bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamically United Double Network Structure Based on Polydopamine to Enhance pH‐Sensitive Seaweed‐Based Film for Medicine
Authors: Yan Ming , Shi Junfeng , Tang Song , Zhou Guohang , Zeng Jiexiang , Zhang Yixin , Zhang Hong , Yu Yue , Guo Jing 
Published: February 2022

AbstractThe drug‐loaded and seaweed‐based composite film with high mechanical properties was prepared based on the dynamically united calcium alginate/carboxymethyl chitosan (CA/CMCS) double network structure with the help of polydopamine (PDA). The enhancement mechanism could be attributed to three aspects. Firstly, a dynamic cross‐linking network formed by Schiff base reaction between CMCS and oxidized starch (OXS). Secondly, sodium alginate (SA) and CaCl2 formed an ion cross‐linking network. Finally, PDA and CMCS underwent the Michael addition reaction to form dynamic covalent bonds that dynamically combined the two networks. The effect of CMCS content on wettability and mechanical properties of the composite film was explored in order to improve the comprehensive properties used in the medical field. The drug‐loaded film containing ciprofloxacin inclusion compound had excellent slow‐release performance and pH sensitivity. It had obvious antibacterial properties against Escherichia coli and Staphylococcus aureus, and the excellent cell growth rate. It has broad prospects as a wound dressing to treat bacterial infections and smart drug delivery, and is expected to be applied in the field of biomedicine.
Electromagnetic Properties of Polypyrrole Metallic Magnetic Nanocomposites: First‐Principles Study
Authors: Wang Yesong , Huang Xinshu , Lu Liying , Shi Jing , Liu Jiang 
Published: February 2022

AbstractConductive polypyrrole (PPy) is an excellent polymer material for microwave absorption, which is vital for reducing electromagnetic interference (EMI) for electronic devices. To improve the microwave absorption capability and enhance the thermal stability and mechanical ductility of conductive PPy, metallic magnetic nanoparticles can be added to form PPy nanocomposites. In this paper, we present the first study to compute the electromagnetic properties of PPy nanocomposites based on the first principles method. It is discovered that (1) while doping can improve the microwave absorbing properties of PPy material, the absorption performance does not necessarily increase with the number of doping position; (2) conductivity and absorption coefficient increase significantly for the PPy nanocomposite compared with PPy. The dielectric loss is more than 2 at about 2 eV; (3) reflectivity and absorption coefficient decrease with the increase of PPy content in PPy/Co nanocomposite; (4) the average magnetic moment of the PPy nanocomposite is the same as that of pure nanoparticles, and this indicates that only nanoparticles generate magnetic loss for the nanocomposite.
Boosting Vascular Imaging‐Performance and Systemic Biosafety of Ultra‐Small NaGdF4 Nanoparticles via Surface Engineering with Rationally Designed Novel Hydrophilic Block Co‐Polymer
Authors: Jiang Zhilin , Xia Bin , Ren Feng , Bao Bolin , Xing Wei , He Tao , Li Zhen 
Published: February 2022

AbstractRevealing the anatomical structures, functions, and distribution of vasculature via contrast agent (CA) enhanced magnetic resonance imaging (MRI) is crucial for precise medical diagnosis and therapy. The clinically used MRI CAs strongly rely on Gd‐chelates, which exhibit low T1 relaxivities and high risks of nephrogenic systemic fibrosis (NSF) for patients with renal dysfunction. It is extremely important to develop high‐performance and safe CAs for MRI. Herein, it is reported that ultra‐small NaGdF4 nanoparticles (UGNs) can serve as an excellent safe MRI CA via surface engineering with rationally designed novel hydrophilic block co‐polymer (BPn). By optimizing the polymer molecular weights, the polymer‐functionalized UGNs (i.e., UGNs‐BP14) are obtained to exhibit remarkably higher relaxivity (11.8 mm–1 s–1 at 3.0 T) than Gd‐DTPA (3.6 mm–1 s–1) due to their ultracompact and abundant hydrophilic surface coating. The high performance of UGNs‐BP14 enables us to sensitively visualize microvasculature with a small diameter of ≈0.17 mm for up to 2 h, which is the thinnest blood vessel and the longest time window for low field (1.0 T) MR angiography ever reported, and cannot be achieved by using the clinically used Gd‐DTPA under the same conditions. More importantly, renal clearable UGNs‐BP14 show lower risks of inducing NSF in comparison with Gd‐DTPA due to their negligible release of Gd3+ ions after modification with the novel hydrophilic block copolymer. The study presents a novel avenue for boosting imaging‐performance and systemic biosafety of UGNs as a robust MRI CA with great potential in precise diagnosis of vasculature‐related diseases.
Using electronic health records to explore negotiations around euthanasia decision making for dogs and cats in the UK
Authors: Gray Carol , Radford Alan 
Published: February 2022

AbstractBackgroundEnd‐of‐life decision making for animals happens daily in veterinary practice. However, access to such discussions as they happen is difficult, in view of the highly emotional circumstances of end‐of‐life consultations. Despite the expanding literature on euthanasia, few studies have explored the circumstances of euthanasia disagreement or delay.MethodsTo explore euthanasia discussions in veterinary practice, consultations recorded in electronic health records in a UK veterinary surveillance database (SAVSNET) were examined. From a sample of 2000 identified consultations, 69 canine and 76 feline consultations were purposively sampled for detailed thematic analysis. Specifically, consultations were selected if they involved a decision to delay euthanasia, including disagreement about the timing of euthanasia.ResultsReasons identified for euthanasia refusal or delay included client‐related factors (e.g., allowing other family members to say goodbye, differing opinions on the quality of life) and veterinary surgeon‐related factors (eg, the wish to carry out further investigations or to try a new treatment). In the instance of refusal or delay, palliative treatment was commonly provided to preserve animal welfare.ConclusionThis study illustrates some of the processes used to negotiate end‐of‐life decision making in dogs and cats. Its findings shed light on the importance of palliative care in providing owners with time to decide.
Overcoming absorption effects in the determination of light elements in beverages by total‐reflection X‐ray spectrometry
Authors: Maltsev Artem S. , Yusupov Rafail A. , Bakhteev Sait A. 
Published: February 2022

AbstractTotal‐reflection X‐ray fluorescence spectrometry (TXRF) is one of the analytical methods for the rapid and cost‐efficient multielemental analysis of solid and liquid objects. However, the method has some issues in the quantitative analysis due to the possible matrix effects. Since alcoholic and nonalcoholic beverages contain a high percentage of carbohydrates (especially sucrose), ethanol, and other organic compounds, the issues of matrix effects are significant and should be studied. Basically, absorption effects appear in the determination of “light” elements as P, S, K, and Ca. This article showed the capabilities of TXRF applying to the determination of “light” elements in alcoholic and nonalcoholic beverages using two sample preparation techniques: direct analysis and acid digestion. Due to the lack of certified reference materials for beverages, the model solutions with a matrix of 5% sugar in water were prepared according to the developed experimental design. The absorption effects that influenced the accuracy of TXRF analysis of beverages were demonstrated and quantitatively estimated. The quantification procedures for direct analysis of beverages were optimized using external calibration. The real samples of wine, beer, juice, and soft drink were analyzed using the offered approaches, and results of TXRF were compared to inductively coupled plasma mass spectrometry.
Non-Autonomous Evolutionary Equations
Authors: Seifert Christian , Trostorff Sascha , Waurick Marcus 
Published: February 2022

AbstractPreviously, we focussed on evolutionary equations of the form
$$\displaystyle \left (\overline {\partial _{t,\nu }M(\partial _{t,\nu })+A}\right )U=F. $$

∂

t
,
ν

M
(

∂

t
,
ν

)
+
A

¯

U
=
F
.
In this chapter, where we turn back to well-posedness issues, we replace the material law operator M(∂t,ν), which is invariant under translations in time, by an operator of the form
$$\displaystyle \mathcal {M}+\partial _{t,\nu }^{-1}\mathcal {N}, $$

ℳ
+

∂

t
,
ν

−
1

N
,
where both
$$\mathcal {M}$$

ℳ
and
$$\mathcal {N}$$

N
are bounded linear operators in
$$L_{2,\nu }(\mathbb {R};H)$$

L

2
,
ν

(
ℝ
;
H
)
. Thus, it is the aim in the following to provide criteria on
$$\mathcal {M}$$

ℳ
and
$$\mathcal {N}$$

N
under which the operator
$$\displaystyle \partial _{t,\nu }\mathcal {M}+\mathcal {N}+A $$

∂

t
,
ν

ℳ
+
N
+
A
is closable with continuous invertible closure in
$$L_{2,\nu }(\mathbb {R};H)$$

L

2
,
ν

(
ℝ
;
H
)
. In passing, we shall also replace the skew-selfadjointness of A by a suitable real part condition. Under additional conditions on
$$\mathcal {M}$$

ℳ
and
$$\mathcal {N}$$

N
, we will also see that the solution operator is causal. Finally, we will put the autonomous version of Picard’s theorem into perspective of the non-autonomous variant developed here.
Evolutionary Inclusions
Authors: Seifert Christian , Trostorff Sascha , Waurick Marcus 
Published: February 2022

AbstractThis chapter is devoted to the study of evolutionary inclusions. In contrast to evolutionary equations, we will replace the skew-selfadjoint operator A by a so-called maximal monotone relation A ⊆ H × H in the Hilbert space H. The resulting problem is then no longer an equation, but just an inclusion; that is, we consider problems of the form
$$\displaystyle (u,f)\in \overline {\partial _{t,\nu }M(\partial _{t,\nu })+A}, $$

(
u
,
f
)
∈

∂

t
,
ν

M
(

∂

t
,
ν

)
+
A

¯

,
where
$$f\in L_{2,\nu }(\mathbb {R};H)$$

f
∈

L

2
,
ν

(
ℝ
;
H
)
is given and
$$u\in L_{2,\nu }(\mathbb {R};H)$$

u
∈

L

2
,
ν

(
ℝ
;
H
)
is to be determined. This generalisation allows the treatment of certain non-linear problems, since we will not require any linearity for the relation A. Moreover, the property that A is just a relation and not neccessarily an operator can be used to treat hysteresis phenomena, which for instance occur in the theory of elasticity and electro-magnetism.
Approximation of martingale couplings on the line in the adapted weak topology
Authors: Beiglböck M. , Jourdain B. , Margheriti W. , Pammer G. 
Published: February 2022

AbstractOur main result is to establish stability of martingale couplings: suppose that $$\pi $$
π
is a martingale coupling with marginals $$\mu , \nu $$

μ
,
ν

. Then, given approximating marginal measures $$\tilde{\mu }\approx \mu , \tilde{\nu }\approx \nu $$

μ
~

≈
μ
,

ν
~

≈
ν

in convex order, we show that there exists an approximating martingale coupling $$\tilde{\pi }\approx \pi $$

π
~

≈
π

with marginals $$\tilde{\mu }, \tilde{\nu }$$

μ
~

,

ν
~

. In mathematical finance, prices of European call/put option yield information on the marginal measures of the arbitrage free pricing measures. The above result asserts that small variations of call/put prices lead only to small variations on the level of arbitrage free pricing measures. While these facts have been anticipated for some time, the actual proof requires somewhat intricate stability results for the adapted Wasserstein distance. Notably the result has consequences for several related problems. Specifically, it is relevant for numerical approximations, it leads to a new proof of the monotonicity principle of martingale optimal transport and it implies stability of weak martingale optimal transport as well as optimal Skorokhod embedding. On the mathematical finance side this yields continuity of the robust pricing problem for exotic options and VIX options with respect to market data. These applications will be detailed in two companion papers.
A hyper-parameter tuning approach for cost-sensitive support vector machine classifiers
Authors: Guido Rosita , Groccia Maria Carmela , Conforti Domenico 
Published: February 2022

AbstractIn machine learning, hyperparameter tuning is strongly useful to improve model performance. In our research, we concentrate our attention on classifying imbalanced data by cost-sensitive support vector machines. We propose a multi-objective approach that optimizes model’s hyper-parameters. The approach is devised for imbalanced data. Three SVM model’s performance measures are optimized. We present the algorithm in a basic version based on genetic algorithms, and as an improved version based on genetic algorithms combined with decision trees. We tested the basic and the improved approach on benchmark datasets either as serial and parallel version. The improved version strongly reduces the computational time needed for finding optimized hyper-parameters. The results empirically show that suitable evaluation measures should be used in assessing the classification performance of classification models with imbalanced data.
Optimization approaches for defining storage strategies in maritime container terminals
Authors: Ambrosino Daniela , Xie Haoqi 
Published: February 2022

AbstractIn maritime container terminals, yards have a primary role in permitting the efficient management of import and export flows. In this work, a mixed 0/1 linear programming model and a heuristic approach are proposed for defining storage rules in order to minimize the space used in the export yard. The minimization of land space is pursued by defining the rules to allocate containers into the bay-locations of the yard, in such a way as to minimize the number of bay-locations used and the empty slots within them. The main aim of this work is to propose a solution approach for permitting the yard manager to compare yard storage strategies for different transport demands, in such a way to be able to evaluate and, eventually, modify the storage strategy when the characteristics of the transport demand change. Computational experiments, based on both real instances and generated ones, are presented. All instances are derived by a case study related to an Italian terminal.
The net effect of advice on strategy-proof mechanisms: an experiment for the Vickrey auction
Authors: Masuda Takehito , Mikami Ryo , Sakai Toyotaka , Serizawa Shigehiro , Wakayama Takuma 
Published: February 2022

AbstractWe conduct laboratory experiments for the multi-unit Vickrey auction with and without advice to subjects on strategy-proofness. The rate of truth-telling among the subjects without advice stays at 20%, whereas the rate increases to 47% among those who have received advice. By conducting similar experiments for the pay-your-bid auction, which is not strategy-proof, we confirm that the increase in truth-telling is due significantly to the net advice effect (i.e., the effect beyond the so-called experimenter demand effect). Moreover, we find that providing advice improves efficiency in the Vickrey auction, particularly in the early periods, when the subjects are less experienced. In general, subjects tend to overbid in Vickrey auction experiments. Our results indicate the possibility that providing simple advice decreases such overbidding by promoting a better understanding of the strategy-proofness of the Vickrey auction. Strategy-proof mechanisms are sometimes criticized because players often fail to recognize the benefit of telling the truth. However, our observations show that introducing advice on the property of strategy-proofness helps them behave “correctly.”
Quantifying Firebrand Production and Transport Using the Acoustic Analysis of In-Fire Cameras
Authors: Thompson Dan K. , Yip Daniel A. , Koo Eunmo , Linn Rod , Marshall Ginny , Refai Razim , Schroeder Dave 
Published: February 2022

AbstractFirebrand travel and ignition of spot fires is a major concern in the Wildland-Urban Interface and in wildfire operations overall. Firebrands allow for the efficient breaching across fuel-free barriers such as roads, rivers and constructed fuel breaks. Existing observation-based knowledge on medium-distance firebrand travel is often based on single tree experiments that do not replicate the intensity and convective updraft of a continuous crown fire. Recent advances in acoustic analysis, specifically pattern detection, has enabled the quantification of the rate at which firebrands are observed in the audio recordings of in-fire cameras housed within fire-proof steel boxes that have been deployed on experimental fires. The audio pattern being detected is the sound created by a flying firebrand hitting the steel box of the camera. This technique allows for the number of firebrands per second to be quantified and can be related to the fire's location at that same time interval (using a detailed rate of spread reconstruction) in order to determine the firebrand travel distance. A proof of concept is given for an experimental crown fire that shows the viability of this technique. When related to the fire's location, key areas of medium-distance spotting are observed that correspond to regions of peak fire intensity. Trends on the number of firebrands landing per square metre as the fire approaches are readily quantified using low-cost instrumentation.
Optical, photoluminescence, and E.S.R spectral analysis of manganese ions in phosphate glasses melted under various conditions and impact of gamma irradiation
Authors: ElBatal F. H. , Azooz M. A. , Hamdy Y. M. , ElDin F. M. Ezz , Abo-Naf S. M. , ElBatal H. A. 
Published: February 2022

AbstractGlasses from NaCa fluorophosphate doped with varying MnO2 dopant (0.25, 0.50, 1.0%) and melted under different conditions were prepared by normal melting annealing technique. Collective optical, FTIR, photoluminescence, and E.S.R spectral measurements for the various MnO2-doped glasses were done. Optical spectrum of the undoped host fluorophosphate glass reveals only distinct UV absorption which is correlated to contaminated trace iron (Fe3+) ions present as impurities. The MnO2-doped glasses show the same UV absorption beside two additional bands, a small one at 410 nm which is assumed to originate from (Mn2+) ions of spin-forbidden nature and a broad visible and distinct band centered at 500 nm representing the absorption of trivalent manganese (Mn3+) ions of spin-allowed nature. The effects of varying melting conditions reveal obvious changes in the intensities of the two visible bands. FTIR spectra reveal extended vibrational peaks due to phosphate (PO4) groups with sharing of some fluorophosphate (PO3F) groups and the introduction of increasing percent of the dopant that causes minor variations in the FTIR spectra. Photoluminescence spectra reveal a broad emission band centered at about 635 nm and the intensity of the emission band increases with the increase of MnO2 content and is more distinct in glass melted under reducing conditions than that melted at normal condition. E.S.R spectral measurements were carried out to confirm the optical results indicating the existence of measurable divalent Mn2+ ions which increases in reducing conditions. The effects of gamma irradiation (6Mrad dose) on the studied spectral properties were evaluated.
Effect of acid-alkali treatment on serum protein adsorption and bacterial adhesion to porous titanium
Authors: Zhong Juan , Li Xuelian , Yao Yitong , Zhou Jing , Cao Shanshan , Zhang Xinping , Jian Yutao , Zhao Ke 
Published: February 2022

AbstractModification of the titanium (Ti) surface is widely known to influence biological reactions such as protein adsorption and bacterial adhesion in vivo, ultimately controlling osseointegration. In this study, we sought to investigate the correlation of protein adsorption and bacterial adhesion with the nanoporous structure of acid-alkali-treated Ti implants, shedding light on the modification of Ti implants to promote osseointegration. We fabricated nontreated porous Ti (NTPT) by powder metallurgy and immersed it in mixed acids and NaOH to obtain acid-alkali-treated porous Ti (AAPT). Nontreated dense sample (NTDT) served as control. Our results showed that nanopores were formed after acid-alkali treatment. AAPT showed a higher specific surface area and became much more hydrophilic than NTPT and NTDT (p < 0.001). Compared to dense samples, porous samples exhibited a lower zeta potential and higher adsorbed protein level at each time point within 120 min (p < 0.001). AAPT formed a thicker protein layer by serum precoating than NTPT and NTDT (p < 0.001). The main adsorbed proteins on AAPT and NTPT were albumin, α1 antitrypsin, transferrin, apolipoprotein A1, complement C3 and haptoglobin α1 chain. The amounts of bacteria adhering to the serum-precoated samples were lower than those adhering to the nonprecoated samples (p < 0.05). Lower-molecular-weight proteins showed higher affinity to porous Ti. In conclusion, acid-alkali treatment facilitated protein adsorption by porous Ti, and the protein coating tended to prevent bacteria from adhering. These findings may be utilized for Ti implant modification aimed at reducing bacterial adhesion and enhancing osseointegration.
Student Self-perception on Digital Literacy in STEM Blended Learning Environments
Authors: Le Branda , Lawrie Gwendolyn A. , Wang Jack T. H. 
Published: February 2022

AbstractAs students transition into tertiary blended learning environments, their digital literacy in terms of technical capabilities have potential to impact on their access to digital resources. The first foundational year of STEM degrees includes compulsory courses across a broad range of scientific areas, each of which incorporates online technology in a discipline-specific manner. Given the diversity of online resources that STEM students need to access across their first-year coursework, this study applies learning analytical methods to determine whether students’ perceived level of digital literacy has an effect on their navigation of learning management systems (LMS) and overall academic performance. The frequency and nature of LMS interactivity were examined across four first-year STEM courses offered in the same semester at a single institution, using a K-means cluster analysis to group student responses. It was observed that high achieving students accessed LMS resources more frequently than mid or low-achieving students across all four STEM courses. Students’ perceived level of digital literacy was collected via survey (n = 282), and students were sorted high (n = 106) and low-level (n = 176) of perceived digital literacy—HDL and LDL, respectively. HDL students were not consistently found in the high-achieving academic group and did not perform better in their overall grade when compared to LDL students. LDL students were observed to perform better in specific online assessment tasks, which may be attributed to their increased frequency of LMS interactivity. These findings highlight the delicate balance between students’ perceived level of digital literacy, motivation for engaging with online learning environments, and academic performance.
Dangerous liasons and hot customers for banks
Authors: Cerqueti Roy , Pampurini Francesca , Pezzola Annagiulia , Quaranta Anna Grazia 
Published: February 2022

AbstractUnderstanding the correlation between different customers’ loss of creditworthiness is crucial to credit risk analysis. This paper describes a novel method, based on a weighted network model, in which a set of firms, customers of the same bank, represent the nodes while their links and weights derive from the total transaction amounts. We explore the contagion mechanism deriving from the transmission of the difficulties of one customer to other clients of the same bank so highlighting areas where contagion risk is higher. We use a real proprietary data set provided by a bank to illustrate the proposed approach.