bluuebunny/crossref_metadata_2025_split huggingface dataset:
High strength and toughness of double physically cross‐linked hydrogels composed of polyvinyl alcohol and calcium alginate
Authors: Chen Jiwei , Yang Zhaokun , Shi Dongjian , Zhou Tianyang , Kaneko Daisaku , Chen Mingqing 
Published: November 2020

AbstractThe weak mechanical properties of hydrogels, especially physically cross‐linked hydrogels are usually a major factor to hinder their application. To solve this problem, in this work, we prepared a high strength and toughness of double physically cross‐linked (PDN) hydrogels composed of crystalline domain cross‐linked polyvinyl alcohol (PVA) and Ca2+‐cross‐linked alginate (Alg). With a further annealing treatment, the noncovalent cross‐linked network via the formed crystalline promote the as‐prepared PDN PVA/Alg hydrogel to exhibit well mechanical properties with the tensile strength of ~1.94 MPa, elongation at break of ~607% and Young's modulus of ~0.45 MPa (above 70 wt% of water content). By analyzing the mechanism of improving the hydrogel mechanical properties, it is found that annealing can effectively improve the crystallinity of PVA in the hydrogel, and then greatly improve the mechanical properties of the hydrogel. This provides a general method for improving the mechanical properties of PVA PDN hydrogels. In addition, the PDN PVA/Alg hydrogel was also proved to have good ionic conductivity of 1.70 S m−1. These desirable properties make the prepared physically cross‐linked hydrogels promising materials for medical and biosensing fields.
Effects of interlayer density and surfactant on coupled thermal stress and moisture absorption in modified montmorillonite/polypropylene nanocomposite
Authors: Mahdavi Ehsan , Haghighi‐Yazdi Mojtaba , Mashhadi Mahmoud Mosavi , Khaledialidusti Rasoul 
Published: November 2020

AbstractModified montmorillonite/polypropylene nanocomposites (NCs) are increasingly used in industrial applications such as subsea pipelines because hexadecyltrimethyl ammonium montmorillonite (HDTMA+‐Mt) enhances thermomechanical and barrier properties of the amorphous polymer. Two coupled physics of moisture adsorption and thermal loading are investigated. Molecular dynamics simulates HDTMA+‐Mt polymer NC using three force fields including polymer consistent force field and condensed‐phase optimized molecular potentials, and embedded‐atom method. Mechanical properties and self‐diffusion coefficient are investigated at temperature levels of 100 and 298 K, and water content of 0.021 and 0.133 g/g. These properties are evaluated at 1.0 atm pressure for four different volume fractions (vol%) of the HDTMA+‐Mt. The modeling procedure is verified by obtaining the glass transition temperature (Tg) of the NC by scanning the temperature from 200 K (glassy state) up to 325 K (rubbery state). It is observed that the Tg is very close to the experimental value available in the literature. The result of the modeling shows that the increase of clay content of the NC decreases the self‐diffusion coefficient of the material. It is seen that the clay nanoparticle can significantly hinder the degradation of mechanical properties of the NC even when both temperature and water content increase.
Heterogeneous Kinetics of Thiourea Electro‐Catalytic Oxidation Reactions on Palladium Surface in Aqueous Medium
Authors: Shabik Md. Fazle , Begum Humayra , Rahman Mohammed M. , Marwani Hadi M. , Hasnat Mohammad A. 
Published: November 2020

AbstractThe electrochemical behaviors of thiourea (TU) oxidation have been studied at Palladium (Pd) electrode in the acidic medium by recording cyclic voltammograms (CVs). The influence of pH was investigated in the pH range of 1.0 to 9.0. Facilitated adsorption of TU on electrode surface results in enhanced catalytic response in acidic medium and maximum electro‐catalytic response was found at pH∼3.0. Chronoamperometric (CA) experiment determined this oxidation as 1e‐ transfer process and the variation of TU concentration reveals a 1st order kinetics. In the CV responses, the large value of peak separation (▵Ep >380 mV) calculated by the variation of scan rate indicates that oxidation of TU is an irreversible process. With the aid of convolution potential sweep voltammetry (CPSV), the standard rate constant (k°) for the reaction was found to be 7.1×10−4cm/s and the formal potential constant (E°′ ) was evaluated to be ∼0.37 V vs Ag/AgCl (sat. KCl). The value of transfer coefficient (α) was found to vary from 0.74 to 0.40 with applied potential (E). From the potential dependent variation of transfer coefficient (α) and activation energy (▵G≠), it was concluded that the overall electrochemical oxidation of TU follows a stepwise mechanism at lower potential (<0.40) V and a concerted one at relatively higher potential (>0.40) V. The FTIR analysis of the product after oxidation of TU molecules confirmed the appearance of a new sharp band near 530 cm−1 due to the formation of S−S bonds suggesting formation of formamidine disulfide (FD) ions.
Model robust profile monitoring for the generalized linear mixed model for Phase I analysis
Authors: Bandara Keerthi , Abdel‐Salam Abdel‐Salam G. , Birch Jeffrey B. 
Published: November 2020

AbstractThe generalized linear mixed model (GLMM) becomes very popular in profile monitoring, especially when the production processes follow nonnormal distribution. In most of the real‐life applications in industry, medicine, biology…and so on researchers assume that the response variable follows a Bernoulli or Binomial distribution. The majority of previous studies in profile monitoring focused on parametric modeling using the logistic regression model, with both fixed or random effects, under the assumption of correct model specification. This research considers those cases where the parametric logistic regression model for the family of profiles is unknown or at least uncertain. Consequently, we propose two mixed model methods to monitor profiles from the exponential family: a nonparametric (NP) regression method based on the penalized spline regression technique and a semiparametric method (model robust profile monitoring for the generalized linear mixed model) which combines the advantages of both the parametric and NP methods. Several Hotelling T2 charts that have been studied for a binary response variable with replicates for Phase I profile monitoring. The performance of the proposed method is evaluated by using mean squares of errors and probability of signals criteria. The results showed satisfactory performance of the proposed control charts.
Can failure be prevented? Using longitudinal data to identify at‐risk students upon entering secondary school
Authors: Vinas‐Forcade Jennifer , Mels Cindy , Van Houtte Mieke , Valcke Martin , Derluyn Ilse 
Published: November 2020

In 2016, Uruguay started gathering longitudinal student data to improve educational trajectories by putting in place an ‘early alert’ system. Underlying the system is the understanding that prior schooling predicts likelihood of grade repetition and grade repetition predicts later school dropout, while close follow‐up can help prevent both repetition and dropout. We used a database of administrative registries from a national public primary school graduating cohort on their last year in primary and first year in secondary education (2015–2016, n = 36,754). We conducted two‐level cross‐classified logistic regression analyses to assess the suitability of using features of Uruguayan students’ primary school trajectories, individual, family and primary school characteristics to predict their success or failure in their first year of secondary school. All considered prior schooling factors (previous repetition experiences, achievement, behaviour and absenteeism), the student’s family socio‐economic status (SES) and primary school’s SES composition, as well as the location of the school in an urban or rural setting, help explain differences in chances of first‐year success or failure (grade repetition) in secondary school. While these results support the ‘early alert’ system’s approach, predictive performance analyses are needed when using explanatory models for planning interventions with scarce resources and making decisions affecting individual students’ trajectories. The importance of testing resulting models’ sensitivity, as well as their false positive rates, is highlighted.
A new feasible approach based on utility of ninhydrin for selective fluorimetric analysis of baclofen. Application to content uniformity evaluation
Authors: Abu‐hassan Ahmed A. , Ali Ramadan , Derayea Sayed M. 
Published: November 2020

AbstractIn the current proposed analysis, a new, feasible, and selective fluorimetric approach was designed for baclofen assay. Baclofen is a medication prescribed as a therapy for muscle spasticity that originated from multiple sclerosis or a spinal cord injury, and other cases such as hiccups. The analytical approach relies on the use of ninhydrin to form a fluorescent derivative that was monitored at λex 386 nm or λem 480 nm. Under suitable reaction conditions, the primary amino moiety in baclofen was condensed with ninhydrin and phenylacetaldehyde in the presence of Teorel buffer as a buffered medium. The method exhibited linearity when baclofen concentration was plotted against response in the range 1–10 μg ml−1. Adjustment of the reaction variables and study of validation parameters according to ICH directives were performed correctly. An interference study was implemented to ensure that no discrepancy from the excipient had occurred. Finally, the proposed method was applied successfully for baclofen assay in dosage form and extended to test Mylobac content uniformity.
A new model to analyze the temperature effect on the microalgae performance at large scale raceway reactors
Authors: Rodríguez‐Miranda Enrique , Acién Francisco G. , Guzmán Jose L. , Berenguel Manuel , Visioli Antonio 
Published: November 2020

AbstractIn this study a simplified temperature model for raceway reactors is developed, allowing to determine the temperature of the microalgae culture as a function of reactor design and environmental conditions. The model considers the major phenomena taking place in raceway reactors, especially heat absorption by radiation and heat losses by evaporation among others. The characteristic parameters of the model have been calibrated using genetic algorithms, next being validated with a long set of more than 50 days covering different weather conditions. It is worth to highlight the use of the developed model as a tool to analyze the influence of the temperature on the performance of microalgae cultures at large scale. As example, the annual variation of the performance of up to five different microalgae strains has been determined by computing the temperature index, thus the normalized value of performance of whatever microalgae at the real temperature with respect to that achievable at optimal temperature can be established. Results confirm that only strains tolerant to wide ranges of temperature can be efficiently produced all the year around in large scale outdoor raceway reactors without additional temperature control systems.
Stakeholder engagement is evolving: Do investors play a main role?
Authors: Ruiz Silvia , Romero Silvia , Fernandez‐Feijoo Belen 
Published: November 2020

AbstractStakeholder engagement, an essential component of the sustainability reporting strategy, is changing, as is the position of the different stakeholders in this evolving scenario. In this paper, we explore the effect of the pressure that a specific group of stakeholders, investors, exerts on the quality of the sustainability information disclosed. We intend to analyze if there has been a change in the role that investors play in sustainability reporting. By focusing on investors, we are paying attention to one of the less studied groups within the sustainability stakeholders. To this aim, we carry out a content analysis of the sustainability information disclosed by U.S. (shareholder‐oriented country) and Spanish (stakeholder‐oriented country) listed companies during the years 2013 to 2016. Our findings confirm the key role that investors play in the companies' sustainability strategies, demanding more and better sustainability information. We also find a reduction in the quality of sustainability disclosures in Spanish companies in the last year of our sample, showing a relevant change in this country that has been leading the sustainability rankings until now. The results of this paper are useful to investors and companies, as they reflect the changes on the information they demand, and for regulators, in order to create the adequate legal framework that will improve the quality of reporting. Regulators and financial agents should acknowledge this new scenario to adapt norms and actions accordingly.
Hypothalamic injury patterns after resection of craniopharyngiomas and correlation to tumor origin: A study based on endoscopic observation
Authors: Yang Le , Xie ShenHao , Tang Bin , Wu Xiao , Tong ZhiGao , Fang Chao , Ding Han , Bao YouYuan , Zheng SuYue , Hong Tao 
Published: November 2020

AbstractThe precise understanding of hypothalamic injury (HI) patterns and their relationship with different craniopharyngioma (CP) classifications remains poorly addressed. Here, four HI patterns after CP resection based on endoscopic observation were introduced. A total of 131 CP cases treated with endoscopic endonasal approach (EEA) were reviewed retrospectively and divided into four HI patterns: no‐HI, mild‐HI, unilateral‐HI and bilateral‐HI, according to intraoperative findings. The outcomes were evaluated and compared between groups in terms of weight gain, endocrine status, electrolyte disturbance and neuropsychological function before and after surgery. A systematic correlation was found between CP origin and subsequent HI patterns. The majority of intrasellar and suprasellar stalk origins lead to a no‐HI pattern, the central‐type CP mainly develops a mild or bilateral HI pattern, and the majority of tumors with hypothalamic stalk origins result in unilateral HI and sometimes bilateral HI patterns. The proportion of tumors with a maximum diameter >3 cm in the no‐HI group was higher than that in the mild‐HI group, BMI and quality of life in the no‐HI group showed better results than those in the other groups. The incidence of new‐onset diabetes insipidus in the bilateral‐HI group was significantly higher than that in the other groups. Memory difficulty was observed mainly in the unilateral‐HI and bilateral‐HI groups. However, the outcomes of electrolyte disturbance, sleep, and cognitive disorder in the unilateral‐HI group were significantly better than those in the bilateral‐HI group. This study suggests the possibility of using pre‐ and intraoperative observation of CP origin to predict four HI patterns and even subsequent outcomes after tumor removal.
Biological Relevance of RGD‐Integrin Subtype‐Specific Ligands in Cancer
Authors: Sani Saidu , Messe Mélissa , Fuchs Quentin , Pierrevelcin Marina , Laquerriere Patrice , Entz‐Werle Natacha , Reita Damien , Etienne‐Selloum Nelly , Bruban Véronique , Choulier Laurence , Martin Sophie , Dontenwill Monique 
Published: November 2020

AbstractIntegrins are heterodimeric transmembrane proteins able to connect cells with the micro‐environment. They represent a family of receptors involved in almost all the hallmarks of cancer. Integrins recognizing the Arg‐Gly‐Asp (RGD) peptide in their natural extracellular matrix ligands have been particularly investigated as tumoral therapeutic targets. In the last 30 years, intense research has been dedicated to designing specific RGD‐like ligands able to discriminate selectively the different RGD‐recognizing integrins. Chemists′ efforts have led to the proposition of modified peptide or peptidomimetic libraries to be used for tumor targeting and/or tumor imaging. Here we review, from the biological point of view, the rationale underlying the need to clearly delineate each RGD‐integrin subtype by selective tools. We describe the complex roles of RGD‐integrins (mainly the most studied αvβ3 and α5β1 integrins) in tumors, the steps towards selective ligands and the current usefulness of such ligands. Although the impact of integrins in cancer is well acknowledged, the biological characteristics of each integrin subtype in a specific tumor are far from being completely resolved. Selective ligands might help us to reconsider integrins as therapeutic targets in specific clinical settings.
Microenvironment‐Sensitive Fluorescent Ligand Binds Ascaris Telomere Antiparallel G‐Quadruplex DNA with Blue‐Shift and Enhanced Emission
Authors: Yu Quan‐Qi , Gao Juan‐Juan , Lang Xue‐Xian , Li Hong‐Yao , Wang Ming‐Qi 
Published: November 2020

AbstractThe development of small molecules that can selectively target G‐quadruplex (G4) DNAs has drawn considerable attention due to their unique physiological and pathological functions. However, only a few molecules have been found to selectively bind a particular G4 DNA structure. We have developed a fluorescence ligand Q1, a molecular scaffold with a carbazole–pyridine core bridged by a phenylboronic acid side chain, that acts as a selective ascaris telomere antiparallel G4 DNA ASC20 ligand with about 18 nm blue‐shifted and enhanced fluorescence intensity. Photophysical properties revealed that Q1 was sensitive to the microenvironment and gave the best selectivity to ASC20 with an equilibrium binding constant Ka=6.04×105 M−1. Time‐resolved fluorescence studies also demonstrated that Q1 showed a longer fluorescence lifetime in the presence of ASC20. The binding characteristics of Q1 with ASC20 were shown in detail in a fluorescent intercalator displacement (FID) assay, a 2‐Ap titration experiment and by molecular docking. Ligand Q1 could adopt an appropriate pose at terminal G‐quartets of ASC20 through multiple interactions including π–π stacking between aromatic rings; this led to strong fluorescence enhancement. In addition, a co‐staining image showed that Q1 is mainly distributed in the cytoplasm. Accordingly, this work provides insights for the development of ligands that selectively targeting a specific G4 DNA structure.
Analytic formulas of peak current in cyclic voltammogram: Machine learning as an alternative way?
Authors: Sun Sheng , Zhang Bochao , Wang Jiahao , Li Kaikai , Gao Yao , Zhang Tong‐Yi 
Published: November 2020

AbstractCyclic voltammetry is most widely used in the study of electrode kinetics. The peak current density (Ip) in a cyclic voltammogram (CV) is a function of many parameters involved in the kinetics, thereby being an indicator of the reaction mechanism. Analytic expressions of Ip for reversible and irreversible reactions, proposed by Randles–Sevcik equations via dimensional analysis and numerical solutions of dimensionless equations, play the central role in the analysis of experimental results of CV. Great difficulties are encountered, however, to derive an expression of Ip in the quasireversible region by classical methods, and hence, an analytic formula is lacking yet to cover the entire reaction spectrum. The present work demonstrates the success of machine learning (ML) as an alternative way to find simple and analytic formulas of Ip for the reversible and irreversible reactions and then for the entire reaction spectrum, purely based on data from CV simulations. Two analytic formulas of Ip, both with high accuracy, are proposed by using symbolic regression combining with sparse regression. The simpler and physically meaningful one is obtained by combining ML with expert knowledge of mathematical expressions. The paper illustrates the powerful capability of ML, or by combining with expert knowledge, as a promising universal and practical tool to analyze complex electrochemical kinetics.
Near‐Infrared Boron Difluoride Formazanate Dyes
Authors: Buguis Francis L. , Maar Ryan R. , Staroverov Viktor N. , Gilroy Joe B. 
Published: November 2020

AbstractNear‐infrared (NIR) dyes are sought after for their utility in light harvesting, bioimaging, and light‐mediated therapies. Since long‐wavelength photoluminescence typically involves extensive π‐conjugated systems of double bonds and aromatic rings, it is often assumed that NIR dyes have to be large molecules that require complex syntheses. We challenge this assumption by demonstrating that facile incorporation of tertiary amine groups into readily available 3‐cyanoformazans affords efficient production of relatively simple NIR‐active BF2 formazanate dyes (λabs=691–760 nm, λPL=834–904 nm in toluene). Cyclic voltammetry experiments on these compounds reveal multiple reversible redox waves linked to the interplay between the tertiary amine and BF2 formazanate moieties. Density‐functional calculations indicate that the NIR electronic transitions in BF2 formazanates are of π→π*‐type, but do not always involve strong charge transfer.
1,2,4‐Oxadiazole Topsentin Analogs with Antiproliferative Activity against Pancreatic Cancer Cells, Targeting GSK3β Kinase
Authors: Carbone Daniela , Parrino Barbara , Cascioferro Stella , Pecoraro Camilla , Giovannetti Elisa , Di Sarno Veronica , Musella Simona , Auriemma Giulia , Cirrincione Girolamo , Diana Patrizia 
Published: November 2020

AbstractA new series of topsentin analogs, in which the central imidazole ring of the natural lead was replaced by a 1,2,4‐oxadiazole moiety, was efficiently synthesized. All derivatives were pre‐screened for antiproliferative activity against the National Cancer Institute (NCI‐60) cell lines panel. The five most potent compounds were further investigated in various pancreatic ductal adenocarcinoma (PDAC) cell lines, including SUIT‐2, Capan‐1, and Panc‐1 cells, eliciting EC50 values in the micromolar and sub‐micromolar range, associated with significant reduction of cell migration. These remarkable results might be explained by the effects of these new topsentin analogues on epithelial‐to‐mesenchymal transition markers, including SNAIL‐1/2 and metalloproteinase‐9. Moreover, flow cytometric analysis after Annexin V‐FITC and propidium iodide staining demonstrated that these derivatives enhanced apoptosis of PDAC cells. Keeping with these data, the PathScan intracellular signaling and ELISA array revealed cleavage of caspase‐3 and PARP and a significant inhibition of GSK3β phosphorylation, suggesting this kinase as a potential downstream target of our novel compounds. This was further supported by a specific assay for the evaluation of GSK3β activity, showing IC50 values for the most active compounds against this enzyme in the micromolar range.