenatal Imaging Findings Predict Obstructive Fetal Airways Requiring EXIT
Authors: Cash Harrison , Bly Randall , Masco Vanessa , Dighe Manjiri , Cheng Edith , Delaney Shani , Ma Kimberly , Perkins Jonathan A.
Published: August 2020

Objective

Detection of fetal airway compromise through imaging raises the possible need for ex utero intrapartum treatment (EXIT) procedures. Despite EXIT procedures involving massive resource utilization and posing increased risk to the mother, decisions for EXIT are usually based on anecdotal experience. Our objectives were to analyze prenatal consultations with potential fetal airway obstruction for imaging and obstetric findings used to determine management strategy.

Methods

Retrospective chart review was performed for prenatal abnormal fetal airway consults between 2004–2019 at a quaternary pediatric facility. Data collected included demographics, imaging characteristics, delivery information, and airway management. Our primary outcome was EXIT performance and the secondary outcome was postnatal airway management. Fisher's exact test was used to compare management decisions, outcomes, and imaging findings.

Results

Thirty‐seven patients met inclusion criteria. The most common diagnoses observed were lymphatic malformation, teratoma, and micrognathia. Of the imaging findings collected, only midline neck mass location was associated with EXIT procedure performance. Factors associated with invasive airway support at birth were mass‐induced in‐utero neck extension and neck vessel compression, polyhydramnios, and micrognathia.

Conclusions

Multidisciplinary input and interpretation of prenatal imaging can guide management of fetal airway‐related pathology. EXIT is an overall safe procedure and can decrease risk due to airway obstruction at birth. We identified in‐utero neck extension, neck vessel compression, micrognathia, and polyhydramnios as better indicators of a need for invasive airways measures at birth and suggest use of these criteria in combination with clinical judgement when recommending EXIT.

Level of Evidence

4 Laryngoscope, 131:E1357–E1362, 2021
Lipid Composition of Liposomal Membrane Largely Affects Its Transport and Uptake through Small Intestinal Epithelial Cell Models
Authors: Konishi Keisuke , Du Lei , Francius Grégory , Linder Michel , Sugawara Tomoaki , Kurihara Hideyuki , Takahashi Koretaro
Published: August 2020

Lipid composition of liposomal bilayer should alter the cell response for permeability, transport, and uptake in small intestine. This work was done to investigate the transport and uptake of liposomes composed of docosahexaenoic acid‐enriched phosphatidylcholine (PtdCho), phosphatidylserine (PtdSer), and sulfoquinovosyl diacylglycerol (SQDG) derived from marine products on multilamellar vesicles (MLV) in small intestinal epithelial cell models. The results showed that addition of PtdSer and SQDG as liposomal bilayer could improve the efficiency entrapment of liposomes. The liposomes containing PtdSer showed higher transport and uptake through both Caco‐2 cell and M cell monolayers as compared to PtdCho‐MLV. SQDG‐containing liposomes exhibited only higher transport through M cell monolayer, while its uptake effect was higher both in Caco‐2 cell and M cell monolayers. The results of experiments done with endocytosis inhibitors indicated that PtdCho‐MLV must be transported via macropinocytosis and uptaken by phagocytosis in M cell monolayer model. PtdCho/PtdSer‐MLV and PtdCho/SQDG‐MLV might be transported and uptaken through M cell monolayer by phagocytosis. The result also indicated that PtdCho/SQDG‐MLV could open the tight junction of small intestinal epithelial cell monolayers. Furthermore, our findings demonstrated that the surface status of cholesterol‐containing liposomes were smooth, but they did not affect their transport and uptake through Caco‐2 cell and M cell monolayers.
Characterization and modification of the molecular weight distribution within dissolved organic matter using flow field‐flow fractionation
Authors: Fu Xiaowei , Pan Jizheng , Xu Huacheng
Published: August 2020

Dissolved organic matter (DOM) exists ubiquitously in the aquatic environment with varying chemical compositions and a wide molecular weight (MW) distribution, which, as a result, exhibits differing impacts on the behavior and fate of contaminants. The current methods for the MW characterization of DOM usually possess some weaknesses and therefore, some novel techniques are needed. In this study, the feasibility and sensitivity of flow field‐flow fractionation (FlFFF) system were studied for the MW characterization of DOMs from various origins. The systematic evaluation of FlFFF indicated that a mobile phase consisting of 10 mM NaCl and 5 mM H3BO3 and with a pH of 8 was optimal, and the fractionation program with a cross‐flow rate of 2 mL/min and a focusing time of 2 min resulted in the most efficient MW fractionation. Compared to natural waters, the standard DOM materials possessed a high proportion of humic‐like substances and narrow MW distribution. The quantification analysis showed that chromophoric organic ligands were mainly distributed in the high (i.e., 100 kDa–0.45 μm) and low (i.e., 0.3–1 kDa) MW fractions for natural waters, but in the medium (i.e., 1–100 kDa) and low MW fractions for the standard DOM materials. However, the fluorescent humic‐like substances were predominantly distributed within the medium and low MW fractions, irrespective of DOM types. This study showed the feasibility and sensibility of FlFFF in fractionating DOM samples, and can be used to quantify the different MW distribution of chromophoric and fluorescent components in standard and natural DOM.
Evaluation of diagnostic pigments to estimate phytoplankton size classes
Authors: Chase Alison P. , Kramer Sasha J. , Haëntjens Nils , Boss Emmanuel S. , Karp‐Boss Lee , Edmondson Mimi , Graff Jason R.
Published: August 2020

Phytoplankton accessory pigments are commonly used to estimate phytoplankton size classes, particularly during development and validation of biogeochemical models and satellite ocean color‐based algorithms. The diagnostic pigment analysis (DPA) is based on bulk measurements of pigment concentrations and relies on assumptions regarding the presence of specific pigments in different phytoplankton taxonomic groups. Three size classes are defined by the DPA: picoplankton, nanoplankton, and microplankton. Until now, the DPA has not been evaluated against an independent approach that provides phytoplankton size calculated on a per‐cell basis. Automated quantitative cell imagery of microplankton and some nanoplankton, used in combination with conventional flow cytometry for enumeration of picoplankton and nanoplankton, provide a novel opportunity to perform an independent evaluation of the DPA. Here, we use a data set from the North Atlantic Ocean that encompasses all seasons and a wide range of chlorophyll concentrations (0.18–5.14 mg m−3). Results show that the DPA overestimates microplankton and picoplankton when compared to cytometry data, and subsequently underestimates the contribution of nanoplankton to total biomass. In contrast to the assumption made by the DPA that the microplankton size class is largely made up of diatoms and dinoflagellates, imaging‐in‐flow cytometry shows significant presence of diatoms and dinoflagellates in the nanoplankton size class. Additionally, chlorophyll bis commonly attributed solely to picoplankton by the DPA, but Chl b‐containing phytoplankton are observed with imaging in both nanoplankton and microplankton size classes. We suggest revisions to the DPA equations and application of uncertainties when calculating size classes from diagnostic pigments.
Morphometric Optical Imaging of Microporated Nail Tissue: An Investigation of Intermethod Agreement, Reliability, and Technical Limitations
Authors: Ortner Vinzent K. , Holmes Jon , Haedersdal Merete , Philipsen Peter A.
Published: August 2020

Background and Objectives

While optical imaging is a useful technique to quantitate morphological differences and treatment effects, comparative investigations of the various techniques are lacking. This study aimed at evaluating intermethod agreement, reliability, and technical limitations of wide‐field microscopy (WFM), reflectance confocal microscopy (RCM), and optical coherence tomography (OCT) for morphometry by assessing fractionally ablated nail tissue.

Study Design/Materials and Methods

Fifty healthy nail clippings were processed with a fractionated CO2‐laser (20 mJ/microbeam, density 15%), measured with calipers, and imaged using WFM, OCT, and RCM. Images were assessed for nail plate thickness, micropore dimensions, degree of poration, and artifacts. Repeated measurements (2–5) were taken to evaluate method repeatability using Cronbach's α and coefficients of variation (CoV), and estimate the intermethod correlation through linear correlation assessment (Pearson correlation coefficient [PCC]), ranked correlation (Kendall's tau; tau‐c), and intraclass correlation (Shrout‐Fleiss reliability coefficient; ICC).

Results

The repeatability varied substantially between methods and target measurements. The level of intermethod agreement for thickness measurements performed with calipers, WFM, and OCT was high (tau‐c ≥ 0.7; ICC ≥ 0.8; PCC ≥ 0.9). RCM could only image 28 out of 50 samples due to its limited penetration depth. OCT demonstrated the highest repeatability of all imaging techniques (CoV 4–7%) and nail thickness showed the highest measurement reliability (α = 0.92). Micropore dimensions correlated strongest between OCT and RCM (tau‐c/ICC/PCC ≥ 0.5). All modalities were prone to artifacts, which may have adversely affected measurement variation and intermethod agreement.

Conclusion

Intermethod agreement and reliability appear to be highly dependent on the specific modality and target measurement. To reap the benefits of each technique while mitigating their limitations, an integrated approach to optical imaging is recommended. Lasers Surg. Med. © 2020 Wiley Periodicals LLC
Solvability of an inhomogeneous boundary value problem for steady MHD equations
Authors: Zhang Zhibing , Zhao Chunyi
Published: August 2020

In this paper, we consider the steady MHD equations with inhomogeneous boundary conditions for the velocity and the tangential component of the magnetic field. Using a new construction of the magnetic lifting, we obtain existence of weak solutions under sharp assumption on boundary data for the magnetic field.
On the number of eigenvalues for parameter‐dependent diffusion problem on time scales
Authors: Gulsen Tuba , Jadlovská Irena , Yilmaz Emrah
Published: August 2020

In this study, we consider parameter‐dependent diffusion eigenvalue problem on time scales. An upper bound on the number of eigenvalues for this problem on a finite time scale is given.
Follistatin treatment modifies DNA methylation of the CDX2 gene in bovine preimplantation embryos
Authors: Ashry Mohamed , Rajput Sandeep K. , Folger Joseph K. , Yang Chunyan , Knott Jason G. , Smith George W.
Published: August 2020

CDX2 plays a crucial role in the formation and maintenance of the trophectoderm epithelium in preimplantation embryos. Follistatin supplementation during the first 72 hr of in vitro culture triggers a significant increase in blastocyst rates, CDX2 expression, and trophectoderm cell numbers. However, the underlying epigenetic mechanisms by which follistatin upregulates CDX2 expression are not known. Here, we investigated whether stimulatory effects of follistatin are linked to alterations in DNA methylation within key regulatory regions of the CDX2 gene. In vitro‐fertilized (IVF) zygotes were cultured with or without 10 ng/ml of recombinant human follistatin for 72 hr, then cultured without follistatin until Day 7. The bisulfite‐sequencing analysis revealed differential methylation (DM) at specific CpG sites within the CDX2 promoter and intron 1 following follistatin treatment. These DM CpG sites include five hypomethylated sites at positions −1384, −1283, −297, −163, and −23, and four hypermethylated sites at positions −1501, −250, −243, and +20 in the promoter region. There were five hypomethylated sites at positions +3060, +3105, +3219, +3270, and +3545 in intron 1. Analysis of transcription factor binding sites using MatInspector combined with a literature search revealed a potential association between differentially methylated CpG sites and putative binding sites for key transcription factors involved in regulating CDX2 expression. The hypomethylated sites are putative binding sites for FXR, STAF, OCT1, KLF, AP2 family, and P53 protein, whereas the hypermethylated sites are putative binding sites for NRSF. Collectively, our results suggest that follistatin may increase CDX2 expression in early bovine embryos, at least in part, by modulating DNA methylation at key regulatory regions.
Voiding dynamics in women with urinary incontinence but without voiding symptoms
Authors: Valdevenito Juan P. , Mercado‐Campero Alejandro , Naser Michel , Castro Daniela , Ledesma Marta , Arribillaga Leandro
Published: August 2020

Aims

To describe the voiding pattern (VP) of women with urinary incontinence but without voiding symptoms and compare their clinical and urodynamic features between those voiding with and without a measurable detrusor contraction (DET‐cont).

Methods

Retrospective analysis of a prospectively built database of female urodynamic studies (UDS). Women with voiding symptoms and having medical history of different factors that could alter the lower urinary tract function were excluded. All UDS were performed following the ICS guidelines. DET‐cont and abdominal straining (ABD‐strain) were defined as an increase ≥10 cm H2O over the baseline for pdet and pabd at Qmax, respectively.

Results

A total of 186 women were included in the analysis. Mean age was 58 ± 10.7 years (24‐83). Most women showed a VP with DET‐cont (77.4%), with or without ABD‐strain. When compared to women voiding without DET‐cont, those with DET‐cont were younger (P = .004), more likely to have detrusor overactivity (P = .035) and better urinary sphincter competency in the UDS (P = .018). On multivariate analysis, the presence of DET‐cont was associated with age ≤50 years (P = .004) and the absence of urodynamic stress urinary incontinence (SUI) or SUI with abdominal leak point pressure ≥100 cm H2O (P = .008).

Conclusions

Most women without voiding symptoms show a VP characterized by a measurable detrusor contraction, with or without ABD‐strain. The results suggest that the VP may vary independently with aging and with changes in the state of the urinary sphincter, emphasizing that for the interpretation of micturition in women different aspects must be considered.
Fixed interval scheduling with third‐party machines
Authors: Fridman Ilia , Kovalyov Mikhail Y. , Pesch Erwin , Ryzhikov Andrew
Published: August 2020

We study a problem of scheduling n jobs on machines of two types: in‐house machines and third‐party machines. Scheduling on in‐house machines incurs no additional costs, while using third‐party machines implies costs depending on their number and the time of usage. Each job has a fixed time interval for being processed which can be divided and allocated among several machines, as long as there is only one machine processing the job at any time. No machine can process more than one job at a time. Jobs can be rejected, and they are of different importance that is reflected in the weight of each job. The objective is to find a subset of the jobs and the number of third‐party machines for any period of time so that the accepted jobs can be feasibly scheduled, the total weight of the accepted jobs is maximized, and the total machine usage costs does not exceed a given upper bound. We also study a similar problem in which the objective is to maximize the total time at which at least one job is processed. Both problems are encountered in situations in which certain activities with given start and completion times have to be serviced by human operators. Examples are air traffic control and the monitoring safe vehicle unloading. Other examples are the employment of subcontractors in agriculture, construction or transportation. We will present NP‐hardness proofs, polynomial and pseudo‐polynomial optimal algorithms and an approximation algorithm for these problems and their special cases. These problems admit graph‐theoretical interpretations associated with finding independent sets and a proper vertex coloring in interval graphs.
Ethyl cyanoacrylate ordered porous films prepared via in‐situ polymerization and static breath figures process
Authors: Ghasemi Seyed Morteza , Besharati Mahtab
Published: August 2020

Ordered microporous films were fabricated via static breath figure process and in situ polymerization of ethyl cyanoacrylate (ECA) monomers. The influences of various parameters including solvent type (dichloromethane and chloroform), ECA concentration (0.2 and 1 wt%), temperature (17°C and 26°C), and substrate (glass, mica, PE, PP, and PET) were investigated on the structure of breath Figure (BF) films. Highly ordered porous films were generally formed at lower concentration of ECA and at 17°C for dichloromethane (DCM) and at 26°C for chloroform (CLF). The pores average diameter (D̅) of the films were in the range of 1 to 5 μm. The formation of regular porous structures were elucidated using the Marangoni (thermocapillary) convection flow and the rate of the polymer precipitation around the water droplets. There were an optimum ΔT (the temperature difference between the air and the solution surface) to create ordered BF film, regardless of solvent type. The prepared films have potential for templating applications.
Improved thermal and electrical properties of epoxy resin composites by dopamine and silane coupling agent modified hexagonal BN
Authors: Zhang Yiran , Tuo Rui , Yang Wei , Wu Jiale , Zhu Jie , Zhang Chong , Lin Jun , Bian Xingming
Published: August 2020

The high thermal conductivity epoxy resin composites filled with inorganic filler can improve the low thermal conductivity of epoxy resin. However, a large number of fillers with high thermal conductivity will reduce other properties of the composites, which limits their use under high voltage, high temperature and strong mechanical force during operation. In this study, the dopamine‐modified BN (DBN) and k‐DBN (DBN modified by coupling agent KH‐560) were prepared by employed the dopamine with catechol groups and coupling agent to modify boron nitride. The thermal conductivity, thermal stability, and dielectric properties of composites with different contents of modified fillers were studied. The results showed that surface modification improved the dispersibility of BN in the resin matrix and compatibility with the resin. Among BN/EP, DBN/EP, k‐DBN/EP composites, k‐DBN/EP composites had the highest thermal conductivity at the same number of additions. When the k‐DBN/EP content was 30 wt%, the thermal conductivity of the composite was 0.892 W/(m·K), which was an increase of 25.5% compared with the BN/EP composite. The appropriate amount of BN filling (20 wt%) can improve the breakdown strength of the composite material.
Application of semi‐in situ liquid exfoliation of graphite to the scalable production of graphene‐epoxy nanocomposites
Authors: Orawiec Marcin , Belton Daniel , Telford Richard , Surtees Alexander
Published: August 2020

Recent advances in graphite wet exfoliation methods include new solvent systems, exfoliation‐assisting agents such as pyrophosphate and use of graphite‐intercalated compounds. These open new avenues for the scalable and versatile production of graphene/nanographite composites, with the prospect of reducing barriers to the adoption of these materials for real‐world applications. This article proposes a semi‐in situ exfoliation method in which graphite is exfoliated directly in the epoxy/cosolvent system via high‐shear mixing. The method is tested with three different solvent systems: epoxy/acetone; epoxy/N‐Methyl‐2‐pyrrolidone (NMP); and epoxy/NMP/water. Tailoring of mechanical properties of the composites is achieved by adjusting the mixing and centrifugation times and the temperature of the process. The incorporation of graphite microparticles in the composites has a positive influence on strength and flexibility at the expense of rigidity resulting in a 13.4% increase in ultimate tensile strength (UTS) and 73% in elongation at break (εmax) at 0.04 wt% loading. The proposed method also leads to nanocomposites with enhanced properties at low‐filler loadings. For example, the 0.01 wt% loading gave a 7.4% increase in Young's modulus, 10.6% in UTS, and 9.1% in εmax. The scalability and versatility of this method make it a promising alternative for industrial production of epoxy/graphene nanocomposites.
On the fixed‐time consensus problem for nonlinear uncertain multiagent systems under switching topology
Authors: Dávila Jorge , Pisano Alessandro
Published: August 2020

This article proposes a novel local interaction rule providing leader‐following and leader‐less consensus in a network of nonlinear uncertain first‐order agents communicating through a connected and switching graph topology. Particularly, the proposed interaction rule guarantees that consensus is achieved after a finite settling time, which admits an upper bound independent of the initial conditions of the agents' states. This property, called fixed‐time convergence, is achieved, thanks to homogeneous polynomial terms of suitable order in the local interaction rule. A Lyapunov‐based analysis is presented to support the convergence features of the proposed interaction protocol. Simulation results are presented in order to corroborate the theoretical findings.
Geographical addressing strategy for space‐ground integrated network
Authors: Xiao Yunlu , Zhang Tao , Sun Meng
Published: August 2020

To provide a connection between low earth orbit (LEO) satellite network and terrestrial Internet, a geographical addressing strategy for LEO network is proposed in this paper. When the IP geo‐subnet is divided based on location, the terrestrial users inside and satellite routers above each subnet could be allocated and maintain IP addresses under the regulation of IP network. The addressing strategy is implemented in the first hop and last hop of packet transmission. This paper proves that the application of geo‐subnets could effectively reduce the route table size and generation time in large‐scale space‐ground integrated network as well as maintain the stability of route table when the user condition alters. The performance loss of abnormal addressing caused by the change of satellite coverage would decrease with the reduction of geo‐subnet area. However, the decrease rate would decline during the subnet subdivision and therefore has limited optimization for abnormal addressing. The routing broadcast strategy proposed in this paper could effectively reduce the system packet loss brought by abnormal user at the same geo‐subnet division. Simulation confirms that the geographical addressing strategy combined with routing broadcast optimization in this paper could achieve more than 90% network throughput while reducing 76% of the routing cost.
Coupling PEDOT on Mesoporous Vanadium Nitride Arrays for Advanced Flexible All‐Solid‐State Supercapacitors
Authors: Chen Minghua , Fan He , Zhang Yan , Liang Xinqi , Chen Qingguo , Xia Xinhui
Published: August 2020

Tailored construction of advanced flexible supercapacitors (SCs) is of great importance to the development of high‐performance wearable modern electronics. Herein, a facile combined wet chemical method to fabricate novel mesoporous vanadium nitride (VN) composite arrays coupled with poly(3,4‐ethylenedioxythiophene) (PEDOT) as flexible electrodes for all‐solid‐state SCs is reported. The mesoporous VN nanosheets arrays prepared by the hydrothermal–nitridation method are composed of cross‐linked nanoparticles of 10–50 nm. To enhance electrochemical stability, the VN is further coupled with electrodeposited PEDOT shell to form high‐quality VN/PEDOT flexible arrays. Benefiting from high intrinsic reactivity and enhanced structural stability, the designed VN/PEDOT flexible arrays exhibit a high specific capacitance of 226.2 F g−1 at 1 A g−1 and an excellent cycle stability with 91.5% capacity retention after 5000 cycles at 10 A g−1. In addition, high energy/power density (48.36 Wh kg−1 at 2 A g−1 and 4 kW kg−1 at 5 A g−1) and notable cycling life (91.6% retention over 10 000 cycles) are also achieved in the assembled asymmetric flexible supercapacitor cell with commercial nickel–cobalt–aluminum ternary oxides cathode and VN/PEDOT anode. This research opens up a way for construction of advanced hybrid organic–inorganic electrodes for flexible energy storage.
Nanosized Zirconium Porphyrinic Metal–Organic Frameworks that Catalyze the Oxygen Reduction Reaction in Acid
Authors: Chen Gan , Stevens Michaela Burke , Liu Yunzhi , King Laurie A. , Park Jihye , Kim Taeho Roy , Sinclair Robert , Jaramillo Thomas F. , Bao Zhenan
Published: August 2020

Porphyrinic metal–organic frameworks (PMOFs) are very appealing electrocatalytic materials, in part, due to their highly porous backbone, well‐defined and dispersed metal active sites, and their long‐range order. Herein a series of (Co)PCN222 (PCN: porous coordination network) (nano)particles with different sizes are successfully prepared by coordination modulation synthesis. These particles exhibit stability in 0.1 m HClO4 electrolyte with no obvious particle size or compositional changes observed after being soaked for 3 days in the electrolyte or during electrocatalysis. This long‐term stability enables the in‐depth investigation into the electrocatalytic oxygen reduction, and it is further demonstrated that the (Co)PCN222 particle size correlates with its catalytic activity. Of the three particle sizes evaluated (characteristic length scales of 200, 500, and 1000 nm), the smallest size demonstrates the highest mass activity while the largest size has the highest surface area normalized activity. Together these results highlight the importance of determining the structural stability of framework catalysts and provide insights into the important roles of particle size, opening new avenues to investigate and improve the electrocatalytic performance of this class of framework material.
Impact of etcd deployment on Kubernetes, Istio, and application performance
Authors: Larsson Lars , Tärneberg William , Klein Cristian , Elmroth Erik , Kihl Maria
Published: August 2020

This experience article describes lessons learned as we conducted experiments in a Kubernetes‐based environment, the most notable of which was that the performance of both the Kubernetes control plane and the deployed application depends strongly and in unexpected ways on the performance of the etcd database. The article contains (a) detailed descriptions of how networking with and without Istio works in Kubernetes, based on the Flannel Container Networking Interface (CNI) provider in VXLAN mode with IP Virtual Server (IPVS)‐backed Kubernetes Services, (b) a comprehensive discussion about how to conduct load and performance testing using a closed‐loop workload generator, and (c) an open source experiment framework useful for executing experiments in a shared cloud environment and exploring the resulting data. It also shows that statistical analysis may reveal the data resulting from such experiments to be misleading even when careful preparations are made, and that nondeterministic behavior stemming from etcd can affect both the platform as a whole and the deployed application. Finally, it is demonstrated that using high‐performance backing storage for etcd can reduce the occurrence of such nondeterministic behaviors by a statistically significant (P < .05) margin. The implication of this experience article is that systems researchers studying the performance of applications deployed on Kubernetes cannot simply consider their specific application to be under test. Instead, the particularities of the underlying Kubernetes and cloud platform must be taken into account, in particular because their performance can impact that of etcd.
Exceptional avian pellet from the Paleocene of Patagonia and description of its content: a new species of calyptocephalellid (Neobatrachia) anuran
Authors: Muzzopappa Paula , Martinelli Agustín G. , Garderes Juan P. , Rougier Guillermo W.
Published: August 2020

A fossil gastric pellet from the Danian ‘Banco Negro Inferior’ of the Salamanca Formation at Punta Peligro Locality (Chubut, Argentina) and its 3D preserved fossil content is studied herein. The structure of the pellet and the condition of the enclosed bones suggest that it was produced by a bird of prey, although birds of any kind are as yet unknown from osteological remains in the Banco Negro ecosystem. The content of the pellet originated from a single anuran individual, representing a new species of the genusCalyptocephalella, is described herein asC. sabrosasp. nov. The new find highlights the broad temporal, geographical and taxonomic diversity of this frog genus in Patagonia's geological past.
Typification of Linnaean specific names in the genus Galium (Rubiaceae)
Authors: Ferrer‐Gallego P. Pablo
Published: August 2020

The lectotypification of ten Linnaean names in the genus Galium: G. aristatum, G. hierosolymitanum, G. laevigatum, G. maritimum, G. palustre, G. purpureum (≡ Asperula purpurea), G. pusillum, G. rubrum, G. saxatile, and G. uliginosum, is discussed. The designation of the nomenclatural types is based on the consultation of Linnaeus's original material and the literature cited in the respective protologues. The names are lectotypified using specimens from BIF‐LAPP (Linnaean herbarium from the Iter Lapponicum), BM (Clifford Herbarium), LINN, and UPS (UPS‐BURSER and UPS‐LINN), and an illustration of Boccone (1697). An epitype is also designated for G. laevigatum due to ambiguity in the interpretation of the lectotype. Linnaeus's original material of G. minutum, G. rubioides, and G. sylvaticum could not be found.
AACRAO president helps to steer course in turbulent times
Authors: Enos Gary A.
Published: August 2020

Twice since the start of 2020, Jack Miner has found himself adjusting to a new role amid a public health crisis. Miner began work as Vice Provost for Enrollment Management at the University of Cincinnati just weeks before the COVID‐19 crisis emerged, then ascended to the president's role at the American Association of Collegiate Registrars and Admissions Officers as the association was forced to cancel its April annual meeting.
Incidence of pre‐eclampsia and other perinatal complications among pregnant women with congenital heart disease: systematic review and meta‐analysis
Authors: Martinez‐Portilla R. J. , Poon L. C. , Benitez‐Quintanilla L. , Sotiriadis A. , Lopez M. , Lip‐Sosa D. L. , Figueras F.
Published: August 2020

Objective

It has been proposed recently that pre‐eclampsia (PE) may originate from maternal cardiac maladaptation rather than primary placental insult. As congenital heart disease (CHD) is associated with reduced adaptation to the hemodynamic needs of pregnancy, it is hypothesized that women with CHD have an increased risk of PE. The aim of this systematic review was to investigate the risk of PE in pregnant women with CHD.

Methods

A systematic search was performed to identify relevant studies published in English, Spanish, French, Italian, Chinese or German, with no time restrictions, using databases such as PubMed, Web of Science and SCOPUS. Randomized controlled trials and observational studies (prospective or retrospective cohorts) of pregnant women with a history of CHD were sought. The main outcome was the incidence of PE (including eclampsia and HELLP syndrome). For quality assessment of the included studies, two reviewers assessed independently the risk of bias. For the meta‐analysis, the incidence of PE in pregnancies (those beyond 20 weeks' gestation) was calculated using single‐proportion analysis by random‐effects modeling (weighted by inverse variance). Heterogeneity between studies was assessed using the χ2(Cochran's Q), tau2andI2statistics. Subgroup analysis was performed, and meta‐regression was used to assess the influence of several covariates on the pooled results.

Results

A total of 33 studies were included in the meta‐analysis, including 40 449 women with CHD and a total of 40 701 pregnancies. The weighted incidence of PE was 3.1% (95% CI, 2.2–4.0%), with true‐effect heterogeneity of 93% according toI2, and no publication bias found. No difference was found in the weighted incidence of PE between studies including cyanotic CHDvsthose excluding (or not reporting) cyanotic CHD (2.5% (95% CI, 1.6–3.4%)vs4.1% (95% CI, 2.4–5.7%);P = 0.0923). Meta‐regression analysis showed that the only cofactor that significantly influenced the incidence of PE in each study was the reported incidence of aortic stenosis; studies with a higher incidence of aortic stenosis had a higher incidence of PE (estimate: 0.0005;P = 0.038).

Conclusions

We failed to demonstrate an incidence of PE above the expected baseline risk in women with CHD. This observation contradicts the theory of the cardiac origin of PE. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.
Crop growth and soil water fluxes at erosion‐affected arable sites: Using weighing lysimeter data for model intercomparison
Authors: Groh Jannis , Diamantopoulos Efstathios , Duan Xiaohong , Ewert Frank , Herbst Michael , Holbak Maja , Kamali Bahareh , Kersebaum Kurt‐Christian , Kuhnert Matthias , Lischeid Gunnar , Nendel Claas , Priesack Eckart , Steidl Jörg , Sommer Michael , Pütz Thomas , Vereecken Harry , Wallor Evelyn , Weber Tobias K.D. , Wegehenkel Martin , Weihermüller Lutz , Gerke Horst H.
Published: August 2020

Agroecosystem models need to reliably simulate all biophysical processes that control crop growth, particularly the soil water fluxes and nutrient dynamics. As a result of the erosion history, truncated and colluvial soil profiles coexist in arable fields. The erosion‐affected field‐scale soil spatial heterogeneity may limit agroecosystem model predictions. The objective was to identify the variation in the importance of soil properties and soil profile modifications in agroecosystem models for both agronomic and environmental performance. Four lysimeters with different soil types were used that cover the range of soil variability in an erosion‐affected hummocky agricultural landscape. Twelve models were calibrated on crop phenological stages, and model performance was tested against observed grain yield, aboveground biomass, leaf area index, actual evapotranspiration, drainage, and soil water content. Despite considering identical input data, the predictive capability among models was highly diverse. Neither a single crop model nor the multi‐model mean was able to capture the observed differences between the four soil profiles in agronomic and environmental variables. The model's sensitivity to soil‐related parameters was apparently limited and dependent on model structure and parameterization. Information on phenology alone seemed insufficient to calibrate crop models. The results demonstrated model‐specific differences in the impact of soil variability and suggested that soil matters in predictive agroecosystem models. Soil processes need to receive greater attention in field‐scale agroecosystem modeling; high‐precision weighable lysimeters can provide valuable data for improving the description of soil–vegetation–atmosphere process in the tested models.
A Canary in a COVID Coal Mine: Building Better Healthcare Biopreparedness Policy
Authors: Popescu Saskia
Published: August 2020

The SARS‐CoV‐2/COVID‐19 pandemic has been devastating to the U.S. health‐care system and sheds light on gaps in preparedness and response to biological threats. From limited personal protective equipment to staffing issues, hospitals are struggling to respond to the novel coronavirus outbreak. Unfortunately, hospital biopreparedness is a product of prioritization for hospital leadership and either exists or is neglected. Federal efforts to enhance health‐care readiness have done little to drive true change across the U.S. health‐care infrastructure. From optional efforts like the tiered hospital approach to special pathogens to the regulatory rule from the Centers for Medicare and Medicaid Services, federal efforts to build a resilient health‐care infrastructure against biological threats are woefully inadequate and dependent upon hospital leadership priorities. The COVID‐19 pandemic has revealed a need to implement regulatory requirements on health‐care facilities to invest in continued preparedness for biological events.