Fundamental Motif Research Articles

General Regio- and Diastereoselective Allylic C-H Oxygenation of Internal Alkenes.

Branched allylic esters and carboxylates are fundamental motifs prevalent in natural products and drug molecules. The direct allylic C-H oxygenation of internal alkenes represents one of the most straightforward approaches, bypassing the requirement for an allylic leaving group as in the classical Tsuji-Trost reaction. However, current methods suffer from limited scope─often accompanied by selectivity issues─thus hampering further development. Herein we report a photocatalytic platform as a general solution to these problems, enabling the coupling of diverse internal alkenes with carboxylic acids, alcohols, and other O-nucleophiles, typically in a highly regio- and diastereoselective manner.

Design of a Biohybrid Materials Circuit with Binary Decoder Functionality.

Synthetic biology applies concepts from electrical engineering and information processing to endow cells with computational functionality. Transferring the underlying molecular components into materials and wiring them according to topologies inspired by electronic circuit boards has yielded materials systems that perform selected computational operations. However, the limited functionality of available building blocks is restricting the implementation of advanced information-processing circuits into materials. Here, a set of protease-based biohybrid modules the bioactivity of which can either be induced or inhibited is engineered. Guided by a quantitative mathematical model and following a design-build-test-learn (DBTL) cycle, the modules are wired according to circuit topologies inspired by electronic signal decoders, a fundamental motif in information processing. A 2-input/4-output binary decoder for the detection of two small molecules in a material framework that can perform regulated outputs in form of distinct protease activities is designed. The here demonstrated smart material system is strongly modular and can be used for biomolecular information processing for example in advanced biosensing or drug delivery applications.

Guanidinium Hypoiodite-Catalyzed Intramolecular Oxidative Coupling Reaction of Oxindoles with β-Dicarbonyls.

Spiro[indoline-3,4'-piperidine] is a fundamental motif present in various biologically active compounds. Here, we report an intramolecular oxidative coupling reaction of oxindoles with β-dicarbonyls in the presence of a guanidinium hypoiodite catalyst, providing spiro-coupling products in moderate to excellent yields. Furthermore, a chiral hypoiodite catalyst derived from the chiral guanidinium organocatalyst is effective for the challenging asymmetric carbon-carbon bond-forming reaction, affording optically active spiro[indoline-3,4'-piperidines].

A Unified Approach to Decarboxylative Halogenation of (Hetero)aryl Carboxylic Acids.

Aryl halides are a fundamental motif in synthetic chemistry, playing a critical role in metal-mediated cross-coupling reactions and serving as important scaffolds in drug discovery. Although thermal decarboxylative functionalization of aryl carboxylic acids has been extensively explored, the scope of existing halodecarboxylation methods remains limited, and there currently exists no unified strategy that provides access to any type of aryl halide from an aryl carboxylic acid precursor. Herein, we report a general catalytic method for direct decarboxylative halogenation of (hetero)aryl carboxylic acids via ligand-to-metal charge transfer. This strategy accommodates an exceptionally broad scope of substrates. We leverage an aryl radical intermediate toward divergent functionalization pathways: (1) atom transfer to access bromo- or iodo(hetero)arenes or (2) radical capture by copper and subsequent reductive elimination to generate chloro- or fluoro(hetero)arenes. The proposed ligand-to-metal charge transfer mechanism is supported through an array of spectroscopic studies.

Narrating the Wound: Trauma and Memory in Coleridge’s ‘Ancient Mariner’ and Poe’s ‘The Raven’

Demystifying the puzzle of the ancient Mariner's real story and identity has been the aim of many critics. Direct analysis of the poem would always propound a crossing of boundaries between the real and the uncanny without providing a clear interpretation of the actual context of the mariner’s tale. The mariner’s dilemma occurs when he shoots an albatross without any distinct reason, thus resulting in the death of all the crew members who turn into eccentric creatures. Accentuating his sense of guilt, the mariner stops a guest from entering a wedding and starts narrating his story. Whereas the guest never questions the reliability of the fictitious elements of the mariner's account, the readers do. Similarly, Edgar Allan Poe’s speaker posits questions to an un-welcomed guest, a raven, who visits him at night and gets infuriated at the consistent answer he receives from him: ‘Nevermore’. The readers are aware that the speaker is suffering from a psychological disorder since he insists the raven would reply to his distorted inquiries. This paper reads the mariner’s as well as the Raven’s speaker’s quandaries in association with trauma theory highlighting their traumatic experiences and underscoring the unreliability of their narration by diagnosing them as patients of post-traumatic stress disorder (PTSD). Reference will be made to the importance of the albatross and the raven as fundamental motifs that project the characters’ psychological predicaments resulting in the implausible tales they both recount.

Salvation in the rhythm? Crisis and limitation in Henry Maldiney

In the frame of an in-depth analysis on the fundamental motifs and main intentions of the works of Henry Maldiney, the essay focuses on the relationship between the dimensions of «limitation» and «unlimited» – the latter understood as the emergence of the «unlimited» within the very heart of a «limited» living body –, crucial for understanding Maldiney’s anti-objectivist attitude and his conception of reality as a surprise. More specifically, the author brings to the fore the concepts of «crisis», «rhythm» and «form», also with regard to the aesthetic-artistic experience, and how the rhythmic nature of a living form can ensure an approach to reality which does not overlook its nature of surprise.

Sema and Soma in the Poems about Death by Constantine P. Cavafy

The aim of this article is to analyse Constantine P. Cavafy’s poems on death with the help of theoretical and hermeneutical literary principles and the interplay of the Greek words sema (“a grave”) and soma (“the body”). The aim is to study their forms and symbolisms as one of the fundamental motifs of Cavafy’s oeuvre. Simultaneously, the article will compare the poetic symbols with ancient philosophy on death (exemplified by Plato), as well as with the later authors’ (for instance, Stéphane Mallarmé’s) symbolistic considerations of death, which inspired Cavafy’s, modern, poetry. Through a textual analysis of his poetry on death, the poet’s influence and the sense of destruction he arouses in the reader will be explored. Furthermore, the article will focus on the thymotic power of his poetry, arguing that this author of historical heritage—that is, of the inheritance of Eros inheritance—is also an author of the inheritance of Thanatos.

Selective Carbon‐Carbon Bond Amination with Redox‐Active Aminating Reagents: A Direct Approach to Anilines†

Main observation and conclusionAmines are among the most fundamental motifs in chemical synthesis, and the introduction of amine building blocks via selective C—C bond cleavage allows the construction of nitrogen compounds from simple hydrocarbons through direct skeleton modification. Herein, we report a novel method for the preparation of anilines from alkylarenes via Schmidt‐type rearrangement using redox‐active amination reagents, which are easily prepared from hydroxylamine. Primary amines and secondary amines were prepared from corresponding alkylarenes or benzyl alcohols under mild conditions. Good compatibility and valuable applications of the transformation were also displayed.

Current Understanding of the Structure, Stability and Dynamic Properties of Amyloid Fibrils.

Amyloid fibrils are supramolecular protein assemblies represented by a cross-β structure and fibrous morphology, whose structural architecture has been previously investigated. While amyloid fibrils are basically a main-chain-dominated structure consisting of a backbone of hydrogen bonds, side-chain interactions also play an important role in determining their detailed structures and physicochemical properties. In amyloid fibrils comprising short peptide segments, a steric zipper where a pair of β-sheets with side chains interdigitate tightly is found as a fundamental motif. In amyloid fibrils comprising longer polypeptides, each polypeptide chain folds into a planar structure composed of several β-strands linked by turns or loops, and the steric zippers are formed locally to stabilize the structure. Multiple segments capable of forming steric zippers are contained within a single protein molecule in many cases, and polymorphism appears as a result of the diverse regions and counterparts of the steric zippers. Furthermore, the β-solenoid structure, where the polypeptide chain folds in a solenoid shape with side chains packed inside, is recognized as another important amyloid motif. While side-chain interactions are primarily achieved by non-polar residues in disease-related amyloid fibrils, the participation of hydrophilic and charged residues is prominent in functional amyloids, which often leads to spatiotemporally controlled fibrillation, high reversibility, and the formation of labile amyloids with kinked backbone topology. Achieving precise control of the side-chain interactions within amyloid structures will open up a new horizon for designing useful amyloid-based nanomaterials.

A novel motif of Rad51 serves as an interaction hub for recombination auxiliary factors.

Homologous recombination (HR) is essential for maintaining genome stability. Although Rad51 is the key protein that drives HR, multiple auxiliary factors interact with Rad51 to potentiate its activity. Here, we present an interdisciplinary characterization of the interactions between Rad51 and these factors. Through structural analysis, we identified an evolutionarily conserved acidic patch of Rad51. The neutralization of this patch completely abolished recombinational DNA repair due to defects in the recruitment of Rad51 to DNA damage sites. This acidic patch was found to be important for the interaction with Rad55-Rad57 and essential for the interaction with Rad52. Furthermore, biochemical reconstitutions demonstrated that neutralization of this acidic patch also impaired the interaction with Rad54, indicating that a single motif is important for the interaction with multiple auxiliary factors. We propose that this patch is a fundamental motif that facilitates interactions with auxiliary factors and is therefore essential for recombinational DNA repair.

Dictionary learning in Fourier-transform scanning tunneling spectroscopy

Modern high-resolution microscopes are commonly used to study specimens that have dense and aperiodic spatial structure. Extracting meaningful information from images obtained from such microscopes remains a formidable challenge. Fourier analysis is commonly used to analyze the structure of such images. However, the Fourier transform fundamentally suffers from severe phase noise when applied to aperiodic images. Here, we report the development of an algorithm based on nonconvex optimization that directly uncovers the fundamental motifs present in a real-space image. Apart from being quantitatively superior to traditional Fourier analysis, we show that this algorithm also uncovers phase sensitive information about the underlying motif structure. We demonstrate its usefulness by studying scanning tunneling microscopy images of a Co-doped iron arsenide superconductor and prove that the application of the algorithm allows for the complete recovery of quasiparticle interference in this material.

Generating Kranok patterns with an interactive evolutionary algorithm

The kranok pattern is a classical Thai pattern, often seen in the ornamentation of Thai religious artifacts such as Tripiṭaka cabinets, temple doors and coffins. All Thai trainee artists must practice drawing the kranok pattern because it is a fundamental motif in Thai traditional decorative art. Individual skilled artists and instructors have their own preferred ways of drawing the pattern, and their styles differ in ornamental details. Nevertheless, all make use of similar basic structures. Most trainees learn a range of styles by observing experienced artists. After exploring the methods of drawing used by experts and published in textbooks, we designed an algorithm for automatically generating kranok patterns. We used an interactive evolutionary algorithm (IEA) to improve the aesthetic appeal of the generated patterns in response to users’ feedback. The aim of our work was not to replace artists with machines, but to enhance human artistic expression. Specifically, the work aimed to help users without artistic skills to create kranok patterns in their own style. The algorithm facilitated the creation of a variety of personalized kranok patterns – diverse in their expressive curvature, refinement and proportions – that were satisfying to the varying preferences of a range of users. We also analyzed the proposed algorithm’s behavior in terms of its convergence to generate specific shapes. The proposed method was examined by 28 respondents (27 Thai and 1 foreign) who were selected to include representatives of both sexes as well as experts in both Thai drawing and evolutionary algorithms. The results from our questionnaires showed that all respondents were satisfied with the generated kranok patterns: one respondent was ‘completely satisfied’, seventeen ‘very satisfied’, seven ‘moderately satisfied’, and three ‘slightly satisfied’.

Topographic Mapping as a Basic Principle of Functional Organization for Visual and Prefrontal Functional Connectivity.

The organization of region-to-region functional connectivity has major implications for understanding information transfer and transformation between brain regions. We extended connective field mapping methodology to 3-D anatomic space to derive estimates of corticocortical functional organization. Using multiple publicly available human (both male and female) resting-state fMRI data samples for model testing and replication analysis, we have three main findings. First, we found that the functional connectivity between early visual regions maintained a topographic relationship along the anterior-posterior dimension, which corroborates previous research. Higher order visual regions showed a pattern of connectivity that supports convergence and biased sampling, which has implications for their receptive field properties. Second, we demonstrated that topographic organization is a fundamental aspect of functional connectivity across the entire cortex, with higher topographic connectivity between regions within a functional network than across networks. The principle gradient of topographic connectivity across the cortex resembled whole-brain gradients found in previous work. Last but not least, we showed that the organization of higher order regions such as the lateral prefrontal cortex demonstrate functional gradients of topographic connectivity and convergence. These organizational features of the lateral prefrontal cortex predict task-based activation patterns, particularly visual specialization and higher order rules. In sum, these findings suggest that topographic input is a fundamental motif of functional connectivity between cortical regions for information processing and transfer, with maintenance of topography potentially important for preserving the integrity of information from one region to another.

On Bruno Schulz’s Bookplates

The Polish version of the article was published in Roczniki Humanistyczne vol. 64, issue 1 (2016).
 The article enters into a dialogue with the interpretation of Bruno Schulz’s bookplates made by Władysław Panas in his book Bruno od Mesjasza (Bruno of the Messiah) (Lublin 2001). An attempt to understand them in a different (less holistic) way leads the author of the article to the conclusion that in Schulz’s plates the first veiled variant of the mythical Book may be seen—of the fundamental motif of Bruno Schulz’s later literary work.

Imágenes y memoria: el pasado futuro, el futuro pasado y el presente futuro en La tumba del relámpago


 En este artículo se propone analizar el motivo clásico de la memoria; desentrañaremos las ékfrasis de las imágenes contenidas en los tejidos más importantes que funcionan como testimonios de memoria; para conseguirlo, consideraremos la visión andina del tiempo y su concepción mítica: en el texto —así como en los ponchos— encontramos un fin que marca un comienzo, y un comienzo que a su vez marca un fin. Proponemos el análisis del proceso de construcción de ékfrasis por parte de la voz narrativa que utiliza algunos submotivos relacionados con el motivo central de la memoria: el conocimiento, el mundo al revés, el eterno retorno, el olvido y las dimensiones complejas del tiempo donde se conjugan el pasado, el presente y el futuro, consideraremos la propuesta del comparativismo, específicamente los elementos básicos de la imagología y la tematología. El papel que cumple la memoria como motivo fundamental en la conformación de nuestra humanidad se relaciona con la visión mítica andina que hace posible los saltos temporales y los resignifica en la trama de la novela que marca el fin de la lucha de los comuneros —la tumba del relámpago— para conseguir la recuperación de sus tierras y sus posibilidades de vida digna.

From alkylarenes to anilines via site-directed carbon-carbon amination.

Anilines are fundamental motifs in various chemical contexts, and are widely used in the industrial production of fine chemicals, polymers, agrochemicals and pharmaceuticals. A recent development for the synthesis of anilines uses the primary amination of C-H bonds in electron-rich arenes. However, there are limitations to this strategy: the amination of electron-deficient arenes remains a challenging task and the amination of electron-rich arenes has a limited control over regioselectivity-the formation of meta-aminated products is especially difficult. Here we report a site-directed C-C bond primary amination of simple and readily available alkylarenes or benzyl alcohols for the direct and efficient preparation of anilines. This chemistry involves a novel C-C bond transformation and offers a versatile protocol for the synthesis of substituted anilines. The use of O2 as an environmentally benign oxidant is demonstrated, and studies on model compounds suggest that this method may also be used for the depolymerization of lignin.

Interfacial Interaction between FeOOH and Ni–Fe LDH to Modulate the Local Electronic Structure for Enhanced OER Electrocatalysis

Toward the pursuit of high-performance Ni2+/Co2+/Fe3+-relevant oxygen evolution reaction (OER) electrocatalysts, the modulation of local electronic structure of the active metal sites provides the fundamental motif, which could be achieved either through direct modifications of local chemical environment or interfacial interaction with a second metal substrate which possesses high electronegativity (typically noble metal Au). Herein, we report that the local electronic structure of Ni–Fe layered double hydroxide (LDH) could be favorably modulated through strong interfacial interactions with FeOOH nanoparticles (NPs). The biphasic and multiscale composites FeOOH/LDH demonstrated an increasingly pronounced synergy effect for OER catalysis when the average size of FeOOH NPs decreases from 18.0 to 2.0 nm. Particularly, the composite with average size of FeOOH NPs of 2.0 nm exhibited an overpotential of 174 mV at 10 mA cm–2 and a tafel slope of 27 mV dec–1 in 1.0 M KOH, outmatching all the noble and non-noble ...

Die Entstehung des Gleichnisses vom reichen Kornbauern (Lk 12,13–21)

The Lukan parable of the Rich Fool (Lk 12,13–21) substantially bears the signature of the third gospel’s author. Luke takes fundamental motifs from Jesus’ speech about worrying, which is available to him in written form (Lk 12,22–34; cf. Mt 6,19–33). The parable’s narrative structure on the other hand stems from the Menippean branch of Cynic Philosophy, where several variations of it are documented. By combining these elements the writer compiles a new parable, also adding characteristic features of his own narrative style. Thus, the paragraph Lk 12,13–21 is clearly an example of its author’s literary creativity.

One-pot aminobenzylation of aldehydes with toluenes

Amines are fundamental motifs in bioactive natural products and pharmaceuticals. Using simple toluene derivatives, a one-pot aminobenzylation of aldehydes is introduced that provides rapid access to amines. Simply combining benzaldehydes, toluenes, NaN(SiMe3)2, and additive Cs(O2CCF3) (0.35 equiv.) generates a diverse array of 1,2-diarylethylamine derivatives (36 examples, 56–98% yield). Furthermore, suitably functionalized 1,2-diarylethylamines were transformed into 2-aryl-substituted indoline derivatives via Buchwald–Hartwig amination. It is proposed that the successful deprotonation of toluene by MN(SiMe3)2 is facilitated by cation–π interactions between the arene and the group(I) cation that acidify the benzylic C–Hs.

Water–NO Complex Formation and Chain Growth on Cu(111)

We report the novel structure of a water–NO (nitric oxide) complex on Cu(111) by using scanning tunneling microscopy, electron energy loss spectroscopy, and noncontact atomic force microscopy. The fundamental motif of the complex is a triangular cluster, including four NO molecules and three water molecules. As coverage increases, the complex grows into a chain structure on the surface. The preferential formation of such unique complexes suggests that there is attractive interaction between water and NO that is strong enough to overcome NO–NO and water–water interactions. The origin of the interaction is argued in terms of electrostatics, where water donates a polar OH group to NO which is negatively charged via electron transfer from the surface.