bluuebunny/crossref_metadata_2025 huggingface dataset:
On enhanced exponential‐cum‐ratio estimators using robust measures of location
Authors: Gulzar Muhammad Awais , Latif Waqas , Abid Muhammad , Nazir Hafiz Zafar , Riaz Muhammad
Published: December 2021

Many studies are mainly concerned with the estimation of finite population mean and the well‐known preferences for it are ratio estimators. This article offers a remedy for improvement in the estimation of a study variable, based on supplementary information related to dual auxiliary variables in the context of simple random sampling without replacement scheme. We proposed two new general classes of exponential‐cum‐ratio estimators to estimate a finite population mean utilizing dual auxiliary variables with suitable combinations of the conventional and nonconventional measures. The expression for the mean square error (MSE) and theoretical conditions for proposed classes have been obtained for evaluation purposes. The performance of the proposed classes has been compared with existing estimators in terms of MSE. It is revealed that proposed estimators are more efficient than usual and existing estimators considered in this article. The simulation and robustness studies are also part of this article. Moreover, a variety of real data sets is also considered for an empirical study to support the theoretical results.
Microwave Assisted Cu‐Mediated Trifluoromethylation of Pyrimidine Nucleosides
Authors: Mangla Priyanka , Sanghvi Yogesh S. , Prasad Ashok K.
Published: December 2021

Trifluoromethylated nucleosides, such as trifluridine, have widespread applications in pharmaceuticals as anticancer and antiviral agents. However, site‐selective addition of a trifluoromethyl group onto a nucleobase typically requires either inconvenient multi‐step synthesis or expensive trifluoromethylation reagents, or results in low yield. This article describes a simple, scalable, and high‐yielding protocol for late‐stage direct trifluoromethylation of pyrimidine nucleosides via a microwave‐irradiated pathway. First, 5‐iodo pyrimidine nucleosides undergo complete benzoylation to obtain N3‐benzoyl‐3',5'‐di‐O‐benzoyl‐5‐iodo‐pyrimidine nucleosides as key precursors. Next, trifluoromethylation is carried out under both conventional and microwave heating using an inexpensive and commercially accessible Chen's reagent, i.e., methyl fluorosulfonyldifluoroacetate, to produce N3‐benzoyl‐3',5'‐di‐Obenzoyl‐5‐trifluoromethyl‐pyrimidine nucleosides. The microwave‐assisted transformation accentuates its simplicity, mild reaction conditions, and dominance, providing a facile route to access trifluoromethylation. Finally, the envisioned 5‐trifluoromethyl pyrimidine nucleosides are obtained by a routine debenzoylation procedure. This concludes a convenient three‐step synthesis to obtain trifluridine and its 2'‐modified analogs on a gram scale with consistently high yields, starting from their respective iodo‐precursors, and requires only one chromatographic purification at the trifluoromethylation step. Furthermore, this operationally simple protocol can be utilized as a definitive methodology to produce various other trifluoromethylated therapeutics. © 2021 Wiley Periodicals LLC.

Basic Protocol: Synthesis of 5‐trifluoromethyl pyrimidine nucleosides 4a‐c

Alternate Protocol: Conventional trifluoromethylation: Synthesis of N3‐benzoyl‐3',5'‐di‐O‐benzoyl‐5‐trifluoromethyl pyrimidine nucleosides (3a‐c)
Growth, Magnetic, and Optoelectronic Properties of Fe Doped MAPbI3 Crystals
Authors: Fu Haoran , Shu Huchen , Xu Zhiwen , Tao Hong , Fu Qiuming , Zhao Hongyang , Weng Jun , Xiong Liwei
Published: December 2021

Organic–inorganic hybrid perovskite is a wide family in which CH3NH3PbI3 is investigated mostly due to its superior optoelectronic and photovoltaic properties in solar cells. The doping in CH3NH3PbI3 is an effective way to adjust their properties. Fe is chosen as a dopant and CH3NH3(Pb1−xFex)I3 (x = 0, 0.2, 0.6) single crystals are grown successfully. Their optoelectronic and magnetic properties are investigated. It shows antiferromagnetic when x = 0.6 while others show paramagnetic. The photodetector when x = 0.6 also shows best behavior. It is meaningful to design such ferromagnetic photovoltaic halide perovskite and investigate the role of the doping magnetic elements.
The Ethical Implications of Big Data Research in Public Health: “Big Data Ethics by Design” in the UK‐REACH Study
Authors: Reed‐Berendt Ruby , Dove Edward S. , Pareek Manish ,   UK‐REACH Study Collaborative Group
Published: December 2021

In this article, we analyze legal and ethical issues raised in Big Data health research projects in the Covid‐19 era and consider how these issues might be addressed in ways that advance positive values (e.g., furtherance of respect for persons and accordance with relevant legal frameworks) while mitigating or eliminating any negative aspects (e.g., exacerbation of social inequality and injustice). We apply this analysis specifically to UK‐REACH (The United Kingdom Research Study into Ethnicity and Covid‐19 Outcomes in Healthcare Workers), a project with which we are involved. We argue that Big Data projects like UK‐REACH can be conducted in an ethically robust manner and that funders and sponsors ought to encourage similar projects to drive better evidence‐based public policy in public health. As part of this, we advocate that a Big Data ethics‐by‐design approach be undertaken when such projects are constructed. This principle extends the work of those who advocate ethics by design by addressing prominent issues in Big Data health research projects; it holds that ethical values and principles in Big Data health research projects are best adhered to when they are already integrated into the project aims and methods at the design stage. In advocating this principle, we present a unique perspective regarding pressing ethical problems around large‐scale, data‐driven Covid‐19 research, as well as legal issues associated with processing ostensibly anonymized health data.
Electrodetermination of Gallic Acid Using Multi‐walled Carbon Nanotube Paste Electrodes and N‐Octylpyridinium Hexafluorophosphate
Authors: Gidi Leyla , Honores Jessica , Ibarra José , Jesús Aguirre María , Arce Roxana , Ramírez Galo
Published: December 2021

In this work, the determination of gallic acid was performed using surface‐renewable carbon paste electrodes fabricated with multi‐walled carbon nanotubes (MWCNT) and a mixture of N‐octylpyridinium hexafluorophosphate (OPyPF6) ionic liquid with mineral oil (MO) as binder. This system shows remarkable amperometric sensor characteristics and promotes a better electronic transfer. An electroanalytical study of gallic acid shows a linear range from 4.98±0.25 to 74.1±2.2 μmol L−1, with R2=0.9958 and an experiment a limit of detection of 2.70±0.08 μmol L−1 (S/N=3), and a sensitivity of 0.029 μA μmol−1 L.
Fast determination of paracetamol and its hydrolytic degradation product p‐aminophenol by capillary and microchip electrophoresis with contactless conductivity detection
Authors: Alatawi Hanan , Hogan Anna , Albalawi Ibtihaj , O'Sullivan‐Carroll Emma , Wang Yineng , Moore Eric
Published: December 2021

Paracetamol (PAC) is one of the most extensively used analgesics and antipyretic drugs to treat mild and moderate pain. P‐aminophenol (PAP), the main hydrolytic degradation product of PAC, can be found in environmental water. Recently, CE has been developed for the detection of a wide variety of chemical substances. The purpose of this study is to develop a simple and fast method for the detection and separation of PAC and its main hydrolysis product PAP using CE and microchip electrophoresis with capacitively coupled contactless conductivity detection. The determination of these compounds using microchip electrophoresis with capacitively coupled contactless conductivity detection is being reported for the first time. The separation was run for all analytes using a BGE (20 mM β‐alanine, pH 11) containing 14% (v/v) methanol. The RSDs obtained for migration time were less than 4%, and RSDs obtained for peak area were less than 7%. The detection limits (S/N = 3) that were achieved ranged from 0.3 to 0.6 mg/L without sample preconcentration. The presented method showed rapid analysis time (less than 1 min), high efficiency and precision, low cost, and a significant decrease in the consumption of reagents. The microchip system has proved to be an excellent analytical technique for fast and reliable environmental applications.
Progesterone receptor isoform ratio dictates antiprogestin/progestin effects on breast cancer growth and metastases: A role for NDRG1
Authors: Abascal María Florencia , Elia Andrés , Alvarez Michelle , Pataccini Gabriela , Sequeira Gonzalo , Riggio Marina , Figueroa Virginia , Lamb Caroline A. , Rojas Paola A. , Spengler Eunice , Martínez‐Vazquez Paula , Burruchaga Javier , Liguori Marcos , Sahores Ana , Wargon Victoria , Molinolo Alfredo , Hewitt Stephen , Lombes Marc , Sartorius Carol , Vanzulli Silvia Inés , Giulianelli Sebastián , Lanari Claudia
Published: December 2021

Progesterone receptors (PRs) ligands are being tested in luminal breast cancer. There are mainly two PR isoforms, PRA and PRB, and their ratio (PRA/PRB) may be predictive of antiprogestin response. Our aim was to investigate: the impact of the PR isoform ratio on metastatic behaviour, the PR isoform ratio in paired primary tumours and lymph node metastases (LNM) and, the effect of antiprogestin/progestins on metastatic growth. Using murine and human metastatic models, we demonstrated that tumours with PRB > PRA (PRB‐H) have a higher proliferation index but less metastatic ability than those with PRA > PRB (PRA‐H). Antiprogestins and progestins inhibited metastatic burden in PRA‐H and PRB‐H models, respectively. In breast cancer samples, LNM retained the same PRA/PRB ratio as their matched primary tumours. Moreover, PRA‐H LNM expressed higher total PR levels than the primary tumours. The expression of NDRG1, a metastasis suppressor protein, was higher in PRB‐H compared to PRA‐H tumours and was inversely regulated by antiprogestins/progestins. The binding of the corepressor SMRT at the progesterone responsive elements of the NDRG1 regulatory sequences, together with PRA, impeded its expression in PRA‐H cells. Antiprogestins modulate the interplay between SMRT and AIB1 recruitment in PRA‐H or PRB‐H contexts regulating NDRG1 expression and thus, metastasis. In conclusion, we provide a mechanistic interpretation to explain the differential role of PR isoforms in metastatic growth and highlight the therapeutic benefit of using antiprogestins in PRA‐H tumours. The therapeutic effect of progestins in PRB‐H tumours is suggested.
Myxobacteria from animal dung pellets collected from northwestern Himalayas: A new source of di‐isobutyl phthalate
Authors: Sharma Arushi , Kumar Amit , Babu Vikash , Ali Asif , Katoch Meenu
Published: December 2021

Myxobacteria have emerged as a rich manufacturer of a wide array of natural products captivating both the academic and drug discovery communities. Attempts to unearth novel bioactive, myxobacteria from unexploited habitats are far from exhaustion. This study reports the isolation of myxobacteria from dung pellets collected from various regions of northwestern Himalayas. The isolated myxobacteria were functionally characterized to evaluate their bioactive capability. Of all the isolates, ST/P/71 exhibited broad range activities such as anticancer against all the four human cancer cell lines with IC50 in range of 2.03–9.65 µg/ml, antimicrobial against all the tested human pathogens, also exhibiting biofilm inhibition with MBIC50 at 10.4 µg/ml against Salmonella typhimurium. Consequently, ST/P/71 was chosen for fermentation and isolation of bioactive secondary metabolite through semi‐preparative HPLC. It yielded compound 1, characterized as di‐isobutyl phthalate (DiBP) based on nuclear magnetic resonance (NMR) and mass data. DiBP exhibited promising cytotoxic activity against the lung cancer cell line (A549) at an IC50 values 3.09 µg/ml and biofilm inhibition activity against Bacillus subtilis and Salmonella typhimurium with MBIC50 2.703 and 9.263 µg/ml, respectively. ST/P/71 was identified as Myxococcus fulvus. Thus, M. fulvus ST/P/71 isolated from northwestern Himalayas is a new source of DiBP.
Development of an isothermal recombinase‐aided amplification assay for the rapid and visualized detection of Klebsiella pneumoniae
Authors: Hou Laiwang , Li Darong , Zhang Ni , Zhao Jiayi , Zhao Yong , Sun Xiaohong
Published: December 2021

BACKGROUND

Klebsiella pneumoniae is a zoonotic opportunistic pathogen, leading to severe infections in dairy cows and humans. Efficient, on‐site and accurate detection of K. pneumoniae is necessary to reduce the harm of cow mastitis and human infections. The objective of this study was to establish a recombinase‐aided amplification (RAA) method combined with lateral flow dipstick (LFD) for rapid detection of K. pneumoniae.

RESULTS

The primer concentration, incubation temperature and incubation time of the RAA reaction were optimized. When the primer concentration was 100 nmol L–1, the strongest band could be obtained by incubation at 37 °C for 20 min. The RAA‐LFD method had high specificity to K. pneumoniae and showed no cross‐reaction with other pathogens. In addition, the detection limit of RAA‐LFD for K. pneumoniae was 20 fg genomic DNA and 2.5 × 102 CFU mL−1 of bacteria in pure culture, which is 100 times higher than that of polymerase chain reaction (PCR) detection. Moreover, the RAA‐LFD method can detect K. pneumoniae at initial concentrations as low as 2.5 CFU per 25 mL in artificially spiked milk samples after at least incubation for 6 h. Importantly, RAA‐LFD had a high agreement with a test accuracy of 96.9%, compared with the biochemical identification method. Also, the detection accuracy of RAA‐LFD was higher than that of the PCR assay (95.3%).

CONCLUSIONS

The results demonstrated that the RAA‐LFD assay is an accurate, sensitive, simple and point‐of‐use detection method for K. pneumoniae, which could be used as a potential application in the research laboratory and for disease diagnosis. © 2021 Society of Chemical Industry
Direct H abstraction by molecular oxygen from unsaturated C3–C5 hydrocarbons: A theoretical study
Authors: Alarcon Juan F. , Mebel Alexander M.
Published: December 2021

Potential energy surfaces for the H abstraction reactions by molecular oxygen from unsaturated closed‐shell C3–C5 hydrocarbons, including allene and propyne (C3H4), propene (C3H6), diacetylene (C4H2), vinylacetylene (C4H4), 1,3‐butadiene (C4H6), butene isomers (C4H8), cyclopentadiene (C5H6), and cyclopentene (C5H8), which were earlier identified among the main pyrolysis products of jet fuel components, have been explored at the CCSD(T)‐F12/cc‐pVTZ‐f12//ωB97XD/6‐311G** + ZPE(ωB97XD/6‐311G**) level of electronic structure theory. The results of the ab initio calculations were then utilized in transition state theory calculations of the reaction rate constants. The H abstraction reactions by O2 appeared to be most favorable from the allylic sites and from allene and propyne forming the propargyl radical, with the reactions involving the cyclic allylic sites in cyclopentadiene and cyclopentene exhibiting the lowest reaction endothermicities and barriers. They are followed by the reaction of O2 with cyclopentene producing cyclopent‐1‐en‐4‐yl and the reactions with vinylacetylene and 1,3‐butadiene forming the resonantly stabilized i‐C4H3 and i‐C4H5 radical products. The H abstractions from primary and secondary vinylic sites as well as from acetylenic sites are significantly less favorable and unlikely to compete. The calculated rate constants have been validated against the previous experimental and theoretical results for propene and butene isomers. All considered reactions of H abstraction by O2 are predicted to be rather slow, with their rate constants at 1500 K being on the order of 10–17‐10–16 cm3 molecule–1 s–1 and exhibiting a well‐defined Arrhenius behavior. Modified Arrhenius expressions for the reaction rate constants both in forward and reverse directions and Evans–Polanyi relationship between the activation and reaction energies have been generated and proposed for kinetic combustion models. The H abstractions by O2 forming the resonantly stabilized radicals were concluded to likely contribute to the initiation of oxidation of the unsaturated C3–C5 species produced in the pyrolysis of the important components of jet fuels.
Kinetics of alkaline hydrolysis of synthetic organic esters
Authors: Maeng Do Young , McNeill V. Faye
Published: December 2021

The hydrolysis of phthalates and other synthetic organic esters (SEs) in the indoor environment may be connected with poor indoor air quality and “sick building syndrome.” We have made laboratory measurements of the alkaline hydrolysis kinetics and mechanisms of 2,2,4‐trimethyl‐1,3‐pentanediol monoisobutyrate (TMPD‐MIB), butylparaben (BP), bis(2‐ethylhexyl) adipate (DEHA), and butyl benzyl phthalate (BBzP) in bulk aqueous solutions at room temperature, using UPLC‐QToF‐MS to detect the reactants over the course of the reactions. The determined alkaline hydrolysis second‐order rate constants for TMPD‐MIB, BP, DEHA, and BBzP at pH 13 were (9.8 ± 1.3) × 10−3 M−1 s−1, (1.24 ± 0.17) × 10−4 M−1 s−1, (4.8 ± 0.6) × 10−4 M−1 s−1, and (5.9 ± 0.8) × 10−2 M−1 s−1, respectively. The results suggest that hydrolysis may be a major degradation pathway for these compounds in the indoor environment under alkaline conditions.
Influence of nonlinear production on the global solvability of an attraction‐repulsion chemotaxis system
Authors: Viglialoro Giuseppe
Published: December 2021

This paper is dedicated to the attraction‐repulsion chemotaxis‐system

defined in Ω, a smooth and bounded domain of , with . Moreover, and are suitably regular functions generalizing, for and α, the prototypes , , and , . We focus our analysis on the value , establishing the temporal interval of existence of solutions to problem (). When zero‐flux boundary conditions are fixed, we prove the following results, all excluding chemotactic collapse scenarios under certain correlations between the attraction and repulsive effects describing the model. To be precise, for every , and (resp. ), there exists (resp. ) such that if (resp. ), any sufficiently regular initial datum (resp. enjoying some smallness assumptions) produces a unique classical solution to problem () which is global, i.e. , and such that u, v and w are uniformly bounded. Conversely, the same conclusion holds true for every , , and any sufficiently regular .

Further, in a remark of the manuscript, we also address an open question posed in [21].
Characterization of Retinal Architecture in Spinocerebellar Ataxia Type 3 and Correlation with Disease Severity
Authors: Rezende Filho Flávio Moura , Jurkute Neringa , de Andrade João Brainer Clares , Marianelli Bruna Ferraço , Ferraz Sallum Juliana M. , Yu‐Wai‐Man Patrick , Barsottini Orlando G. , Pedroso José Luiz
Published: December 2021

Background

Neurodegeneration affects the brain and peripheral nervous system in spinocerebellar ataxia type 3 (SCA3). As the retina is also involved, studying the retinal architecture in a cohort of patients could reveal clinically relevant biomarkers.

Objective

The aim is to investigate retinal architecture in SCA3 to identify potential biomarkers.

Methods

We evaluated 38 patients with SCA3 and 25 healthy age‐matched controls, who underwent visual acuity assessment, intraocular pressure measurement, and fundoscopy and macular and peripapillary spectral domain optical coherence tomography (SD‐OCT). We measured the peripapillary retinal nerve fiber layer (pRNFL) thickness in each quadrant of the temporal‐superior‐nasal‐inferior‐temporal chart and the macular layer thicknesses in each sector of the inner circle of the Early Treatment Diabetic Retinopathy Study (IC‐ETDRS) grid. Linear regression analysis was employed to test the associations between retinal parameters and age, disease duration, CAG repeats, and SARA (Scale of the Assessment and Rating of Ataxia) and ICARS (International Cooperative Ataxia Rating Scale) scores in SCA3.

Results

In all sectors, except for the temporal quadrant, pRNFL was significantly thinner in SCA3 patients than in controls. Average total macular, ganglion cell layer (GCL), and inner plexiform layer (IPL) thicknesses were significantly decreased in SCA3 patients in comparison to controls. The average total macular thickness and the average thicknesses of RNFL, GCL, and IPL negatively correlated with ICARS scores, whereas average GCL and IPL thicknesses negatively correlated with SARA scores.

Conclusions

The retinal ganglion cells, their dendrites, and axons are selectively affected in SCA3 patients. The RNFL, GCL, and IPL thicknesses in SD‐OCT correlate with the clinical phenotype and represent potential biomarkers for future clinical trials and natural history studies. © 2021 International Parkinson and Movement Disorder Society
Clifford algebra multivectors and kernels for melanoma classification
Authors: Akar Mutlu , Sirakov Nikolay M. , Mete Mutlu
Published: December 2021

Melanoma is a deadly skin disease. Availability of digital skin lesion datasets ease the exploration of ample classification studies. Both theoretical and heuristics improvements are achieved thanks to these new datasets. Being one of many high‐level feature‐driven classification methods, support vector machines (SVMs) are widely used in the literature as melanoma classifiers. Almost all of these studies are using a limited set of predefined kernels. In this study, we propose a newly developed Clifford kernel for the classification of dermoscopic skin lesions. We develop Clifford‐based linear, polynomial, and exponential kernels in the Clifford algebra (CA) Cℓ5, 0 0‐, 2‐, and 4‐vector subspaces. CAs are noncommutative but associative and distributive over addition. We showed that the newly developed Clifford kernels are embedded into SVM classifiers to successfully identify malignant skin lesions in a binary classification settings. Clifford kernel results are compared with mostly used gaussian and polynomial kernels with real‐valued SVM classifiers. Accuracy of all classifiers are assessed with cross‐validation using imbalanced and balanced datasets of 112, 162, and 192 lesions. SVM kernels in comparison are parameterized to scan wide range of possibilities. We show that Clifford‐based polynomial kernels outperforms in all, balanced and imbalanced, datasets having average accuracy of 83%. The consistence of high accuracies obtained with Clifford polynomial kernel shows that skin lesion features are logically designed and Clifford‐based SVM is able to model class separations in the feature space.
Magnetless nonreciprocal filtering diplexing antenna
Authors: Zang Jiawei , Wang Shouyuan , Pan Juan , An Shaogeng , Chen Lin
Published: December 2021

This paper presents a magnetless nonreciprocal diplexing antenna that uses time modulation. The device combines the functions of diplexers, filters, isolators, and antennas in a highly integrated manner. The magnetless nonreciprocity response is achieved by applying time modulation to the resonators of the filtering structures. These resonators are implemented in quarter‐wavelength microstrip lines terminated with varactors that are time modulated by low‐frequency signals fed from Coplanar Waveguides built on the ground plane of the microstrip structure. A prototype multilayer patch antenna is fabricated, which is fed through two orthogonal feedlines and the radiating square patch is coupled by a square ring slot etched in the ground plane. The experimental results show that a gain of 4 dB, out‐of band rejection of 22 dB, in‐band isolation of 20 dB, and inter‐port isolation of 35 dB is obtained at both 1.5 GHz (lower band) and 1.8 GHz (higher band).
A micropolar isotropic plasticity formulation for non‐associated flow rule and softening featuring multiple classical yield criteria
Authors: Panteghini Andrea , Lagioia Rocco
Published: December 2021

The Cosserat continuum is very effective in regularizing the ill‐posed governing equations of the Cauchy/Maxwell continuum. An elasto‐plastic constitutive model for the linear formulation of the Cosserat continuum is here presented, which features non‐associated flow, hardening/softening behaviour and multiple yield and plastic potential surfaces, whilst linear hyper‐elasticity is adopted to reproduce the recoverable response. For the definition of the yield and plastic potential functions, the equivalent von Mises stress is formulated using energy considerations and the theory of representations, the latter being also used to retrieve an expression for the Lode's angle. The recent Generalized classical criterion is then used to define the yield and plastic potential functions so that Lode's angle‐dependent deviatoric sections can be used.
On the equilibrium electrostatic potential and light‐induced charge redistribution in halide perovskite structures
Authors: Regaldo Davide , Bojar Aleksandra , Dunfield Sean P. , Lopez‐Varo Pilar , Frégnaux Mathieu , Dufoulon Vincent , Zhang Shan‐Ting , Alvarez José , Berry Joseph J. , Puel Jean‐Baptiste , Schulz Philip , Kleider Jean‐Paul
Published: December 2021

Lead halide perovskites are semiconductor materials which are employed as nonintentionally doped absorbers inserted between two selective carrier transport layers (SCTL), realizing a p‐i‐n or n‐i‐p heterojunction. In our study, we have developed and investigated a lateral device, based on methylammonium lead iodide (MAPbI3) in which the p‐i‐n heterojunction develops in the horizontal direction. Our research suggests that the effective doping level in the MAPbI3 film should be very low, below 1012 cm−3. Along the vertical direction, this doping level is not enough to screen the electric field of the buried heterojunction with the SCTL. The perovskite work function is therefore affected by the work function of the SCTL underneath. From drift‐diffusion simulations, we show that intrinsic perovskite‐SCTL structures develop mV range surface photovoltages (SPVs) under continuous illumination. However, perovskite‐SCTL structures can develop SPVs of hundreds of mV, as confirmed by our measurements. We therefore analyzed the compatibility between low doping and low defect densities in the perovskite layer and such high SPV values using numerical modeling. It is shown that these high SPV values could originate from electronic processes due to large band offsets in the buried perovskite‐SCTL heterojunctions, or at the SCTL‐transparent conductive oxide (TCO) buried heterojunction. However, such electronic processes can hardly explain the long SPV persistence after switching off the illumination.
Investigation of the Phase Splitting Behaviour of U(VI) and Th(IV) loaded Trialkyl Phosphate Solvents in the Absence of Aqueous Phase
Authors: Sarkar Subramee , Ammath Suresh , Kirubananthan Subashree , Suneesh Asokan Sudha
Published: December 2021

Tri‐n‐butyl phosphate (TBP), a universally recognized solvent, has got lesser organic phase splitting or third phase formation tendency during the extraction of U(VI) as compared to tetravalent metal ions. Thus, the lighter members of trialkyl phosphates (TalP) (i. e.) tri‐n‐propyl phosphate (TPP) and triethyl phosphate (TEP) having higher third phase formation tendency would provide an opportunity to comprehend the aggregation of U(VI) loaded TalP solvents. As the above lighter TalPs exhibit higher aqueous solubility, the conventional measurement of third phase limit or Limiting Organic Concentration (LOC) by mixing organic and aqueous phases cannot be employed for the investigation of U(VI) third phase in TalPs. This has led to the development of a novel method to examine U(VI) third phase in aqueous soluble TalP solvent systems without aqueous feed solution. After validation, the newly developed method has then been utilized to determine the LOC for 1.1 M TPP in n‐alkane. The variation of extractant structure, diluent chain length, nature of metal ion and temperature on the third phase of 1.1 M TalP systems has been evaluated along with their molecular level understanding using Dynamic Light Scattering.
Recent Advances for the Synthesis of N‐Unsubstituted Pyrroles
Authors: Efimov Ilya V. , Kulikova Larisa N. , Miftyakhova Almira R. , Matveeva Maria D. , Voskressensky Leonid G.
Published: December 2021

Pyrroles are an interesting class of heterocyclic compounds due to their widespread use both in medical chemistry and in the chemistry of new materials. Search and development of new effective methods for the synthesis of the pyrrole ring is an urgent task. Along with this, the systematization of already known synthesis methods is an equally important task. Herein, we focused on the results of the synthesis of NH‐pyrroles that have been obtained since 2015.
Novel Water Dispersible and Magnetically Recoverable Palladium Nano Catalyst for Room‐Temperature Suzuki‐Miyaura Coupling Reaction
Authors: Gholinejad Mohammad , Mirmohammadi Soheil , Sansano Jose M.
Published: December 2021

In this work, a new magnetic composite comprising starch, imidazolium and triazol groups is used as a support for stabilization of palladium nanoparticles. This material has been characterized by different techniques showing the presence of small and uniform Pd nanoparticles in about 2 nm size. Measuring contact angle confirmed important role of starch on increasing hydrophilic nature of the catalyst. Using 0.05 mol% of this catalyst aryl iodides or bromides reacted with boronic acids at room temperature in aqueous media and the corresponding products are obtained in very good to excellent yields. Hot filtration and PVPy poisoning tests confirmed the heterogeneous nature of the catalyst. E‐factor of the catalyst was found in acceptable range and close to green chemistry standards. This catalyst is magnetically recovered and recycled for 10 consecutive times with small decrease in activity. Also, the robustness of this catalytic system is demonstrated by the characterization of the reused catalyst.
Anion Complexation Strongly Influences the Reactivity of Octafluorocyclooctatetraene
Authors: Milagros Muriel‐Olaya M. , Alkorta Ibon , Elguero José
Published: December 2021

Six stationary points (three minima and three TS) in the thermal energy profile of octafluorocyclooctatetraene (F8‐COT) have been explored. The TSs corresponding to the inversion process of F8‐COT and its transformation in perfluoro bicyclo[2.2.2]octa‐2,5,7‐triene (F8‐BOT) and subsequent to perfluoro tetracyclo[4.2.0.02.02,8,05,7]octene (F8‐TCO) have been characterized. The results have been compared to the energy profile in the parent compound (cyclooctatetraene or COT). In addition, the effect of the formation of anion‐π complexes in the reaction profile has been explored. The results have been rationalized using the electrostatic potential of the isolated stationary points and thermodynamic cycles involving the complex formation in the minima and TS and the barriers in the isolated molecules. Moreover, the electron density has been analyzed with the AIM methodology.
Size‐Transformable Bicomponent Peptide Nanoparticles for Deep Tumor Penetration and Photo‐Chemo Combined Antitumor Therapy
Authors: Ma Teng , Chen Rong , Lv Niannian , Chen Yu , Qin Huiming , Jiang Hao , Zhu Jintao
Published: December 2021

The suitable size of multifunctional nanomedicines strongly influences their physicochemical properties and actions in biological systems, for example, prolonged blood circulation time, efficient tumor accumulation, and deep tumor penetration. However, it is still a great challenge to construct size‐transformable nanoparticles (NPs) for both efficient accumulation and penetration throughout tumor tissue. Herein, a size‐transformed multifunctional NP is developed through a simple bicomponent assembling strategy for enhanced tumor penetration and efficient photo‐chemo combined antitumor therapy, due to the acidic tumor microenvironment and near infrared‐laser irradiation induced size‐shrink. This multifunctional bicomponent NP (PP NP) driven by electrostatic interaction is composed of negatively charged peptide amphiphile (PA1) and positively charged peptide prodrug (PA2). PP NPs (≈170 nm) have been proven to improve blood circulation time and stability in biological environments. Interestingly, PP NPs can reassemble small NPs (<30 nm) by responding to acidic tumor microenvironment and near‐infrared laser irradiation, which facilitates deep tumor penetration and improves cellular internalization. By integrating fluorescence imaging, tumor targeting, deep tumor penetration, and combined photo‐chemotherapy, PP NPs exhibit excellent in vivo antitumor efficacy. This study might provide an insight for developing a bicomponent assembling system with efficient tumor penetration and multimode for antitumor therapy.
Unpacking Language Teacher Educators’ Expertise: A Complexity Theory Perspective
Authors: Yuan Rui , Yang Min
Published: December 2021

Informed by the perspective of complexity theory, this study seeks to explore two English‐as‐a‐foreign‐language (EFL) teacher educators’ expertise in Hong Kong. Drawing on data from interviews, field observation, and informal communication over one academic year, the study revealed that the teacher educators' expertise entailed different components: 1) a dialogic teaching approach informed by research‐based and contextualized knowledge; 2) emotional intelligence for maintaining personal emotional wellbeing and channeling emotions for effective teaching; 3) a reflective and agentive mindset for continuous learning; as well as 4) willingness and capacity to promote and distribute expertise in multiple communities. The participants’ expertise functioned and transformed through their continuing engagement in different forms of teacher education practice, influenced by their personal beliefs and situated contexts. The study concludes with practical implications for language teacher educators on how to develop their expertise as a complex, adaptive, and evolving system in daily practice.
Mimicking focal epileptic seizures‐episodic pain due to a facial foreign body in a puppy: Imaging characteristics and treatment
Authors: De Bonis Andrea , Marsh Oliver , Stabile Fabio
Published: December 2021

A 4‐month‐old female entire Cavalier King Charles Spaniel was referred for investigation into a 3‐week history of suspected focal onset seizures, characterised by head nodding and eyelid twitching. An inflammatory soft‐tissue reaction surrounding a suspected foreign body (FB) in the subcutaneous tissue and muscles at the level of the left maxilla in the caudal aspect of the left maxillary second molar was detected using MRI. The presence of the FB was confirmed ultrasonographically. This was found to be a grass seed upon surgical removal. The previously reported clinical signs resolved immediately after the surgery. It was suspected that the FB and secondary inflammatory reaction incited a form of trigeminal neuralgia manifesting as paroxysmal head nodding and facial twitching. A form of trigeminal neuralgia should be included in the differential diagnosis of facial focal motor seizures and should be investigated accordingly before initiating any antiepileptic treatment.
Soil moisture and electrical conductivity relationships under typical Loess Plateau land covers
Authors: Turkeltaub Tuvia , Wang Jiao , Cheng Qinbo , Jia Xiaoxu , Zhu Yuanjun , Shao Ming‐An , Binley Andrew
Published: December 2021

Vegetation changes that are driven by soil conservation measures significantly affect subsurface water flow patterns and soil water status. Much research on water consumption and sustainability of newly introduced vegetation types at the plot scale has been done in the Loess Plateau of China (LPC), typically using local scale measurements of soil water content (SWC). However, information collected at the plot scale cannot readily be up‐scaled. Geophysical methods such as electromagnetic induction (EMI) offer large spatial coverage and, therefore, could bridge between the scales. A noninvasive, multicoil, frequency domain, EMI instrument was used to measure the apparent soil electrical conductivity (σa) from six effective depths under four typical land‐covers (shrub, pasture, natural fallow, and crop) in the north of the LPC. Concurrently, SWC was monitored to a depth of 4 m using an array of 44 neutron probes distributed along the plots. The measurements of σa for six effective depths and the integrated SWC over these depths, show consistent behavior. High variability of σa under shrub cover, in particular, is consistent with long term variability of SWC, highlighting the potential unsustainability of this land cover. Linear relationships between SWC and σa were established using cumulative sensitivity forward models. The conductivity–SWC model parameters show clear variation with depth despite lack of appreciable textural variation. This is likely related to the combined effect of elevated pore water conductivity as was illustrated by the simulations obtained with water flow and solute transport models. The results of the study highlight the potential for the implementation of the EMI method for investigations of water distribution in the vadose zone of the LPC, and in particular for qualitative mapping of the vulnerability to excessive vegetation demands and hence, unsustainable land cover.
New insights into René Magritte's early surrealist painting La salle d'armes
Authors: Defeyt Catherine , Vandepitte Francisca , Herens Elodie , Strivay David
Published: December 2021

Painted in 1925 or 1926, over an older composition, La salle d'armes, is among the first Magritte's surrealist paintings. It is also one of the only four Magritte's using enamels reported in the René Magritte Catalog Raisonné. This paper presents the material and technical study conducted on this double painting. The complementary imaging and analytical methods applied for this purpose provided substantial information on both, the visible image and the hidden one. Concerning the latter, for instance, the obtained results permitted to identify a cubo‐futurist oil painting from the very early 1920s.
A Symmetric F−H−F Hydrogen Bond in Strontium Bifluoride, Sr[HF2]2
Authors: Stene Riane E. , Graubner Tim , Ivlev Sergei I. , Karttunen Antti J. , Kraus Florian
Published: December 2021

Single crystal X‐ray diffraction shows the hydrogen bond within the [F−H−F]− anion of Sr[HF2]2 to be symmetric with H−F bond lengths of 1.143(5) Å and an intramolecular F⋅⋅⋅F distance of 2.2826(18) Å. The [HF2]− anion adopts crystallographic C2‐symmetry, however, it is essentially linear with a F−H−F angle of 174(4)°. Solid‐state quantum chemical calculations agree with the experimental findings, showing a slightly bent F−H−F angle of 177.8°. The decomposition of Sr[HF2]2 to SrF2 and HF is endothermic by +64 kJ/mol at room temperature. The bonding in the [F−H−F]− anion is clearly ionic both in the solid state and gas phase.
Symmetries and conformal bridge in Schwarschild-(A)dS black hole mechanics
Authors: Achour Jibril Ben , Livine Etera R.
Published: December 2021

Abstract

We show that the Schwarzschild-(A)dS black hole mechanics possesses a hidden symmetry under the three-dimensional Poincaré group. This symmetry shows up after having gauge-fixed the diffeomorphism invariance in the symmetry-reduced homogeneous Einstein-Λ model and stands as a physical symmetry of the system. It dictates the geometry both in the black hole interior and exterior regions, as well as beyond the cosmological horizon in the Schwarzschild-dS case. It follows that one can associate a set of non-trivial conserved charges to the Schwarzschild-(A)dS black hole which act in each causally disconnected regions. In T-region, they act on fields living on spacelike hypersurface of constant time, while in R-regions, they act on time-like hypersurface of constant radius. We find that while the expression of the charges depend explicitly on the location of the hypersurface, the charge algebra remains the same at any radius in R-regions (or time in T-regions). Finally, the analysis of the Casimirs of the charge algebra reveals a new solution-generating map. The $$ \mathfrak{sl}\left(2,\mathrm{\mathbb{R}}\right) $$
sl

2
ℝ

Casimir is shown to generate a one-parameter family of deformation of the black hole geometry labelled by the cosmological constant. This gives rise to a new conformal bridge allowing one to continuously deform the Schwarzschild-AdS geometry to the Schwarzschild and the Schwarzschild-dS solutions.
Towards low-cost machine learning solutions for manufacturing SMEs
Authors: Kaiser Jan , Terrazas German , McFarlane Duncan , de Silva Lavindra
Published: December 2021

Machine learning (ML) is increasingly used to enhance production systems and meet the requirements of a rapidly evolving manufacturing environment. Compared to larger companies, however, small- and medium-sized enterprises (SMEs) lack in terms of resources, available data and skills, which impedes the potential adoption of analytics solutions. This paper proposes a preliminary yet general approach to identify low-cost analytics solutions for manufacturing SMEs, with particular emphasis on ML. The initial studies seem to suggest that, contrarily to what is usually thought at first glance, SMEs seldom need digital solutions that use advanced ML algorithms which require extensive data preparation, laborious parameter tuning and a comprehensive understanding of the underlying problem. If an analytics solution does require learning capabilities, a ‘simple solution’, which we will characterise in this paper, should be sufficient.
Cybernetics, operations research and information theory at the Ulm School of Design and its influence on Latin America
Authors: Oswald David
Published: December 2021

The Chilean Cybersyn project, an attempt to manage a nation’s economy by cybernetic methods, has evoked more and more interest in recent years. The project’s design lead and several team members were alumni of the Ulm School of Design—an institution that has been labelled “Bauhaus successor” and today is famous for a no-arts and method-led design approach with strong societal aspirations. The school also influenced the emerging design discipline in Latin America during the 1960s and 70s. This article reviews topics in the Ulm curriculum that influenced “Ulmian” thinking, but often remained unnoticed in design centred publications. Cybernetics, Operations Research and Information Theory and their relation to design are discussed and the related scholars are portrayed critically.
High-resolution three‑dimensional contrast‑enhanced magnetic resonance venography in children: comparison of gadofosveset trisodium with ferumoxytol
Authors: Shahrouki Puja , Khan Sarah N. , Yoshida Takegawa , Iskander Paul J. , Ghahremani Shahnaz , Finn J. Paul
Published: December 2021

Background

Gadofosveset is a gadolinium-based blood pool contrast agent that was approved by the United States Food and Drug Administration in 2008. Its unanticipated withdrawal from production in 2016 created a void in the blood pool agent inventory and highlighted the need for an alternative agent with comparable imaging properties.

Objective

The purpose of our study is to compare the diagnostic image quality, vascular contrast-to-noise ratio (CNR) and temporal signal characteristics of gadofosveset trisodium and ferumoxytol at similar molar doses for high-resolution, three-dimensional (3-D) magnetic resonance (MR) venography in children.

Materials and methods

The medical records and imaging data sets of patients who underwent high-resolution 3-D gadofosveset-enhanced MR venography (GE-MRV) or ferumoxytol-enhanced MR venography (FE-MRV) were retrospectively reviewed. Two groups of 20 pediatric patients (age- and weight-matched with one patient common to both groups; age range: 2 days–15 years) who underwent high-resolution 3-D GE-MRV or FE-MRV at similar molar doses were identified and analyzed. Qualitative analysis of image quality and vessel definition was performed by two blinded pediatric radiologists. Interobserver agreement was assessed with the AC1 (first-order agreement coefficient) statistic. Signal-to-noise ratio (SNR) and CNR of the inferior vena cava and aorta were measured in the steady-state venous phase. Medical records were retrospectively reviewed for any adverse reactions associated with either contrast agent.

Results

Measured SNR and CNR of the inferior vena cava were higher for FE-MRV than GE-MRV (P = 0.034 and P < 0.001, respectively). The overall image quality score and individual vessel scores of FE-MRV were equal to or greater than GE-MRV (P = 0.084), with good interobserver agreement (AC1 = 0.657). The venous signal on FE-MRV was stable over the longest interval measured (1 h, 13 min and 46 s), whereas venous signal on GE-MRV showed more variability and earlier loss of signal. No adverse reactions were noted in any patient with either contrast agent.

Conclusion

Ferumoxytol produces more uniform and stable enhancement throughout the entire venous circulation in children than gadofosveset, offering a wider time window for optimal image acquisition. FE-MRV offers a near-ideal approach to high-resolution venography in children at all levels of anatomical complexity.
Immunogenicity of the BNT162b2 mRNA COVID-19 vaccine in older residents of a long-term care facility: relation with age, frailty and prior infection status
Authors: Seiffert Piotr , Konka Adam , Kasperczyk Janusz , Kawa Jacek , Lejawa Mateusz , Maślanka-Seiffert Barbara , Zembala-John Joanna , Bugdol Monika , Romanik Małgorzata , Bułdak Rafał , Marcisz Czesław , Derejczyk Jarosław , Religa Dorota
Published: December 2021

Clinical and biological assessment of the COVID-19 vaccine efficacy in the frail population is of crucial importance. The study focuses on measuring the levels of anti-SARS-CoV-2 IgG antibodies before and after BNT162b2 mRNA COVID-19 vaccination among long-term care facility (LTCF) elderly residents. We conducted a prospective, single-center, observational study among LTCF residents. The study protocol was based on three blood sample acquisitions: first taken at baseline—5 days before the first dose of the vaccine, second—20 days after the first dose, and third—12 days after the second shot of the vaccine. The comparison was made for two cohorts: patients with and without prior COVID-19 infection. The data was collected from January to March 2021. A total number of 78 LTCF residents (55 women and 23 men) aged 62–104, 85.72 ± 7.59 years (mean ± SD), were enrolled in the study. All study participants were investigated for the presence of SARS-CoV-2 anti-spike (S) protein IgG, using a chemiluminescent immunoassay. Frailty was assessed with the Clinical Frailty Scale. Among elderly COVID-19 survivors in LTCF, a single dose of vaccine significantly increased anti-SARS-CoV-2 IgG antibody levels. IgG concentration after a single and double dose was comparable, which may suggest that elderly COVID-19 survivors do not require a second dose of vaccine. For residents without a previous history of COVID-19, two doses are needed to achieve an effective serological response. The level of anti-SARS-CoV-2 IgG antibodies after vaccination with BNT162b2 mRNA COVID-19 did not correlate with the frailty and age of the studied individuals.