bluuebunny/crossref_metadata_2025 huggingface dataset:
Technical Note: Evaluation of audiovisual biofeedback smartphone application for respiratory monitoring in radiation oncology
Authors: Capaldi Dante P. I. , Nano Tomi F. , Zhang Hao , Skinner Lawrie B. , Xing Lei
Published: September 2020

Purpose

Radiation dose delivered to targets located near the upper abdomen or thorax are significantly affected by respiratory motion, necessitating large margins, limiting dose escalation. Surrogate motion management devices, such as the Real‐time Position Management (RPM™) system (Varian Medical Systems, Palo Alto, CA), are commonly used to improve normal tissue sparing. Alternative to current solutions, we have developed and evaluated the feasibility of a real‐time position management system that leverages the motion data from the onboard hardware of Apple iOS devices to provide patients with visual coaching with the potential to improve the reproducibility of breathing as well as improve patient compliance and reduce treatment delivery time.

Methods and materials

The iOS application, coined the Instant Respiratory Feedback (IRF) system, was developed in Swift (Apple Inc., Cupertino, CA) using the Core‐Motion library and implemented on an Apple iPhone® devices. Operation requires an iPhone®, a three‐dimensional printed arm, and a radiolucent projector screen system for feedback. Direct comparison between IRF, which leverages sensor fusion data from the iPhone®, and RPM™, an optical‐based system, was performed on multiple respiratory motion phantoms and volunteers. The IRF system and RPM™ camera tracking marker were placed on the same location allowing for simultaneous data acquisition. The IRF surrogate measurement of displacement was compared to the signal trace acquired using RPM™ with univariate linear regressions and Bland‐Altman analysis.

Results

Periodic motion shows excellent agreement between both systems, and subject motion shows good agreement during regular and irregular breathing motion. Comparison of IRF and RPM™ show very similar signal traces that were significantly related across all phantoms, including those motion with different amplitude and frequency, and subjects’ waveforms (all r > 0.9, P < 0.0001). We demonstrate the feasibility of performing four‐dimensional cone beam computed tomography using IRF which provided similar image quality as RPM™ when reconstructing dynamic motion phantom images.

Conclusions

Feasibility of an iOS application to provide real‐time respiratory motion is demonstrated. This system generated comparable signal traces to a commercially available system and offers an alternative method to monitor respiratory motion.
Technical Note: Fricke dosimetry for blood irradiators
Authors: Mantuano Andrea , Salata Camila , Mota Carla Lemos , Pickler Arissa , Pacífico Leonardo de Castro , Magalhães Luís Alexandre Gonçalves , Almeida Carlos Eduardo de
Published: September 2020

Purpose

The Fricke dosimeter has been shown to be a viable option as an absorbed dose standard. This work aims to provide the dose distribution in an irradiator container during blood irradiation using Fricke dosimetry.

Methods

Measurements were performed using a Gammacell Elan 3000 blood irradiator at Hemocenter in Rio de Janeiro, Brazil. A specific phantom was constructed and patented by the authors to perform these measurements. Fricke solution was prepared according to international protocols, and polyethylene bags filled with Fricke solution (n = 19) were spatially distributed within the phantom. Control bags were also submitted to the same process, except the irradiation. The irradiation time was calculated to give 25.7 Gy to the central portion of the phantom, the same dose used for blood bags.

Results

Encouraging results were obtained with an overall uncertainty of 2.1% (k = 1). The obtained results were compared with the doses calculated by the physicist from Hemocenter based on parameters provided by the manufacturer. The mean dose delivered to the Fricke bag in the center of the phantom (cavity 2) was 28.7 ± 0.5 Gy, which is 12% higher than the planned dose of 25.7 Gy.

Conclusions

The obtained results showed that the setup (Fricke and phantom) is able to perform dosimetry for blood irradiators. The delivered dose was higher than expected. This highlights the importance in controlling all the parameters during irradiation to ensure the correct dose for all irradiated bags.
Automatic segmentation, classification, and follow‐up of optic pathway gliomas using deep learning and fuzzy c‐means clustering based on MRI
Authors: Artzi Moran , Gershov Sapir , Ben‐Sira Liat , Roth Jonathan , Kozyrev Danil , Shofty Ben , Gazit Tomer , Halag‐Milo Tali , Constantini Shlomi , Ben Bashat Dafna
Published: September 2020

Purpose

Optic pathway gliomas (OPG) are low‐grade pilocytic astrocytomas accounting for 3‐5% of pediatric intracranial tumors. Accurate and quantitative follow‐up of OPG using magnetic resonance imaging (MRI) is crucial for therapeutic decision making, yet is challenging due to the complex shape and heterogeneous tissue pattern which characterizes these tumors. The aim of this study was to implement automatic methods for segmentation and classification of OPG and its components, based on MRI.

Methods

A total of 202 MRI scans from 29 patients with chiasmatic OPG scanned longitudinally were retrospectively collected and included in this study. Data included T2 and post‐contrast T1 weighted images. The entire tumor volume and its components were manually annotated by a senior neuro‐radiologist, and inter‐ and intra‐rater variability of the entire tumor volume was assessed in a subset of scans. Automatic tumor segmentation was performed using deep‐learning method with U‐Net+ResNet architecture. A fivefold cross‐validation scheme was used to evaluate the automatic results relative to manual segmentation. Voxel‐based classification of the tumor into enhanced, non‐enhanced, and cystic components was performed using fuzzy c‐means clustering.

Results

The results of the automatic tumor segmentation were: mean dice score = 0.736 ± 0.025, precision = 0.918 ± 0.014, and recall = 0.635 ± 0.039 for the validation data, and dice score = 0.761 ± 0.011, precision = 0.794 ± 0.028, and recall = 0.742 ± 0.012 for the test data. The accuracy of the voxel‐based classification of tumor components was 0.94, with precision = 0.89, 0.97, and 0.85, and recall = 1.00, 0.79, and 0.94 for the non‐enhanced, enhanced, and cystic components, respectively.

Conclusion

This study presents methods for automatic segmentation of chiasmatic OPG tumors and classification into the different components of the tumor, based on conventional MRI. Automatic quantitative longitudinal assessment of these tumors may improve radiological monitoring, facilitate early detection of disease progression and optimize therapy management.
Cross correlation–based misregistration correction for super resolution T2‐weighted spin‐echo images: application to prostate
Authors: Borisch Eric A. , Grimm Roger C. , Kargar Soudabeh , Kawashima Akira , Rossman Phillip J. , Riederer Stephen J.
Published: September 2020

Purpose

The purpose is to develop a retrospective correction for subtle slice‐to‐slice positional inconsistencies that can occur when overlapped slices are acquired for super resolution in T2‐weighted spin‐echo multislice imaging.

Methods

Spin‐echo acquisition of overlapped slices is typically done using multiple passes. After the passes are assembled into the final slice set, consecutive slices are correlated due to their overlap. Cross correlation was used to measure slice‐to‐slice displacement. After Z‐dependent filtering to preserve true object shape, the displacements were used to correct slice position. The method was tested in a phantom moved slowly (0.16‐0.63 mm/pass) under computer control and in vivo in 16 patients having prostate MRI.

Results

Over the motion range, the correlation method had an accuracy within 0.03 mm/pass and precision ± 0.20 mm (ie, subpixel). Corrected images visually resemble the true object. Over the patient studies, the mean range of motion in the anterior–posterior direction was 1.63 mm. Motion‐corrected axial images and the sagittal reformats were evaluated as significantly superior over those formed without motion correction.

Conclusion

The retrospective correlation‐based motion‐correction method provides significant improvement in the slice‐to‐slice registration necessary for effective super resolution using overlapped slices.
Cardiomyopathy in limb girdle muscular dystrophy R9, FKRP related
Authors: Libell Eric M. , Richardson Julia A. , Lutz Katie L. , Ng Benton Y. , Mockler Shelley R. H. , Laubscher Katie M. , Stephan Carrie M. , Zimmerman Bridget M. , Edens Erik R. , Reinking Benjamin E. , Mathews Katherine D.
Published: September 2020

Introduction

Reported frequencies of cardiomyopathy in limb girdle muscular dystrophy R9 (LGMDR9) vary. We describe the frequency and age at onset of cardiomyopathy in an LDMDR9 cohort.

Methods

Echocardiograms from 56 subjects (157 echocardiograms) with LGMDR9 were retrospectively reviewed. The cumulative probability of having an abnormal echocardiogram as a function of age was assessed by survival analysis for interval‐censored data by genotype. Correlations between cardiac and clinical function were evaluated.

Results

Twenty‐five (45%) participants had cardiomyopathy. The median age at first abnormal echocardiogram for subjects homozygous for the c.826C>A variant was 54.2 y compared to 18.1 y for all other fukutin‐related protein (FKRP) genotypes (P < .0001). There was a weak correlation between ejection fraction and 10‐Meter Walk Test speed (r = 0.25), but no correlation with forced vital capacity (r = 0.08).

Discussion

Cardiomyopathy is prevalent among those with LGMDR9 and occurs later in subjects homozygous for the c.826C>A mutation. These data will help to guide surveillance and management.
Clinical application of fish‐oil intravenous lipid emulsion in adult home parenteral nutrition patients
Authors: Mundi Manpreet S. , Bonnes Sara L. , Salonen Bradley R. , McMahon M. Molly , Martindale Robert , Hurt Ryan T.
Published: September 2020

Background

High–ω‐6 polyunsaturated fatty acids (PUFAs) are noted to contribute to development of intestinal failure–associated liver disease (IFALD) in home parenteral nutrition (HPN). Fish oil (FO) has been added to latest generation of lipid injectable emulsion (ILE) to increase ω‐3:ω‐6 PUFA ratio; however, appropriate dose of FO to treat IFALD is unknown.

Methods

After approval of exclusive FO ILE in the US for pediatric patients, we noted 2 adult patients with ongoing IFALD despite transition to mixed‐oil (MO) ILE. They were transitioned to off‐label FO ILE after review of literature regarding use of FO ILE in adult HPN patients was conducted to guide management.

Results

The first case involves a 40‐year‐old female receiving HPN with IFALD refractory to MO ILE. MO ILE (with 15% FO) was provided at 50 g/d for 3 d/wk and combined with FO ILE at 50 g/d for 4 d/wk. This combination resulted in improvement in liver studies and allowed for decrease in dextrose calories. The second case involves a 49‐year‐old male receiving HPN (secondary to complications of necrotizing pancreatitis) who developed IFALD. FO ILE was used as the sole source of lipids and led to improvement in liver function tests. No evidence of essential fatty acid deficiency was found in either case.

Conclusions

Current case presentations and review of literature support the use of FO ILE to increase ω‐3 PUFAs in patients with IFALD refractory to MO ILE. Additional research is necessary to delineate the dose of FO ILE necessary to achieve benefit.
Algebraic multigrid preconditioning of the Hessian in optimization constrained by a partial differential equation
Authors: Barker Andrew T. , Drăgănescu Andrei
Published: September 2020

We construct an algebraic multigrid (AMG) based preconditioner for the reduced Hessian of a linear‐quadratic optimization problem constrained by an elliptic partial differential equation. While the preconditioner generalizes a geometric multigrid preconditioner introduced in earlier works, its construction relies entirely on a standard AMG infrastructure built for solving the forward elliptic equation, thus allowing for it to be implemented using a variety of AMG methods and standard packages. Our analysis establishes a clear connection between the quality of the preconditioner and the AMG method used. The proposed strategy has a broad and robust applicability to problems with unstructured grids, complex geometry, and varying coefficients. The method is implemented using the Hypre package and several numerical examples are presented.
Pain in intensive care unit patients—A longitudinal study
Authors: Olsen Brita F. , Valeberg Berit T. , Jacobsen Morten , Småstuen Milada C. , Puntillo Kathleen , Rustøen Tone
Published: September 2020

Aim

To assess occurrence of pain during the first 6 days of intensive care unit (ICU) stay and evaluate associations between occurrence of pain and selected patient‐related variables.

Design

A longitudinal study.

Methods

Adult ICU patients from three units were included. Patients' pain was assessed with valid pain assessment tools every 8 hr during their first 6 days in ICU. Possible associations between occurrence of pain and selected patient‐related variables were modelled using multiple logistic regression.

Results

When pain was assessed regularly with pain assessment tools, 10% of patients were in pain at rest and 27% were in pain during turning. The proportions of patients who were in pain were significantly higher for patients able to self‐report pain, compared with patients not able to self‐report (p < .001). Several predictors were associated with being in pain. It is important to be aware of these predictors in order to improve pain management.
RBF‐ENO/WENO schemes with Lax–Wendroff type time discretizations for Hamilton–Jacobi equations
Authors: Abedian Rooholah , Dehghan Mehdi
Published: September 2020

In this research, a class of radial basis functions (RBFs) ENO/WENO schemes with a Lax–Wendroff time discretization procedure, named as RENO/RWENO‐LW, for solving Hamilton–Jacobi (H–J) equations is designed. Particularly the multi‐quadratic RBFs are used. These schemes enhance the local accuracy and convergence by locally optimizing the shape parameters. Comparing with the original WENO with Lax–Wendroff time discretization schemes of Qiu for HJ equations, the new schemes provide more accurate reconstructions and sharper solution profiles near strong discontinuous derivative. Also, the RENO/RWENO‐LW schemes are easy to implement in the existing original ENO/WENO code. Extensive numerical experiments are considered to verify the capability of the new schemes.
Associations of Pregnancy After Bariatric Surgery with Long‐Term Weight Trajectories and Birth Weight: LABS‐2 Study
Authors: Harrod Curtis S. , Elman Miriam R. , Vesco Kimberly K. , Wolfe Bruce M. , Mitchell James E. , Pories Walter J. , Pomp Alfons , Boone‐Heinonen Janne , Purnell Jonathan Q.
Published: September 2020

Objective

This study aimed to examine whether pregnancy following bariatric surgery affects long‐term maternal weight change and offspring birth weight.

Methods

Using data from the Longitudinal Assessment of Bariatric Surgery (LABS)‐2 study, linear regression was used to evaluate percent change in total body weight over a 5‐year follow‐up period among reproductive‐aged women who underwent Roux‐en‐Y gastric bypass or laparoscopic adjustable gastric banding as well as evaluate the association of bariatric procedure type and offspring birth weight.

Results

Of 727 women with preoperative age of 36.1 (6.3) years (mean [SD]) and BMI of 46.9 (7.0) kg/m2, 80 (11%) reported at least one pregnancy. After adjusting for covariates, percent change in total body weight was not significantly different between women who became pregnant and those who did not during a 5‐year follow‐up period (β = 2.02; 95% CI: −1.03 to 5.07; P = 0.19). Additionally, mean birth weight was not significantly different between mothers who underwent Roux‐en‐Y gastric bypass versus laparoscopic adjustable gastric banding (P = 0.99).

Conclusions

Postoperative pregnancy did not diminish long‐term weight loss in women in the LABS‐2 study. The finding of comparable weight loss is relevant for providers counseling women of reproductive age on weight‐loss expectations and family planning following bariatric surgery.
Real time uncertainty estimation in filling stage of resin transfer molding process
Authors: Tifkitsis K. I. , Skordos A. A.
Published: September 2020

This paper addresses the development of a digital twin, based on an inversion procedure, integrating process monitoring with simulation of composites manufacturing to provide a real time probabilistic estimation of process outcomes. A computationally efficient surrogate model was developed based on Kriging. The surrogate model reduces the computational time allowing inversion in real time. The tool was implemented in the filling stage of an resin transfer molding processing of a carbon fiber reinforced part resulting in the probabilistic prediction of unknown parameters. Flow monitoring data were acquired using dielectric sensors. The inverse scheme based on Markov Chain Monte Carlo uses input parameters, such as permeability and viscosity, as unknown stochastic variables. The scheme enhances the model by reducing model parameter uncertainty yielding an accurate on line estimation of process outcomes and critical events such as racetracking. The inverse scheme provides a prediction of filling duration with an error of about 5% using information obtained within the first 30% of the process.
Influence of the thermomechanical degradation on the formation of the crystalline structure of PHBV evaluated by temperature‐resolved SAXS experiments
Authors: Carli Larissa N. , Daitx Tales S. , Gonçalves Gustavo P. O. , Bianchi Otávio , Crespo Janaina S. , Mauler Raquel S.
Published: September 2020

In this work, the influence of the thermomechanical degradation of poly(hydroxybutyrate‐co‐hydroxyvalerate) (PHBV) during melt processing on the formation of its crystalline structure was investigated by temperature‐resolved small angle X‐ray scattering (SAXS) and complementary techniques, thus combining different tools in the characterization of polymeric structures. PHBV was processed in an internal mixer at 170°C for 7 minutes at four rotation speeds (50, 100, 150, and 200 rpm), in order to obtain samples with molar masses ranging from 125 000 to 64 000 g mol−1. The processing at higher rotation speeds resulted in the formation of thinner, smaller, and/or imperfect crystallites, which melt at lower temperatures. Moreover, the melting curves were broader than those associated with the unprocessed PHBV, suggesting a change in the size distribution of the crystallites. These results were corroborated by lamellar long period values and crystalline and amorphous thickness as determined by SAXS, where the sample processed at 200 rpm presented the most evident effects of the melt processing.
Synthesis of functionalized copolymers and their compatibilization effects on acrylonitrile butadiene styrene/poly(butylene terephthalate) blends
Authors: Li Kunquan , Wu Wenjian , Chai Shengyong , Tang Lei , Li Jide , Li Yan , Liu Qin , Chen Lin
Published: September 2020

In this study, the copolymers of methyl methacrylate‐co‐glycidyl methacrylate (MGD) with different epoxy contents and molecular weights, the styrene‐co‐glycidyl methacrylate (SGD) and methyl methacrylate‐co‐maleic anhydride (MAD) were synthesized. The synthesized copolymers, styrene‐co‐maleic anhydride (SMA) and styrene‐acrylonitrile‐co‐glycidyl methacrylate (SAG) were used as compatibilizers to enhance the impact strength of the acrylonitrile butadiene styrene/poly(butylene terephthalate) (ABS/PBT). The effects of differences in the structure, reactive group type, and molecular weight of the compatibilizers on the mechanical properties, phase morphology, melt viscosity, thermal stability, and melting temperature of the blend were studied. The results showed that functionalized copolymers were successfully synthesized with high monomer conversions. Addition of the functionalized copolymers increased melt viscosity but did not considerably affect thermal stability, tensile strength, flexural strength and melting temperature of the ABS/PBT blends. The compatibilizers improved the dispersion of the PBT phase and prevented brittle fracture, thereby increasing the impact strength of the blend. Among the studied compositions, the ABS/PBT/MGD‐5 blend exhibited the highest impact strength of 25.8 kJ/m2 and an appropriate melt flow index of 19.1 g/10 minutes. The compatibilizer should have an appropriate molecular weight to improve the interface bonding force. Regarding the melting viscosity, the reactive group content and compatibilizer dosage should be adjusted to ensure high impact strength.
Registration of ‘Purl’ soft white winter wheat
Authors: Carter A. H. , Balow K. A. , Shelton G. B. , Burke A. B. , Hagemeyer K. E. , Worapong J. , Higginbotham R. W. , Chen X. M. , Engle D. A. , Murray T. D. , Morris C. F.
Published: September 2020

There are numerous traits that soft white winter (SWW) wheat (Triticum aestivum L.) cultivars require to be successful in the U.S. Pacific Northwest. High yield potential, high grain volume weight, acceptable end‐use quality, winter hardiness, resistance to Cephalosporium stripe, and high falling number are just a few of the desired traits. Although many of these traits are driving factors toward releasing a new cultivar, two traits are essential if a cultivar is to be successful in the Pacific Northwest: stripe rust resistance and strawbreaker foot rot (eyespot) resistance. The objective of this research was to develop a SWW cultivar with improved resistance to current stripe rust races, that carries genes for strawbreaker foot rot resistance, is winter hardy, and has high yield potential in the intermediate (400–500 mm) and high (>500 mm) rainfall regions of eastern Washington. ‘Purl’ (Reg. no. CV‐1166, PI 691558) SWW wheat was developed and released in March 2018 by the Agricultural Research Center of Washington State University. Purl was tested under the experimental designations MAS08019‐92‐1‐S‐s and WA8234, which were assigned through progressive generations of advancement. Purl is a semi‐dwarf cultivar adapted to intermediate‐ to high‐rainfall wheat production regions of Washington. Purl has high‐temperature adult‐plant resistance to stripe rust, carries the Pch1 gene for strawbreaker foot rot, is intermediate in height, has midseason maturity, and has high test weight and grain yield potential. Purl has end‐use quality properties similar to those of ‘Stephens’, ‘Puma’, and ‘Madsen’ and is suitable for cookie, cake, and cracker production.
Sequential crosslinking for mechanical property development in high sulfur content composites
Authors: Thiounn Timmy , Karunarathna Menisha S. , Slann Lauren M. , Lauer Moira K. , Smith Rhett C.
Published: September 2020

This report details how sequential crosslinking processes can be applied to develop properties in sulfur‐bisphenol A composites. Olefinic carbons were first crosslinked by inverse vulcanization (InV) at 180°C and then aryl carbon crosslinking was affected via radical‐induced aryl halide‐sulfur polymerization (RASP) at 220°C. To demonstrate that these two crosslinking mechanisms are orthogonal and can be used to affect stepwise property changes, O,O′‐diallyl‐2,2′,5,5′‐tetrabromobisphenol A was selected as a comonomer. After InV of the monomer with 90 wt% sulfur, a flexible plastic material having an elongation at break of 89% was obtained, whereas after heating this premade polymer to initiate RASP, the polymer develops a threefold increase in its tensile strength and has an elongation at break of only 29%. The sequential crosslinking strategy demonstrated herein thus provides an innovative approach to tuning the properties of high sulfur‐content materials.
Effect of sour tea supplementation on liver enzymes, lipid profile, blood pressure, and antioxidant status in patients with non‐alcoholic fatty liver disease: A double‐blind randomized controlled clinical trial
Authors: Izadi Fatemeh , Farrokhzad Amirhosein , Tamizifar Babak , Tarrahi Mohammad Javad , Entezari Mohammad Hassan
Published: September 2020

The aim of this study was to evaluate the efficacy of sour tea supplementation in patients with nonalcoholic fatty liver disease (NAFLD). Seventy NAFLD patients were enrolled in this randomized, double‐blind, placebo‐controlled clinical trial. Participants received sour tea in the form of a 450 mg capsule or a placebo capsule daily for 8 weeks. Anthropometric indices, liver enzymes, lipid profile, blood pressure, and antioxidant status were evaluated at the baseline and at the end of the study. Sixty‐one participants completed the study. After 8 weeks, sour tea administration significantly decreased serum triglyceride (TG) (p = .03), alanine aminotransferase (ALT) (p = .01), and aspartate aminotransferase (AST) (p = .004) levels compared with the placebo. In addition, sour tea supplementation resulted in a significant reduction in systolic blood pressure (SBP) (p = .03) and diastolic blood pressure (DBP) (p = .04), and a significant increase in serum total antioxidant capacity (TAC) levels (p ˂ .001) compared with the placebo. However, no significant changes in anthropometric measures, total cholesterol (TC), low‐density lipoprotein cholesterol (LDL‐c), and high‐density lipoprotein cholesterol (HDL‐c) levels were observed after sour tea supplementation compared with the placebo (p > .05). Sour tea supplementation may be effective in improving serum TG, liver enzymes, and blood pressure in patients diagnosed with NAFLD. Further studies are needed to address the exact mechanism of action of these effects.
Analogies between the topological insulator phase of 2D Dirac materials and the superradiant phase of atom‐field systems
Authors: Calixto Manuel , Romera Elvira , Castaños Octavio
Published: September 2020

A semiclassical phase‐space perspective of band‐ and topological‐insulator regimes of 2D Dirac materials and normal‐ and superradiant phases of atom‐field interacting models is given in terms of delocalization, entropies, and quantum correlation measures. From this point of view, the low‐energy limit of tight‐binding models describing the electronic band structure of topological 2D Dirac materials such as phosphorene and silicene with tunable band gaps share similarities with Rabi‐Dicke and Jaynes‐Cummings atom‐field interaction models, respectively. In particular, the edge state of the 2D Dirac materials in the topological insulator phase exhibits a Schrödinger's cat structure similar to the ground state of two‐level atoms in a cavity interacting with a one‐mode radiation field in the superradiant phase. Delocalization seems to be a common feature of topological insulator and superradiant phases.
Resolution enhancement of overlapping peaks of ion mobility spectrometry based on improved particle swarm optimization algorithm
Authors: Zhang Shulei , Li Junhui , Xie Chengyi , Wu Qidi , Yu Jiancheng , Tang Keqi
Published: September 2020

Rationale

Ion mobility spectrometry (IMS) is a powerful analytical tool that has been widely applied in many fields. However, the limited structural resolution of IMS results in peak overlapping in the analysis of samples with similar structures. We propose a novel method, improved particle swarm optimization (IPSO), for the separation of IMS overlapping peaks.

Methods

This method, which prevents local optimization, is used to identify the peak model coefficients of IMS. Moreover, we use the half‐peak width characteristics of IMS to determine the particle position range, which eliminates impossible combinations of single peaks and reduces the difficulty of identification of coefficients.

Results

During a comparison in performance between IPSO and the genetic algorithm (GA), the results show that the maximum separation error of IPSO is only 1.45%, while the error of the GA is up to 17.43%. Moreover, the time consumed by IPSO is 95% less than that of the GA, and IPSO has a greater robustness under the same separation error conditions.

Conclusions

The method proposed provides accurate analytical results in separating overlapping IMS peaks even in cases of severe overlaps, which greatly enhances the structural resolution of IMS.
A miniaturized spray‐assisted fine‐droplet‐formation‐based liquid‐phase microextraction method for the simultaneous determination of fenpiclonil, nitrofen and fenoxaprop‐ethyl as pesticides in soil samples
Authors: Turan Nouha Bakaraki , Bakirdere Sezgin
Published: September 2020

Rationale

Pesticides are a group of micropollutants that persist for a long time in the environment and pose threats to life. Much effort has been devoted to developing pre‐concentration methods capable of producing samples suitable for the detection of pesticides. However, better methods are still required to detect these compounds when they are present in trace concentrations in soils.

Method

Spray‐assisted fine‐droplet‐formation‐based liquid‐phase microextraction was used to prepare soil samples containing three different pesticides, fenpiclonil, nitrofen and fenoxaprop‐ethyl, for subsequent analysis by gas chromatography/mass spectrometry (GC/MS). A spraying apparatus was used for the dispersion of the extraction solvent into the sample/standard solution to improve the extraction efficiency. Optimization studies were performed to lower the detection limits of these analytes and the results obtained by the application of the newly developed system were compared with those obtained using the conventional GC/MS method.

Results

A calibration curve over the range 5.0–100 μg L−1 was obtained under the optimal conditions. The limits of detection and quantification were 1.56–1.80 μg L−1 and 5.21–5.98 μg L−1, respectively. The enhancements in detection ability over the conventional method for the three tested pesticides were 188.01, 176.96 and 517.14 for fenpiclonil, nitrofen and fenoxaprop‐ethyl, respectively Recovery studies performed in soil samples were satisfactory reflecting accurate applicability of the developed method.

Conclusions

The developed microextraction method is a time‐saving and simple version of the traditional dispersive liquid–liquid microextraction method that also reduces the use of dispersive solvents.
Coated glass capillaries as SPME devices for DART mass spectrometry
Authors: Cody Robert , Maleknia Simin D.
Published: September 2020

Rationale

Solid‐phase microextraction (SPME) provides high‐throughput sample cleanup and pre‐concentration. Here we demonstrate coated glass capillaries (CGCs) as SPME devices for specific applications in direct analysis in real time (DART) mass spectrometry, referred to as “CGC‐DART”, for rapid screening of environmental contaminants at low parts‐per‐trillion detection limits and with accurate identification of analytes.

Methods

The extraction is performed in a one‐step process in minutes by dipping the CGC in solutions containing the analytes, and then placing the CGC in a DART source for analysis. CGCs are disposable and relatively inexpensive in comparison with SPME devices, and can be prepared with hydrophobic, hydrophilic or mixed‐mode materials similar to SPME. CGCs were prepared by adsorption coating with incubation of capillaries in saturated solutions of octadecylamine or covalent activation of silanes.

Results

Quantitation is shown with perfluorooctanoic acid (PFOA) at 1 ppt to 100 ppb, with the lowest detection at 500 parts‐per quadrillion (ppq) in tap water. One‐step extraction of contaminated groundwater from Northern Queensland, Australia, revealed perfluorooctane sulfonate (PFOS) and perfluorohexanesulfonamide as well as C4–C8 perfluoroalkyl carboxylic acids. A soil sample taken near a former military air base (New Hampshire, USA) revealed the presence of perfluorononanoic acid (PFNA) at 1 ppb and traces of perfluoroheptanoic acid.

Conclusions

CGC‐DART enabled one‐step extraction of PFASs in minutes with mL sample volumes at low concentrations as shown for the standards and contaminated soil and water samples. DART‐MS combined with Kendrick mass defect analysis enabled accurate identification of PFASs without chromatography steps, as fluorinated compounds are mass deficient and easily distinguished over background signal.
Severe Nocardia pneumonia in an immunocompromised patient with alpha‐1 antitrypsin deficiency
Authors: Chan Daryl E. C. Y. , Hamed Dima , Lennon Daniel , Wark Peter
Published: September 2020

Pulmonary nocardiosis is an uncommon pulmonary infection that is more likely found in immunocompromised patients with underlying chronic lung disease. The presentation of pulmonary nocardiosis is widely variable and shares features with other types of pulmonary infections. Nocardia is also not as easily isolated on standard culture mediums and hence more difficult to identify. We describe the case of a patient with a severe necrotising pneumonia who was chronically immunosuppressed with steroids and has alpha‐1 antitrypsin deficiency.
Operative and long‐term oncological outcomes in patients undergoing robotic versus laparoscopic surgery for rectal cancer
Authors: Bilgin Ismail Ahmet , Bas Mustafa , Aytac Erman , Benlice Cigdem , Esen Eren , Kirbiyik Ebru , Kiziltas Cansu , Aghayeva Afag , Ozben Volkan , Hamzaoglu Ismail , Karahasanoglu Tayfun , Baca Bilgi
Published: September 2020

Background

This study aimed to compare short‐ and long‐term outcomes after robotic versus laparoscopic approach in patients undergoing curative surgery for rectal cancer.

Methods

Patients undergoing elective robotic and laparoscopic resection for rectal cancer were included. Perioperative clinical characteristics, postoperative short‐ and long‐term outcomes were compared between groups.

Results

There were 72 and 44 patients in robotic (RG) and laparoscopic (LG) groups respectively. No differences were detected regarding patients' demographics, histopathologic outcomes, conversion rates and 30‐day overall postoperative complication rates. Operative time was longer in the RG (341 ± 111.7 vs. 263 ± 97.5 min, p = 0.001) and length of stay was longer in the LG (4.4 ± 1.9 vs. 6.4 ± 2.9 days, p = 0.001). The 5‐year overall and disease‐free survival rates were similar (97.1% and 94.9%, p = 0.78; 86.2% and 82.7%, p = 0.72) between the groups.

Conclusion

This study showed both short and long‐term outcomes of a limited number of included patients between the robotic and laparoscopic surgery were similar. However, future studies and randomized trials are necessary to establish these findings.
Almost output consensus of nonlinear multiagent systems in the presence of external disturbances
Authors: Meng Tingyang , Lin Zongli
Published: September 2020

In this article, we investigate the almost output consensus problem for nonlinear multiagent systems under the influence of external disturbances. The problem of almost output consensus of nonlinear multiagent systems is formulated. Conditions on the nonlinear systems are established under which distributed consensus protocols are designed in a recursive manner. These protocols are shown to achieve almost output consensus, that is, output consensus of the system is achieved in the absence of the disturbances and the L2‐gain from the disturbances to the output consensus error of agents when the system is operating in output consensus can be made arbitrarily small. A simulation example is shown to verify the theoretical results.
Static output feedback passivation revisited and global asymptotic stabilizing properties of a controller
Authors: Stefanovski Jovan D.
Published: September 2020

The class of systems that can be globally asymptotically stabilized by the well‐known control law , is extended, in respect to literature. This control law is suitable for application to systems of unknown structure, and it is shown that it is more advantageous than the linear control law. The stability proof is based on solutions of a newly introduced problem, which is a specialization of the passivation by static output feedback control of a system with nonzero feedforward matrix. Necessary and sufficient conditions for existence of a solution of the problem are given, which include the minimum phase property of the given system. It is explained why the new concept cannot be applied to nonminimum phase systems. It is proved that a class of nonminimum phase systems can be stabilized by the same control law, where is a matrix function, rather than a constant matrix. Illustrative example are given.
Reachable set estimation and synthesis of discrete‐time switched systems
Authors: Zhao Rui , Wang Yijing , Zuo Zhiqiang
Published: September 2020

This article focuses on estimating the reachable set of discrete‐time switched linear systems with unknown disturbance. The discontinuous multiple Lyapunov function, which enables us to reduce the conservatism in the sense of mode‐dependent average dwell‐time, is proposed to estimate the underlying reachable set. The main difficulty of this problem is that the energy may jump at the switching instants. To this end, we seek for another set, which preserves the former reachable set as an inner one, guaranteeing that in the case of escaping the inner reachable set at the switching instants, the state trajectory will arrive at the inner reachable set within finite time. Finally, two numerical examples are given to show the efficiency of the proposed strategy.
Hybrid modelling of low velocity zones in box culverts to assist fish passage: Why simple is better!
Authors: Leng Xinqian , Chanson Hubert
Published: September 2020

A culvert is a covered road structure constructed to pass flood and drainage. The engineering design principle of culverts focuses on optimising flood capacity at the lowest possible cost, resulting in high flow velocity through the barrel. With modern engineering design being more environmentally aware, culverts are considered common barriers for fish migrating upstream due to the excessive barrel velocity. The migration of fish upriver is important for their breeding and feeding activities, contributing to a stable population and species diversity. Improved or novel design for a fish‐friendly culvert is needed to ensure well‐being of local fish community. This article is a review of recent developments in seeking a solution for a better fish‐friendly culvert design. A major common feature of the reviewed studies is the application of hybrid modelling, combining laboratory experiments and numerical Computational Fluid Dynamics (CFD) modelling together. Various design alternatives were compared for pros and cons: channel roughening, installation of speed‐reducing structures (e.g., baffles or beams), and simply widening the channel by adding more culvert units (boxes). Overall, channel widening stands to be a better design choice due to its suitability for both flood passage and fish passage, with little impact on operation safety and a reduced maintenance cost.
Natural disasters as a source of entrepreneurial opportunity: Family business resilience after an earthquake
Authors: Salvato Carlo , Sargiacomo Massimo , Amore Mario Daniele , Minichilli Alessandro
Published: September 2020

Research Summary

What type of firms are more likely to survive or even thrive in disaster events such as earthquakes, wildfires, and the COVID‐19 pandemic? We investigate whether family ownership and industry positioning affect firms' ability to capture opportunities for business recovery after a natural disaster. We analyze the performance of Italian family and nonfamily firms around a disastrous earthquake in 2009. Following the earthquake, family firms performed better than nonfamily firms, especially when multiple family members were involved as owners. Moreover, family ownership is beneficial in industries highly dependent on the public sector. Our findings provide evidence on the superior resilience of family firms by illustrating the characteristics that allow firms hit by disaster events to seize posttraumatic entrepreneurial opportunities for recovery and growth.

Managerial Summary

The purpose of this study was to understand whether a possible explanation of family firms' superior longevity is their resilience to mass emergencies and their ability to transform post‐crisis threats into entrepreneurial opportunities. We found that family firms performed better than their nonfamily peers after the earthquake that hit Central Italy, and especially the area around L'Aquila, in 2009. During disaster events, family ownership resources—focused on the long term and the desire to transfer the business to future generations—provide the firm with the social and emotional capital needed to address the hardship. Moreover, family firms that operated in industries closer to the public demand leveraged the family proximity to politics, further enhancing the processes of recovery and opportunity identification.
Finite sample variance estimation for optimal dynamic treatment regimes of survival outcomes
Authors: Simoneau Gabrielle , Moodie Erica E. M. , Nijjar Jagtar S. , Platt Robert W.
Published: September 2020

Deriving valid confidence intervals for complex estimators is a challenging task in practice. Estimators of dynamic weighted survival modeling (DWSurv), a method to estimate an optimal dynamic treatment regime of censored outcomes, are asymptotically normal and consistent for their target parameters when at least a subset of the nuisance models is correctly specified. However, their behavior in finite samples and the impact of model misspecification on inferences remain unclear. In addition, the estimators' nonregularity may negatively affect the inferences under some specific data generating mechanisms. Our objective was to compare five methods, two asymptotic variance formulas (adjusting or not for the estimation of nuisance parameters) to three bootstrap approaches, to construct confidence intervals for the DWSurv parameters in finite samples. Via simulations, we considered practical scenarios, for example, when some nuisance models are misspecified or when nonregularity is problematic. We also compared the five methods in an application about the treatment of rheumatoid arthritis. We found that the bootstrap approaches performed consistently well at the cost of longer computational times. The asymptotic variance with adjustments generally yielded conservative confidence intervals. The asymptotic variance without adjustments yielded nominal coverages for large sample sizes. We recommend using the asymptotic variance with adjustments in small samples and the bootstrap if computationally feasible. Caution should be taken when nonregularity may be an issue.
Estimating the sample variance from the sample size and range
Authors: Rychtář Jan , T. Taylor Dewey
Published: September 2020

For meta‐analysis studies and systematic reviews, it is important to pool the data from a set of similar clinical trials. To pool the data, one needs to know their SD. Many trial reports, however, contain only the median, the minimum and maximum values, and the sample size. It is therefore important to be able to estimate the SDSfrom the sample sizenand ranger. For smalln ≤ 100, we improve existing estimators ofr/S, the “divisor,” denoted by . This in turn yields improved estimators of the SD in the form on simulated as well as real datasets. We provide numerical values of the proposed estimator as well as approximation by a simple formula . Furthermore, for largen, we provide estimators of the divisor for the normal, exponential, and other bounded and unbounded distributions.
Basking in reflected glory: Reverse status transfer from foreign to home markets
Authors: Chae Heewon , Song Jaeyong , Lange Donald
Published: September 2020

Research summary

In this study, we investigate reverse status transfer from foreign to home country markets. We argue that a positive product status accrued in a leading foreign country, or outside status, increases domestic market performance by providing home country audiences with a means of self‐enhancement. We predict that the impact of outside status will be stronger when the foreign and home countries have similar economic conditions, and when the products are high priced, luxury goods—as social approval and prestige‐seeking are important factors in purchase decisions for these products. We test our hypotheses using a sample of firms and vehicles in the automotive industry. Results from two‐stage multi‐level analysis support our arguments. Our results have several implications for research related to status transfer and international business.

Managerial summary

We look at how consumers in the home country of an automaker (Germany, Japan, and Korea) increase purchases of a car model that wins the J.D. Power APEAL award in the United States. Rather than telling those consumers anything new about the car's quality, the award bestows status on the vehicle from the leading outside market. (We call that reverse status transfer, as it flips the idea that domestic status helps firms competing in foreign markets.) Domestic consumers can share in some of that status by purchasing the vehicle, and they are especially likely to do so when it is a high priced or luxury model, as those aspects amplify the status effects, as does economic similarity between the United States and the home country.
Enhancing Charge Separation through Oxygen Vacancy‐Mediated Reverse Regulation Strategy Using Porphyrins as Model Molecules
Authors: Yin Dan , Ning Xingming , Zhang Ruizhong , Du Peiyao , Zhang Dongxu , Deng Yang , Liu Jia , Zhang Qi , Zhang Zhen , Lu Xiaoquan
Published: September 2020

Highly efficient charge separation has been demonstrated as one of the most significant steps playing decisive roles in enhancing the overall efficiency of photoelectrochemical (PEC) processes. In this study, by employing 5,10,15,20‐tetrakis (4‐carboxyphenyl) porphyrin‐Ni (NiTCPP) as a prototype, an oxygen vacancy (Vo)‐mediated reverse regulation strategy is proposed for tuning hole transfer, which in turn can accelerate the transport of electrons and thus enhancing charge separation. The optimal NiO/NiTCPP system exhibits much higher (≈40 times) photocurrent and longer (≈13 times) lifetime of charge carriers compared with those of pure NiTCPP. Furthermore, the electron transfer kinetic rate constant (Keff) is quantitatively determined by an efficient scanning photoelectrochemical microscopy (SPECM). The Keff of the optimal system has a 5.7‐fold improvement. In addition, the similar enhancement in charge separation from other semiconductors (CoTCPP and FeTCPP) are also observed, indicating that the Vo‐mediated reverse regulation strategy is a promising pathway for tuning the properties of light harvesters in solar energy conversion.
A Tandem 0D/2D/2D NbS2 Quantum Dot/Nb2O5 Nanosheet/g‐C3N4 Flake System with Spatial Charge–Transfer Cascades for Boosting Photocatalytic Hydrogen Evolution
Authors: Lin Bo , Chen Zihao , Song Pin , Liu Haishi , Kang Lixing , Di Jun , Luo Xiao , Chen Longqing , Xue Chao , Ma Bowen , Yang Guidong , Tang Jun , Zhou Jiadong , Liu Zheng , Liu Fucai
Published: September 2020

The relatively high recombination rate of charges remains the most critical limiting factor for solar‐driven water splitting for hydrogen generation. Herein, a tandem 0D/2D/2D NbS2 quantum dot/Nb2O5 nanosheet/g‐C3N4 flake (NSNOCN) system is designed. Owing to the unique spatial‐arrangement and elaborate morphology of 0D NbS2, 2D Nb2O5, and 2D g‐C3N4 in the newly designed NSNOCN, plenty of spatial charge–transfer cascades from g‐C3N4 to NbS2 via Nb2O5 are formed to accelerate separation and transfer of charges significantly, thus contributing to a high photocatalytic H2 generation rate of 13.99 mmol h−1 g−1 (an apparent quantum efficiency of 10.8% at 420 nm), up to 107.6 and 43.7 times by contrast with that of g‐C3N4 and Nb2O5, respectively. This work can provide a new platform in the design of artificial photocatalytic systems with high charge–transfer efficiency.