bluuebunny/crossref_metadata_2025 huggingface dataset:
Probing valley population imbalance in transition metal dichalcogenides via temperature-dependent second harmonic generation imaging
Authors: Mouchliadis Leonidas , Psilodimitrakopoulos Sotiris , Maragkakis George Miltos , Demeridou Ioanna , Kourmoulakis George , Lemonis Andreas , Kioseoglou George , Stratakis Emmanuel
Published: January 2021

Degenerate minima in momentum space—valleys—provide an additional degree of freedom that can be used for information transport and storage. Notably, such minima naturally exist in the band structure of transition metal dichalcogenides (TMDs). When these atomically thin crystals interact with intense laser light, the second harmonic generated (SHG) field inherits special characteristics that reflect not only the broken inversion symmetry in real space but also the valley anisotropy in reciprocal space. The latter is present whenever there exists a valley population imbalance (VPI) between the two valleys and affects the polarization state of the detected SHG. In this work, it is shown that the temperature-induced change of the SHG intensity dependence on the excitation field polarization is a fingerprint of VPI in TMDs. In particular, pixel-by-pixel VPI mapping based on polarization-resolved raster-scanning imaging microscopy was performed inside a cryostat to generate the SHG contrast in the presence of VPI from every point of a TMD flake. The generated contrast is marked by rotation of the SHG intensity polar diagrams at low temperatures and is attributed to the VPI-induced SHG.
Facilely synthesized nitrogen-doped reduced graphene oxide functionalized with copper ions as electrocatalyst for oxygen reduction
Authors: Garino Nadia , Zeng Juqin , Castellino Micaela , Sacco Adriano , Risplendi Francesca , Fiorentin Michele Re , Bejtka Katarzyna , Chiodoni Angelica , Salomon Damien , Segura-Ruiz Jaime , Pirri Candido F. , Cicero Giancarlo
Published: January 2021

Nitrogen-doped reduced graphene oxide is successfully synthesized and functionalized with hydroxylated copper ions via one-pot microwave-assisted route. The presence of cationic Cu coordinated to the graphene layer is fully elucidated through a set of experimental characterizations and theoretical calculations. Thanks to the presence of these hydroxyl-coordinated Cu2+ active sites, the proposed material shows good electrocatalytic performance for the oxygen reduction reaction, as evidenced by an electron transfer number of almost 4 and by high onset and half-wave potentials of 0.91 V and 0.78 V vs. the reversible hydrogen electrode, respectively. In addition, the N-doped Cu-functionalized graphene displays a superior current retention with respect to a commercial Pt/C catalyst during the stability test, implying its potential implementation in high-performance fuel cells and metal-air batteries.
Privacy protections to encourage use of health-relevant digital data in a learning health system
Authors: McGraw Deven , Mandl Kenneth D.
Published: January 2021

The National Academy of Medicine has long advocated for a “learning healthcare system” that produces constantly updated reference data during the care process. Moving toward a rapid learning system to solve intractable problems in health demands a balance between protecting patients and making data available to improve health and health care. Public concerns in the U.S. about privacy and the potential for unethical or harmful uses of this data, if not proactively addressed, could upset this balance. New federal laws prioritize sharing health data, including with patient digital tools. U.S. health privacy laws do not cover data collected by many consumer digital technologies and have not been updated to address concerns about the entry of large technology companies into health care. Further, there is increasing recognition that many classes of data not traditionally considered to be healthcare-related, for example consumer credit histories, are indeed predictive of health status and outcomes. We propose a multi-pronged approach to protecting health-relevant data while promoting and supporting beneficial uses and disclosures to improve health and health care for individuals and populations. Such protections should apply to entities collecting health-relevant data regardless of whether they are covered by federal health privacy laws. We focus largely on privacy but also address protections against harms as a critical component of a comprehensive approach to governing health-relevant data. U.S. policymakers and regulators should consider these recommendations in crafting privacy bills and rules. However, our recommendations also can inform best practices even in the absence of new federal requirements.
Digital oximetry biomarkers for assessing respiratory function: standards of measurement, physiological interpretation, and clinical use
Authors: Levy Jeremy , Álvarez Daniel , Rosenberg Aviv A. , Alexandrovich Alexandra , del Campo Félix , Behar Joachim A.
Published: January 2021

Pulse oximetry is routinely used to non-invasively monitor oxygen saturation levels. A low oxygen level in the blood means low oxygen in the tissues, which can ultimately lead to organ failure. Yet, contrary to heart rate variability measures, a field which has seen the development of stable standards and advanced toolboxes and software, no such standards and open tools exist for continuous oxygen saturation time series variability analysis. The primary objective of this research was to identify, implement and validate key digital oximetry biomarkers (OBMs) for the purpose of creating a standard and associated reference toolbox for continuous oximetry time series analysis. We review the sleep medicine literature to identify clinically relevant OBMs. We implement these biomarkers and demonstrate their clinical value within the context of obstructive sleep apnea (OSA) diagnosis on a total of n = 3806 individual polysomnography recordings totaling 26,686 h of continuous data. A total of 44 digital oximetry biomarkers were implemented. Reference ranges for each biomarker are provided for individuals with mild, moderate, and severe OSA and for non-OSA recordings. Linear regression analysis between biomarkers and the apnea hypopnea index (AHI) showed a high correlation, which reached $$\overline R ^2 = 0.82$$

R

¯

2

=
0.82

. The resulting python OBM toolbox, denoted “pobm”, was contributed to the open software PhysioZoo (physiozoo.org). Studying the variability of the continuous oxygen saturation time series using pbom may provide information on the underlying physiological control systems and enhance our understanding of the manifestations and etiology of diseases, with emphasis on respiratory diseases.
A new-to-nature carboxylation module to improve natural and synthetic CO2 fixation
Authors: Scheffen Marieke , Marchal Daniel G. , Beneyton Thomas , Schuller Sandra K. , Klose Melanie , Diehl Christoph , Lehmann Jessica , Pfister Pascal , Carrillo Martina , He Hai , Aslan Selçuk , Cortina Niña S. , Claus Peter , Bollschweiler Daniel , Baret Jean-Christophe , Schuller Jan M. , Zarzycki Jan , Bar-Even Arren , Erb Tobias J.
Published: January 2021

The capture of CO2 by carboxylases is key to sustainable biocatalysis and a carbon-neutral bio-economy, yet currently limited to few naturally existing enzymes. Here, we developed glycolyl-CoA carboxylase (GCC), a new-to-nature enzyme, by combining rational design, high-throughput microfluidics and microplate screens. During this process, GCC’s catalytic efficiency improved by three orders of magnitude to match the properties of natural CO2-fixing enzymes. We verified our active-site redesign with an atomic-resolution, 1.96-Å cryo-electron microscopy structure and engineered two more enzymes that, together with GCC, form a carboxylation module for the conversion of glycolate (C2) to glycerate (C3). We demonstrate how this module can be interfaced with natural photorespiration, ethylene glycol conversion and synthetic CO2 fixation. Based on stoichiometrical calculations, GCC is predicted to increase the carbon efficiency of all of these processes by up to 150% while reducing their theoretical energy demand, showcasing how expanding the solution space of natural metabolism provides new opportunities for biotechnology and agriculture.
Single-cell fluidic force microscopy reveals stress-dependent molecular interactions in yeast mating
Authors: Mathelié-Guinlet Marion , Viela Felipe , Dehullu Jérôme , Filimonava Sviatlana , Rauceo Jason M. , Lipke Peter N. , Dufrêne Yves F.
Published: January 2021

Sexual agglutinins of the budding yeast Saccharomyces cerevisiae are proteins mediating cell aggregation during mating. Complementary agglutinins expressed by cells of opposite mating types “a” and “α” bind together to promote agglutination and facilitate fusion of haploid cells. By means of an innovative single-cell manipulation assay combining fluidic force microscopy with force spectroscopy, we unravel the strength of single specific bonds between a- and α-agglutinins (~100 pN) which require pheromone induction. Prolonged cell–cell contact strongly increases adhesion between mating cells, likely resulting from an increased expression of agglutinins. In addition, we highlight the critical role of disulfide bonds of the a-agglutinin and of histidine residue H273 of α-agglutinin. Most interestingly, we find that mechanical tension enhances the interaction strength, pointing to a model where physical stress induces conformational changes in the agglutinins, from a weak-binding folded state, to a strong-binding extended state. Our single-cell technology shows promises for understanding and controlling the complex mechanism of yeast sexuality.
miR-379 deletion ameliorates features of diabetic kidney disease by enhancing adaptive mitophagy via FIS1
Authors: Kato Mitsuo , Abdollahi Maryam , Tunduguru Ragadeepthi , Tsark Walter , Chen Zhuo , Wu Xiwei , Wang Jinhui , Chen Zhen Bouman , Lin Feng-Mao , Lanting Linda , Wang Mei , Huss Janice , Fueger Patrick T , Chan David , Natarajan Rama
Published: January 2021

Diabetic kidney disease (DKD) is a major complication of diabetes. Expression of members of the microRNA (miRNA) miR-379 cluster is increased in DKD. miR-379, the most upstream 5′-miRNA in the cluster, functions in endoplasmic reticulum (ER) stress by targeting EDEM3. However, the in vivo functions of miR-379 remain unclear. We created miR-379 knockout (KO) mice using CRISPR-Cas9 nickase and dual guide RNA technique and characterized their phenotype in diabetes. We screened for miR-379 targets in renal mesangial cells from WT vs. miR-379KO mice using AGO2-immunopreciptation and CLASH (cross-linking, ligation, sequencing hybrids) and identified the redox protein thioredoxin and mitochondrial fission-1 protein. miR-379KO mice were protected from features of DKD as well as body weight loss associated with mitochondrial dysfunction, ER- and oxidative stress. These results reveal a role for miR-379 in DKD and metabolic processes via reducing adaptive mitophagy. Strategies targeting miR-379 could offer therapeutic options for DKD.
A single day of TGF-β1 exposure activates chondrogenic and hypertrophic differentiation pathways in bone marrow-derived stromal cells
Authors: Futrega Kathryn , Robey Pamela G. , Klein Travis J. , Crawford Ross W. , Doran Michael R.
Published: January 2021

Virtually all bone marrow-derived stromal cell (BMSC) chondrogenic induction cultures include greater than 2 weeks exposure to transforming growth factor-β (TGF-β), but fail to generate cartilage-like tissue suitable for joint repair. Herein we used a micro-pellet model (5 × 103 BMSC each) to determine the duration of TGF-β1 exposure required to initiate differentiation machinery, and to characterize the role of intrinsic programming. We found that a single day of TGF-β1 exposure was sufficient to trigger BMSC chondrogenic differentiation and tissue formation, similar to 21 days of TGF-β1 exposure. Despite cessation of TGF-β1 exposure following 24 hours, intrinsic programming mediated further chondrogenic and hypertrophic BMSC differentiation. These important behaviors are obfuscated by diffusion gradients and heterogeneity in commonly used macro-pellet models (2 × 105 BMSC each). Use of more homogenous micro-pellet models will enable identification of the critical differentiation cues required, likely in the first 24-hours, to generate high quality cartilage-like tissue from BMSC.
Identification of PIM1 substrates reveals a role for NDRG1 phosphorylation in prostate cancer cellular migration and invasion
Authors: Ledet Russell J. , Ruff Sophie E. , Wang Yu , Nayak Shruti , Schneider Jeffrey A. , Ueberheide Beatrix , Logan Susan K. , Garabedian Michael J.
Published: January 2021

PIM1 is a serine/threonine kinase that promotes and maintains prostate tumorigenesis. While PIM1 protein levels are elevated in prostate cancer relative to local disease, the mechanisms by which PIM1 contributes to oncogenesis have not been fully elucidated. Here, we performed a direct, unbiased chemical genetic screen to identify PIM1 substrates in prostate cancer cells. The PIM1 substrates we identified were involved in a variety of oncogenic processes, and included N-Myc Downstream-Regulated Gene 1 (NDRG1), which has reported roles in suppressing cancer cell invasion and metastasis. NDRG1 is phosphorylated by PIM1 at serine 330 (pS330), and the level of NDRG1 pS330 is associated higher grade prostate tumors. We have shown that PIM1 phosphorylation of NDRG1 at S330 reduced its stability, nuclear localization, and interaction with AR, resulting in enhanced cell migration and invasion.
Structural insights into photoactivation of plant Cryptochrome-2
Authors: Palayam Malathy , Ganapathy Jagadeesan , Guercio Angelica M. , Tal Lior , Deck Samuel L. , Shabek Nitzan
Published: January 2021

Cryptochromes (CRYs) are evolutionarily conserved photoreceptors that mediate various light-induced responses in bacteria, plants, and animals. Plant cryptochromes govern a variety of critical growth and developmental processes including seed germination, flowering time and entrainment of the circadian clock. CRY’s photocycle involves reduction of their flavin adenine dinucleotide (FAD)-bound chromophore, which is completely oxidized in the dark and semi to fully reduced in the light signaling-active state. Despite the progress in characterizing cryptochromes, important aspects of their photochemistry, regulation, and light-induced structural changes remain to be addressed. In this study, we determine the crystal structure of the photosensory domain of Arabidopsis CRY2 in a tetrameric active state. Systematic structure-based analyses of photo-activated and inactive plant CRYs elucidate distinct structural elements and critical residues that dynamically partake in photo-induced oligomerization. Our study offers an updated model of CRYs photoactivation mechanism as well as the mode of its regulation by interacting proteins.
Fast automated detection of COVID-19 from medical images using convolutional neural networks
Authors: Liang Shuang , Liu Huixiang , Gu Yu , Guo Xiuhua , Li Hongjun , Li Li , Wu Zhiyuan , Liu Mengyang , Tao Lixin
Published: January 2021

Coronavirus disease 2019 (COVID-19) is a global pandemic posing significant health risks. The diagnostic test sensitivity of COVID-19 is limited due to irregularities in specimen handling. We propose a deep learning framework that identifies COVID-19 from medical images as an auxiliary testing method to improve diagnostic sensitivity. We use pseudo-coloring methods and a platform for annotating X-ray and computed tomography images to train the convolutional neural network, which achieves a performance similar to that of experts and provides high scores for multiple statistical indices (F1 scores > 96.72% (0.9307, 0.9890) and specificity >99.33% (0.9792, 1.0000)). Heatmaps are used to visualize the salient features extracted by the neural network. The neural network-based regression provides strong correlations between the lesion areas in the images and five clinical indicators, resulting in high accuracy of the classification framework. The proposed method represents a potential computer-aided diagnosis method for COVID-19 in clinical practice.
Rate volatility and asymmetric segregation diversify mutation burden in cells with mutator alleles
Authors: Dowsett Ian T. , Sneeden Jessica L. , Olson Branden J. , McKay-Fleisch Jill , McAuley Emma , Kennedy Scott R. , Herr Alan J.
Published: January 2021

Mutations that compromise mismatch repair (MMR) or DNA polymerase ε or δ exonuclease domains produce mutator phenotypes capable of fueling cancer evolution. Here, we investigate how combined defects in these pathways expands genetic heterogeneity in cells of the budding yeast, Saccharomyces cerevisiae, using a single-cell resolution approach that tallies all mutations arising from individual divisions. The distribution of replication errors present in mother cells after the initial S-phase was broader than expected for a single uniform mutation rate across all cell divisions, consistent with volatility of the mutator phenotype. The number of mismatches that then segregated to the mother and daughter cells co-varied, suggesting that each division is governed by a different underlying genome-wide mutation rate. The distribution of mutations that individual cells inherit after the second S-phase is further broadened by the sequential actions of semiconservative replication and mitotic segregation of chromosomes. Modeling suggests that this asymmetric segregation may diversify mutation burden in mutator-driven tumors.
A framework for identifying the recent origins of mobile antibiotic resistance genes
Authors: Ebmeyer Stefan , Kristiansson Erik , Larsson D. G. Joakim
Published: January 2021

Since the introduction of antibiotics as therapeutic agents, many bacterial pathogens have developed resistance to antibiotics. Mobile resistance genes, acquired through horizontal gene transfer, play an important role in this process. Understanding from which bacterial taxa these genes were mobilized, and whether their origin taxa share common traits, is critical for predicting which environments and conditions contribute to the emergence of novel resistance genes. This knowledge may prove valuable for limiting or delaying future transfer of novel resistance genes into pathogens. The literature on the origins of mobile resistance genes is scattered and based on evidence of variable quality. Here, we summarize, amend and scrutinize the evidence for 37 proposed origins of mobile resistance genes. Using state-of-the-art genomic analyses, we supplement and evaluate the evidence based on well-defined criteria. Nineteen percent of reported origins did not fulfill the criteria to confidently assign the respective origin. Of the curated origin taxa, >90% have been associated with infection in humans or domestic animals, some taxa being the origin of several different resistance genes. The clinical emergence of these resistance genes appears to be a consequence of antibiotic selection pressure on taxa that are permanently or transiently associated with the human/domestic animal microbiome.
Real-time observation of tetrapyrrole binding to an engineered bacterial phytochrome
Authors: Hontani Yusaku , Baloban Mikhail , Escobar Francisco Velazquez , Jansen Swetta A. , Shcherbakova Daria M. , Weißenborn Jörn , Kloz Miroslav , Mroginski Maria Andrea , Verkhusha Vladislav V. , Kennis John T. M.
Published: January 2021

Near-infrared fluorescent proteins (NIR FPs) engineered from bacterial phytochromes are widely used for structural and functional deep-tissue imaging in vivo. To fluoresce, NIR FPs covalently bind a chromophore, such as biliverdin IXa tetrapyrrole. The efficiency of biliverdin binding directly affects the fluorescence properties, rendering understanding of its molecular mechanism of major importance. miRFP proteins constitute a family of bright monomeric NIR FPs that comprise a Per-ARNT-Sim (PAS) and cGMP-specific phosphodiesterases - Adenylyl cyclases - FhlA (GAF) domain. Here, we structurally analyze biliverdin binding to miRFPs in real time using time-resolved stimulated Raman spectroscopy and quantum mechanics/molecular mechanics (QM/MM) calculations. Biliverdin undergoes isomerization, localization to its binding pocket, and pyrrolenine nitrogen protonation in <1 min, followed by hydrogen bond rearrangement in ~2 min. The covalent attachment to a cysteine in the GAF domain was detected in 4.3 min and 19 min in miRFP670 and its C20A mutant, respectively. In miRFP670, a second C–S covalent bond formation to a cysteine in the PAS domain occurred in 14 min, providing a rigid tetrapyrrole structure with high brightness. Our findings provide insights for the rational design of NIR FPs and a novel method to assess cofactor binding to light-sensitive proteins.
Elemental composition control of gold-titania nanocomposites by site-specific mineralization using artificial peptides and DNA
Authors: Ozaki Makoto , Imai Takahito , Tsuruoka Takaaki , Sakashita Shungo , Tomizaki Kin-ya , Usui Kenji
Published: January 2021

Biomineralization, the precipitation of various inorganic compounds in biological systems, can be regulated in terms of the size, morphology, and crystal structure of these compounds by biomolecules such as proteins and peptides. However, it is difficult to construct complex inorganic nanostructures because they precipitate randomly in solution. Here, we report that the elemental composition of inorganic nanocomposites can be controlled by site-specific mineralization by changing the number of two inorganic-precipitating peptides bound to DNA. With a focus on gold and titania, we constructed a gold-titania photocatalyst that responds to visible light excitation. Both microscale and macroscale observations revealed that the elemental composition of this gold-titania nanocomposite can be controlled in several ten nm by changing the DNA length and the number of peptide binding sites on the DNA. Furthermore, photocatalytic activity and cell death induction effect under visible light (>450 nm) irradiation of the manufactured gold-titania nanocomposite was higher than that of commercial gold-titania and titania. Thus, we have succeeded in forming titania precipitates on a DNA terminus and gold precipitates site-specifically on double-stranded DNA as intended. Such nanometer-scale control of biomineralization represent a powerful and efficient tool for use in nanotechnology, electronics, ecology, medical science, and biotechnology.
Strange metal behaviour from charge density fluctuations in cuprates
Authors: Seibold Götz , Arpaia Riccardo , Peng Ying Ying , Fumagalli Roberto , Braicovich Lucio , Di Castro Carlo , Grilli Marco , Ghiringhelli Giacomo Claudio , Caprara Sergio
Published: January 2021

Besides the mechanism responsible for high critical temperature superconductivity, the grand unresolved issue of the cuprates is the occurrence of a strange metallic state above the so-called pseudogap temperature T*. Even though such state has been successfully described within a phenomenological scheme, the so-called Marginal Fermi-Liquid theory, a microscopic explanation is still missing. However, recent resonant X-ray scattering experiments identified a new class of charge density fluctuations characterized by low characteristic energies and short correlation lengths, which are related to the well-known charge density waves. These fluctuations are present over a wide region of the temperature-vs-doping phase diagram and extend well above T*. Here we investigate the consequences of charge density fluctuations on the electron and transport properties and find that they can explain the strange metal phenomenology. Therefore, charge density fluctuations are likely the long-sought microscopic mechanism underlying the peculiarities of the metallic state of cuprates.
Varying pre-plasma properties to boost terahertz wave generation in liquids
Authors: Ponomareva Evgenia A. , Ismagilov Azat O. , Putilin Sergey E. , Tsypkin Anton N. , Kozlov Sergei A. , Zhang Xi-Cheng
Published: January 2021

Laser-driven nonlinear phenomena can both reveal the structural features of materials and become the basis for the development of various translated technologies, including highly intense terahertz sources. Here we realize a modified single-color double-pulse excitation scheme for enhancing the terahertz wave generation in flat liquid jets, and we show that the pre-ionization effect is crucial for finding the optimal input conditions. The experimental results, being supported by numerical simulations, reveal the preference for longer pre-pulses to induce the effective ionization process and shorter signals for the strong laser-plasma interaction. In addition to the identified features of the terahertz wave energy enhancement with respect to the duration change for both pulses and their ratio variation, we state the possibility of achieving the optical-to-THz conversion efficiency value up to 0.1% in the case of double-pulse excitation of an α-pinene jet.
Interaction of edge exciton polaritons with engineered defects in the hyperbolic material Bi2Se3
Authors: Lingstädt Robin , Talebi Nahid , Hentschel Mario , Mashhadi Soudabeh , Gompf Bruno , Burghard Marko , Giessen Harald , van Aken Peter A.
Published: January 2021

Hyperbolic materials exhibit unique properties that enable intriguing applications in nanophotonics. The topological insulator Bi2Se3 represents a natural hyperbolic optical medium, both in the THz and visible range. Here, using cathodoluminescence spectroscopy and electron energy-loss spectroscopy, we demonstrate that Bi2Se3 supports room-temperature exciton polaritons and explore the behavior of hyperbolic edge exciton polaritons, which are hybrid modes resulting from the coupling of the polaritons bound to the upper and lower edges of Bi2Se3 nanoplatelets. We compare Fabry-Pérot-like resonances emerging in edge polariton propagation along pristine and artificially structured edges and experimentally demonstrate the possibility to steer edge polaritons by means of grooves and nanocavities. The observed scattering of edge polaritons by defect structures is found to be in good agreement with finite-difference time-domain simulations. Our findings reveal the extraordinary capability of hyperbolic polariton propagation to cope with the presence of defects, providing an excellent basis for applications such as nanooptical circuitry, nanoscale cloaking and nanoscopic quantum technology.
Pressure-induced Anderson-Mott transition in elemental tellurium
Authors: Oliveira Jaime F. , Fontes Magda B. , Moutinho Marcus , Rowley Stephen E. , Baggio-Saitovitch Elisa , Silva Neto Marcello B. , Enderlein Carsten
Published: January 2021

Elemental tellurium is a small band-gap semiconductor, which is always p-doped due to the natural occurrence of vacancies. Its chiral non-centrosymmetric structure, characterized by helical chains arranged in a triangular lattice, and the presence of a spin-polarized Fermi surface, render tellurium a promising candidate for future applications. Here, we use a theoretical framework, appropriate for describing the corrections to conductivity from quantum interference effects, to show that a high-quality tellurium single crystal undergoes a quantum phase transition at low temperatures from an Anderson insulator to a correlated disordered metal at around 17 kbar. Such insulator-to-metal transition manifests itself in all measured physical quantities and their critical exponents are consistent with a scenario in which a pressure-induced Lifshitz transition shifts the Fermi level below the mobility edge, paving the way for a genuine Anderson-Mott transition. We conclude that previously puzzling quantum oscillation and transport measurements might be explained by a possible Anderson-Mott ground state and the observed phase transition.
Inherited geochemical diversity of 3.4 Ga organic films from the Buck Reef Chert, South Africa
Authors: Alleon Julien , Bernard Sylvain , Olivier Nicolas , Thomazo Christophe , Marin-Carbonne Johanna
Published: January 2021

Archean rocks contain crucial information about the earliest life forms on Earth, but documenting these early stages of biological evolution remains challenging. The main issue lies in the geochemical transformations experienced by Archean organic matter through its multi-billion-year geological history. Here we present spatially resolved chemical investigations conducted on 3.4 Ga organic films from the Buck Reef Chert, South Africa which indicate that they possess significantly different chemical compositions. Since these organic films all underwent the same post-depositional geological history, this geochemical diversity is most likely inherited, reflecting original chemical differences which were not completely obliterated by subsequent burial-induced degradation processes. These results demonstrate that early Archean organic films carry chemical information directly related to their original molecular compositions. This paves the way for the reconstruction of the initial chemical nature of organic microfossils found in ancient rocks, provided that the geologically-induced chemical transformations they underwent are properly constrained.
Infrared Spectroscopy-based Techniques
Authors: Arana Gorka , Madariaga Juan Manuel
Published: January 2021

This chapter covers past and present developments in infrared (IR) spectroscopy in the field of cultural heritage (CH), from the methods used to characterize materials to the procedures aimed at diagnosing the state of conservation of CH assets. A large number of modes of IR spectroscopy are now available, (a) to characterize the nature of organic (and inorganic) compounds present in a CH object, (b) to detect non-original compounds that provide clues on possible decay processes and (c) to follow the effects of a given restoration process. This chapter reviews such techniques and also shows the importance of current chemometric tools to extract as much information as possible from the IR spectra to aid in the fulfillment of the three mentioned objectives that can be provided by modern IR spectroscopic techniques.
Raman Spectroscopy
Authors: Rousaki Anastasia , Vandenabeele Peter
Published: January 2021

Raman spectroscopy has grown to become one of the most important techniques in the field of cultural heritage studies. Benchtop Raman spectrometers, together with their mobile counterparts, are used extensively to characterize the materials and identify possible degradation products on works of art. This chapter describes the fundamentals, techniques and applications of Raman spectroscopy in archaeometry. Moreover, the state-of-the-art instrumentation is discussed together with the traditional and also latest spectroscopic approaches.
Separation Methods
Authors: Alcántara-García Jocelyn
Published: January 2021

The study of cultural heritage objects is challenged by the presence of unique and complex mixtures in various stages of degradation. Therefore, the chemical characterization of cultural heritage materials commonly needs the preliminary separation of their components, achieved through chromatographic methods. The choice of a chromatographic technique is related to the physicochemical characteristics of the components in the mixture (polarity, vapor pressure, etc.), which can be chemically modified through derivatization. This chapter presents an overview of liquid, gas and thin-layer chromatography, three of the most frequently used separation techniques in the study of cultural heritage objects. Each section contains fundamental principles and terminology associated with the method, touches on sample preparation and its importance and provides the reader with references for more in-depth understanding.
Single cell biomass tracking allows identification and isolation of rare targeted therapy-resistant DLBCL cells within a mixed population
Authors: Murray Graeme F. , Guest Daniel , Mikheykin Andrey , Toor Amir , Reed Jason
Published: January 2021

Rare drug tolerant cells are isolated by an interferometric based biomass growth assay in real time.
Recent advances in the use of stimulated Raman scattering in histopathology
Authors: Lee Martin , Herrington C. Simon , Ravindra Manasa , Sepp Kristel , Davies Amy , Hulme Alison N. , Brunton Valerie G.
Published: January 2021

Stimulated Raman histopathology with computer aided diagnosis.
A novel approach for visualization and localization of small amounts of DNA on swabs to improve DNA collection and recovery process
Authors: Kitchner Emma , Chavez Jose , Ceresa Luca , Bus Magdalena M. , Budowle Bruce , Gryczynski Zygmunt
Published: January 2021

In this report, a simple and practical procedure is proposed for DNA localization on a solid matrix e.g., a collection swab.
Open-flow microperfusion combined with mass spectrometry for in vivo liver lipidomic analysis
Authors: Li Tuo , Yang Hui , Li Xing , Hou Yinzhu , Zhao Yao , Wu Wenjing , Zhao Lingyu , Wang Fuyi , Zhao Zhenwen
Published: January 2021

The open-flow microperfusion (OFM) probe can effectively collect lipids for subsequent analysis.
Target-induced activation of polymerase activity for recycling signal amplification cascades for sensitive aptamer-based detection of biomarkers
Authors: Li Yusi , Li Xia , Yang Fang , Yuan Ruo , Xiang Yun
Published: January 2021

Target-induced activation of a polymerase leads to two recycling cascades for signal amplification detection of platelet-derived growth factor BB with high sensitivity.
Ultrasensitive detection of cyclin D1 by a self-enhanced ECL immunosensor based on Bi2S3quantum dots
Authors: Liu Lixiao , Yang Anzi , Luo Wen , Liu Huaxiao , Liu Xuan , Zhao Wenbo
Published: January 2021

Strong ECL of Bi2S3QDs and emission mechanisms were studied and the assembled Au@Cu-Bi2S3QDs nanocomposites based sandwich immunosensor was applied to ultrasensitive detection of CCND1 protein.
A label-free electrochemical sensor for ultrasensitive microRNA-21 analysis based on the poly(l-cysteine)/MoS2 sensing interface
Authors: Yao Yao , Pan Hemeng , Luo Yi , Zhu Dan , Chao Jie , Su Shao , Wang Lianhui
Published: January 2021

A label-free electrochemical sensor was constructed based on the Pl-Cys/MoS2 sensing interface for miRNA-21 detection with high performance.
Ag-Catalyzed ring-opening of tertiary cycloalkanols for C–H functionalization of cyclic aldimines
Authors: Wang Jingjing , Liu Xue , Wu Ziyan , Li Feng , Zhang Ming-Liang , Mi Yiman , Wei Junhao , Zhou Yao , Liu Lantao
Published: January 2021

Silver-catalyzed direct C–H functionalization of cyclic aldimines with cyclopropanols and cyclobutanols via a radical-mediated C–C bond cleavage strategy has been realized, generating the desired products in decent yields with wide substrate scope.
A versatile click chemistry-based approach for functionalizing biomaterials of diverse nature with bioactive peptides
Authors: Martin-Gómez Helena , Oliver-Cervelló Lluís , Sánchez-Campillo Iván , Marchán Vicente , Ginebra Maria-Pau , Mas-Moruno Carlos
Published: January 2021

A versatile and straightforward strategy to functionalize biomaterials is described. This click chemistry-based methodology was successfully used to functionalize polylactic acid, gold and titanium surfaces.
Crystalline supramolecular organic frameworksviahydrogen-bonding between nucleobases
Authors: Martín-Arroyo Miguel , Castells-Gil Javier , Bilbao Nerea , Almora-Barrios Neyvis , Martí-Gastaldo Carlos , González-Rodríguez David
Published: January 2021

We describe here the first crystalline hydrogen-bonded organic framework made from complementary guanine and cytosine nucleobases.
Oxyphosphoranes as precursors to bridging phosphate-catecholate ligands
Authors: Yang Xin , Wei Rui , Shi Yaping , Liu Liu Leo , Wu Yile , Zhao Yufen , Stephan Douglas W.
Published: January 2021

Chelating bridging diphosphate bimetallic complexes are derived from reactions of an oxyphosphorane with metal halides.
A ratiometric fluorescent probe for monitoring pH fluctuations during autophagy in living cells
Authors: Wang Shan , Wang Bingya , Zhu Lei , Hou Ji-Ting , Yu Kang-Kang
Published: January 2021

We present a ratiometric fluorescent probe for monitoring pH featuring superb photostability and chemostability.
Highly regioselective palladium-catalyzed domino reaction for post-functionalization of BODIPY
Authors: Wang Sisi , Wang Zhaoli , Gao Hu , Jiang Liang , Liu Hui , Wu Fan , Zhao Yue , Chan Kin Shing , Shen Zhen
Published: January 2021

A series of benzo[a]-fused BODIPYs and the corresponding isomeric naphthyl-BODIPYs have been synthesized through a facile one-pot palladium-catalyzed domino reaction of BODIPY precursors (2-bromo-BODIPYs) with diarylethynes.
A theoretical insight on the anion⋯anion interactions observed in the solid state structure of a hetero-trinuclear complex
Authors: Ghosh Kousik , Frontera Antonio , Chattopadhyay Shouvik
Published: January 2021

A hetero-nuclear cobalt(iii)/potassium complex has been synthesized and characterized by several analytical techniques. DFT computations indicate the existence of anion⋯anion interactions in its solid state.
Study of an SmBO3–ScBO3 system and new SmSc(BO3)2 orthoborate
Authors: Kuznetsov Artem B. , Kokh Konstantin A. , Kononova Nadezda G. , Shevchenko Vyacheslav S. , Rashchenko Ssergey V. , Lapin Ivan N. , Svetlichnyi Valery A. , Uralbekov Bolat , Bolatov Asset , Simonova Ekaterina A. , Kokh Alexander E.
Published: January 2021

A new SmSc(BO3)2 compound was discovered from the study of SmBO3–ScBO3 phase diagram.
Multiscale exploration of hydrocarbon adsorption and hopping through ZSM-5 channels – from Monte Carlo modelling to experiment
Authors: Strzempek Maciej , Tarach Karolina , Góra-Marek Kinga , Rey Fernando , Palomino Miguel , Valencia Susana , Piskorz Witold
Published: January 2021

In this article the results of statistical MC modelling corroborated by the FT-IR spectroscopy and gravimetric adsorption studies of low aliphatic hydrocarbons in ZSM-5 (Si/Al = 28 or silicalite) are presented. The extension of the Dubbeldam's forcefield for inclusion of the finite Al-containing zeolites is proposed.
Unveiling the stability of Sn/Si/graphite composites for Li-ion storage by physical, electrochemical and computational tools
Authors: Ruderman Andrés , Smrekar Sacha , Bracamonte M. Victoria , Primo Emiliano N. , Luque Guillermina L. , Thomas Jorge , Leiva Ezequiel , Monti Gustavo A. , Barraco Daniel E. , Vaca Chávez Fabián
Published: January 2021

Complex materials composed of two and three elements with high Li-ion storage capacity are investigated and tested as lithium-ion battery (LiB) negative electrodes.
Carbon-based catalysts for Fischer–Tropsch synthesis
Authors: Chen Yanping , Wei Jiatong , Duyar Melis S. , Ordomsky Vitaly V. , Khodakov Andrei Y. , Liu Jian
Published: January 2021

The substantial progress of application of carbon-based catalysts in FTS has been systematically summarized and discussed in this review article.
Multicomponent diffusion in atmospheric aerosol particles
Authors: Wallace Brandon J. , Price Chelsea L. , Davies James F. , Preston Thomas C.
Published: January 2021

Condensed phase mass transport in single aerosol particles is investigated using a linear quadrupole electrodynamic balance (LQ-EDB) and the Maxwell–Stefan (MS) framework.
Recovery of viable ammonia–nitrogen products from agricultural slaughterhouse wastewater by membrane contactors: a review
Authors: Brennan Brian , Lawler Jenny , Regan Fiona
Published: January 2021

Efficient removal of nitrogen from wastewater is vital to ensure the safekeeping of waterways and their biota.
Galactooligosaccharide pretreatment alleviates damage of the intestinal barrier and inflammatory responses in LPS-challenged mice
Authors: Wang Geng , Sun Wanjing , Pei Xun , Jin Yuyue , Wang Haidong , Tao Wenjing , Xiao Zhiping , Liu Lujie , Wang Minqi
Published: January 2021

Pure galactooligosaccharides protect mice from damage of the intestinal barrier and inflammatory responses caused by lipopolysaccharides, and restore the production of propionate, butyrate, and total short-chain fatty acids.
Tunable magnetothermal properties of cobalt-doped magnetite–carboxymethylcellulose ferrofluids: smart nanoplatforms for potential magnetic hyperthermia applications in cancer therapy
Authors: Leonel Alice G. , Mansur Alexandra A. P. , Carvalho Sandhra M. , Outon Luis Eugenio F. , Ardisson José Domingos , Krambrock Klaus , Mansur Herman S.
Published: January 2021

Cobalt-doped magnetite–carboxymethylcellulose ferrofluids for magnetic hyperthermia in anti-cancer therapy – smart nanoheaters.
Atmospheric chemistry of oxazole: the mechanism and kinetic studies of the oxidation reaction initiated by OH radicals
Authors: Shiroudi Abolfazl , Abdel-Rahman Mohamed A. , El-Nahas Ahmed M. , Altarawneh Mohammednoor
Published: January 2021

Oxidation of oxazole by OH˙ radicals studied by DFT methods coupled with reaction kinetics calculations using TST and RRKM theories.
Nonvolatile electrical control of 2D Cr2Ge2Te6 and intrinsic half metallicity in multiferroic hetero-structures
Authors: Ilyas Asif , Xiang Shuling , Chen Miaogen , Khan Muhammad Yar , Bai Hua , He Pimo , Lu Yunhao , Deng Renren
Published: January 2021

The electrical control of two-dimensional (2D) van der Waals ferromagnets is a step forward for the realization of spintronic devices.
Nanoscale light- and voltage-induced lattice strain in perovskite thin films
Authors: Qiu Haian , Mativetsky Jeffrey M.
Published: January 2021

Combined light and voltage stimulus triggers localized cation migration, nonlinear lattice deformation, and nanoscale structural rearrangement in perovskite films providing insight into perovskite optoelectronic device instability.
Extended curly arrow rules to rationalise and predict structural effects on quantum interference in molecular junctions
Authors: O'Driscoll Luke J. , Bryce Martin R.
Published: January 2021

An extension to curly arrow rules for the prediction of quantum interference behaviour in conjugated molecular wires widens the scope of this simple graphical method to wires containing heteroatoms, cross-conjugation and/or non-alternant structures.
Dopant-site lattice turbulence of Cu-substituted Nb2O5 for efficient nitrogen electroreduction
Authors: Wang Jia , Li Guangkai , Wei Tao , Zhou Shizheng , Ji Xuqiang , Liu Xien
Published: January 2021

Cu-Nb2O5 with abundant lattice disturbances anchored on a carbon material exhibits excellent activity and high selectivity for N2 electroreduction to NH3 in acidic electrolyte.
Robust anomalous Hall effect and temperature-driven Lifshitz transition in Weyl semimetal Mn3Ge
Authors: Wang Xiaolei , Pan Dong , Zeng Qingqi , Chen Xue , Wang Hailong , Zhao Duo , Xu Zhiyang , Yang Qianqian , Deng Jinxiang , Zhai Tianrui , Wu Guangheng , Liu Enke , Zhao Jianhua
Published: January 2021

We provide direct evidence of robust anomalous Hall effect and temperature-induced Lifshitz transition in a hexagonal Mn3X system. It presents a promising route for effectively modulating the Fermi level location in topological Weyl semimetals.
Degradable polyanhydride networks derived from itaconic acid
Authors: Sajjad Hussnain , Lillie Leon M. , Lau C. Maggie , Ellison Christopher J. , Tolman William B. , Reineke Theresa M.
Published: January 2021

Tunable and degradable crosslinked-polyanhydride networks from renewably derived itaconic anhydrides and multifunctional thiols have been developed.
Metallaphotoredox-catalyzed C–H activation: regio-selective annulation of allenes with benzamide
Authors: Li Tianlei , Li Jishun , Zhu Zihao , Chen Yuyuan , Li Xueyao , Yang Qingyun , Xia Jie , Zhang Wenxuan , Zhang Chao , Pan Weidong , Wu Song
Published: January 2021

We have developed an efficient annulation of benzamides with allenes using cobalt and photoredox dual catalysis under an oxygen atmosphere. The transformation features an alternative strategy for the regeneration of a cobalt catalyst with the aid of Eosin Y.
Synthesis of polycyclic naphthols and naphthalenes via tandem Ti(Oi-Pr)4-promoted photoenolization Diels–Alder reaction and aromatization
Authors: Lu Xiao-Long , Yang Baochao , He Haibing , Gao Shuanhu
Published: January 2021

An efficient approach to naphthol and naphthalene scaffolds has been developed using a sequence involving tandem Ti(Oi-Pr)4-promoted photoenolization Diels–Alder (PEDA) and aromatization reactions.
Design of (β-diazo-α,α-difluoroethyl)phosphonates and their application as masked carbenes in visible light-promoted coupling reactions with sulfonic acids
Authors: Mei Haibo , Liu Jiang , Pajkert Romana , Wang Li , Röschenthaler Gerd-Volker , Han Jianlin
Published: January 2021

A new kind of (β-diazo-α,α-difluoroethyl)phosphonate was designed and used as masked carbenes in visible-light-promoted reactions with sulfonic acids.
Template-driven construction of [8]-imidazolium macrocycles
Authors: Hua Kai , Gan Ming-Ming , Liu Xue-Ru , Zhang Le , An Yuan-Yuan , Han Ying-Feng
Published: January 2021

A controllable and efficient template-driven strategy for the rational construction of polyimidazolium macrocycles has been developed.
Rapid and economic preparation of wearable thermotherapy pad based on simple cut-patterning of metal foil supported by plastic sheets
Authors: Ha Sung-Hun , Kim Jong-Man
Published: January 2021

A simple, economic, and reproducible fabrication route to high-performance stretchable heaters is proposed towards wearable thermotherapy.
The yield and quality of Pleurotus abieticola grown on nematode-infected Pinus massoniana chips
Authors: Guo Xia , Sun Lei , Li Changtian , Fu Yongping , Song Bing , Li Yu
Published: January 2021

In this study, we investigated the use of nematode-infected Pinus massoniana chips (NPC) as the main ingredient in Pleurotus abieticola substrate.
Slippery liquid infused porous surfaces with corrosion resistance potential on aluminum alloy
Authors: Yu Peng , Lian Zhongxu , Xu Jinkai , Yu Huadong
Published: January 2021

The slippery liquid infused porous surface has developed into a potential technology to solve the problem of poor durability in corrosion resistance.
Fabrication of green poly(vinyl alcohol) nanofibers using natural deep eutectic solvent for fast-dissolving drug delivery
Authors: Zhang Qingmiao , Lin Zhuangsheng , Zhang Wenkun , Huang Ting , Jiang Jingjing , Ren Yu , Zhang Ruiqi , Li Wen , Zhang Xiaoli , Tu Qin
Published: January 2021

We report an environmental friendly method to construct honey/ASA embedded poly(vinyl alcohol) nanofibers based on natural deep eutectic solvent for fast-dissolving drug delivery firstly.
Aromatic nature of neutral and dianionic 1,4-diaza-2,3,5,6-tetraborinine derivatives
Authors: Ota Kei , Kinjo Rei
Published: January 2021

The parameters relevant to aromaticity of boron-rich inorganic benzene analogues (B4N2R6) have been computationally investigated by using HOMA, ELF, PDI, NICSzz, ACID and ASE.
Selective coordination with heterogeneous metal atoms for inorganic–organic hybrid layers
Authors: Kim Seong Jun , Jeon In Su , Song Wooseok , Myung Sung , Lim Jongsun , Lee Sun Sook , Chung Taek-Mo , An Ki-Seok
Published: January 2021

The fabrication of a metal–organic nanostructure was demonstrated by the hybrid synthesis process. The metal atoms such as Sn and Zn were sequentially coordinated on specific functional groups of the main organic layer by vapor phase metalation.
Time-resolved detection of SDS-induced conformational changes in α-synuclein by a micro-stopped-flow system
Authors: Takaramoto Shunki , Nakasone Yusuke , Sadakane Kei , Maruta Shinsaku , Terazima Masahide
Published: January 2021

Dynamics of conformation changes of α-synuclein induced by the presence of SDS micelles are revealed using time-resolved diffusion, CD, and FRET measurements combined with a micro-stopped flow system.
The importance of intramolecular hydrogen bonds on the translocation of the small drug piracetam through a lipid bilayer
Authors: Coimbra João T. S. , Feghali Ralph , Ribeiro Rui P. , Ramos Maria J. , Fernandes Pedro A.
Published: January 2021

Using computational strategies and an analogue compound, we explore and measure the impact of intramolecular hydrogen bonds on the translocation of the small drug piracetam, through biological membrane models.