bluuebunny/crossref_metadata_2025_split huggingface dataset:
Criteria and potential predictors of severity in patients with COVID-19
Authors: Zayed Niveen E. , Abbas Ahmad , Lutfy Samah Mohamad 
Published: February 2022

Abstract
Background
The challenge in treating severe COVID-19 in the absence of targeted medication is enforcing physicians to search carefully for clinical predictors of severity.

Aim
To define the profile of patients at risk of severe COVID-19 and to assess for certain predictors.

Methods
Confirmed COVID-19 cases were classified into the following: group A: mild/moderate cases and group B: severe/critical cases according to the selected criteria. History, radiological assessment, complete blood count, lactate dehydrogenase (LDH), myocardial enzymes, serum ferritin, and D dimer were assessed. Patients were followed for the need of ICU and mechanical ventilation. Duration till conversion, length of stay, and mortality were recorded.

Results
A total of 202 patients were analyzed. Group B had higher age (53.2 ± 12.6 vs 40.3 ± 10.3, P < 0.001), more prevalence of DM (60.61% vs 16.57% P < 0.001), hypertension (51.52% vs 20.12%, P < 0.001), ischemic heart (27.27% vs 3.55%, P < 0.001), bronchial asthma (36.36% vs 3.55%, P < 0.001), COPD (9.09% vs 1.18%, P = 0.03), higher mean platelet volume (MPV) (12.76 ± 7.13 vs 10.51 ± 7.78 (fL), P < 0.001), higher serum ferritin (954 ± 138 vs 447 ± 166 ng/ml, P < 0.001), higher LDH (604 ± 220 vs 384 ± 183 U/L, P-value < 0.001), higher creatine phosphokinase (24.27 ± 5.82 vs 16.4 ± 4.87 IU/L, P < 0.001), and higher mortality (30.3% vs 0.6%, P < 0.001). Multivariate regression of predictors of severity identified three predictors; age, MPV, serum ferritin, and IHD.

Conclusions
The current study places of interest the characteristic host-related features of severe COVID-19 and draws attention to potential predictors.
Changes in ionised calcium in cases of ethylene glycol poisoning
Authors: Stasinskis Roberts , Stasinska Katrina , Mukans Maksims , Graudins Andis , Liguts Viesturs , Lejnieks Aivars 
Published: February 2022

Ethylene glycol is a toxic alcohol that occurs in a variety of chemical preparations. In patients poisoned with ethylene glycol, diagnosis is usually based on clinical suspicion and non-specific tests. Hypocalcaemia is often present and results from production of calcium oxalate crystals from oxalic acid.
Assess whether reduction in ionized calcium concentration is a common finding in ethylene glycol poisoning, whether it can be appropriate additional marker for the prognosis of outcome.
Retrospective clinical records review of patients with a diagnosis of ethylene glycol poisoning at the Riga East University Hospital from 1 January 2012 to 31 December 2020. Ethylene glycol exposure was confirmed retrospectively, qualitatively in all patients. Results of blood gas samples and serum creatinine were analysed and abnormalities were compared amongst various groups.
Ionized calcium concentration in arterial blood was below the normal range in 59% of cases at the time of presentation and more commonly associated with a blood pH < 7.3 in 79% of cases. The number of patients with low ionized calcium concentration increased over time. However, the number of patients with blood pH ≥7.3 fell during the same time period. Linear regression analysis did not show a significant correlation between low ionized calcium and blood pH. However, analysis of results from the time of presentation revealed a moderate negative correlation between low ionized calcium concentration and blood pH and lactate concentration. There was also a moderate correlation between low ionized calcium concentration and serum creatinine.
A low ionised calcium concentration was a common finding in cases of ethylene glycol poisoning and was more commonly associated with patients exhibiting metabolic acidosis or developing acute kidney injury. Ionised calcium concentration and pH value may be additional markers for the diagnosis and risk stratification of severity from ethylene glycol poisoning.
Potencial biorremediador da microalga Chlorella vulgaris BEIJERINCK em meio composto por águas residuárias
Authors: Assis Neto Djalma Queiroga de , Lopes Thiago Santos de Almeida , Santos Whelton Brito dos , Ferreira Weruska Brasileiro , Lima Vera Lucia Antunes de 
Published: February 2022

A dessalinização de águas salobras subterrâneas é, em muitas localidades, a única solução para o abastecimento de água. Porém, o processo de dessalinização por membrana de osmose inversa produz um rejeito poluente e de difícil tratamento. Similarmente, o efluente produzido pelo tratamento de esgoto doméstico em filtro anaeróbio também necessita de um pós-tratamento para se adequar às normas de despejo em corpos hídricos. Assim, a biorremediação de águas residuárias, utilizando microalgas, surge como uma opção de tratamento desse rejeito. O objetivo deste trabalho foi avaliar e otimizar o potencial biorremediativo da espécie de microalga Chlorella vulgaris em meio composto por rejeito de dessalinização por osmose inversa e efluente de tratamento de esgoto doméstico em filtro anaeróbio. Na metodologia foi utilizado o planejamento experimental por delineamento composto central rotacionado (DCCR), tendo como variáveis independentes: pH, fotoperíodo e proporção de efluentes. Os parâmetros analisados foram a Demanda Química de Oxigênio (DQO) e o Fósforo Total (PT). As taxas de remoção para a variável DQO variaram entre 28,73 e 70,73% e para a variável PT as taxas ficaram entre 52,19 e 100%. A otimização estatística dos modelos mostrou uma remoção teórica combinada de 69,08% para DQO e 89,34 PT.
Digital Election Model In The Election Of Regional Head And Deputy Head In Indonesia
Authors: Januwarso Arief , Sukristiyanto Agus , Darmawan Arief 
Published: February 2022

This study aims to develop a model for digital general election in the election of Regional Head and Deputy Head. The focus of this research is on the simultaneous regional elections in 2020 in the regencies of Jember, Malang, Lamongan and Sidoarjo. In the research method, a qualitative-descriptive approach was used, with a phenomenological basis. The results of the study indicated that the legitimacy of authority in the 2020 Regional Head and Deputy Head Elections has decreased or the elections had incomplete legitimacy. This can be seen from the percentages of votes for the winners of the local elections, who received less than 50% in the regencies of Jember, Malang, Lamongan and Sidoarjo. Recommendations are offered for the development of a new regional election system, which may attain full power legitimacy, as follows. First, the digital-based electoral system needs to be improved. Second, election needs to be socialized as early as possible. Third, political education needs to be developed by political parties, through political school programs with competent teachers. Fourth, the model, which needs to be set up with a bottom-up system through full community participation, may produce a pattern of regional election that is more in line with the conditions and desires of the people so that the people can give full power (full legitimacy) for the winners to manage the regional government.
Deep learning application for stellar parameters determination: I-constraining the hyperparameters
Authors: Gebran Marwan , Connick Kathleen , Farhat Hikmat , Paletou Frédéric , Bentley Ian 
Published: February 2022

Abstract
Machine learning is an efficient method for analysing and interpreting the increasing amount of astronomical data that are available. In this study, we show a pedagogical approach that should benefit anyone willing to experiment with deep learning techniques in the context of stellar parameter determination. Using the convolutional neural network architecture, we give a step-by-step overview of how to select the optimal parameters for deriving the most accurate values for the stellar parameters of stars:

T

eff

{T}_{{\rm{eff}}}

,

log
g

\log g

, [M/H], and

v

e

sin
i

{v}_{e}\sin i

. Synthetic spectra with random noise were used to constrain this method and to mimic the observations. We found that each stellar parameter requires a different combination of network hyperparameters and the maximum accuracy reached depends on this combination as well as the signal-to-noise ratio of the observations, and the architecture of the network. We also show that this technique can be applied to other spectral-types in different wavelength ranges after the technique has been optimized.
Exploring Senior High School Students’ English Academic Resilience in the Chinese Context
Authors: Liu Honggang , Han Xueke 
Published: February 2022

Abstract
While academic resilience has been a hot topic in positive psychology, there is still scope for researchers to explore it in the field of applied linguistics. Drawing on the framework of L2 (second language) learners’ resilience proposed by T. Y. Kim and Y. K. Kim (2017), the current study aims to examine senior high school students’ English academic resilience (EAR) and its relationship to their English achievement (EA). This study comprises a survey of 454 senior high school students. Follow-up interviews were carried out to triangulate the quantitative findings. The descriptive results demonstrate that students’ EAR is above the average, and its five subscales obtain medium to medium-higher levels due to the mean scores. It shows that students have good EAR that enables them to deal with academic adversity. The correlational analysis shows a low positive correlation between EAR and EA in general, and the subscales share medium to low correlations with students’ EA. EAR has a certain influence on EA, but the correlation may be influenced by other learner variables. Based on the results, suggestions on improving students’ EAR are provided.
Achieving Self-Imitation for English Intonation Learning: The Role of Corrective Feedback
Authors: Li Zhongmin , Lian Andrew-Peter 
Published: February 2022

AbstractCorrective feedback is crucial for pronunciation teaching. However, in current pronunciation teaching practice, the corrective feedback provided usually fails to locate pronunciation problems and inform learners of the differences between their mispronunciations and the correct form. Based on the motor theory, this study attempted to explore a new way of corrective feedback for pronunciation teaching. Specifically, the learners’ speech output was modified and then was played back to them as an input model for learning. In this way, the learners can imitate the pronunciation model of their own voices, achieving self-imitation. This study included two experiments. The first explored the viability of obtaining one’s self-perceived voice through delayed feedback paradigm. The second experiment examined the effectiveness of self-imitation for English intonation learning. Results showed that imitating the pronunciation model of one’s own voice can reduce the learners’ phonological memory load, assist critical listening and facilitate accurate phonetic realizations of the target intonation.
Nitrieren von Fe-Cr-Legierungen
Authors: Schacherl R. E. , Mittemeijer E. J. 
Published: February 2022

Kurzfassungen
Zur Untersuchung der Morphologie und Wachstumskinetik nitrierter Schichten von Fe-Cr-Legierungen wurden Legierungen mit 4 Gew.-%, 7 Gew.-%, 13 Gew.-% und 20 Gew.-% Cr in einer NH3/H2-Gasatmosphäre (bei 450 °C, 580 °C und 700 °C) nitriert. Die Untersuchung der Gefügemorphologie der Nitrierschichten wurde mithilfe von Licht- und Rasterelektronenmikroskopie durchgeführt. Die Variation der Elementzusammensetzung in den Nitrierschichten wurde durch Elektronenstrahlmikroanalyse (ESMA) bestimmt. Zur quantitativen Beschreibung des Stickstoffdiffusionsprofiles in den Nitrierschichten wurde ein numerisches Modell entwickelt. Die berechneten Stickstoffprofile wurden den gemessenen (ESMA) Profilen angepasst, wobei die folgenden Anpassungsparameter angewendet wurden: Stickstoffoberflächenkonzentration, Löslichkeitsprodukt von Chrom und Stickstoff in der Ferrit-Matrix sowie ein Parameter, welcher die Zusammensetzung des ausgeschiedenen Chromnitrides festlegt. Um die berechneten Profile an die gemessenen anzupassen, wurde zwischen mobilem und immobilem Überschussstickstoff in der Nitrierschicht unterschieden.
Verzugskompensation mittels Gasabschreckung in flexiblen Düsenfeldern*
Authors: Hunkel M. , Schüttenberg S. , Frerichs F. , Fritsching U. , Zoch H.-W. 
Published: February 2022

Kurzfassungen
Der durch die Wärmebehandlung ausgelöste Bauteilverzug wird im Rahmen eines Teilprojekts des Sonderforschungsbereichs „Distortion Engineering“ an der Universität Bremen auf der Basis lokal asymmetrischer Abschreckvorgänge in gasförmigen Medien analysiert und modellmäßig beschrieben. An geometrisch einfachen Bauteilen wie Ringen aus 100Cr6 und Wellen aus 20MnCr5 wird sowohl das Verzugspotenzial aufgrund (gezielt) asymmetrischer Abschreckung untersucht als auch die Möglichkeiten der Verzugskompensation mittels Gasabschreckung in flexiblen Düsenfeldern aufgezeigt. Für einzelne Bauteile konnte aufgrund der asymmetrischen Abschreckung ein deutlicher Verzug provoziert werden. Bei Bauteilen, deren Verzugspotenzial a priori bekannt war, konnte die asymmetrische Gasabschreckung zur Kompensation des Verzugs verwendet werden.
Depth-resolved X-ray residual stress analysis in PVD (Ti, Cr) N hard coatings
Authors: Genzel Christoph , Reimers Walter 
Published: February 2022

AbstractPhysical vapour deposition (PVD) of thin hard coatings on TiN basis is usually performed at rather low temperatures (TD< 500 °C) far from thermal equilibrium, which leads to high intrinsic residual stresses in the growing film. In contrast to the extrinsic thermal residual stresses which can easily be estimated from the difference of the coefficients of thermal expansion between the substrate and the coating, a theoretical prediction of the intrinsic residual stresses is difficult, because their amount as well as their distribution within the film depend in a very complex way on the deposition kinetics. By the example of strongly fibre-textured PVD (Ti, Cr)N coatings which have been prepared under defined variation of the deposition parameters in order to adjust the residual stress distribution within the coatings, the paper compares different X-ray diffraction techniques with respect to their applicability for detecting residual stresses which are non-uniform over the coating thickness.
Characterization of thermal and anodic oxide layers on β- and on near-β-titanium alloys for biomedical application
Authors: Velten D. , Schenk-Meuser K. , Biehl V. , Duschner H. , Breme J. 
Published: February 2022

Abstract
β- and near-β-Ti alloys for biomedical applications show a favourable mix of mechanical, biological and biocompatible properties. In this study, oxide layers on Ti13Nb13Zr, Ti15Mo5Zr3Al, Ti30Nb and Ti30Ta were prepared by thermal and anodic oxidation, in order to adjust constant, reproducible and well-defined surface properties. The thickness, the phase composition and the element composition of the oxide layers were determined. The corrosion properties were investigated by current density –potential curves under physiological conditions. Depending on the oxidation parameters, film thicknesses in the range 10 – 250 nm can be prepared. The thermal oxide layers consist predominantly of TiO2 in rutile structure while the anodized samples show a mixture of anatase and amorphous TiO2. In addition, certain amounts of mixed oxides of titanium and alloying elements such as TiZrO4 or TiNb2O7 are found in the oxide films. The corrosion resistance of the oxidized samples is increased as compared with the polished samples whose current densities in the range of passivity are comparable to that of Ti6Al4V.
Micromechanisms and modelling of crack initiation and growth in tool steels: role of primary carbides
Authors: Mishnaevsky Leon L. , Lippmann Nils , Schmauder Siegfried 
Published: February 2022

AbstractMicromechanisms of damage initiation and crack growth in high speed and cold work steels are investigated using scanning electron microscopyin situexperiments. The role of primary carbides in initiation and growth of cracks in tool steels is clarified. It is shown that initial microcracks in the steels are formed in primary carbides and then join together. A hierarchical finite element model of damage initiation, which included a macroscopic model of the deformation of the specimen under real experimental conditions and a mesomechanical model of damage in real microstructures of steels, was developed. Using the hierarchical model, the conditions of local failure in the steels have been obtained. In order to study the effect of carbide arrangement on fracture, numerical simulations of fracture in steels with different ideal carbide arrangements were carried out and compared with each other. It is found that the heterogeneous arrangements of primary carbides can lead to strong deviations of a crack from the mode I path and, therefore, to a significant increase of the fracture energy of the steels.
Dislocation microstructures of single crystal ⟨001⟩ CMSX-4 specimens tensile tested at 700 and 1000°C
Authors: Schubert Florian , Penkalla Heinz-Josef , Singheiser Lorenz 
Published: February 2022

Abstract
Two principal methods are used to derive constitutive equations for single crystal Ni-base superalloys: development of a creep potential according the Hill’s theory and the summarization of all activated slip systems: theoretically, the octahedral and the cubic slip system must be considered. An overview of dislocation structure evolution has been performed using transmission electron microscopy (TEM) techniques on 〈001〉-orientated CMSX-4 specimens after tensile tests. The aim of the applied conventional TEM methods was to provide with more details about the influence of temperature and deformation rate on the deformation behaviour of CMSX-4 nickel-base single crystal. A correlation of the γ' phase deformation mechanisms and associated mechanical responses for different tensile testing conditions has been done. With TEM methods the dislocation dipole identification as well as the stacking fault nature has been demonstrated.
Influence of mechanical surface treatments on the HCF performance of the Ni-superalloy Udimet 720 LI
Authors: Lindemann Janny , Grossmann Kim , Wagner Lothar 
Published: February 2022

Abstract
Shot peening was performed on smooth (geometrical notch factor k
t = 1.0) and circumferentially notched (k
t = 2.3 and 3.5) specimens. In addition, some notched (k
t = 3.5) specimens were deep rolled. Axial fatigue tests were done at room temperature and 650 °C using a stress ratio of R = 0.1. At ambient temperature, shot peening markedly increased the high-cycle fatigue (HCF) strengths at R = 0.1 of smooth and, particularly, notched specimens with respect to the electropolished reference samples. In contrast, shot peening was found to decrease the HCF strength of smooth samples at elevated temperature (650 °C) while the HCF strength of notched specimens was slightly increased. Best elevated-temperature HCF strength of notched conditions was observed after deep rolling.
Precipitation of β-phase and twinning during deformation of Mg–Al alloy AZ91 at 150 °C after solution treatment
Authors: Zhang Ping , Blum Wolfgang 
Published: February 2022

Abstract
Precipitation of β-phase and deformation twinning have been studied in a solid solution-treated AZ91 alloy, which was subjected to compressive creep loading at 150 °C and 100 MPa for 163 h. It was found that nucleation of β-phase in solution-treated AZ91 is enhanced by concurrent deformation under creep conditions at 150 °C. The relatively fine precipitate structure leads to a reduction in minimum creep rate and, therefore, to an increase in creep life by a factor of 10 compared to the as-cast condition at the investigated conditions. In addition, twinning occurred in coarse grains of hard orientation. The twin boundaries lead to formation of incoherent precipitates and discontinuous precipitation within the former grains.
Nanograin size, high-nitrogen austenitic stainless steels
Authors: Speidel Markus O. 
Published: February 2022

Abstract
A new class of high-strength steels has been developed by combining solid solution hardening and grain boundary hardening in high-nitrogen austenitic stainless steels. Average grain diameters from 50 to 250 nm can be achieved, and yield strength levels of more than 2000 MPa in the solution-annealed condition have been measured. The effect of nitrogen solid solution hardening and grain boundary hardening is systematically explored.
Strength and ductility of thin Cu wires
Authors: Khatibi Golta , Stickler Roland , Weiss Brigitte 
Published: February 2022

Abstract
The stress– strain behavior of thin copper wires in the range 20 – 250 μm diameter and various purities (3N, 5N) have been investigated. The wires were subjected to a recrystallization heat treatment and tensile properties were determined. Tensile testing was performed using a microtensile testing machine equipped with a non-contacting laser-optical speckle correlation sensor adapted for high-resolution strain measurement. The fracture elongation of all specimens exhibited lower values than that of bulk Cu with a decreasing trend for thinner wires. High-purity wires with a pronounced bamboo structure showed a size dependence of the yield strength which increased with decreasing wire diameter. Surface topography and fracture surfaces of the specimens were examined. The microstructural investigations were performed to arrive at an understanding and interpretation of our experimental results.
Phase diagram of the Al–Cu–Fe quasicrystal-forming alloy system
Authors: Zhang Liming , Lück Reinhard 
Published: February 2022

Abstract
The microstructures of as-cast and slowly solidified Al– Cu–Fe ternary alloys in the vicinity of the icosahedral phase region have been investigated using light microscopy and scanning electron microscopy. The chemical composition of the different phases present has been determined by energy-dispersive X-ray spectroscopy with a correction of electron probe microscopy analysis. The solidification process was studied by means of the differential thermal analysis and magnetothermal analysis measurements. In contrast to the equilibrium phase diagram, fast cooling leads to the formation of a metastable β′ phase (an ordered cubic structure) rather than to the formation of the φ phase. The nucleation of ω phase is very sluggish during the solidification. The results are presented as solidification paths, superimposed onto the liquidus surface projection to demonstrate the solidification sequences.
Effect of Sr on the microstructure and corrosion properties of the as-cast Mg–Zn–Zr alloy
Authors: Wu Jinxiang , Cao Xin , Xu Chunxiang , Dong Yuxing , Di Xinming , Zhang Jinshan 
Published: February 2022

Abstract
The effect of Sr on the microstructure of Mg–Zn–Zr alloys was investigated by means of scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction. An immersion experiment and electrochemical experiment were designed to study the effect of Sr on the corrosion performance of the alloys. The results show that the addition of Sr promotes the formation of Mg17Sr2 phase in the alloy, and this stripe phase appears at the alloy grain boundaries. With the increase in Sr content, a network structure is formed at the grain boundary, creating a corrosion barrier to prevent further corrosion of the alloy. The study found that Mg-4Zn-0.4Zr-1.0Sr alloy has the best corrosion performance.