bluuebunny/crossref_metadata_2025 huggingface dataset:
Simultaneous determination of poly‐ and perfluoroalkyl substances and organophosphorus flame retardants in serum by ultra‐performance liquid chromatography/tandem mass spectrometry
Authors: Li Jinhong , Li Qiang , Li Jiufeng , Zhang Yunhui
Published: April 2022

Rationale

Poly‐ and perfluoroalkyl substances (PFASs) and organophosphorus flame retardants (OPFRs) are two types of emerging organic pollutants with potential human health hazards. Here, a rapid and sensitive method was developed for the determination of sixteen PFASs and seven OPFRs in human serum by ultra‐performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS).

Methods

After optimizing the chromatographic and mass spectrometric conditions, respectively, 100 μL of serum sample was liquid–liquid extracted using 8 mL of methyl tert‐butyl ether. The 23 targets were quantified within 8 min. All targets were quantified by the isotope‐internal standard method in both negative‐ and positive‐ion mode by UPLC/MS/MS.

Results

The method was validated in terms of sensitivity, linearity, precision, and accuracy. The limit of detection ranged between 0.004 and 0.650 ng/mL. Recoveries ranged from70.0% to 118.9% with a relative standard deviation lower than 20%. The developed method was successfully applied to analyze targeted analytes in human serum samples. A total of 13 of 23 analytes were detected in over 50% of samples.

Conclusions

A sensitive and rapid method was developed to quantify sixteen PFASs and seven OPFRs in serum. Sensitivity, linearity, recovery, and precision were validated and found to be satisfactory. This method can be a valuable tool for evaluation of exposure to both PFASs and OPFRs with high separation efficiency and sensitivity.
Isolated diaphragm weakness and the diagnostic value of phrenic nerve stimulation
Authors: Dhillon Sarbroop , Abeyweera Prarthana , Kosky Christopher , Harrison Lisa , Isaac Ashvin , Noffsinger William , Pang Elaine , Needham Merrilee , Stell Rick , Singh Bhajan
Published: April 2022

Acute onset, atraumatic, bilateral diaphragm paralysis due to isolated bilateral phrenic neuropathy is uncommon. Respiratory physicians should be alert to this disorder because it is associated with considerable morbidity and diagnosis is often delayed. These case reports highlight important aspects of the presentation, investigations and management of this disorder.
Effects of cover crops on soil thermal properties of a corn cropping system
Authors: Mendis Sidath Subodha , Udawatta Ranjith , Anderson Stephen H. , Ansari Jamshid , Salceda Miguel
Published: April 2022

Soil thermal properties play many major roles in a soil as they influence the soil temperature and define the soil microclimate, which regulates many soil health parameters as well as life cycles of soil biota. Although cover crops (CC) can affect soil thermal properties, they are one of the least studied areas. This study compared the effects of CC on soil thermal properties in a corn (Zea mays L.) cropping system at the Elsberry Plant Material Center–USDA in Missouri (USA). The study design consisted of (a) no‐till CC (NC), (b) conventional till no CC (CN), (c) no‐till no CC (NN), and (d) grass (G) treatments. The first CC establishment in the NC treatment was done in October 2019. Soil cores were collected in April 2021 from 0‐to‐40‐cm depth at 10‐cm increments (96 samples) and analyzed for volumetric heat capacity (Cv), soil thermal conductivity (λ), soil thermal diffusivity (α), soil organic carbon (SOC), bulk density (BD), and volumetric water content (θ). As per the results, NC did not significantly improve SOC, BD, or soil thermal properties, because the biomass accumulation by CC was not enough due to the lack of CC establishment duration. The G treatment showed significantly higher Cv and lower λ in several soil depths. The study outcomes suggested that long‐term maintenance of CC with cropping systems are needed in quantifying the effects of CC on soil thermal properties.
Biomimic Trained Immunity‐MSCs Delivery Microcarriers for Acute Liver Failure Regeneration
Authors: Wang Jinglin , Huang Danqing , Ren Haozhen , Shang Luoran
Published: April 2022

Mesenchymal stem cells (MSCs) have a demonstrated value for acute liver failure (ALF) regeneration, while their delivery stratagems with long‐term biological functions, low immune response, and high biocompatibility are still a challenge. Here, a lipopolysaccharide (LPS)‐loaded photoresponsive cryogel porous microcarrier (CPM) for MSCs delivery and colonization is presented to promote defect liver regeneration. The CPMs are fabricated with graphene oxide, poly(N‐isopropylacrylamide), and gelatin methacrylate (GelMA) via droplet microfluidic technology and a gradient‐cooling procedure. Benefitting from the biocompatible GelMA component and the porous microstructure of the CPMs, MSCs can be nondestructively captured and abundantly delivered. Because the LPS can be released from the CPMs under NIR irradiation, the delivered MSCs are imparted with the feature of “trained immunity.” Thus, when the MSCs‐laden CPMs are tailored into the liver matched patches by bioprinting and applied in ALF rats, they display superior anti‐inflammatory and more significant liver regeneration properties than the untrained MSCs. These features make the CPMs an excellent MSCs delivery system for clinical applications in tissue repair.
Research on the construction of accounting information audit quality control system based on blockchain
Authors: Wang Juanling
Published: April 2022

Audit quality control plays an irreplaceable role in improving the quality of accounting information, and it is also of great significance to the normal operation and development of enterprises. Blockchain is a security technology, which guarantees the security of data to a great extent. Information security is the basis for the quality control of accounting information auditing, and all audit quality control activities start with information data. Therefore, the integration of blockchain technology is essential for audit quality control. This article aims to build an audit quality control system, so that everyone first understands the blockchain security technology and accounting information audit quality control related theories. This article puts forward the method of setting up variables and constructing the accounting information audit quality control system to solve the current problem of low audit quality in China. The experimental results of this article show that blockchain technology is beneficial to ensure the security of audit information and can improve audit quality by 20%.
Borssele V slip joint connection: design, certification and installation of the world's first full‐size submerged slip joint
Authors: Suur Sander , Hengeveld Ferdy
Published: April 2022

In April 2020 the world's first full‐size submerged slip joint connection was installed at the Borssele Site V offshore wind farm. This event marked the launch of a new, alternative transition piece/monopile (TP/MP) connection for the offshore wind market. An extensive qualification programme in terms of numerical modelling and testing was set up prior to installing the slip joint. This process was witnessed, reviewed and accepted by DNVGL. It led to a certified slip joint design for Borssele V, with a 9.5 MW wind turbine generator (WTG) on top of the foundation as well as an A‐level component certificate for the slip joint in general. The installation of the slip joint for Borssele V was the first use of this connection in a commercial full‐size wind turbine.

The implementation of the slip joint connection at Borssele V demonstrated the benefits of the slip joint in terms of simple, safe and fast installation as well as the option for using the slip joint submerged, thus allowing a more optimized weight/length split between MP and TP and the use of smaller installation vessels. A monitoring campaign was executed during and after installation to provide lessons for future slip joint designs.

Reducing the levelized cost of energy (LCoE) requires big steps in technology innovation. The Borssele V offshore wind farm offered a unique opportunity to demonstrate to the industry that the slip joint connection is fully feasible and ready for practical implementation.

The slip joint: simple connection, ingenious design.
Supporting Multilingual Black Children: Building on Black Language Genius
Authors: Frieson Brittany L. , Presiado Vivian E.
Published: April 2022

Negative societal beliefs and language ideologies about Black Language speakers continue to shape how Black Language is perceived from deficit perspectives in schools. However, educators must challenge these negative ideologies by amplifying the rich linguistic features that Black Language speakers already have by positioning these language practices as valuable resources in the classroom. From translanguaging and critical perspectives, the authors demonstrate how multilingual Black American children use various complex language and literacy practices to make sense of their worlds, including vignettes from bilingual classrooms and childhood memories. The authors offer practical implications using classroom and community examples that can serve as models to educators on how to support and build upon the richness of Black Language speakers’ literacy and language practices.
Budesonide orodispersible tablets for induction of remission in patients with active eosinophilic oesophagitis: A 6‐week open‐label trial of the EOS‐2 Programme
Authors: Miehlke Stephan , Schlag Christoph , Lucendo Alfredo J. , Biedermann Luc , Vaquero Cecilio Santander , Schmoecker Christoph , Hayat Jamal , Hruz Petr , Ciriza de los Rios Constanza , Bredenoord Albert Jan , Vieth Michael , Schoepfer Alain , Attwood Stephen , Mueller Ralph , Burrack Sarah , Greinwald Roland , Straumann Alex ,   International EOS‐2 Study Group
Published: April 2022

Background

A novel budesonide orodispersible tablet (BOT) has been proven effective in adult patients with active eosinophilic oesophagitis (EoE) in a 6‐week placebo‐controlled trial (EOS‐1).

Aims

To report the efficacy of an open‐label induction treatment with BOT in a large prospective cohort of EoE patients within the EOS‐2 study.

Methods

Patients with clinico‐histological active EoE were treated with BOT 1 mg BID for 6 weeks. The primary endpoint was clinico‐histological remission (≤2 points on numerical rating scales [0–10] each for dysphagia and odynophagia, and peak eosinophil count <16 eos/mm2 hpf (corresponds to <5 eos/hpf)). Further study endpoints included clinical and histological remission rates, change in the EEsAI‐PRO score, change in peak eosinophil counts, and deep endoscopic remission using a modified Endoscopic Reference Score.

Results

Among 181 patients enrolled, 126 (69.6%) achieved clinico‐histological remission (histological remission 90.1%, clinical remission 75.1%). The mean peak eosinophil counts decreased by 283 eos/mm2 hpf (i.e., by 89.0%). Mean EEsAI‐PRO score decreased from baseline by 29 points and deep endoscopic remission was achieved in 97 (53.6%) patients. The majority of patients judged tolerability as good or very good (85.6%) and compliance was high (96.5%). Local candidiasis was suspected in 8.3% of patients; all were of mild severity, resolved with treatment and none led to premature withdrawal from the study.

Conclusions

In this large prospective trial, a 6‐week open‐label treatment with BOT 1 mg BID was highly effective and safe in achieving clinico‐histological remission of active EoE and confirmed the results of the placebo‐controlled EOS‐1 trial.
Assessment of agreement using the equine glandular gastric disease grading system in 84 cases
Authors: Pratt Stefanie , Bowen Ian , Hallowell Gayle , Shipman Emma , Redpath Adam
Published: April 2022

Introduction

Equine glandular gastric disease (EGGD) is a common condition causing signs of gastric pain although lesions are highly variable in their appearance. The only definitive method to diagnose EGGD ante‐mortem is gastroscopy. The current recommended method for describing these lesions is the European College of Equine Internal Medicine (ECEIM) guidelines; however, repeatability between users is variable. This study aimed to validate the reliability of lesion descriptions using ECEIM consensus guidelines, using four blinded equine internal medicine diplomates.

Methods

Ninety‐two horses with EGGD with pre‐ and post‐treatment gastroscopy images were identified using the electronic record at a UK equine hospital between 2012 and 2019. Eight horses were excluded due to non‐diagnostic images. Four blinded observers used the recommended grading system to describe images and outcomes. Intraclass correlation coefficients and Krippendorff's alpha were used to determine reliability and agreement, respectively.

Results

Intraclass correlation coefficient for severity was 0.782 (95% confidence interval [CI] 0.722–0.832), for distribution was 0.671 (95% CI 0.540–0.763), for the descriptor raised was 0.635 (95% CI 0.479–0.741), fibrinosuppurative was 0.745 (95% CI 0.651–0.812), haemorrhagic was 0.648 (95% CI 0.513–0.744), hyperaemic was 0.389 (95% CI 0.232–0.522) and for outcome was 0.677 (95% CI 0.559–0.770). Krippendorff's alpha for severity was 0.466 (95% CI 0.466–0.418), for distribution was 0.304 (95% CI 0.234–0.374), for the descriptor raised was 0.268 (95% CI 0.207–0.329), fibrinosuppurative was 0.406 (95% CI 0.347–0.463), haemorrhagic was 0.287 (95% CI 0.229–0.344), hyperaemic was 0.112 (95% CI 0.034–0.188) and for outcome was 0.315 (95% CI 0.218–0.408).

There was moderate reliability determined between observers using intra‐class correlation coefficients and unacceptable agreement determined between observers using Krippendorff's alpha.

Discussion

These results suggest that the current grading system is not comparable between observers, indicating the need to review the grading system or define more robust criteria.
Food web perspectives and methods for riverine fish conservation
Authors: Naman Sean M. , White Seth M. , Bellmore J. Ryan , McHugh Peter A. , Kaylor Matthew J. , Baxter Colden V. , Danehy Robert J. , Naiman Robert J. , Puls Amy L.
Published: April 2022

Food web analyses offer useful insights into understanding how species interactions, trophic relationships, and energy flow underpin important demographic parameters of fish populations such as survival, growth, and reproduction. However, the vast amount of food web literature and the diversity of approaches can be a deterrent to fisheries practitioners engaged in on‐the‐ground research, monitoring, or restoration. Incorporation of food web perspectives into contemporary fisheries management and conservation is especially rare in riverine systems, where approaches often focus more on the influence of physical habitat and water temperature on fish populations. In this review, we first discuss the importance of food webs in the context of several common fisheries management issues, including assessing carrying capacity, evaluating the effects of habitat change, examining species introductions or extinctions, considering bioaccumulation of toxins, and predicting the effects of climate change and other anthropogenic stressors on riverine fishes. We then examine several relevant perspectives: basic food web description, metabolic models, trophic basis of production, mass‐abundance network approaches, ecological stoichiometry, and mathematical modeling. Finally, we highlight several existing and emerging methodologies including diet and prey surveys, eDNA, stable isotopes, fatty acids, and community and network analysis. Although our emphasis and most examples are focused on salmonids in riverine environments, the concepts are easily generalizable to other freshwater fish taxa and ecosystems.

This article is categorized under:

Water and Life > Nature of Freshwater Ecosystems

Water and Life > Conservation, Management, and Awareness

Water and Life > Methods
Dynamical Bond Formation in KNi2Se2
Authors: Neilson James R. , Fry‐Petit Allyson M. , Drichko Natalia , Stone Matthew B. , Llobet Anna , Balasubramanian Mahalingam , Suchomel Matthew R. , McQueen Tyrel M.
Published: April 2022

Emphanisis, or the appearance out of nothing, has been used to describe the phenomena of spontaneous atom off‐centering and dipole formation at elevated temperatures in lead chalcogenides. Here, we provide spectroscopic evidence of spontaneous formation of metal‐metal bonds above T∼50 K in the layered metal KNi2Se2. These bonds form zig‐zag chains that lower the local symmetry from tetragonal to monoclinic. Energy‐resolved pair distribution function measurements exclude a pure phonon origin of our observations, and instead imply the existence of extra, slowly fluctuating, Ni−Ni bonds above T=50 K. Density functional theory calculations support this lower symmetry configuration as an instability of tetragonal KNi2Se2. We thus demonstrate that the phenomena of emphansis is not limited to local electric dipole formation, but can also be driven by the formation of metal‐metal bonds.
Three different ways for the synthesis of the metalloid cluster [Ge9(HyptBuPh2)3]−
Authors: Kunz Tanja , Şahin Orhan , Schnepf Andreas
Published: April 2022

The metalloid cluster [Ge9(HyptBuPh2)3]K (1) (HyptBuPh2=Si(SiMe3)2(SitBuPh2)) is obtained through three different reaction courses. These are the disproportionation reaction of GeIBr and subsequent substitution of the bromine atoms, the reaction of the germanium subhalide cluster Ge14Br8(PEt3)4 with KHyptBuPh2 and the reaction of the Zintl phase K4Ge9 with ClHyptBuPh2. The different reaction courses are described, together with the characterization and follow‐up reaction of the new metalloid cluster 1.
Effect of gravity and initial stress on a nonlocal thermo‐viscoelastic medium with two‐temperature and fractional derivative heat transfer
Authors: Said Samia M. , Abd‐Elaziz Elsayed M. , Othman Mohamed I. A.
Published: April 2022

The basic equations for a nonlocal thermoelastic–viscoelastic medium are formulated based on the multi‐phase‐lag model with a fractional derivative heat transfer. Using suitable nondimensional variables, the problem is solved using the Fourier series and Laplace transforms to solve the problem of a thermal shock problem to obtain the exact expressions of physical fields. The numerical results obtained have been illustrated graphically to illustrate the effect of the initial stress, gravity, nonlocal parameter, two‐temperature parameter, and time‐fractional derivative parameter on the physical variables.
A comparative study of high‐resolution methods for nonlinear hyperbolic problems
Authors: Lochab Ruchika , Kumar Vivek
Published: April 2022

This paper reviews some of the established high‐resolution (HR) schemes for computing solutions to hyperbolic systems by means of a finite volume (FV) framework. The objective of this research is to assess the ability of various HR flux limiting techniques to capture intense shocks and discontinuities. A crucial design factor in developing these methods is selecting a suitable flux‐limiter, so a review of different flux‐limiters for standard explicit FV frameworks has also been included. A brief discussion of the HR total variation diminishing (TVD) numerical schemes, starting from some historical introduction, going on to exploring the design principles behind the HR, second‐order, oscillation free schemes, turning towards high order nonlinear techniques and ending with an overview of some of the most significant developments and applications in the last decades has been covered. Several one‐dimensional and two‐dimensional benchmark examples with severe and challenging wave configurations have been utilized to compare the various numerical approaches. These nonlinear test cases have been selected such that the computational setups are as basic as possible.
Global structure of two dimensional Riemann solutions to the Euler system for isentropic Chaplygin gas
Authors: Cheng Jie , Chen Fangqi , Wang Zejun
Published: April 2022

In this paper, we study the two dimensional Riemann problem of the Euler system for isentropic Chaplygin gas, and the initial data consist of three pieces constant states divided by an inverted Y‐type curve. The results extended the results in Chen and Qu where the solution of every one dimensional Riemann problem contains no slip plane. We divide the discussion into several cases and for each case, we give the structure of the solution containing slip planes by the method of generalized characteristic analysis.
Generalized Moore‐Gibson‐Thompson thermoelastic fractional derivative model without singular kernels for an infinite orthotropic thermoelastic body with temperature‐dependent properties
Authors: Abouelregal Ahmed E. , Fahmy Mohammad A.
Published: April 2022

Many challenges in different applied fields of research, such as materials science, viscoelasticity, biological sciences, physics, and mechanical engineering, require the study of derivative operators using single singular or nonsingular kernels. Atangana and Baleanu (AB) constructed a novel fractional derivative without a singular kernel based on the extended Mittag–Leffler function to overcome the singular kernel problem seen in previous definitions of fractional‐order derivatives. In this article, we provide a novel mathematical thermoelastic heat conduction model that includes the fractional AB derivative operators. In addition, the Moore–Gibson–Thompson (MGT) equation has been incorporated into the proposed heat transport model. The proposed model has been applied to study an infinite orthotropic material with a cylindrical aperture, and the thermal conductivity coefficient of the body depends on the temperature change. The Laplace transform approach has been used to solve the system of governing partial differential equations (PDEs). To assess the validity of the proposed model and for the purposes of comparison, the numerical results have been depicted in figures as well as in tables.
“A Senior Wrangler Among Senior Wranglers”: The Mathematical Education of Robert Leslie Ellis
Authors: Barrow-Green June
Published: April 2022

This chapter charts Ellis’s mathematical education, from his childhood in Bath under the tutelage of Thomas Stephens Davies to the end of his student days at Cambridge when, in January 1840, he graduated as senior wrangler.
Ellis’s Character, John Grote and the Cambridge Network
Authors: Gibbins John R.
Published: April 2022

This chapter explores two questions: what did Ellis bring to Cambridge, and what did Cambridge do for Ellis? The answers will be reached through primary source materials available in Trinity College Library and at Cambridge University Library. Two forms of analysis will intertwine: the first a textual study of sources on Ellis’s character and friendships, and the second a contextual study of the Cambridge he inhabited, Trinity College and the Cambridge Network in particular – networks that shaped and provoked his unique and original contributions to knowledge. While rich and well connected, confidently established within the Whig aristocratic elite, Ellis was sometimes portrayed as timid and reclusive. Why, with ‘abundance of character and richness of endowment’ did he appear ‘different to different people?’ What explains the attestations to his charismatic personality, Stoic character and his devoted following? The best evidential account is provided by his closest and most loyal friend of two decades John Grote (1813-1866), the Knighbridge Professor of Moral Philosophy and Vicar of Trumpington, and Charles Astor Bristed, a relative stranger whose path crossed with Ellis and Grote.
Ellis on Mathematical Statistics and Probability
Authors: Stigler Stephen M.
Published: April 2022

Robert Leslie Ellis’s work in mathematical statistics and probability can be conveniently grouped under three headings: (1) his 1844 critique of the justifications of the method of least squares, (2) his short 1842 paper on the foundations of probability (with a brief follow-up in 1854), and (3) his return to least squares in 1850. The first of these was a brilliant dissection of two major and one minor derivation of least squares, each under different sets of assumptions. It was the most cited and admired of his mathematical works during his lifetime, and indeed in the nineteenth century. The second was not influential in the 19th century, but it may be the most cited of his works in the twentieth century, when, after the contributions of John Venn (1834–1923), it caught the eyes of a number of philosophers as a partial anticipation of Venn. The third, his return to the topic of 1844, after an 1850 review by John F.W. Herschel (1792–1871) had added a new wrinkle to an old topic, may have been less successful, but it still sheds new light on his understanding. I propose to treat these three topics in that order, with the emphasis being on a brief summary of the issues and a critique of how they may be thought of in the light of current historical understanding. Regarding the third, I will also present a previously unpublished letter from Ellis on the topic.
Robert Leslie Ellis: An Almost Perfect Moral Nature
Authors: Richards Joan L.
Published: April 2022

Sophia De Morgan met Robert Ellis when he was a student at Cambridge, and ever-after remembered him to possess an “almost perfect moral nature.” Her response to the sickly young man was typical of the ways Victorians responded to invalids like John Keats or Elizabeth Barrett Browning. But Ellis was neither a poet nor a woman. In the case of Ellis, the evidence of his moral character lay in the facility with which he practiced mathematics. Throughout the eighteenth century, the success of Newtonian cosmology served the English as a guarantee that in mathematics they could align their thoughts with the mind of God and by so doing truly understand the world in which they lived. As they moved into the nineteenth century, however, this assurance of unity between the human and the divine was being challenged on many fronts. When Sophia attributed “an almost perfect moral character” to the sickly young man, she was recognizing him as an ally in a battle for England’s soul that centered on the nature of mathematics.
Disclosure of a Participant’s HIV Status During a Household Community HIV Testing Project
Authors: Miller Leigh Ann , Molchan Carin , Williams Daniel B. , Grasso Michael , Nangombe Hilma , Low Andrea , Wolkon Adam , Justman Jessica , Hamunime Ndapewa
Published: April 2022

The narrative is framed within the context of ways that public health interventions balance the rights of individuals and community when related to infectious diseases. This central example is from a community-based HIV testing program in an area with high HIV prevalence. We describe a breach of confidentiality resulting from an involuntary disclosure of a participant’s HIV status. This breach of confidentiality occurs within a family. The narrative considers the respective rights of individuals and community members related to disclosure of HIV status and pays attention to how roles (e.g., health care worker, sexual partner) influence decisions regarding disclosure of someone’s HIV status. There were clear testing program guidelines for how, when, and where to disclose HIV status of household members. Standard operating procedures and careful training were meant to protect data confidentiality and privacy of patients. In practice, things were messier and less clear. The narrative describes how this confidentiality breach occurred, what was done to ensure the participant was safe after the fact and ways to amend the breach on a systems level.
Exploring Public Health’s Role in Addressing Historical Trauma Among U.S. Indigenous Populations
Authors: Gartner Danielle R. , Wilbur Rachel E.
Published: April 2022

Despite decades of often well-intentioned work, public health interventions can fail to achieve desired outcomes within Native American communities. These failures may not be due to a lack of motivation on either side. Rather, they stem from a history of colonization which continues to impact the fundamental structure of public health as well as Native American responses to public health intervention. We purport that there are discrepancies between the tools provided in much of public health’s core training and the reality and needs of work in Indian Country. These discrepancies, including a fundamental lack of knowledge about historical trauma events and the ways their impacts reverberate through communities, families, and individuals, contribute to continued experiences of health disparities by Native Americans. Using narrative, this paper offers examples of this schism and is followed by four actionable steps that individuals working in settler public health institutions can take when approaching work with Native nations and communities.
The Influence of Different Excavation Methods on Deep Foundation Pit and Surrounding Environment
Authors: Yang Yongming , Li Xiwen , Chen Yao
Published: April 2022

Taking a deep foundation pit in Shijiazhuang, Beijing as the background of the project, combined with the excavation range of the deep foundation pit and the spatial location and geometry of the surrounding engineering bodies, FLAC3D software is used to establish a numerical model of the deep foundation pit excavation containing the deep foundation pit, surrounding buildings and underground tunnels and other engineering bodies. The numerical model truly reflects the geometric size and spatial location relationship between deep foundation pit and surrounding engineering bodies. Based on the numerical model, the numerical simulation of deep foundation pit excavation under different excavation methods was carried out. The analysis of the horizontal displacement of the support structure during the excavation of the deep foundation pit, the investigation of the surrounding buildings and surface settlement and the deformation of the metro tunnel. The influence mechanism of different excavation methods on the safety of deep foundation pit, surrounding buildings and tunnel were discussed. It is concluded that the excavation method has less influence on the deformation and displacement of the deep foundation pit and the surrounding buildings and tunnels under the condition of shallow excavation depth. As the excavation depth increases, the effect of the excavation method on the deformation of the deep foundation pit, buildings, tunnels and surface settlement increases. The layered excavation method is suitable for deep foundation pits with shallow excavation depths, while the layered section excavation method is more suitable for deep foundation pits with deep excavation depths. Deep foundation pit excavation has a smaller effect on the deformation of the tunnel. The surrounding buildings have a greater influence on the deformation during the excavation of the deep foundation pit, but the effect of the buildings on it is less than the limiting effect of the prestressing anchor cables on the deformation of the deep foundation pit.
Study on Critical Shaft Length in Underground Metro Tunnel with One End to Outside
Authors: Wang Tingting , Geng Pengqiang , Weng Miaocheng , Liu Fang
Published: April 2022

A 1:15 small-scale model was built based on a blocked tunnel at one end of Chongqing rail transit, the reliability of FDS numerical simulation was verified by experiments. Adopts the FDS18.0 software for the shaft seal at the end of the tunnel, and discusses the fire location, fire heat release rate on the effects of the shaft of natural smoke extraction mode when fire between seal and shaft, shaft smoke exhaust volume significantly greater than other fire source position, the critical length of shaft is bigger, when fire heat release rate between 2.5 MW to 7.5 MW. The critical shaft length decreases with the increase of shaft height, but has nothing to do with the heat release rate of fire source. A critical shaft length prediction model for tunnel closure at one end is proposed.
Evaluation the Level of Service of Signalized Intersection: Al-Amreia Intersection as a Case Study
Authors: Rajab Noor A. , Awad Hamid A. , Alrawi Firas
Published: April 2022

One of the main element in the network is the intersection which consider as the critical points because there are many conflict in this element. The capability and quality of operation of an intersection was assessed to provide a better understanding of the network's traffic efficiency. In Baghdad city, the capital of/Iraq the majority of the intersections are operated under the congestion status and with level of service F, therefore theses intersection are consider as high spot point of delay in the network of Baghdad city. In this study we selected Al-Ameria signalized intersection as a case study to represent the delay problem in the intersections in Baghdad. The intersection is located in the west of Bagdad city, this intersection realizes a huge traffic, and there are a lot of tourist attractions near to the study area. The aim of this research is to enhance traffic operations, improve the level of service and decrease the delay in Al-Ameria signalized intersection by examine four suggested alternative. Special teams with a special tools are collected traffic and geometric data for the intersection. HCS 2010 program are used in this study to measure the delay and evaluate the level of service in each approach and for the hall of the intersection. The result of this study show that the intersection is operated under the breakdown condition with level of service F for all approaches. The results highlighted that the fourth alternative is the best suitable suggestion to enhance the level of service for the intersection. The fourth alternative recommended to construct a flyover from the North bound towards the South bound the level of service improve from F to C for the base year and for the target year.
Study on Deterioration Rule of Water-Binder Ratio on Mechanical Properties and Frost Resistance of Concrete
Authors: Gong Xu , Yu Hongfa , Wu Chengyou
Published: April 2022

Based on the rapid freeze-thaw (F-T) cycle test, the changes of relevant indexes (mass, relative dynamic elastic modulus, mechanical properties and thickness of concrete F-T damage layer) of concrete and mortar specimens with three water-binder ratios under F-T cycle was systematically studied. The results show that the quality, relative dynamic elastic modulus and mechanical properties of concrete and mortar decrease with the increase of F-T cycles, the thickness of F-T damaged layer of concrete increases in different degrees. The degree of F-T damage of mortar specimen is obviously lower than that of concrete specimen. Through regression analysis, it is find that the relative dynamic elastic modulus of concrete were significantly related to the relative dynamic elastic modulus of mortar, the thickness of concrete damage layer and the relative dynamic elastic modulus of concrete, it shows that one of the factors causing the F-T damage of concrete is the damage of mortar.
Coulomb and Higgs branches from canonical singularities. Part I. Hypersurfaces with smooth Calabi-Yau resolutions
Authors: Closset Cyril , Schäfer-Nameki Sakura , Wang Yi-Nan
Published: April 2022

Abstract

Compactification of M-theory and of IIB string theory on threefold canonical singularities gives rise to superconformal field theories (SCFTs) in 5d and 4d, respectively. The resolutions and deformations of the singularities encode salient features of the SCFTs and of their moduli spaces. In this paper, we build on Part 0 of this series [1] and further explore the physics of SCFTs arising from isolated hypersurface singularities. We study in detail these canonical isolated hypersurface singularities that admit a smooth Calabi-Yau (crepant) resolution. Their 5d and 4d physics is discussed and their 3d reduction and mirrors (the magnetic quivers) are determined in many cases. As an explorative tool, we provide a Mathematica code which computes key quantities for any canonical isolated hypersurface singularity, including the 5d rank, the 4d Coulomb branch spectrum and central charges, higher-form symmetries in 4d and 5d, and crepant resolutions.
Positivity of the Veneziano amplitude in D = 4
Authors: Maity Pronobesh
Published: April 2022

Abstract

The Veneziano amplitude was put forward as a solution to the axioms of the S-matrix bootstrap. However, unitarity, reflected in the positivity of the coefficients in the Gegenbauer expansion of the amplitude is not obvious. In this note we compute the generating function of these coefficients in terms of the Appell hypergeometric function. We use this to read off an exact form of this coefficient on the leading Regge trajectory in D = 4. We find that it decays with the spin but always remains positive. Since for large spin these coefficients are expected to be smaller than those on the subleading trajectories, our result indicates the positivity of the full Veneziano amplitude in D = 4.
Estimation of secondary cancer projected risk after partial breast irradiation at the 1.5 T MR-linac
Authors: De-Colle C. , Dohm O. , Mönnich D. , Nachbar M. , Weidner N. , Heinrich V. , Boeke S. , Gani C. , Zips D. , Thorwarth D.
Published: April 2022

Purpose

For patients treated with partial breast irradiation (PBI), potential long-term treatment-related toxicities are important. The 1.5 T magnetic resonance guided linear accelerator (MRL) offers excellent tumor bed visualization and a daily treatment plan adaption possibility, but MRL-specific electron stream and return effects may cause increased dose deposition at air–tissue interfaces. In this study, we aimed to investigate the projected risk of radiation-induced secondary malignancies (RISM) in patients treated with PBI at the 1.5 T MRL.

Methods

Projected excess absolute risk values (EARs) for the contralateral breast, lungs, thyroid and esophagus were estimated for 11 patients treated with PBI at the MRL and compared to 11 patients treated with PBI and 11 patients treated with whole breast irradiation (WBI) at the conventional linac (CTL). All patients received 40.05 Gy in 15 fractions. For patients treated at the CTL, additional dose due to daily cone beam computed tomography (CBCT) was simulated. The t‑test with Bonferroni correction was used for comparison.

Results

The highest projected risk for a radiation-induced secondary cancer was found for the ipsilateral lung, without significant differences between the groups. A lower contralateral breast EAR was found for MRL-PBI (EAR = 0.89) compared to CTL-PBI (EAR = 1.41, p = 0.01), whereas a lower thyroid EAR for CTL-PBI (EAR = 0.17) compared to MRL-PBI (EAR = 0.33, p = 0.03) and CTL-WBI (EAR = 0.46, p = 0.002) was observed. Nevertheless, when adding the CBCT dose no difference between thyroid EAR for CTL-PBI compared to MRL-PBI was detected.

Conclusion

Better breast tissue visualization and the possibility for daily plan adaption make PBI at the 1.5 T MRL particularly attractive. Our simulations suggest that this treatment can be performed without additional projected risk of RISM.
Influence of welding parameters on grain size, HAZ and degree of dilution of 6063-T5 alloy: optimization through the Taguchi method of the GMAW process
Authors: Meseguer-Valdenebro José L. , Martínez-Conesa Eusebio , Portoles Antonio
Published: April 2022

The aim of this work is to design experiments using Taguchi’s method that determine the influence of welding parameters on the grain size, heat-affected zone and degree of dilution of the 6063-T5 alloy. The welding process used is GMAW, and the welding parameters are the power, welding speed and bevel spacing. The study of the influence of these welding parameters on the measurements made during welding (which are the size of the heat-affected zone, the degree of dilution and the grain size) allows one to determine the quality of the joint. In addition, the welding parameter that most influences the minimisation of these three measurements will be determined.
High frequency-based protection algorithm for meshed MTDC systems
Authors: Abu-Elanien Ahmed E. B. , Elserougi Ahmed A.
Published: April 2022

This research presents a high frequency-based algorithm for zonal protection of meshed Multi-Terminal high voltage Direct Current (MTDC) systems. Discrete wavelet transform (DWT) is used to capture high frequency current transients from one end of each line. The faulty line is identified by analyzing two distinct high frequency bands form the captured transients. The characteristics of these current transients during normal condition are different from faulty condition. A four-terminal meshed MTDC model is used to test the performance of the protection algorithm. Various faults with different fault scenarios were simulated using four-terminal meshed MTDC model. The simulation results showed success of the algorithm in identifying internal faults. Moreover, the high frequency algorithm showed robustness against other abnormal conditions such as AC faults and sudden change of wind power.
Arithmetic statistics of Prym surfaces
Authors: Laga Jef
Published: April 2022

We consider a family of abelian surfaces over$$\mathbb {Q}$$Qarising as Prym varieties of double covers of genus-1 curves by genus-3 curves. These abelian surfaces carry a polarization of type (1, 2) and we show that the average size of the Selmer group of this polarization equals 3. Moreover we show that the average size of the 2-Selmer group of the abelian surfaces in the same family is bounded above by 5. This implies an upper bound on the average rank of these Prym varieties, and gives evidence for the heuristics of Poonen and Rains for a family of abelian varieties which are not principally polarized. The proof is a combination of an analysis of the Lie algebra embedding$$F_4\subset E_6$$F4⊂E6, invariant theory, a classical geometric construction due to Pantazis, a study of Néron component groups of Prym surfaces and Bhargava’s orbit-counting techniques.
High-speed flat-detector computed tomography for temporal bone imaging and postoperative control of cochlear implants
Authors: Eisenhut Felix , Taha Lava , Manhart Michael , Thimsen Vivian , Mantsopoulos Konstantinos , Iro Heinrich , Hornung Joachim , Dörfler Arnd , Lang Stefan
Published: April 2022

Purpose

Flat-detector computed tomography (FD-CT) is the standard for cochlear implant (CI) imaging. FD-CT systems differ in technical characteristics. Our aim was an evaluation of two different FD-CT generations with different protocols and hardware regarding image quality, radiation dose, and scan time.

Methods

Two temporal bone specimens (− / + CI = TB0/TB1) were scanned using three different scanners: two FD-CT systems with different scanning protocols (standard FD-CT: 20 s 70 kV, 20 s 109 kV; high-speed FD-CT [HS-FD-CT]: 7 s 109 kV, 9 s 109 kV, 14 s 72 kV) and MS-CT (5 s 120 kV). Acquired datasets were evaluated in consensus reading regarding qualitative and quantitative parameters: addressing CI- and cochlea-specific parameters, cochlea delineation, lamina spiralis ossea visibility, distinction of single CI electrodes, determination of intracochlear implant position, stapes delineation, and mastoidal septation were assessed. Addressing protocol-specific parameters, radiation dose (dose-length-product/DLP), and scan time were assessed.

Results

Two HS-FD-CT protocols (14 s/9 s) provide higher or equivalent diagnostic information regarding CI- and cochlea-specific parameters compared to both standard FD-CT protocols. The fastest HS-FD-CT protocol (7 s)—providing inferior diagnostic information compared to all other FD-CT protocols—still exceeds MS-CT. The highest DLP was recorded for the 14 s HS-FD-CT protocol (TB1 = 956 mGycm); the lowest DLPs were recorded for the 7 s HS-FD-CT protocol (TB0 = 188 mGycm) and for MS-CT (TB0 = 138 mGycm), respectively. HS-FD-CT allows a significant reduction of scan time compared to standard FD-CT.

Conclusion

High-speed FD-CT improves visualization of temporal bone anatomy and postoperative assessment of CIs by combining excellent image quality, fast scan time, and reasonable radiation exposure.
A Journey Undertaken by Families to Access General Surgical Care for their Children at Muhimbili National Hospital, Tanzania; Prospective Observational Cohort Study
Authors: Philipo Godfrey Sama , Bokhary Zaitun Mohamed , Bayyo Neema Lala , Bandyopadhyay Soham , Pueschel Miriam Gerd , Bakari Rajabu Athumani , Lakhoo Kokila
Published: April 2022

Background

A majority of the 2 billion children lacking access to safe, timely and affordable surgical care reside in low‐and middle‐income countries. A barrier to tackling this issue is the paucity of information regarding children's journey to surgical care. We aimed to explore children's journeys and its implications on accessing general paediatric surgical care at Muhimbili National Hospital (MNH), a tertiary centre in Tanzania.

Methods

A prospective observational cohort study was undertaken at MNH, recruiting patients undergoing elective and emergency surgeries. Data on socio‐demographic, clinical, symptoms onset and 30‐days post‐operative were collected. Descriptive statistics and Mann–Whitney, Kruskal–Wallis and Fisher's exact tests were used for data analysis.

Result

We recruited 154 children with a median age of 36 months. The majority were referred from regional hospitals due to a lack of paediatric surgery expertise. The time taken to seeking care was significantly greater in those who self‐referred (p = 0.0186). Of these participants, 68.4 and 31.1% were able to reach a referring health facility and MNH, respectively, within 2 h of deciding to seek care. Overall insurance coverage was 75.32%. The median out of pocket expenditure for receiving care was $69.00. The incidence of surgical site infection was 10.2%, and only 2 patients died.

Conclusion

Although there have been significant efforts to improve access to safe, timely and affordable surgical care, there is still a need to strengthen children's surgical care system. Investing in regional hospitals may be an effective approach to improve access to children surgical care.
Kidney biopsy adequacy and complications in children — does technique matter?
Authors: Pettit Chen , Kanagaratnam Roshana , Coughlan Finbarr , Graf Nicole , Hahn Deirdre , Durkan Anne
Published: April 2022

Kidney biopsy is part of the diagnostic workup of many children with renal disease. Traditionally, a perpendicular approach to the biopsy has been used, but more recently, some proceduralists have favoured a tangential approach. It is not clear if one technique is superior with regards to tissue adequacy or complication rates. In our centre, interventional radiologists (IR) use general anaesthetic and a tangential approach, whereas paediatric nephrologists (PN) use sedation and a perpendicular approach. We examined consecutive native kidney biopsies performed between January 2008 and December 2017 for adequacy (sufficient tissue for light and electron microscopy and immunofluorescence) and examined the electronic medical records for data regarding technique and complications. IR performed 72 (29%) of the 245 native kidney biopsies, obtaining more total glomeruli (median 39 vs 16, p < 0.001) and more glomeruli per tissue core (median 13 vs 8, p < 0.001) than PN. No differences in specimen adequacy were observed between the two groups (79% IR vs 81% PN, p = 0.75) and a diagnosis could be made in 99% and 94% respectively (p = 0.1). A statistically lower rate of peri-nephric haematoma (28% vs 42%, p = 0.04) was detected in the IR group, but there were no significant differences in other complications. One patient required a blood transfusion (PN) and another required surgical intervention for a perinephric haematoma (IR).

Conclusion: IR obtained larger samples and number of glomeruli, but the overall adequacy for native kidney biopsies was good using both perpendicular and tangential techniques, with low rates of significant complications.

What is Known:• Kidney biopsy is integral to the diagnostic work-up of many children with kidney disease.• Kidney biopsy is a safe procedure with well-established complications in a minority of children.

What is New:• Interventional radiologists had higher biopsy yield than paediatric nephrologists, possibly due to the tangential approach.• Biopsy adequacy rates are high using both techniques and provided a diagnosis in over 95% of cases.