bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiplexed imaging analysis of the tumor-immune microenvironment reveals predictors of outcome in triple-negative breast cancer
Authors: Patwa Aalok , Yamashita Rikiya , Long Jin , Risom Tyler , Angelo Michael , Keren Leeat , Rubin Daniel L.
Published: July 2021

Triple-negative breast cancer, the poorest-prognosis breast cancer subtype, lacks clinically approved biomarkers for patient risk stratification and treatment management. Prior literature has shown that interrogation of the tumor-immune microenvironment may be a promising approach to fill these gaps. Recently developed high-dimensional tissue imaging technology, such as multiplexed ion beam imaging, provide spatial context to protein expression in the microenvironment, allowing in-depth characterization of cellular processes. We demonstrate that profiling the functional proteins involved in cell-to-cell interactions in the microenvironment can predict recurrence and overall survival. We highlight the immunological relevance of the immunoregulatory proteins PD-1, PD-L1, IDO, and Lag3 by tying interactions involving them to recurrence and survival. Multivariate analysis reveals that our methods provide additional prognostic information compared to clinical variables. In this work, we present a computational pipeline for the examination of the tumor-immune microenvironment using multiplexed ion beam imaging that produces interpretable results, and is generalizable to other cancer types.
Adaptive divergence and post-zygotic barriers to gene flow between sympatric populations of a herbivorous mite
Authors: Villacis-Perez Ernesto , Snoeck Simon , Kurlovs Andre H. , Clark Richard M. , Breeuwer Johannes A. J. , Van Leeuwen Thomas
Published: July 2021

Plant-herbivore interactions promote the generation and maintenance of both plant and herbivore biodiversity. The antagonistic interactions between plants and herbivores lead to host race formation: the evolution of herbivore types specializing on different plant species, with restricted gene flow between them. Understanding how ecological specialization promotes host race formation usually depends on artificial approaches, using laboratory experiments on populations associated with agricultural crops. However, evidence on how host races are formed and maintained in a natural setting remains scarce. Here, we take a multidisciplinary approach to understand whether populations of the generalist spider miteTetranychus urticaeform host races in nature. We demonstrate that a host race co-occurs among generalist conspecifics in the dune ecosystem of The Netherlands. Extensive field sampling and genotyping of individuals over three consecutive years showed a clear pattern of host associations. Genome-wide differences between the host race and generalist conspecifics were found using a dense set of SNPs on field-derived iso-female lines and previously sequenced genomes ofT. urticae. Hybridization between lines of the host race and sympatric generalist lines is restricted by post-zygotic breakdown, and selection negatively impacts the survival of generalists on the native host of the host race. Our description of a host race among conspecifics with a larger diet breadth shows how ecological and reproductive isolation aid in maintaining intra-specific variation in sympatry, despite the opportunity for homogenization through gene flow. Our findings highlight the importance of explicitly considering the spatial and temporal scale on which plant-herbivore interactions occur in order to identify herbivore populations associated with different plant species in nature. This system can be used to study the underlying genetic architecture and mechanisms that facilitate the use of a large range of host plant taxa by extreme generalist herbivores. In addition, it offers the chance to investigate the prevalence and mechanisms of ecological specialization in nature.
Diversity of neurovascular coupling dynamics along vascular arbors in layer II/III somatosensory cortex
Authors: Rungta Ravi L. , Zuend Marc , Aydin Ali-Kemal , Martineau Éric , Boido Davide , Weber Bruno , Charpak Serge
Published: July 2021

The spatial-temporal sequence of cerebral blood flow (CBF), cerebral blood volume (CBV) and blood velocity changes triggered by neuronal activation is critical for understanding functional brain imaging. This sequence follows a stereotypic pattern of changes across different zones of the vasculature in the olfactory bulb, the first relay of olfaction. However, in the cerebral cortex, where most human brain mapping studies are performed, the timing of activity evoked vascular events remains controversial. Here we utilized a single whisker stimulation model to map out functional hyperemia along vascular arbours from layer II/III to the surface of primary somatosensory cortex, in anesthetized and awake Thy1-GCaMP6 mice. We demonstrate that sensory stimulation triggers an increase in blood velocity within the mid-capillary bed and a dilation of upstream large capillaries, and the penetrating and pial arterioles. We report that under physiological stimulation, response onset times are highly variable across compartments of different vascular arbours. Furthermore, generating transfer functions (TFs) between neuronal Ca2+ and vascular dynamics across different brain states demonstrates that anesthesia decelerates neurovascular coupling (NVC). This spatial-temporal pattern of vascular events demonstrates functional diversity not only between different brain regions but also at the level of different vascular arbours within supragranular layers of the cerebral cortex.
Ultrastructure of influenza virus ribonucleoprotein complexes during viral RNA synthesis
Authors: Nakano Masahiro , Sugita Yukihiko , Kodera Noriyuki , Miyamoto Sho , Muramoto Yukiko , Wolf Matthias , Noda Takeshi
Published: July 2021

The single-stranded, negative-sense, viral genomic RNA (vRNA) of influenza A virus is encapsidated by viral nucleoproteins (NPs) and an RNA polymerase to form a ribonucleoprotein complex (vRNP) with a helical, rod-shaped structure. The vRNP is responsible for transcription and replication of the vRNA. However, the vRNP conformation during RNA synthesis is not well understood. Here, using high-speed atomic force microscopy and cryo-electron microscopy, we investigated the native structure of influenza A vRNPs during RNA synthesis in vitro. Two distinct types of vRNPs were observed in association with newly synthesized RNAs: an intact, helical rod-shaped vRNP connected with a folded RNA and a deformed vRNP associated with a looped RNA. Interestingly, the looped RNA was a double-stranded RNA, which likely comprises a nascent RNA and the template RNA detached from NPs of the vRNP. These results suggest that while some vRNPs keep their helical structures during RNA synthesis, for the repeated cycle of RNA synthesis, others accidentally become structurally deformed, which likely results in failure to commence or continue RNA synthesis. Thus, our findings provide the ultrastructural feature of vRNPs during RNA synthesis.
What is Organometallic Chemistry
Authors: Nakazawa Hiroshi
Published: July 2021

This chapter describes the basics of organometallic chemistry for readers relatively new to the subject. Organometallic chemistry is the field of chemistry that was born and grew up between metal complex chemistry and organic chemistry. It thus incorporates aspects from both ways of thinking. This chapter briefly describes its history.
Basic Concepts Relating to Organometallic Complexes
Authors: Nakazawa Hiroshi
Published: July 2021

Just as the octet rule is a basic rule in organic chemistry, the EAN (Effective Atomic Number = 18-electron) rule is fundamental and useful in organometallic chemistry. In discussing a transition metal complex, it is important that the number of valence electrons of the metal and the number of electrons supplied from the ligands around the metal can be counted. This chapter explains how to perform electron counting both from the transition metal side and the ligand side. It would be extremely challenging to attempt to remember how many electrons are donated by each ligand, due to the enormous number and variety of ligands, but using the concepts described in this chapter, a solution is presented and there is no need to remember the details for individual ligands. Once the 18-electron rule is mastered, it is possible to predict the stability and the reasonable structure of any given transition metal complex, as well as the formal oxidation number and d-electron number of the transition metal. Moreover, in a multinuclear complex, the bond order between the metal atoms can be predicted.
Bonds in Organometallic Complexes
Authors: Nakazawa Hiroshi
Published: July 2021

Since a transition metal methyl complex corresponds to a compound in which one hydrogen atom of methane is replaced by a transition metal (M), the M–C linkage is considered to be a σ-bond and covalent. To understand the properties and reactivity of organometallic complexes, it is important to understand the character of M–C σ-bonds in transition metal alkyl complexes. The polarization of the bond and the effect of other C substituents on the strength of M–C bonds are explained. Taking a metal–carbonyl (CO) bond and a metal–olefin bond as examples, the σ-donation of electrons from a ligand to a metal and the π-back donation from a metal to a ligand are described. In addition, the Dewar–Chatt–Duncanson model is also explained. It is necessary to understand the application of molecular orbital theory to transition metal complexes. Although crystal field theory explains in a clear and simple way how the transition metal d orbital energies split when ligands approach the metal to form a complex, and this is sufficient for understanding Werner type complexes, it is insufficient for understanding organometallic complexes. Ligand field theory therefore emerged, combining molecular orbital and crystal field theory concepts, while remaining relatively simple. Applying this theory, it is apparent why organometallic complexes follow the 18-electron rule. In this chapter, crystal field theory, and its successor, ligand field theory, are described.
Chemistry of Transition Metal Complexes with Group 15 Elements: Transition Metal Complexes with One Lone Pair of Electrons on the Coordinating Atom
Authors: Matsuzaka Hiroyuki , Mizuta Tsutomu
Published: July 2021

This chapter outlines the chemistry of transition metal complexes with amide (–NR2) and phosphide (–PR2) ligands. Such species may be considered as metalla-amines and -phosphines: the Group 15 atom in the complex still possesses a reactive lone pair of electrons, which may be used to form multiple bonds to the metal via π overlap with suitable vacant metal orbitals. The N or P atom thus acts as an intramolecular Lewis base. Bridging structures resulting in multinuclear complexes are also found. Synthesis and reactivity patterns of amide and phosphide complexes are addressed in detail. In addition to the MPR2-type species noted above, phosphorus exhibits complexes in which it is pentavalent.
Chemistry of Transition Metal Complexes with Group 16 Elements: Transition Metal Complexes with Two Lone Pairs of Electrons on the Coordinating Atom
Authors: Osakada Kohtaro
Published: July 2021

The synthesis, bonding and properties of metal complexes with ligating Group 16 atoms O and S are discussed in this chapter. Despite the high electronegativity of these elements, M–OR and M–SR complexes show properties more consistent with coordination bonds of covalent character. Typical reactions such as the insertion of small molecules into M–O and M–S bonds, and coupling of thiolate ligands with organic ligands are presented.
Problem Solutions
Authors: Nakazawa Hiroshi
Published: July 2021

To understand the basics and make effective use of the knowledge described in this book, 20 practice problems are dispersed through chapters 2 to 7. In this chapter, model answers to these practice problems are presented to encourage the reader's deeper understanding. In addition to the direct answers, the thinking and logic required to reach the answers are also described, helping readers to establish their knowledge.
Direct analysis of fulvic acids adsorbed onto capped gold nanoparticles by laser desorption ionization Fourier-transform ion cyclotron resonance mass spectrometry
Authors: Giannopoulos Konstantinos , Benettoni Pietro , Holbrook Timothy R. , Reemtsma Thorsten , Wagner Stephan , Lechtenfeld Oliver J.
Published: July 2021

Laser desorption ionization Fourier-transform ion cyclotron resonance mass spectrometry for direct molecular characterization of nanoparticle coronas.
Ferrite-encapsulated nanoparticles with stable photothermal performance for multimodal imaging-guided atherosclerotic plaque neovascularization therapy
Authors: Yang Zhuowen , Yao Jianting , Wang Jianxin , Zhang Cong , Cao Yang , Hao Lan , Yang Chao , Wu Changjun , Zhang Jingqi , Wang Zhigang , Ran Haitao , Tian Ye
Published: July 2021

A strategy of “ferrite-encapsulated nanoparticles-mediated photothermal therapy” was proposed, which combined stable photothermal performance and multimodal imaging-guided photothermal therapeutic effect to suppress the plaque angiogenesis.
Phosphinate esters as novel warheads for activity-based probes targeting serine proteases
Authors: Kahler Jan Pascal , Verhelst Steven H. L.
Published: July 2021

Phosphinate electrophiles are developed as activity-based probes for serine proteases. They can be used for gel-based profiling as well as for microscopy-based detection, and their use is here demonstrated on neutrophil serine proteases.
Clostridioides difficile toxin A-mediated Caco-2 cell barrier damage was attenuated by insect-derived fractions and corresponded to increased gene transcription of cell junctional and proliferation proteins
Authors: Dong Liyou , Tomassen Monic M. , Ariëns Renata M. C. , Oosterink Els , Wichers Harry J. , Veldkamp Teun , Mes Jurriaan J. , Govers Coen
Published: July 2021

Protein-enriched insect fractions mitigated Clostridium difficile toxin A-mediated Caco-2 barrier damage by increasing gene transcription of cell junctional and proliferation proteins.
Excellent kinetics of single-phase Gd-doped ceria fuel electrodes in solid oxide cells
Authors: Nenning Andreas , Holzmann Manuel , Fleig Jürgen , Opitz Alexander K.
Published: July 2021

Solid oxide fuel electrodes with pure GDC as the functional layer exhibit excellent kinetics, in line with mechanistic impedance modelling.
Gallium nanoparticles as novel inhibitors of Aβ40 aggregation
Authors: Torres Kyabeth M. , Delgado Ambar S. , Serrano Erika R. , Falcón-Cruz Nitza V. , Meléndez Anamaris , Ramos Idalia , Du Deguo , Oyola Rolando
Published: July 2021

Amyloid beta (Aβ) plaques accumulate between neurons disrupting neuronal integrity during amyloidosis-related diseases such as Alzheimer's disease. GaN nanoparticles effectively inhibit Aβ40 aggregation in vitro.
Enhanced detection and annotation of small molecules in metabolomics using molecular-network-oriented parameter optimization
Authors: Xu Rui , Lee Jisun , Chen Li , Zhu Jiangjiang
Published: July 2021

An integrated molecular-network-based optimization strategy for enhanced metabolomics analysis is reported.
Enhancement of sensitivity for dichlorvos detection by a low-weight gelator based on bolaamphiphile amino acid derivatives decorated with a hybrid graphene quantum dot/enzyme/hydrogel
Authors: Sahub Chonticha , Andrews Jessica L. , Smith James P. , Mohamad Arif Maya A. , Tomapatanaget Boosayarat , Steed Jonathan W.
Published: July 2021

The use of fluorescent gel blends with GQDs provides new insights into gel formation and hydrogen peroxide detection utilizing the peroxidase-like catalytic activity of graphene quantum dots. This hybrid hydrogel enhances the performance of hybrid hydrogel properties by a low molecular weight gelator with the assistance of GQDs and phosphate buffer and taking an advantage of sensing application with a highly potential sensitivity and stability.
Simple glycerol-assisted and morphology controllable solvothermal synthesis of CeVO4/BiVO4 hierarchical hollow microspheres with enhanced photocatalytic activities
Authors: Wang Miao , Guo Yingying , Wang Zedong , Cui Huihui , Sun Tongming , Tang Yanfeng
Published: July 2021

CeVO4/BiVO4 heterostructures were synthesized and achieved a significantly improved photocatalytic efficiency towards MB under visible-light irradiation.
Highly sensitive colorimetric sensing of copper(ii) ions based on “CLICK-17” DNAzyme-catalyzed azide modified gold nanoparticles and alkyne capped dsDNA cycloaddition
Authors: Yan Weicong , Zhong Zhensheng , Ma Jie , Rujiralai Thitima
Published: July 2021

We report selective and visual detection of Cu2+ based on aggregation of azide modified gold nanoparticles induced by CLICK-17 DNAzyme and Cu2+ or Cu+ catalyzed click reaction between azide-AuNPs and alkyne-dsDNA.
Conversion of CO2 into cyclic carbonate catalyzed by an N-doped mesoporous carbon catalyst
Authors: Liu Dan , Fu Jinxia , Zhou Kuo , Kang Shimin , Cai Zhuodi , Xu Yongjun , Duan Peigao
Published: July 2021

Ammonium hydroxide is first used as a nitrogen source to synthesize N-doped mesoporous carbon spheres (N-MCSs). Using N-MCS800 as a catalyst, the TOF of the cycloaddition of CO2 with epichlorohydrin is 236 h−1.
Effect of methoxy-substitutions on the hole transport properties of carbazole-based compounds: pros and cons
Authors: Salman Seyhan , Sallenave Xavier , Bucinskas Audrius , Volyniuk Dmytro , Bezvikonnyi Oleksandr , Andruleviciene Viktorija , Grazulevicius Juozas Vidas , Sini Gjergji
Published: July 2021

The methoxy substituents in these compounds reduce the hole mobilities due to the enhanced molecular polarity, a detrimental effect which can be importantly reduced by designing linear D–A–D architectures.
Model‐agnostic online forecasting for PV power output
Authors: Lee HyunYong , Lee Jun‐Gi , Kim Nac‐Woo , Lee Byung‐Tak
Published: July 2021

A reliable forecasting model is required for photovoltaic (PV) power output because solar energy is highly volatile. Another driver for the need of a reliable forecasting model is concept drift, which means that the statistical properties of the data change over time. In this paper, an online forecasting method to handle concept drift is proposed. First, the problem of forecasting in batch learning is transformed into a forecasting in online learning setting. Then, an online learning algorithm is applied, which is good for handling concept drift. Through experiments using the real‐world data, it is shown that the method noticeably improves performance compared to the case where a trained model is used. Under various concept drift scenarios, the method improves performance by up to 87.3%. It is also shown that the re‐training method (a representative existing method) has several limitations. This method requires several issues to be solved, such as selection of a proper window size, and this is evident through results showing different performance under different settings. In contrast, the method shows a reliable and desirable performance under various concept drift scenarios and thus outperforms the re‐training method. The method improves performance by up to 79%.
The role of AGN and obscuration in the position of the host galaxy relative to the main sequence
Authors: Mountrichas G. , Buat V. , Yang G. , Boquien M. , Burgarella D. , Ciesla L. , Malek K. , Shirley R.
Published: July 2021

We use X-ray active galactic nuclei (AGN) observed by the Chandra X-ray Observatory within the 9.3 deg2 Boötes field of the NDWFS to study whether there is a correlation between X-ray luminosity (LX) and star formation rate (SFR) of the host galaxy, at 0.5 < z < 2.0, with respect to the position of the galaxy to the main sequence (SFRnorm). About half of the sources in the X-ray sample have spectroscopic redshifts. We also construct a reference galaxy catalogue. For both datasets we use photometric data from the optical to the far-infrared compiled by the HELP project, and apply spectral energy distribution fitting, using the X-CIGALE code. We exclude quiescent sources from both the X-ray and the reference samples. We also account for the mass completeness of our dataset, in different redshifts bins. Our analysis highlights the importance of studying the SFR–LX relation in a uniform manner, taking into account systematics and selection effects. Our results suggest, in less massive galaxies (log [M*(M⊙)] ∼ 11), that an AGN enhances the SFR of the host galaxy by ∼50% compared to non-AGN systems. A flat relation is observed for the most massive galaxies. The SFRnorm does not evolve with redshift. The results, although tentative, are consistent with a scenario where, in less massive systems, both AGN and star formation are fed by cold gas supplied by a merger event. In more massive galaxies the flat relation could be explained by a different supermasssive black hole fuelling mechanism that is decoupled from the star formation of the host galaxy (e.g., hot diffuse gas). Finally, we compare the host galaxy properties of X-ray absorbed and unabsorbed sources. Our results show no difference, which suggests that X-ray absorption is not linked with the properties of the galaxy.
Altérisations, schizes et politiques de la croyance
Authors: Selim Monique
Published: July 2021

Cet article saisit les caractéristiques marquantes de la croyance actuellement en commençant par la réarticuler aux situations et enjeux sociaux, économiques et politiques qui déterminent les formes présentes du capitalisme. Isoler épistémologiquement la croyance serait en effet la répliquer, la renforcer inexorablement encroyantà sa consistance consubstantielle. Partant de cette hypothèse, l’auteure met l’accent sur le marché qui sous-tend la prolifération des croyances et des offres de salut. À travers plusieurs exemples de terrains (Bangladesh, Inde, Vietnam, Laos, Birmanie), elle analyse les processus fondamentaux de relégation, de réification identitaire, d’altérisation qui régissent les scènes toujours politiques des croyances avant de conclure sur les renaturalisations morales en jeu.
La problématique de la religion dans le discours freudien
Authors: Birman Joël
Published: July 2021

Cet essai vise à effectuer la problématisation de l’expérience religieuse dans le discours freudien, selon une perspective métapsychologique, afin de caractériser cette expérience comme une illusion découlant du désarroi originaire du sujet. Parallèlement, la lecture de la religion effectuée par le discours freudien renvoie à l’Illuminisme, dans une perspective généalogique, de sorte que la religion serait une vision de monde qui s’opposerait au discours de la science.
Insomnie bei Demenzen
Authors: Mayer Geert , Frohnhofen Helmut
Published: July 2021

Schlafstörungen gehen Demenzen häufig voran und können deren Verlauf verschlimmern. Die Interaktion ist bidirektional. Beide Erkrankungen haben gemeinsame Symptome wie kognitive Einschränkungen und Veränderungen von Schlafstruktur und Qualität. Wenn sich die Demenz einmal manifestiert hat, können Schlafstörungen wie obstruktive Schlafapnoe, Restless-legs-Syndrom und Parasomnien die Symptomatik verstärken. Die Schlafstruktur zeigt eine Verminderung von langsamwelligem Schlaf und häufiges nächtliches Erwachen mit längeren Wachzeiten. Schlaf ermöglicht es, mittels Aktivierung des glymphatischen Systems Aß- und Tau-Proteine, die sich im Wachen angesammelt haben, aus dem ZNS auszuschleusen. Wegen der bidirektionalen Interaktionen ist es erforderlich, Schlafstörungen vermehrte Aufmerksamkeit zu schenken und sie früh zu diagnostizieren und zu behandeln, um einer Verschlimmerung einer existierenden oder sich entwickelnden Demenz vorzubeugen. Eine Anzahl von subjektiven Fragebögen und objektiven Instrumenten wie Polysomnografie und Aktigrafie stehen für die Diagnostik zur Verfügung. Begleitende Schlafstörungen sollten immer mit behandelt werden (z. B. nasale Überdrucktherapie bei Schlafapnoe).

Prävention oder Behandlung sollten immer Verhaltenstherapien wie körperliche Aktivierung, soziale Interaktion und ausreichende Exposition gegenüber Tageslicht beinhalten. Einige Antidepressiva, Melatonin, neue duale Orexinrezeptorantagonisten (in Deutschland nicht zugelassen) und wenige Hypnotika können zur Behandlung empfohlen werden. Die Schlafprobleme der betreuenden Personen sollten in den Behandlungsablauf eingeschlossen werden, um die Lebensqualität der Erkrankten zu optimieren.
Is it Possible to Derive the Dresdner Correction Formula Using a Finite Element Program?
Authors: Janknecht Peter
Published: July 2021

Introduction The aim was to construct a model cornea by CAD and finite element software to find out how the intraocular pressure compares to the forces for applanation at the outside
of the model cornea. These data were to be compared to the Dresdner correction formula. Thereby, it was possible to find out whether the model was plausible and to find hints as to why a
correction for how the intraocular pressure depends on the corneal thickness is necessary at all.

Methods Using the open-source software FreeCad and geometrical data for the cornea of the literature, an average cornea was constructed. On this average cornea, a finite element
analysis was performed using the free software z88aurora. The intraocular pressure was measured by applanation of the outer cornea. The necessary forces were analysed.

Results In this model, the intraocular pressure had to be corrected depending on the corneal thickness. The correction factor was kmean; finite
elements = 19.17 – 0.0334*corneal thickness. The necessary correction did not exclusively depend on the relation between the endothelial area and the area of the outer cornea: for this
relation alone the correction would have been karea-relation = 1.0361 – 0.0006*corneal thickness.

Discussion The model correction formula was close to the Dresdner formula. The relation between endothelial area and the area of the outer cornea could only explain about half of the
necessary correction.
REM-Schlafverhaltensstörung
Authors: Heidbreder Anna , Stefani Ambra
Published: July 2021

Die Rapid-Eye-Movement (REM)-Schlafverhaltensstörung (RBD) ist eine Parasomnie, bei der es zu einem unwillkürlichen Ausleben von Trauminhalten während des REM-Schlafes kommt. Die physiologische Muskelatonie während des REM-Schlafes ist aufgehoben. Die Mehrheit (> 90 %) der Patienten mit einer isolierten RBD (iRBD) entwickeln im weiteren Verlauf eine alpha-Synukleinopathie (M. Parkinson, Demenz mit Lewy-Körperchen, Multisystematrophie). Liegt eine RBD vor, führt die Degeneration von Schaltkreisen des Nucleus subcoeruleus, die inhibierend auf die medulläre Formatio reticularis und in die spinalen Vorderhörner einwirken, dazu, dass Bewegungen während des REM-Schlafs möglich werden. Um die Diagnose einer RBD stellen zu können, ist der Nachweis einer fehlenden Muskeltonusabsenkung während des REM-Schlafes (REM-sleep without atonia, RWA) notwendig, was nur mit Hilfe einer Videopolysomnografie möglich ist. Grundvoraussetzung für die Beurteilung von Verhaltensauffälligkeiten und Vokalisationen ist die zeitsynchrone Aufzeichnung von Video und Ton. Kurative oder krankheitsmodulierende Therapien existieren nicht. Groß angelegte Behandlungsstudien, die einen Effekt in der symptomatischen Behandlung nachweisen, liegen ebenfalls nicht vor, sodass Therapieempfehlungen meist auf Expertenmeinungen und Daten retrospektiver Fallserien basieren. Dabei zeigten sich Melatonin 3–12 mg und Clonazepam 0,25–2 mg als wirksam. Da die RBD ein Frühstadium einer neurodegenerativen Erkrankung darstellt, bietet sie sich in der Zukunft als Ausgangspunkt für neuroprotektive Studien an.
1.5 Photochemistry and Radical Generation: Approaches in Mechanism Elucidation
Authors: Cahoon S. B. , Yoon T. P.
Published: July 2021

The development of photocatalytic reactions has reemerged as an active area of research in organic synthesis. A large variety of synthetically valuable transformations have now been developed that take advantage of the ease by which photocatalysts generate a variety of open-shelled reactive intermediates. The study of the mechanisms of these reactions, however, is a challenge, especially in increasingly sophisticated reactions that often involve multiple steps and complex reaction mixtures. Multiple complementary techniques often need to be utilized in tandem in order to develop a detailed understanding of these reactions. The first part of this review outlines many of the most common techniques that are used to interrogate the initiation and product-formation steps of a photocatalytic transformation. The second part describes case studies that provide contextual examples of how photophysical, electrochemical, physical organic, and computational investigations can be used together to provide insights into the mechanisms of complex photocatalytic reactions.
1.12 Intermolecular Radical C—H Functionalization
Authors: Bietti M. , Dénès F.
Published: July 2021

The generation of carbon-centered radicals via intermolecular hydrogen-atom transfer (HAT) from C—H bonds to an abstracting species (HAT reagent) represents a significant challenge in terms of reactivity, site-selectivity and stereoselectivity. The radical species resulting from such a transfer can then engage in carbon—carbon or carbon—heteroatom bond formation, possibly through the intervention of transition-metal catalysts, leading to a variety of functionalized products. This chapter aims to provide the reader with useful guidelines to understand, predict, and design selective radical transformations based upon initial HAT from a C—H bond coupled to different radical-capture strategies. A selection of examples that illustrate different approaches to implement HAT reactions in synthetically useful procedures are presented.
1.13 Intramolecular Hydrogen-Atom Transfer
Authors: Treacy S. M. , Zhang X. , Rovis T.
Published: July 2021

Recent advances in intramolecular hydrogen-atom transfer (HAT) have demonstrated significant utility in C—H functionalization through highly reactive open-shell intermediates. The intramolecular transposition of radical reactivity from select functional groups to generate more stable carbon-centered radicals often proceeds with high regioselectivity, providing novel bond disconnections at otherwise inert and largely indistinguishable positions. This chapter explores the functional groups capable of intramolecular HAT to generate remote radicals and the transformations currently available to the synthetic chemist.
Functional hydrogels for diabetic wound management
Authors: Gao Daqian , Zhang Yidan , Bowers Daniel T. , Liu Wanjun , Ma Minglin
Published: July 2021

Diabetic wounds often have a slow healing process and become easily infected owing to hyperglycemia in wound beds. Once planktonic bacterial cells develop into biofilms, the diabetic wound becomes more resistant to treatment. Although it remains challenging to accelerate healing in a diabetic wound due to complex pathology, including bacterial infection, high reactive oxygen species, chronic inflammation, and impaired angiogenesis, the development of multifunctional hydrogels is a promising strategy. Multiple functions, including antibacterial, pro-angiogenesis, and overall pro-healing, are high priorities. Here, design strategies, mechanisms of action, performance, and application of functional hydrogels are systematically discussed. The unique properties of hydrogels, including bactericidal and wound healing promotive effects, are reviewed. Considering the clinical need, stimuli-responsive and multifunctional hydrogels that can accelerate diabetic wound healing are likely to form an important part of future diabetic wound management.
Atomic force microscopy—A tool for structural and translational DNA research
Authors: Main Kavit H. S. , Provan James I. , Haynes Philip J. , Wells Geoffrey , Hartley John A. , Pyne Alice L. B.
Published: July 2021

Atomic force microscopy (AFM) is a powerful imaging technique that allows for structural characterization of single biomolecules with nanoscale resolution. AFM has a unique capability to image biological molecules in their native states under physiological conditions without the need for labeling or averaging. DNA has been extensively imaged with AFM from early single-molecule studies of conformational diversity in plasmids, to recent examinations of intramolecular variation between groove depths within an individual DNA molecule. The ability to image dynamic biological interactions in situ has also allowed for the interaction of various proteins and therapeutic ligands with DNA to be evaluated—providing insights into structural assembly, flexibility, and movement. This review provides an overview of how innovation and optimization in AFM imaging have advanced our understanding of DNA structure, mechanics, and interactions. These include studies of the secondary and tertiary structure of DNA, including how these are affected by its interactions with proteins. The broader role of AFM as a tool in translational cancer research is also explored through its use in imaging DNA with key chemotherapeutic ligands, including those currently employed in clinical practice.
Gas density distribution in a clustered-gas jet produced from a supersonic slit nozzle under high backing pressure
Authors: Xu Huwang , Chen Guanglong , Patel D. N. , Cao Yunjiu , Ren Li , Xu Hongxia , Shao Huili , He Jianping , Kim Dong Eon
Published: July 2021

A gas jet produced by adiabatic expansion of gas through a slit nozzle into a vacuum has been served as a target in the study of high harmonic generation or laser wakefield electron acceleration. In this work, Mach–Zehnder interferometry was utilized to obtain the gas density distribution in an argon cluster gas jet produced from a supersonic slit nozzle. The interference fringe distortion caused by the gas jet along the slit width under high backing pressure was recorded and inverted to a gas density profile. The gas backing pressure was up to 80 bars to obtain a gas jet with a higher density. It is found that the gas density in the jet is not uniform along the width direction of the slit nozzle and is the highest at the center of the jet. Along the gas jet, the highest gas density roughly decreases linearly. However, a steep density gradient is observed at P0 = 60–80 bars. Meanwhile, the highest gas density depends linearly on the gas backing pressure and the degree of dependence gradually decreases along the gas jet.
Individual variation influences avoidance behaviour of invasive common carp (
Authors: Bzonek Paul A. , Kim Jaewoo , Mandrak Nicholas E.
Published: July 2021

Uncontrolled biological invasions are reducing freshwater ecosystem diversity and resilience. Research is needed to evaluate whether non-structural deterrents are feasible within lock or canal environments. This study examined common carp (Cyprinus carpio) and buffalo hybrid (Ictiobus) movement patterns in response to acoustic and stroboscopic deterrents. Twelve strobe lights and one underwater speaker were deployed across the centre of a ship slip, with an environment analogous to a navigation canal. Common carp (n = 6) and Ictiobus (n = 4) were implanted with acoustic telemetry tags, and their behaviours were examined under control, stroboscopic, and acoustic stimuli for 60-min trial periods. Trials were run during the day and night for six straight days. Linear models determined that the stroboscopic and acoustic stimuli altered fish positioning within the ship slip, but produced weaker avoidance responses than those observed elsewhere. Weak responses were likely due to a strong preference for the open end of the ship slip and a lack of acoustic refuge during the acoustic treatment. Avoidance responses also differed widely among individuals of the same species, with fish expressing repeatability of avoidance radius size across trials. Ambient and stimulus sound-pressure levels should be carefully considered when deploying acoustic deterrents.
A summer and winter’s tale: factors influencing avian community composition and species abundances in lowland subtropical floodplain forests in central eastern Australia
Authors: Fitzgerald Mark , Gorta Simon , Kooyman Robert M.
Published: July 2021

The ecology of avian community assembly in subtropical climate areas with seasonal and year-to-year variability is complex and poorly understood. To test for variation in year–year and seasonal (summer–winter) avian community composition and species abundances, we established 10 transects (200 m long) and sampled twice yearly for 7 years. To differentiate year–year and seasonal (summer–winter) patterns from the potential disturbance effects caused by human activities associated with music festivals (events), we monitored community composition and species abundances on sites close to disturbance areas (impact) and sites distant from disturbances (control). Impacts from large scale music events included loud noise, and thousands of vehicle and people movements on a daily basis. Raw count, abundance-weighted, and feeding guild data were analysed using multivariate and univariate methods. Seasonal (summer–winter) patterns of food resource availability in dominant forest trees (fruit and nectar resources) were identified. We found strong signals for the influence of seasonality and seasonal resource availability on community composition and feeding guild representation (nectivores and frugivores). We detected somewhat weaker effects for location relative to disturbance (control vs impact) and weak effects for sample timing associated with disturbance from the events. Avian community composition showed high similarity between control and impact sites, was dynamic in space and time (year to year) and showed strong local and regional trends in response to seasonality. Avian species abundances were greater in less disturbed (control) forest habitats, highlighting the fundamental value of conservation reserves in protecting higher quality avian habitats.
Nonlinear dynamical properties of frequency swept fiber-based semiconductor lasers
Authors: Slepneva Svetlana , Pimenov Alexander
Published: July 2021

We investigate dynamics of semiconductor lasers with fiber-based unidirectional ring cavity that can be used as frequency swept sources. We identify key factors behind the reach dynamical behavior of such lasers using state-of-the-art experimental and analytical methods. Experimentally, we study the laser in static, quasi-static and synchronization regimes. We apply experimental methods such as optical heterodyne or electric field reconstruction in order to characterize these regimes or study the mechanisms of transition between them. Using a delay differential equation model, we demonstrate that the presence of chromatic dispersion can lead to destabilization of the laser modes through modulational instability, which results in undesirable chaotic emission. We characterize the instability threshold both theoretically and experimentally, and demonstrate deterioration of the Fourier domain mode locking regime near the threshold.
X-ray to MR: the progress of flexible instruments for endovascular navigation
Authors: Abdelaziz Mohamed E M K , Tian Libaihe , Hamady Mohamad , Yang Guang-Zhong , Temelkuran Burak
Published: July 2021

Interventional radiology and cardiology are rapidly growing areas of minimally invasive surgery, covering multiple diagnostic and interventional procedures. Treatment via endovascular techniques has become the go-to approach, thanks to its minimally invasive nature and its effectiveness in reducing hospitalisation and total time to recovery when compared to open surgery. Although x-ray fluoroscopy is currently the gold standard imaging technique for endovascular interventions, it presents occupational safety hazards to medical personnel and potential risks to patients, especially paediatric patients, because of its inherent ionising radiation. Magnetic resonance imaging (MRI), with its unique ability to provide radiation-free imaging, and acquiring morphologic and functional information, holds great promise in the advancement of image-guided navigation through the vasculature. Moreover, MRI has the potential to combine diagnosis, therapy and early evaluation of therapy in the same intervention. However, MR-guided interventions face a major challenge due to the presence of a large magnetic field (1.5/3 Tesla), which limits the set of materials suitable for the construction of key instrumentation (sheaths, catheters and guidewires). Despite these challenges, in recent years, significant progress has been made in the development of interventional devices, which comprise biocompatible, MR safe and MR visible materials. In an attempt to encourage and accelerate the development of MR-guided endovascular instrumentation, we present a systematic and illustrated overview of the plethora of work targeting to overcome the aforementioned limitations which are underpinned by the interdependent advancements in science, technology, engineering, mathematics and medicine (STEMM).
Homogenization of hyperbolic equations with periodic coefficients in ℝ^{𝕕}: Sharpness of the results
Authors: Dorodnyi M. , Suslina T.
Published: July 2021

In

L
2

(

R

d

;

C

n

)

L_2(\mathbb {R}^d;\mathbb {C}^n)

, a selfadjoint strongly elliptic second order differential operator

A

ε

\mathcal {A}_\varepsilon

is considered. It is assumed that the coefficients of

A

ε

\mathcal {A}_\varepsilon

are periodic and depend on

x

/

ε

\mathbf {x}/\varepsilon

, where

ε
>
0

\varepsilon >0

 is a small parameter. We find approximations for the operators

cos
⁡
(

A

ε

1

/

2

τ
)

\cos (\mathcal {A}_\varepsilon ^{1/2}\tau )

and

A

ε

−
1

/

2

sin
⁡
(

A

ε

1

/

2

τ
)

\mathcal {A}_\varepsilon ^{-1/2}\sin (\mathcal {A}_\varepsilon ^{1/2}\tau )

in the norm of operators acting from the Sobolev space

H
s

(

R

d

)

H^s(\mathbb {R}^d)

to

L
2

(

R

d

)

L_2(\mathbb {R}^d)

(with suitable

s
s

). We also find approximation with corrector for the operator

A

ε

−
1

/

2

sin
⁡
(

A

ε

1

/

2

τ
)

\mathcal {A}_\varepsilon ^{-1/2}\sin (\mathcal {A}_\varepsilon ^{1/2}\tau )

in the

(

H
s

→

H
1

)

(H^s \to H^1)

-norm. The question about the sharpness of the results with respect to the type of the operator norm and with respect to the dependence of estimates on

τ
\tau

is studied. The results are applied to study the behavior of the solutions of the Cauchy problem for the hyperbolic equation

∂
τ
2

u

ε

=
−

A

ε

u

ε

+

F

\partial _\tau ^2 \mathbf {u}_\varepsilon = -\mathcal {A}_\varepsilon \mathbf {u}_\varepsilon + \mathbf {F}

.
Characterizing compact coincidence sets in the obstacle problem—a short proof
Authors: Eberle S. , Weiss G.
Published: July 2021

The objective of this article is to present a concise and easy-to-extend proof of the known fact that coincidence sets of global solutions of the obstacle problem that are bounded and have nonempty interior are ellipsoids.
Radiation and scattering in electromagnetic waveguides near thresholds
Authors: Plamenevskii B. , Poretskii A.
Published: July 2021

A waveguide occupies a three-dimensional domain

G
G

with several cylindrical outlets to infinity and is described by the stationary Maxwell system with perfectly conductive boundary conditions. It is assumed that the medium filling the waveguide is homogeneous and isotropic at infinity in a limiting sense. The paper is devoted to description of the behavior of the scattering matrix, radiation conditions, and solutions as the spectral parameter tends to a threshold. In particular, it is shown that the scattering matrix has finite one-sided limits at every threshold and the limits are expressed in terms of the “scattering matrix stable near the threshold”.
Target enrichment improves phylogenetic resolution in the genus Zanthoxylum (Rutaceae) and indicates both incomplete lineage sorting and hybridization events
Authors: Reichelt Niklas , Wen Jun , Pätzold Claudia , Appelhans Marc S
Published: July 2021

Background and Aims

Zanthoxylum is the only pantropical genus within Rutaceae, with a few species native to temperate eastern Asia and North America. Efforts using Sanger sequencing failed to resolve the backbone phylogeny of Zanthoxylum. In this study, we employed target-enrichment high-throughput sequencing to improve resolution. Gene trees were examined for concordance and sectional classifications of Zanthoxylum were evaluated. Off-target reads were investigated to identify putative single-copy markers for bait refinement, and low-copy markers for evidence of putative hybridization events.

Methods

A custom bait set targeting 354 genes, with a median of 321 bp, was designed for Zanthoxylum and applied to 44 Zanthoxylum species and one Tetradium species as the outgroup. Illumina reads were processed via the HybPhyloMaker pipeline. Phylogenetic inferences were conducted using coalescent and maximum likelihood methods based on concatenated datasets. Concordance was assessed using quartet sampling. Additional phylogenetic analyses were performed on putative single and low-copy genes extracted from off-target reads.

Key Results

Four major clades are supported within Zanthoxylum: the African clade, the Z. asiaticum clade, the Asian–Pacific–Australian clade and the American–eastern Asian clade. While overall support has improved, regions of conflict are similar to those previously observed. Gene tree discordances indicate a hybridization event in the ancestor of the Hawaiian lineage, and incomplete lineage sorting in the American backbone. Off-target putative single-copy genes largely confirm on-target results, and putative low-copy genes provide additional evidence for hybridization in the Hawaiian lineage. Only two of the five sections of Zanthoxylum are resolved as monophyletic.

Conclusions

Target enrichment is suitable for assessing phylogenetic relationships in Zanthoxylum. Our phylogenetic analyses reveal that current sectional classifications need revision. Quartet tree concordance indicates several instances of reticulate evolution. Off-target reads are proven useful to identify additional phylogenetically informative regions for bait refinement or gene tree based approaches.
Probabilistic identification of bacterial essential genes via insertion density using TraDIS data with Tn5 libraries
Authors: Nlebedim Valentine U , Chaudhuri Roy R , Walters Kevin
Published: July 2021

Motivation

Probabilistic Identification of bacterial essential genes using transposon-directed insertion-site sequencing (TraDIS) data based on Tn5 libraries has received relatively little attention in the literature; most methods are designed for mariner transposon insertions. Analysis of Tn5 transposon-based genomic data is challenging due to the high insertion density and genomic resolution. We present a novel probabilistic Bayesian approach for classifying bacterial essential genes using transposon insertion density derived from transposon insertion sequencing data. We implement a Markov chain Monte Carlo sampling procedure to estimate the posterior probability that any given gene is essential. We implement a Bayesian decision theory approach to selecting essential genes. We assess the effectiveness of our approach via analysis of both simulated data and three previously published Escherichia coli, Salmonella Typhimurium and Staphylococcus aureus datasets. These three bacteria have relatively well characterized essential genes which allows us to test our classification procedure using receiver operating characteristic curves and area under the curves. We compare the classification performance with that of Bio-Tradis, a standard tool for bacterial gene classification.

Results

Our method is able to classify genes in the three datasets with areas under the curves between 0.967 and 0.983. Our simulated synthetic datasets show that both the number of insertions and the extent to which insertions are tolerated in the distal regions of essential genes are both important in determining classification accuracy. Importantly our method gives the user the option of classifying essential genes based on the user-supplied costs of false discovery and false non-discovery.

Availability and implementation

An R package that implements the method presented in this paper is available for download from https://github.com/Kevin-walters/insdens.

Supplementary information

Supplementary data are available at Bioinformatics online.