bluuebunny/crossref_metadata_2025_split huggingface dataset:
SO2 Capture Using Porous Organic Cages
Authors: Martínez‐Ahumada Eva , He Donglin , Berryman Victoria , López‐Olvera Alfredo , Hernandez Magali , Jancik Vojtech , Martis Vladimir , Vera Marco A. , Lima Enrique , Parker Douglas J. , Cooper Andrew I. , Ibarra Ilich A. , Liu Ming 
Published: May 2021

AbstractWe report the first experimental investigation of porous organic cages (POCs) for the demanding challenge of SO2 capture. Three structurally related N‐containing cage molecular materials were studied. An imine‐functionalized POC (CC3) showed modest and reversible SO2 capture, while a secondary‐amine POC (RCC3) exhibited high but irreversible SO2 capture. A tertiary amine POC (6FT‐RCC3) demonstrated very high SO2 capture (13.78 mmol g−1; 16.4 SO2 molecules per cage) combined with excellent reversibility for at least 50 adsorption–desorption cycles. The adsorption behavior was investigated by FTIR spectroscopy, 13C CP‐MAS NMR experiments, and computational calculations.
Influence of soapstone waste on the mechanical and rheological properties of high‐density polyethylene
Authors: de Sousa Giulia Simão , da Silva Geovane de Almeida Santos , d'Almeida José Roberto Moraes 
Published: May 2021

AbstractSoapstone is an abundant mineral in Ouro Preto ‐ Minas Gerais, Brazil and its main destination is in the production of craftsmanship. Rock recovery in those activities is low and the waste disposal is done with little control, which can be hazardous to the environment. This work proposes an alternative use of such potentially harmful waste as reinforcement in a novel polymer matrix composite, which can be particularly attractive to the automotive industry and of which very little information is available elsewhere in the literature. Firstly, the characterization of the waste was performed. Particle size and shape parameters were determined by automated image analysis and the mineralogical composition was determined by X‐ray diffraction, infrared, and Raman spectroscopy. High‐density polyethylene was used as matrix and the composites were made in three matrix/filler ratios: 90/10, 80/20, and 70/30 by weight. Tensile and rheological properties were measured in order to determine the influence of the particles on the polymer mechanical behavior and processing conditions. The materials showed a pseudoplastic behavior and the filler's influence was more pronounced in the 70/30 composites, which showed higher viscosities than the neat polymer. The addition of particles resulted in more brittle and rigid composites, with higher values of tensile strength.
Design, synthesis, and pharmacological characterization of some 2‐substituted‐3‐phenyl‐quinazolin‐4(3H)‐one derivatives as phosphodiesterase inhibitors
Authors: Amin Kamilia M. , Hegazy Gehan H. , George Riham F. , Ibrahim Nahla R. , Mohamed Nada M. 
Published: May 2021

AbstractSome 3‐phenyl‐quinazolin‐4(3H)‐one‐2‐thioethers (3a–e, 5a,b, 7a–e, 9a–d, 10a–d, and 12) along with 2‐aminoquinazoline derivatives 13a–c were prepared and screened for their in vitro phosphodiesterase (PDE) inhibitory activity. Some compounds such as 7d,e, 9a,b,d, 10a,d, and 13b exhibited promising activity as compared with the non‐selective PDE inhibitor IBMX. This inhibitory activity was validated by molecular docking in the active site of PDE7A and PDE4 to investigate their selectivity. Furthermore, the most active compound 10d (IC50 = 1.15 μM) was tested in vivo using behavioral tests. Compound 10d was able to pass the blood–brain barrier and improve scopolamine‐induced cognitive deficits. Therefore, this core can be considered as a promising scaffold for further optimization to obtain new compounds with better PDE7A selective inhibition.
Production of myo‐inositol: Recent advance and prospective
Authors: Li Yunjie , Han Pingping , Wang Juan , Shi Ting , You Chun 
Published: May 2021

AbstractMyo‐inositol and its derivatives have been extensively used in the pharmaceutics, cosmetics, and food and feed industries. In recent years, compared with traditional chemical acid hydrolysis, biological methods have been taken as viable and cost‐effective ways to myo‐inositol production from cheap raw materials. In this review, we provide a thorough overview of the development, progress, current status, and future direction of myo‐inositol production (e.g., chemical acid hydrolysis, microbial fermentation, and in vitro enzymatic biocatalysis). The chemical acid hydrolysis of phytate suffers from serious phosphorous pollution and intricate product separation, resulting in myo‐inositol production at a high cost. For microbial fermentation, creative strategies have been provided for the efficient myo‐inositol biosynthesis by synergetic utilization of glucose and glycerol in Escherichia coli. in vitro cascade enzymatic biocatalysis is a multienzymatic transformation of various substrates to myo‐inositol. Here, the different in vitro pathways design, the source of selected enzymes, and the catalytic condition optimization have been summarized and analyzed. Also, we discuss some important existing challenges and suggest several viewpoints. The development of in vitro enzymatic biosystems featuring low cost, high volumetric productivity, flexible compatibility, and great robustness could be one of the promising strategies for future myo‐inositol industrial biomanufacturing.
Promotion and Tuning of the Electrochemical Reduction of Hetero‐ and Homobimetallic Zinc Complexes**
Authors: Kelsey Shaun R. , Kumar Amit , Oliver Allen G. , Day Victor W. , Blakemore James D. 
Published: May 2021

AbstractCompounds containing multiple metals attract significant interest due to the useful redox and reactivity properties of such species. Here, the electrochemical properties of a family of macrocyclic complexes that feature a zinc(II) center paired with a secondary redox‐inactive metal cation in heterobimetallic (Na+, Ca2+, Nd3+, Y3+) motifs or homobimetallic (Zn2+) motifs have been investigated. The new complexes were prepared via a divergent strategy, isolated, and structurally characterized with single‐crystal X‐ray diffraction (XRD) analysis. XRD results show that the structures of the complexes are modulated by the identity of the incorporated secondary metal ions. Cyclic voltammetry data reveal that ligand‐centered reduction is promoted in the bimetallic complexes and that the paired metal ions synergistically influence the redox properties of the complexes. Similar to prior work from our group and others, the bimetallic complexes containing stronger Lewis acids undergo more significant reduction potential shifts; contrasting with prior work on complexes containing redox‐active metals, however, the zinc(II) complexes studied here display faster electron transfer (as judged by lower reorganization energies, λ) when incorporating di‐ or tri‐valent Lewis acids in contrast to monovalent (and more weakly acidic) sodium. The quantified trends in these data offer insights that could help distinguish metal‐ versus ligand‐centered reduction of bimetallic complexes.
Catalytic Transfer Deuteration and Hydrodeuteration: Emerging Techniques to Selectively Transform Alkenes and Alkynes to Deuterated Alkanes
Authors: Vang Zoua Pa , Hintzsche Samuel J. , Clark Joseph R. 
Published: May 2021

AbstractIncreasing demand for deuterium‐labeled organic molecules has spurred a renewed interest in selective methods for deuterium installation. Catalytic transfer deuteration and transfer hydrodeuteration are emerging as powerful techniques for the selective incorporation of deuterium into small molecules. These reactions not only obviate the use of D2 gas and pressurized reaction setups but provide new opportunities for selectively installing deuterium into small molecules. Commercial or readily synthesized deuterium donors are typically employed as easy‐to‐handle reagents for transfer deuteration and hydrodeuteration reactions. In this minireview, recent advances in the catalytic transfer deuteration and hydrodeuteration of alkenes and alkynes for the selective synthesis of deuterated alkanes will be discussed.
Towards DNA‐Encoded Micellar Chemistry: DNA‐Micelle Association and Environment Sensitivity of Catalysis
Authors: Klika Škopić Mateja , Gramse Christian , Oliva Rosario , Pospich Sabrina , Neukirch Laura , Manisegaran Magiliny , Raunser Stefan , Winter Roland , Weberskirch Ralf , Brunschweiger Andreas 
Published: May 2021

AbstractThe development of DNA‐compatible reaction methodologies is a central theme to advance DNA‐encoded screening library technology. Recently, we were able to show that sulfonic acid‐functionalized block copolymer micelles facilitated Brønsted acid‐promoted reactions such as the Povarov reaction on DNA‐coupled starting materials with minimal DNA degradation. Here, the impact of polymer composition on micelle shape, and reaction conversion was investigated. A dozen sulfonic acid‐functionalized block copolymers of different molar mass and composition were prepared by RAFT polymerization and were tested in the Povarov reaction, removal of the Boc protective group, and the Biginelli reaction. The results showed trends in the polymer structure‐micellar catalytic activity relationship. For instance, micelles composed of block copolymers with shorter acrylate ester chains formed smaller particles and tended to provide faster reaction kinetics. Moreover, fluorescence quenching experiments as well as circular dichroism spectroscopy showed that DNA‐oligomer‐conjugates, although highly water‐soluble, accumulated very effectively in the micellar compartments, which is a prerequisite for carrying out a DNA‐encoded reaction in the presence of polymer micelles.
Structure and Reactivity of N‐Heterocyclic Alkynyl Hypervalent Iodine Reagents
Authors: Le Du Eliott , Duhail Thibaut , Wodrich Matthew D. , Scopelliti Rosario , Fadaei‐Tirani Farzaneh , Anselmi Elsa , Magnier Emmanuel , Waser Jerome 
Published: May 2021

AbstractEthynylbenziodoxol(on)e (EBX) cyclic hypervalent iodine reagents have become popular reagents for the alkynylation of radicals and nucleophiles, but only offer limited possibilities for further structure and reactivity fine‐tuning. Herein, the synthesis of new N‐heterocyclic hypervalent iodine reagents with increased structural flexibility based on amide, amidine and sulfoximine scaffolds is reported. Solid‐state structures of the reagents are reported and the analysis of the I−Calkyne bond lengths allowed assessing the trans‐effect of the different substituents. Molecular electrostatic potential (MEP) maps of the reagents, derived from DFT computations, revealed less pronounced σ‐hole regions for sulfonamide‐based compounds. Most reagents reacted well in the alkynylation of β‐ketoesters. The alkynylation of thiols afforded more variable yields, with compounds with a stronger σ‐hole reacting better. In metal‐mediated transformations, the N‐heterocyclic hypervalent iodine reagents gave inferior results when compared to the O‐based EBX reagents.
Magnetic Modulation in Heteroallene and Heterocumulene Based tert‐butyl Nitroxide Diradicals: Spin Delocalization and Conformation Play Crucial Roles
Authors: Sarbadhikary Prodipta , Misra Anirban 
Published: May 2021

AbstractWe have theoretically investigated the magnetic properties of heteroallene (>C=C=X−) and heterocumulene (>C=C=C=X−) based tert‐butyl nitroxide diradicals (X is P/As). Calculation of magnetic exchange coupling constant (J) shows ferromagnetic interaction in heteroallene based diradicals. Whereas, in heterocumulene based diradicals, tuning of J value from antiferro‐ to ferro‐magnetic state is observed from Z‐ to E‐ isomer. Delocalization of spin density from radical site to the coupler (in planar arrangement) is observed in spin distribution analysis which is also advocated by molecular orbital analysis. The typical feature of tert‐butyl nitroxide radical creates spin delocalization along with spin polarization within the coupler. The J values of all the diradicals strongly depend on the dihedral angle between radical center and coupler. Magneto‐structural correlation shows that the change in dihedral angle tunes the magnetic property for both the Z‐ and E‐ isomers of heterocumulenes depending on the spin accumulation on two nearby magnetic centers. The extent of spin delocalization and conformation of spin centers on the molecular axis are important for the different J values observed in our designed systems.
Towards an Understanding of Halide Interactions with the Carbonyl‐Containing Molecule CH3CHO
Authors: Corkish Timothy R. , Haakansson Christian T. , Watson Peter D. , Robinson Hayden T. , McKinley Allan J. , Wild Duncan A. 
Published: May 2021

AbstractThe anion photoelectron spectra of Cl−⋅⋅⋅CD3CDO, Cl−⋅⋅⋅(CD3CDO)2, Br−⋅⋅⋅CH3CHO, and I−⋅⋅⋅CH3CHO are presented with electron stabilisation energies of 0.55, 0.93, 0.48, and 0.40 eV, respectively. Optimised geometries of the singly solvated species featured the halide appended to the CH3CHO molecule in‐line with the electropositive portion of the C=O bond and having binding energies between 45 and 52 kJ mol−1. The doubly solvated Cl−⋅⋅⋅(CH3CHO)2 species features asymmetric solvation upon the addition of a second CH3CHO molecule. Theoretical detachment energies were found to be in excellent agreement with experiment, with comparisons drawn between other halide complexes with simple carbonyl molecules.
A novel twin‐column continuous chromatography approach for separation and enrichment of monoclonal antibody charge variants
Authors: Jing Shu‐Ying , Shi Ce , Leong Hui Yi , Yuan Jun‐Jie , Gao Dong , Wang Hai‐Bin , Yao Shan‐Jing , Lin Dong‐Qiang 
Published: May 2021

AbstractDownstream processing of mAb charge variants is difficult owing to their similar molecular structures and surface charge properties. This study aimed to apply a novel twin‐column continuous chromatography (called N‐rich mode) to separate and enrich acidic variants of an IgG1 mAb. Besides, a comparison study with traditional scaled‐up batch‐mode cation exchange (CEX) chromatography was conducted. For the N‐rich process, two 3.93 mL columns were used, and the buffer system, flow rate and elution gradient slope were optimized. The results showed that 1.33 mg acidic variants with nearly 100% purity could be attained after a 22‐cycle accumulation. The yield was 86.21% with the productivity of 7.82 mg/L/h. On the other hand, for the batch CEX process, 4.15 mL column was first used to optimize the separation conditions, and then a scaled‐up column of 88.20 mL was used to separate 1.19 mg acidic variants with the purity of nearly 100%. The yield was 59.18% with the productivity of 7.78 mg/L/h. By comparing between the N‐rich and scaled‐up CEX processes, the results indicated that the N‐rich method displays a remarkable advantage on the product yield, i.e. 1.46‐fold increment without the loss of productivity and purity. Generally, twin‐column N‐rich continuous chromatography displays a high potential to enrich minor compounds with a higher yield, more flexibility and lower resin cost.
Comparison of multiple tractography methods for reconstruction of the retinogeniculate visual pathway using diffusion MRI
Authors: He Jianzhong , Zhang Fan , Xie Guoqiang , Yao Shun , Feng Yuanjing , Bastos Dhiego C. A. , Rathi Yogesh , Makris Nikos , Kikinis Ron , Golby Alexandra J. , O'Donnell Lauren J. 
Published: May 2021

AbstractThe retinogeniculate visual pathway (RGVP) conveys visual information from the retina to the lateral geniculate nucleus. The RGVP has four subdivisions, including two decussating and two nondecussating pathways that cannot be identified on conventional structural magnetic resonance imaging (MRI). Diffusion MRI tractography has the potential to trace these subdivisions and is increasingly used to study the RGVP. However, it is not yet known which fiber tracking strategy is most suitable for RGVP reconstruction. In this study, four tractography methods are compared, including constrained spherical deconvolution (CSD) based probabilistic (iFOD1) and deterministic (SD‐Stream) methods, and multi‐fiber (UKF‐2T) and single‐fiber (UKF‐1T) unscented Kalman filter (UKF) methods. Experiments use diffusion MRI data from 57 subjects in the Human Connectome Project. The RGVP is identified using regions of interest created by two clinical experts. Quantitative anatomical measurements and expert anatomical judgment are used to assess the advantages and limitations of the four tractography methods. Overall, we conclude that UKF‐2T and iFOD1 produce the best RGVP reconstruction results. The iFOD1 method can better quantitatively estimate the percentage of decussating fibers, while the UKF‐2T method produces reconstructed RGVPs that are judged to better correspond to the known anatomy and have the highest spatial overlap across subjects. Overall, we find that it is challenging for current tractography methods to both accurately track RGVP fibers that correspond to known anatomy and produce an approximately correct percentage of decussating fibers. We suggest that future algorithm development for RGVP tractography should take consideration of both of these two points.
Employing medical anthropology approach as an additional public health strategy in promoting COVID‐19 vaccine acceptance in Bhutan
Authors: Rocha Ian Christopher N. 
Published: May 2021

AbstractBhutan has been commended for their COVID‐19 vaccination campaign, in which the country became the fastest in the world to inoculate nearly all of its adult population in just a few weeks. As a profoundly religious Buddhist kingdom in South Asia, the country successfully utilized a very unique strategy in promoting COVID‐19 vaccine acceptance nationwide. Bhutan incorporated religion, culture, and tradition in their campaign wherein the royal government collaborated with the Zhung Dratsang, the country's central monastic body, in deciding the most auspicious day for the launch of their vaccination rollout by avoiding the one‐month long Dana, selecting the first person to be vaccinated in accordance to the Buddhist astrology, and leading the country in chanting the Sangay Menlha, a mantra believed by many as a powerful prayer in warding off diseases. The launch turned out as a feast for all Bhutanese since it seemingly marked the beginning of the last phase of their COVID‐19 struggle. Incorporating medical anthropology in public health approaches can greatly influence the public, especially when the people are deeply rooted in folk beliefs. This unique strategy can be emulated by many localities with strong influence of cultural traditions and folk beliefs.
Great saves or near misses? Severe maternal outcome in Metro East, South Africa: A region‐wide population‐based case‐control study
Authors: Heitkamp Anke , Vollmer (Murray) Linda , van den Akker Thomas , Gebhardt Gabriel S. , Sandberg Evelien M. , van Roosmalen Jos , ter Wee Marieke M. , de Vries Johanna I. , Theron Gerhard 
Published: May 2021

AbstractObjectiveTo assess the incidence of severe maternal outcome (SMO), comprising maternal mortality (MM) and maternal near miss (MNM), in Metro East health district, Western Cape Province, South Africa between November 2014 and November 2015 and to identify associated determinants leading to SMO with the aim to improve maternity care.MethodsRegion‐wide population‐based case‐control study. Women were included in the study, if they were maternal deaths or met MNM criteria, both as defined by WHO. Characteristics of women with SMO were compared with those of a sample of women without SMO, matched for age and parity, taken from midwifery‐led obstetrical units from two residential areas in Metro East, using multivariate regression analysis.ResultsIncidence of SMO was 9.1 per 1000 live births, and incidence of MNM was 8.6 per 1000 live births. Main causes of SMO were obstetrical hemorrhage and hypertensive disorders. Factors associated with SMO were HIV (adjusted odds ratio [aOR] 24.8; 95% confidence interval [CI] 10.0–61.6), pre‐eclampsia (aOR 17.5; 95% CI 7.9–38.7), birth by cesarean section (aOR 8.4; 95% CI 5.8–12.3), and chronic hypertension (aOR 2.4; 95% CI 1.1–5.1).ConclusionEvaluation of SMO incidence and associated determinants supports optimizing tailored guidelines in Metro‐East health district to improve maternal health.
Dissociation of hydrogen peroxide in water and methanol through a biased molecular dynamics investigation
Authors: Dong Hieu C. , Ho Thi H. , Nguyen Thu M. , Kawazoe Yoshiyuki , Le Hung M. 
Published: May 2021

AbstractThe two dissociation channels of HOOH, namely, HOOH and HOOH, in water and methanol are investigated using umbrella‐sampling ab initio molecular dynamics. Our potential of mean force calculations reveals the HOOH dissociation to be more favorable in methanol with a free energy barrier of 7.56 kcal/mol, while the HOOH dissociation possesses a free energy barrier of 11.46 kcal/mol. In water, the HOOH dissociation channel is more favorable (8.25 kcal/mol), while the HOOH dissociation process requires a higher free energy (11.28 kcal/mol). Such reaction favorability can be explained by inspecting the formation of secondary radical species during the course of multiple hydrogen donating‐accepting processes in each reaction channel. The radical species, that is, H3O• (observed in water) and CH3OH2• (observed in methanol), are the first subordinate species upon the HOOH dissociation. For the HOOH dissociation channel in methanol, the secondary species such as water and formaldehyde can be observed, while the re‐generation of HOOH in water can be spotted.
Bioavailability and toxicity variation of benzo(a)pyrene in three soil–wheat systems: Indicators of soil quality
Authors: Teng Yong , Zhou Qixing 
Published: May 2021

AbstractBenzo(a)pyrene [B(a)P] as a representative polycyclic aromatic hydrocarbons (PAHs) is of worldwide i interest and widely studied in various fields. However, biological and biochemical actions of B(a)P in soil–wheat systems are still rarely reported. In view of the fact that the contents of B[a]P as a ubiquitous soil pollutant in the environment varies greatly, in our study at the laboratory‐scale we explored control factors and aimed to increase basic knowledge of its variations and effects on soil–wheat systems. We studied this for different soil types (red, black, and brown) and for soils newly artificially contaminated (at rates of 0.1, 1, and 10 mg kg−1), to provide some references for complicated 'real' cases. The bioavailability (extractability and bioaccumulation) and basic biological toxicity were tested. Results showed that B(a)P concentrations in soil–wheat (Tritticum aestivum L.) systems extracted by HPCD were insignificantly (p > 0.05) higher than Tenax‐TA, and varied with soil types and spiked concentrations. Also, the root and shoot length were mostly inhibited from 0.88% to 26.35%, and 5.46% to 54.85%, respectively, by B(a)P in different soil types and increased with its increasing concentration. Comparatively, higher bioconcentration factor and translocation factor values were observed under lower group in red soil–wheat systems, and under higher added groups in black and brown soil–wheat systems. Moreover, inhibitive effects posed by B(a)P were mainly targeted at wheat shoots in these soils. This study provided a knowledge of B(a)P in ecosystems with different soil types and specific plant species, further to serve for soil environmental protection with many variations.