bluuebunny/crossref_metadata_2025 huggingface dataset:
Might SARS‐CoV‐2 Have Arisen via Serial Passage through an Animal Host or Cell Culture?
Authors: Sirotkin Karl , Sirotkin Dan
Published: August 2020

Despite claims from prominent scientists that SARS‐CoV‐2 indubitably emerged naturally, the etiology of this novel coronavirus remains a pressing and open question: Without knowing the true nature of a disease, it is impossible for clinicians to appropriately shape their care, for policy‐makers to correctly gauge the nature and extent of the threat, and for the public to appropriately modify their behavior. Unless the intermediate host necessary for completing a natural zoonotic jump is identified, the dual‐use gain‐of‐function research practice of viral serial passage should be considered a viable route by which the novel coronavirus arose. The practice of serial passage mimics a natural zoonotic jump, and offers explanations for SARS‐CoV‐2's distinctive spike‐protein region and its unexpectedly high affinity for angiotensin converting enzyme (ACE2), as well as the notable polybasic furin cleavage site within it. Additional molecular clues raise further questions, all of which warrant full investigation into the novel coronavirus's origins and a re‐examination of the risks and rewards of dual‐use gain‐of‐function research.
Understanding the binding interaction between phenyl boronic acid P1 and sugars: determination of association and dissociation constants using S–V plots, steady‐state spectroscopic methods and molecular docking
Authors: Melavanki Raveendra , Sharma Kalpana , Yallur Basappa Chanabasapa , Kusanur Raviraj , Sadasivuni Kishor Kumar , Singh Diksha , Mane Smita , Katagi Kariyappa , Pattar Shridhar V.
Published: August 2020

Continuous monitoring of glucose and sugar sensing plays a vital role in diabetes control. The drawbacks of the present enzyme‐based sugar sensors have encouraged the investigation into alternate approaches to design new sensors. The popularity of fluorescence sensors is due to their ability to bind reversibly to compounds containing diol. In this study we investigated the binding ability of phenyl boronic acid P1 for monosaccharides and disaccharides (sugars) in aqueous medium at physiological pH 7.4 using steady‐state fluorescence and absorbance. P1 fluorescence was quenched due to formation of esters with sugars. Absorbance and fluorescence measurements led to results that indicated that the sugars studied could be ordered in terms of their affinity to P1, as stated: sucrose > lactose > galactose > xylose > ribose > arabinose. In each case, the slope of modified Stern–Volmer plots was nearly 1, indicating the presence of only a single binding site in boronic acids for sugars. Docking studies were carried out using Schrodinger Maestro v.11.2 software. The binding affinity of phenyl boronic acid P1 with periplasmic protein (PDB ID 2IPM and 2IPL) was estimated using GlideScore.
Genome‐wide analysis of single nucleotide variants allows for robust and accurate assessment of clonal derivation in cell lines used to produce biologics
Authors: Kuhn Alexandre , Le Fourn Valérie , Fisch Igor , Mermod Nicolas
Published: August 2020

A clonally derived (or “monoclonal”) cell line is a cell population derived from a single progenitor cell. Clonally derived cell lines are required for many biotechnological applications. For instance, recombinant mammalian cells used to produce therapeutic proteins are expected by regulatory authorities to be clonally derived. Assurance of clonal derivation (or “clonality”) is usually obtained from the characterization of the procedure used for cell cloning, for instance by assessing the success rate of single‐cell sorting but not by assessing the cell line itself. We have developed a method to assess clonal derivation directly from the genetic makeup of cells. The genomic test of clonality is based on whole‐genome sequencing and statistical analysis of single nucleotide variants. This approach quantifies the clonal fractions present in nonclonal samples and it provides a measure of the probability that a cell line is derived from a single cell. Upon experimental validation of the test, we show that it is highly accurate and that it can robustly detect minor clonal fractions of as little as 1% of the cell population. Moreover, we find that it is applicable to various cell line development protocols. This approach can simplify development protocols and shorten timelines while ensuring clonal derivation with high confidence.
Professional science education videos improve student performance in nonmajor and intermediate biology laboratory courses
Authors: Mutch‐Jones Karen , Sengupta Namrata , Minor V. Christine , Goudsouzian Lara K.
Published: August 2020

Undergraduate biology laboratories emphasize hands‐on skills. Typically, descriptions of manual techniques are delivered via written instruction. Custom‐produced prelab instructional videos, which augment prelab instruction, have come into wider use in recent years. However, institutional and economic barriers can interfere with video production at all colleges and universities. In such cases, professionally produced laboratory instructional videos provide an attractive alternative. We hypothesized that students who watch short, professionally produced instructional videos before performing a laboratory would feel more confident and achieve greater learning gains than students whose prelab instruction was limited to handouts. For this proof of concept study, we investigated the value added when students watched a brief video, twice per lab, in an intermediate molecular biology course at a small, liberal arts university, and in a nonmajors biology course at a large, public research university. Both video and nonvideo comparison groups were administered a pre‐ and postlab exams. A postlab self‐efficacy survey was also administered to video groups. Our results reveal that in three out of the four laboratory classes, students who watched professional instruction videos performed significantly better in both pre‐ and postlab exams. For these students, we observed up to a two‐fold increase in test scores on scientific concepts and techniques. For all classes, most of the video group students reported that the video contributed to their confidence, comprehension of concepts, and understanding of how to conduct the lab. We conclude that professional instructional videos may address production barriers and have the potential to effectively enhance undergraduate science curricula and significantly improve students' performance.
Exploring the determinants of green bond issuance: Going beyond the long‐lasting debate on performance consequences
Authors: Russo Angeloantonio , Mariani Massimo , Caragnano Alessandra
Published: August 2020

In recent years, the need to create new financial tools to mobilize private capital and generate suitable resources to face both social and environmental challenges led to the development of new tools and ideas. In this context, green bonds have emerged as a new financial tool to better respond to sustainability themes. This study is the first attempt to explore in depth the determinants of green bond performance. We focused on three perspectives: the specific characteristics of projects financed through a green bond, the broader firm‐specific corporate sustainability‐oriented strategy of the firm, and a country‐level perspective analyzing the country‐specific determinants of green bond performance. To test the hypotheses a sample of 306 corporate green bonds issued by 85 companies and referring to 1,788 green projects between 2013 and 2016, were retrieved from the Bloomberg database. The results provide interesting theoretical and practical implications for green bond issuers as well as investors and governments interested in green bonds.
Advances and Opportunities in Epigenetic Chemical Biology
Authors: Beyer Jenna N. , Raniszewski Nicole R. , Burslem George M.
Published: August 2020

The study of epigenetics has greatly benefited from the development and application of various chemical biology approaches. In this review, we highlight the key targets for modulation and recent methods developed to enact such modulation. We discuss various chemical biology techniques to study DNA methylation and the post‐translational modification of histones as well as their effect on gene expression. Additionally, we address the wealth of protein synthesis approaches to yield histones and nucleosomes bearing epigenetic modifications. Throughout, we highlight targets that present opportunities for the chemical biology community, as well as exciting new approaches that will provide additional insight into the roles of epigenetic marks.
Genetic Incorporation of Selenotyrosine Significantly Improves Enzymatic Activity of Agrobacterium radiobacter Phosphotriesterase
Authors: An Xiaojing , Chen Chao , Wang Tianyuan , Huang Aiping , Zhang Dawei , Han Ming‐Jie , Wang Jiangyun
Published: August 2020

Tyrosine plays important roles in many enzymes. To facilitate enzyme design, mechanistic studies and minimize structural perturbation in the active site, here we report the genetic incorporation of a novel unnatural amino acid selenotyrosine (SeHF), which has single‐atom replacement in comparison to tyrosine. The arPTE‐(Agrobacterium radiobacter Phosphotriesterase) Tyr309SeHF mutant exhibits a significant 12‐fold increase in kcat and 3.2‐fold enhancement in kcat/KM at pH 7.0. Molecular dynamics simulations show that the SeHF309 mutation results in a conformational switch which opens up the product release pocket and increases the product release rate, thereby elevating the overall enzyme activity. Significant improvement of the catalytic efficiency at neutral pH by single unnatural amino acid (UAA) mutation broadens the application of this enzyme, and provides valuable insights to the mechanism. Our method represents a new approach for designing enzymes with enhanced activity.
Selenoimidazolium Salts as Supramolecular Reagents for Protein Alkylation
Authors: Lim David , Wen Xiaojin , Seebeck Florian P.
Published: August 2020

Se‐benzyl selenoimidazolium salts are characterized by remarkable alkyl‐transfer potential under physiological conditions. Structure‐activity relationship studies show that selective monoalkylation of primary amines depends on supramolecular interactions between the selenoimidazole leaving group and the target nucleophile. We demonstrate that these reagents can be used for site‐selective and nearly quantitative modification of the model protein lysozyme on Lys13, bypassing the higher intrinsic reactivities of Lys1 and Lys33. These observations introduce selenoimidazolium salts as novel class of electrophiles for selective N‐alkylation of native proteins.
How TRIO Enhances Equity for Community College Transfer Students
Authors: Sabay Sarah , Wiles Kristian
Published: August 2020

This chapter is a review of a successful partnership between TRIO Student Support Services (TRIO SSS) programs at South Seattle College and the University of Washington. Practices used by the two institutions are described, with examples and enriching perspectives of student services leaders of each institution.
A review of glioblastoma tumors with primitive neuronal component and a case report of a patient with this uncommon tumor at a rare location
Authors: Shayganfar Azin , Ebrahimian Shadi , Mahzouni Parvin , Shirani Fattane , Aalinezhad Marzieh
Published: August 2020

Glioblastoma with primitive neuronal component should be considered as a differential diagnosis of infratentorial tumors.
Three‐Dimensional Hierarchical Framework Loaded with Lithiophilic Nanorod Arrays for High‐Performance Lithium‐Metal Anodes
Authors: Qi Yanyuan , Lin Lin , Jian Zelang , Qin Kaiyan , Tan Yuxuan , Zou Yujie , Chen Wen , Li Fujun
Published: August 2020

Although the highest theoretical specific capacity and lowest redox potential make lithium metal anodes essential for next‐generation high‐energy batteries, the infinite volume changes and uncontrollable Li dendrites severely restrict their application. Herein, the 3D hierarchical framework (3DHF) loaded with lithiophilic nanorod arrays on interwoven carbon fibers is constructed as a host to stabilize the Li metal anode. With cooperation of the lithiophilicity and the capillary force of the nanorod arrays, molten Li easily wraps the surface of the nanorods to form 3DHF−Li composite anodes. The void spaces and channels among the nanorods may provide a buffer space for Li stripping/plating to relieve the volume changes. In addition, the enlarged specific surface area reduces the local current density to homogenize Li deposition and suppress Li dendrites. The 3DHF−Li anodes exhibit improved cycle stability and rate capability in both symmetric cells and full cells, providing references for the development of Li composite anodes.
Comparison of Chemical and Interpretative Methods: the Carbon–Boron π‐Bond as a Test Case**
Authors: Gupta Radhika , Rezabal Elixabete , Hasrack Golshid , Frison Gilles
Published: August 2020

Quantum chemical calculations and NBO, ETS‐NOCV, QTAIM and ELF interpretative approaches have been carried out on C‐donor ligand‐stabilized dihydrido borenium cations. Numerous descriptors of the C−B π‐bond strength obtained from orbital localization, energy partitioning or topological methods as well as from structural and chemical parameters have been calculated for 39 C‐donor ligands includingN‐heterocyclic carbenes and carbones. Comparison of the results allows the identification ofrelativeandabsolutedescriptors of the π interaction. For both families of descriptors excellent correlations are obtained. This enables the establishment of a π‐donation capability scale and shows that the interpretative methods, despite their conceptual differences, describe the same chemical properties. These results also reveal noticeable shortcomings in these popular methods, and some precautions that need to be taken to interpret their results adequately.
Intrinsic Contributions of 2′‐Hydroxyl to the Hydration of Nucleosides at the Monomeric Level
Authors: Wang Zheng , Liu Jiang , Zhang Yanan , Qi Jiajia , Han Xianglong , Zhao Xuefeng , Bai Ding , Zhao Hang , Chen Qianming
Published: August 2020

Although many reports have revealed structural differences between DNA and RNA at the polymeric level, there are no comparative studies with 2′‐deoxyribonucleoside and ribonucleoside to explore the role of the 2′‐OH group at the monomeric level under the same conditions. Inspired by this, herein, the intrinsic contributions of the 2′‐OH group in the nucleoside have been systematically investigated by directly solving the single‐crystal structures of 2′‐deoxy‐2‐aminoadenosine (1), 2‐aminoadenosine (2), and 2‐aminoarabinofuranosyladenine (3) in water. The 2′‐OH group not only influenced the conformation and base‐pair pattern of the single‐nucleoside molecule, but also played a fundamental role in the entire supramolecular structure. Interestingly, compound 1, which did not contain the 2′‐OH group, displayed strong hydration, whereas 2 and 3 (with the 2′‐OH group in the opposite direction) exhibited no hydration, which was completely different from that observed in nucleic acids. Meanwhile, compound 1 trapped water molecules to form unique trihydrol moieties, which further served as the backbone to construct the simplest double‐chain DNA‐like structures. To this end, to investigate the effect of the biological environment on these unique structures, the solvent was changed from water to phosphate‐buffered saline (PBS). Surprisingly, such a subtle adjustment led to entirely different superstructures, consisting of 2D lamellar structures in water and 3D porous structures in PBS. These large morphological differences could be attributed to delicate ion hydration, which was also confirmed through variable‐temperature X‐ray analysis, SEM, and intermolecular interaction energy calculations. In summary, this study comprehensively investigated the intrinsic contributions of 2′‐hydroxyl to the hydration of nucleosides at the monomeric level; this is helpful to further understand the differences in DNA/RNA and the impact of their surrounding environment.
Cannabidiol Discovery and Synthesis—a Target‐Oriented Analysis in Drug Production Processes
Authors: Aguillón Anderson R. , Leão Raquel A. C. , Miranda Leandro S. M. , de Souza Rodrigo O. M. A.
Published: August 2020

The current state of evidence and recommendations for cannabidiol (CBD) and its health effects change the legal landscape and aim to destigmatize its phytotherapeutic research. Recently, some countries have included CBD as an antiepileptic product for compassionate use in children with refractory epilepsy. The growing demand for CBD has led to the need for high‐purity cannabinoids on the emerging market. The discovery and development of approaches toward CBD synthesis have arisen from the successful extraction of Cannabis plants for cannabinoid fermentation in brewer's yeast. To understand different contributions to the design and enhancement of the synthesis of CBD and its key intermediates, a detailed analysis of the history behind cannabinoid compounds and their optimization is provided herein.
A Trinuclear Cobalt–Organic Framework: Solvatochromic Sensor towards CH2Cl2, and its Derivative as an Anode of Lithium‐Ion Batteries with High Performance
Authors: Qin Bowen , Wu Shuangyu , Gahungu Godefroid , Li He , Zhao Yaling , Zhang Xiaoying , Zhang Jingping
Published: August 2020

Here, a porous cobalt–organic framework with pillared layer structures, namely [Co3OBA3PTD(H2O)2⋅ 2 DMA⋅H2O]n (1, H2OBA=4,4′‐oxybis(benzoic acid); PTD=6‐(pyridin‐4‐yl)‐1,3,5‐triazine‐2,4‐diamine), was fabricated by using cobalt trinuclear nodes, low‐cost carboxylic linker, and accessible nitrogen heterocyclic ligands. This compound exhibited a highly efficient solvatochromism towards CH2Cl2 within one minute and can be used 200 times at least. The corresponding dropper detector was assembled as a practical sensor. Meanwhile, the porous Co3O4 was obtained by a simple but effective annealing treatment. Electrochemical measurements confirm that this Co3O4 material derived from compound 1 shows high and stable lithium storage capabilities (1081.75 mA h g−1 at 200 mA g−1 after 115 cycles) and excellent rate properties.
Chalcogen Stabilized bis‐Hydridoborate Complexes of Cobalt: Analogues of Tetracyclo[4.3.0.02,4.03,5]nonane
Authors: Joseph Benson , Gomosta Suman , Prakash Rini , Roisnel Thierry , Phukan Ashwini K. , Ghosh Sundargopal
Published: August 2020

Treatment of Li[BH3ER] (E=Se or Te, R=Ph; E=S, R=CH2Ph) with [Cp*CoCl]2 led to the formation of hydridoborate complexes, [{CoCp*Ph}{Cp*Co}{μ‐EPh}{μ‐κ2‐E,H‐EBH3}], 1a and 1 b (1 a: E=Se; 1 b: E=Te) and a bis‐hydridoborate species [Cp*Co{μ‐κ2‐Se,H‐SeBH3}]2, 2. All the complexes, 1 a, 1 b and 2 are stabilized by β‐agostic type interaction in which 1 b represents a novel bimetallic borate complex with a rare B−Te bond. QTAIM analysis furnished direct proof for the existence of a shared and dative B‐chalcogen and Co‐chalcogen interactions, respectively. In parallel to the formation of the hydridoborate complexes, the reactions also yielded tetracyclic species, [Cp*Co{κ3‐E,H,H‐E(BH2)2‐C5Me5H3}], 3 a and 3 b (3 a: E=Se and 3 b: E=S), wherein the bridgehead boron atoms are surrounded by one chalcogen, one cobalt and two carbon atoms of a cyclopentane ring. Molecules 3 a and 3 b are best described as the structural mimic of tetracyclo[4.3.0.02,4.03,5]nonane having identical structure and similar valence electron counts.
Unravelling the Time Scale of Conformational Plasticity and Allostery in Glycan Recognition by Human Galectin‐1
Authors: Bertuzzi Sara , Gimeno Ana , Núñez‐Franco Reyes , Bernardo‐Seisdedos Ganeko , Delgado Sandra , Jiménez‐Osés Gonzalo , Millet Oscar , Jiménez‐Barbero Jesús , Ardá Ana
Published: August 2020

The interaction of human galectin‐1 with a variety of oligosaccharides, from di‐(N‐acetyllactosamine) to tetra‐saccharides (blood B type‐II antigen) has been scrutinized by using a combined approach of different NMR experiments, molecular dynamics (MD) simulations, and isothermal titration calorimetry. Ligand‐ and receptor‐based NMR experiments assisted by computational methods allowed proposing three‐dimensional structures for the different complexes, which explained the lack of enthalpy gain when increasing the chemical complexity of the glycan. Interestingly, and independently of the glycan ligand, the entropy term does not oppose the binding event, a rather unusual feature for protein‐sugar interactions. CLEANEX‐PM and relaxation dispersion experiments revealed that sugar binding affected residues far from the binding site and described significant changes in the dynamics of the protein. In particular, motions in the microsecond‐millisecond timescale in residues at the protein dimer interface were identified in the presence of high affinity ligands. The dynamic process was further explored by extensive MD simulations, which provided additional support for the existence of allostery in glycan recognition by human galectin‐1.
Ecological and Economic Evaluation of Hydrogen Production by Different Water Electrolysis Technologies
Authors: Tenhumberg Nils , Büker Karsten
Published: August 2020

The economic and ecological production of green hydrogen by water electrolysis is one of the major challenges within Carbon2Chem® and other power‐to‐X projects. This paper presents an evaluation of the different water electrolysis technologies with respect to their specific energy demand, carbon footprint and the forecast production costs in 2030. From a current perspective alkaline water electrolysis is evaluated as the most favorable technology for the cost‐effective production of low‐carbon hydrogen with fluctuating renewables.
Cancer prevention: When knowledge of cancer prevention is not enough
Authors: Yu Xue Qin , Baade Peter
Published: August 2020

It has long been recognized that knowledge of cancer can influence an individual’s lifestyle and health behaviors, and it is hoped that policy makers and medical professionals will use cancer knowledge as a tool in the fight against cancer. However, it is important not only for levels of cancer prevention knowledge to be increased in the community but also for key barriers to subsequent behavioral changes to be identified and removed if the massive cancer burden in China is to be addressed.
A genetic algorithm‐based intelligent solution for water pipeline monitoring system in a transient state
Authors: Abdelhafidh Maroua , Fourati Mohamed , Chaari Fourati Lamia
Published: August 2020

Water pipeline monitoring system becomes a relevant solution to cope with various pipeline hydraulic failures in order to save the environment from water losses. In this respect, cognitive water distribution system (WDS) combines Internet of Things (IoT) technology with Big Data generated by various connected objects and devices for reliable structural health monitoring of pipelines. Accordingly, designing a scalable WDS with smart leak detection and localization requires a serious study and an adequate planning. In this paper, we suggest a cognitive IoT‐based architecture with adequate data collection based on the Apache Spark framework. Furthermore, our objective is to elaborate a hybrid mechanism that defines and performs accurate leakage identification and localization by taking into account both the steady‐state and transient behavior of water. The bio‐inspired sensitivity analysis of the water pressure profile based on the genetic algorithm ensures the effectiveness and the accuracy of the proposed monitoring solution.
Nuclear Spin Hyperpolarization of NH2‐ and CH3‐Substituted Pyridine and Pyrimidine Moieties by SABRE
Authors: Mandal Ratnamala , Pham Pierce , Hilty Christian
Published: August 2020

Hyperpolarization of N‐heterocycles with signal amplification by reversible exchange (SABRE) induces NMR sensitivity gains for biological molecules. Substitutions with functional groups, in particular in the ortho‐position of the heterocycle, however, result in low polarization using a typical Ir catalyst with a bis‐mesityl N‐heterocyclic carbene ligand for SABRE, presumably due to steric hindrance. With the addition of allylamine or acetonitrile as coligands to the precatalyst chloro(1,5‐cyclooctadiene)[4,5‐dimethyl‐1,3‐bis(2,4,6‐trimethylphenyl)imidazol‐2‐ylidene] iridium, the 1H signal enhancement increased in several substrates with ortho NH2 substitutions. For example, for a proton in 2,4‐diaminopyrimidine, the enhancement factors increased from −7±1 to −210±20 with allylamine or to −160±10 with acetonitrile. CH3 substituted molecules yielded maximum signal enhancements of −25±7 with acetonitrile addition, which is considerably less than the corresponding NH2 substituted molecules, despite exhibiting similar steric size. With the more electron‐donating NH2 substitution resulting in greater enhancement, it is concluded that steric hindrance is not the only dominant factor in determining the polarizability of the CH3 substituted compounds. The addition of allylamine increased the signal enhancement for the 290 Da trimethoprim, a molecule with a 2,4‐diaminopyrimidine moiety serving as an antibacterial agent, to −70.
Loading Copper Atoms on Graphdiyne for Highly Efficient Hydrogen Production
Authors: Hui Lan , Xue Yurui , Yu Huidi , Zhang Chao , Huang Bolong , Li Yuliang
Published: August 2020

Graphdiyne, as a magical support, can anchor zero valence metal atoms, providing us with an opportunity to develop emerging catalysts with the maximized active sites and selectivity. Herein we report high‐performance atom catalysts (ACs), Cu0/GDY, by anchoring Cu atoms on graphdiyne (GDY) for hydrogen evolution reaction (HER). The activity and selectivity of this catalyst are obviously superior to that of commercial 20 wt.% Pt/C, and the turnover frequency of 30.52 s−1 is 18 times larger than 20 wt.% Pt/C. Density functional theory (DFT) calculations demonstrate that the strong p‐d coupling induced charge compensation leads to the zero valence state of the atomic‐scaled transition metal catalyst. Our results show the strong advantages of graphdiyne‐anchored metal atom catalysts in the field of electrochemical catalysis and opens up a new direction in the field of electrocatalysis.
Behavioral Phenotyping for Down Syndrome in Mice
Authors: Roper Randall J. , Goodlett Charles R. , Martínez de Lagrán María , Dierssen Mara
Published: August 2020

Down syndrome (DS) is the most frequent genetic cause of intellectual disability, characterized by alterations in different behavioral symptom domains: neurodevelopment, motor behavior, and cognition. As mouse models have the potential to generate data regarding the neurological basis for the specific behavioral profile of DS, and may indicate pharmacological treatments with the potential to affect their behavioral phenotype, it is important to be able to assess disease‐relevant behavioral traits in animal models in order to provide biological plausibility to the potential findings. The field is at a juncture that requires assessments that may effectively translate the findings acquired in mouse models to humans with DS. In this article, behavioral tests are described that are relevant to the domains affected in DS. A neurodevelopmental behavioral screen, the balance beam test, and the Multivariate Concentric Square Field test to assess multiple behavioral phenotypes and locomotion are described, discussing the ways to merge these findings to more fully understand cognitive strengths and weaknesses in this population. New directions for approaches to cognitive assessment in mice and humans are discussed. © 2020 Wiley Periodicals LLC.

Basic Protocol 1: Preweaning neurodevelopmental battery

Basic Protocol 2: Balance beam

Basic Protocol 3: Multivariate concentric square field test (MCSF)
Optimizing Enzymatic Photo‐Redox Cycles by a Hybrid Protein Complex Chain
Authors: Altamura Emiliano , Albanese Paola , Milano Francesco , Giotta Livia , Trotta Massimo , Ferretta Anna , Cocco Tiziana , Mavelli Fabio
Published: August 2020

The construction from scratch of artificial cells by means of a “bottom up” approach is one of the most ambitious challenges in synthetic biology. Artificial cells capable of imitating the light phase of photosynthesis can be considered photoautotrophs. In bacterial photosynthesis, the first step in the light energy transduction process is the enzymatic photo‐redox cycle catalysed by two membrane protein complexes, that is, the photosynthetic reaction centre (RC) and the ubiquinol oxidase (bc1B). In this work we studied this process in a micellar suspension of both proteins but coupling a bacterial RC with an ortholog bc1 extracted from mammalian mitochondria (bc1M). With this hybrid protein complex chain, the light transduction efficiency turns out to be enhanced up to 90 % by tuning the enzymatic level ratio of the two protein complexes. These results pave the way towards the reconstitution of the entire photosynthetic machinery in artificial membranes for the realization of photoautotrophic artificial cells.
Linear and nonlinear fluctuations of electron‐temperature‐gradient driven mode and electron acoustic mode in a two‐electron temperature nonthermal magnetized plasma
Authors: Razzaq Javaria , Haque Qamar‐ul‐ , Nargis Shahida , Mirza Arshad M.
Published: August 2020

Nonlinear vortical structures and soliton formation are investigated for electron temperature gradient instability in a two‐electron temperature non‐Maxwellian magnetoplasma. The inhomogeneity in magnetic field is also considered. A new set of nonlinear equations, using transport equations of Braginskii”s model, are formulated to study the nonlinear structures. A modified linear dispersion relation of coupled electron temperature gradient (ETG) mode and electron acoustic wave is derived. The ETG instability is found to increase with increase in ηec value that increases with sharp density gradients. The results are applied to auroral region of earth's magnetosphere and the calculated values of the nonlinear electric field of fast solitary waves are found to be in agreement with the Viking satellite observations.
The diagnostic utility of cell block in fine needle aspiration cytology of palpable breast lesions in a Nigerian tertiary health institution
Authors: Obiajulu Fred John Nnaemeka , Daramola Adetola Olubunmi , Anunobi Charles Chidozie , Ikeri Nzechukwu Zimudo , Abdulkareem Fatimah Biade , Banjo Adekunbiola Aina
Published: August 2020

Background

Although fine needle aspiration cytology (FNAC) is highly accurate for detecting breast malignancies, concerns remain among cytopathologists about false‐positive and false‐negative diagnoses. Cell block (CB) preparations have been advocated by some cytopathologists as one of the methods to improve and consolidate the diagnostic accuracy of FNAC. The aim of this study was to determine the diagnostic utility of CB in FNAC of palpable breast lesions among female patients.

Methods

Following FNA, CBs were prepared using 10% neutral‐buffered formalin from the residual breast aspirates of 100 consecutive female patients attending the FNAC clinic. The slides of the conventional smears, CB and excisional biopsies were examined, and results were analysed using the SPSS.

Results

Of the 100 patients that had FNAC, 44 (44%) had excisional biopsy performed. An additional 13% diagnostic yield for malignancy was obtained with the use of CB preparations. CB reduced equivocal diagnoses by 25%, corresponding with 90.9% improvement on definitive diagnoses.

Conclusion

In our setting, the addition of CB to smear remarkably improved the diagnostic utility of breast FNAC by minimising atypical and suspicious for malignancy diagnostic categories.
Analysis of six different homologues of phosphatidylethanol from dried blood spots using liquid chromatography–tandem mass spectrometry
Authors: Aboutara Nadine , Jungen Hilke , Szewczyk Anne , Sterneck Martina , Müller Alexander , Iwersen‐Bergmann Stefanie
Published: August 2020

Phosphatidylethanol (PEth) is a direct biomarker for alcohol consumption consisting of a fraction of different ethanol‐modified, homologue phospholipids. The aim of this study was to validate an ultra‐high‐performance liquid chromatography–tandem mass spectrometry method to quantitate six different homologues of PEth (16:0/18:1, 16:0/18:2, 16:0/20:4, 18:0/18:1, 18:0/18:2, and 18:1/18:1) from dried blood spots (DBSs). DBSs were prepared volumetrically (20 μL of whole blood) and extracted with 1 mL of methanol (0.02 ng/μL internal standards). PEth homologues were separated on a BEH C18 column (2.1 × 150 mm, 1.7 μm) using methanol and ammonium acetate buffer (25 mM) in a 7 min isocratic run. Multiple reaction monitoring mode was used for the detection of PEth and the internal standards. Calibrators (10–1000 ng/mL) and quality controls (40, 400, and 700 ng/mL) were prepared from spiked whole blood; external control samples were obtained from proficiency testing schemes. After a comprehensive validation of the method, quantitative patterns of the different homologues were investigated in PEth positive samples (n = 57) from patients in a transplant setting. Satisfactory chromatographic separation, sensitive detection, and reliable quantification of the PEth homologues in DBSs can be achieved using the liquid chromatography–tandem mass spectrometry (LC/MS/MS) procedure. Validation results, including accuracy, linearity, recovery, matrix effects, and in‐process stability, complied with international standards, and the analytical performance of the procedure was not affected by the hematocrit of the blood samples. Different quantitative patterns of the investigated PEth homologues were observed in authentic samples from liver transplant patients. This method will enable the study of the kinetics of six PEth homologues simultaneously and investigate the meaning of the homologues' distribution in individuals.
The role of domestic policy coalitions in extractive industries' governance: Disentangling the politics of “responsible mining” in the Philippines
Authors: Nem Singh Jewellord , Camba Alvin
Published: August 2020

Under what conditions do global regulatory norms become domesticated in highly contentious policy areas like oil, gas, and mining sectors? Departing from norm diffusion and environmental politics scholarship, the paper draws from the sociological literature on “coalition‐building” to explain the partial, uneven adoption of global regulations aimed at setting standards for corporate behavior in the context of large‐scale mining. We process trace the variation in coalitional politics in the contemporary Philippine's mining regulatory framework through a within‐case comparison of mining policies under Arroyo (2001–2010), Aquino (2010–2016), and Duterte (2016‐present) governments. We argue that the successful inclusion of civil society and mining communities into policy‐making processes can substantively contribute toward mining policies that are acceptable to those who face the socio‐environmental consequences of resource exploitation. In contrast, highly narrow governing coalitions tend to fuel resistance and enhance political opposition vis‐à‐vis large‐scale mineral extraction.
Prediction of heart failure hospitalizations based on the direct measurement of intrathoracic impedance
Authors: Zile Michael R. , Sharma Vinod , Baicu Catalin F. , Koehler Jodi , Tang Anthony S.
Published: August 2020

Aims

OptiVol fluid index was developed as a transthoracic impedance‐based indicator of short‐term risk for heart failure hospitalization (HFH). OptiVol is calculated as the accumulating difference between daily impedance (measured impedance) and long‐term average impedance (reference impedance). Measured impedance alone was thought to have limited prognostic utility; however, measured impedance has the advantage of being simple, direct, and possibly additive to OptiVol fluid index in establishing long‐term HFH risk. We tested the hypothesis that directly measured impedance has independent prognostic value in predicting long‐term HFH risk and that changes in measured impedance result in a change in predicted long‐term HFH risk.

Methods and results

A retrospective analysis of 1719 patients studied in PARTNERS‐HF, FAST, and RAFT studies was performed. Baseline measured impedance was determined using daily values averaged over 1 month, from Month 6 to 7 post implant; change in measured impedance was determined from values averaged over 1 month, from Month 7 to 8 post implant compared with baseline. The predictive value of baseline measured impedance for HFHs was assessed beginning 7 months post implant. The predictive value of a change in measured impedance for a change in HFHs was assessed beginning 8 months post implant. Baseline measured impedance successfully predicted HFHs. For example, 3 year HFH rate for low baseline impedance < 70 Ω was 23%; for high baseline impedance ≥ 70 Ω was 15% (P < 0.001). Changes in measured impedance resulted in changes in predicted HFHs. For example, when a baseline impedance of ≥70 fell during follow‐up to <70 Ω, the subsequent HFHs were 15% compared with 4% in patients with measured impedance that remained >70 Ω (P = 0.004). In addition, when baseline measured impedance fell during follow‐up by >1%, 2%, or 3%, subsequent HFHs increased to 13%, 17%, or 18%, respectively. Finally, the prognostic value of measured impedance was additive to the prognostic value of the OptiVol fluid index.

Conclusions

Direct measurements of intrathoracic impedance using an implanted device can be used to stratify patients at varying risk of long‐term HFH. These direct measurements of impedance have practical clinical appeal because they are simple, continuous, and ambulatory.
Effect of insulin on readmission for heart failure following a hospitalization for acute heart failure
Authors: Bertomeu‐Gonzalez Vicente , Fácila Lorenzo , Palau Patricia , Miñana Gema , Núñez Gonzalo , de la Espriella Rafael , Santas Enrique , Núñez Eduardo , Bodí Vicent , Chorro Francisco Javier , Cordero Alberto , Sanchis Juan , Lupón Josep , Bayés‐Genís Antoni , Núñez Julio
Published: August 2020

Aims

Type 2 diabetes mellitus (T2DM) is common in patients with heart failure (HF) and is related with worse outcomes. Insulin treatment is associated with sodium and water retention, weight gain, and hypoglycaemia—all pathophysiological mechanisms related to HF decompensation. This study aimed to evaluate the association between insulin treatment and the risk of 1 year readmission for HF in patients discharged for acute HF.

Methods and results

We prospectively included 2895 consecutive patients discharged after an episode of acute HF in a single tertiary hospital. Multivariable Cox regression, adapted for competing events, was used to assess the association between insulin treatment and 1 year readmission for HF in patients discharged after acute HF. Participants' mean age was 73.4 ± 11.2 years, 50.8% were women, 44.7% had T2DM [including 527 (18.2%) on insulin therapy], and 52.7% had preserved ejection fraction. At 1 year follow‐up, 518 (17.9%) patients had died and 693 (23.9%) were readmitted for HF. The crude risk of readmission for HF was higher in patients on insulin, with no differences in 1 year mortality. After multivariable adjustment, patients on insulin were at significantly higher risk of 1 year readmission for HF than patients with diabetes who were not on insulin (hazard ratio 1.28; 95% confidence interval 1.04–1.59, P = 0.022) and patients without diabetes (hazard ratio 1.26; 95% confidence interval 1.02–1.55, P = 0.035).

Conclusion

Following acute HF, patients with T2DM on insulin therapy are at increased risk of readmission for HF. Further studies unravelling the mechanisms behind this association are warranted.
Symmetry Decrease between Self‐Assembled Circular TiO4N2‐Based Helicates
Authors: Khalil Georges , Barloy Laurent , Kyritsakas Nathalie , Kauffmann Brice , Chaumont Alain , Henry Marc , Mobian Pierre
Published: August 2020

A multicomponent self‐assembly reaction involving a bis‐biphenolato ligand (LH4), a 2,2'‐bipyrimidine chelate substituted by two (anthryl)vinyl moieties (bAnt) and Ti(OiPr)4 was investigated. An assembly {[Ti3(L)3(bAnt)3]}, composed of three homochiral TiO4N2 nodes, was characterized as being the thermodynamically‐end product. The crystal structure of this circular helicate highlighted an absence of symmetry for this compact compound. DOSY 1H NMR indicated that the nuclearity observed in the solid state for [Ti3(L)3(bAnt)3] was maintained in solution. An intermediate formulated as [Ti4(L)4(bAnt)4] was isolated. The structural analysis revealed that [Ti4(L)4(bAnt)4] was a symmetrical circular hollow helicate composed of four homochiral metallovertices. This study, supported by DFT calculation, brought some evidences on the sequences and the reasons leading to the symmetry decrease for this self‐assembly process.
Palladium‐Catalyzed Regioselective Acylation of Diazines with Toluenes: A New Approach to the Synthesis of ortho‐Diacylbenzenes
Authors: Kianmehr Ebrahim , Seifinoferest Behnoush , Afaridoun Hadi
Published: August 2020

A highly efficient and practical procedure for chemo‐ and regioselective synthesis of ortho‐diacylbenzenes through Pd‐catalyzed oxidative C–H bond activation has been developed. Using this method, a variety of ortho‐diacylbenzenes were prepared in moderate to good yields, by direct acylation of diazines with toluene derivatives as acylation source. Ortho‐diacylbenzenes may be used as precursors in synthesis of pharmaceuticals and agrochemicals.
Synthesis of Novel Cyclic Nitrones with gem‐Difluoroalkyl Side Chains Through Cascade Reactions
Authors: Soulieman Ali , Ibrahim Rima , Barakat Zeinab , Gouault Nicolas , Roisnel Thierry , Boustie Joel , Grée René , Hachem Ali
Published: August 2020

New five‐membered cyclic nitrones with gem‐difluoroalkyl groups in γ‐position have been prepared by a 3‐step sequence starting from propargylic alcohols. This domino process involves a base‐mediated isomerization reaction to enones, which are trapped in situ by nitroalkane anions. In a final step, starting from these key precursors, a reduction‐cyclization process affords the target molecules. Mono‐ and bicyclic nitrones have been prepared by this route which allows, as well, the synthesis of nitrones with functional groups in terminal position of the side chain.
Smell and taste dissociations in the modulation of tonic pain perception induced by a capsaicin cream application
Authors: Cecchini Maria Paola , Riello Marianna , Sandri Angela , Zanini Alice , Fiorio Mirta , Tinazzi Michele
Published: August 2020

Background

Pain is a subjective experience characterized by sensory (intensity) and emotional (unpleasantness) aspects. Although literature reports behavioural effects on pain due to smell and taste influence, to our knowledge the relationship between tonic pain induced by a capsaicin cream and these chemosensory systems has never been explored before. The aim of this study was to investigate the modulation of olfactory and gustatory substances having different valence on tonic pain perception mediated by a capsaicin cream application.

Methods

Sixty healthy volunteers were included in two separated experiments (N = 30 smell; N = 30 taste) and underwent different valence smell and taste stimulations, while receiving painful stimuli. Perception of pain intensity (the sensory component) and unpleasantness (the affective component) was measured with a numerical rating scale, both during the two aforementioned experiments.

Results

Pain unpleasantness rating showed differences only in the smell experiment between the two odourous conditions. In particular, pleasant odour induced lower ratings of pain unpleasantness, while no significant results were found for intensity. Regarding taste, we could not observe significant effects nor for pain unpleasantness or intensity.

Conclusions

These findings highlight the potential role of pleasant odours in influencing the affective aspects of pain perception induced by this kind of tonic pain. Such evidence might provide new insight for using chemosensory substances as analgesics for modulating the cognitive aspects of neuropathic pain.

Significance

This work shows the effect of smell on the emotional component of tonic pain, experimentally induced by capsaicin cream application. Previous literature investigated tonic pain in interaction with smell and/or taste stimuli, but mainly with physical methods such as temperature. Our findings add new information in this field, contributing to a deeper insight on the role of olfaction on this particular kind of tonic pain perception. This approach could open to new investigations aimed to consider odours for pain management.
Intra‐ and Inter‐molecular Sulf‐ hydryl Hydrogen Bonding: Facilitating Proton Transfer Events for Determination of pH in Sea Water
Authors: Sisodia Neel , Miranda Monica , McGuinness Kay L. , Wadhawan Jay D. , Lawrence Nathan S.
Published: August 2020

This work presents the electrochemical response of a 2‐(methylthio)phenol glassy carbon based electrode for a promising voltammetric pH sensor in both buffered and low‐buffered solutions. Electropolymerization of the redox species was performed with the resulting polymer presenting a Nernstian response in buffered media, with a sensitivity of 51 mV/pH unit. The effectiveness of the sulfhydryl bond to facilitate proton transfer from the bulk solution to the phenol molecules has been confirmed, providing an accurate pH measurement of 8.28 in sea water media, compared to that measured with a calibrated glass pH probe of 8.30.
A spatial capture–recapture model with attractions between individuals
Authors: McLaughlin Paul , Bar Haim
Published: August 2020

Over the past two decades there have been many advancements in modeling capture–recapture (CR) data to account for emerging data collection technology and techniques. Spatial capture–recapture (SCR) models have been introduced to estimate population size and numerous other demographic parameters from spatially explicit CR data. Recently SCR models have also begun incorporating realistic animal movement to account for individual dispersion and attraction to resources. While some species of animals are known to exhibit attractive behavior, nearly all SCR models assume complete independence among individual's movement and capture probability. In this article, we introduce an SCR model which allows for attractions between individuals via their daily location. We demonstrate via a simulation study that accounting for the attractions specified by our model, when present, can improve population size estimation. In addition, we apply our model to an iconic SCR dataset to estimate the population size and attraction parameters of a Bengal tiger (Panthera tigris tigris) population.