bluuebunny/crossref_metadata_2025_split huggingface dataset:
Darobactine mit Überlegener Antibiotischer Aktivität Generiert durch Strukturgeleitetes Kryo‐EM‐Biosynthese‐Design**
Authors: Seyfert Carsten E. , Porten Christoph , Yuan Biao , Deckarm Selina , Panter Fabian , Bader Chantal D. , Coetzee Janetta , Deschner Felix , Tehrani Kamaleddin H. M. E. , Higgins Paul G. , Seifert Harald , Marlovits Thomas C. , Herrmann Jennifer , Müller Rolf 
Published: October 2022

AbstractIn den letzten Jahrzehnten ist die Entwicklungspipeline neuer Antibiotika gegen Gram‐negative Bakterien nahezu zum Erliegen gekommen, da die meisten entdeckten Kandidaten Defizite im Bereich der Wirksamkeit, ihrer pharmakokinetischen Eigenschaften oder eine zu hohe Toxizität aufwiesen. Die Darobactine, eine vielversprechende neue Peptid‐Klasse, binden an BamA, ein zuvor von Antibiotika nicht adressiertes Zielprotein der äußeren Membran. Wir haben bereits gezeigt, dass durch Biosynthese‐Modifikationen in einem heterologen Wirt neuartige Darobactine mit erhöhter antibakterieller Aktivität erzeugt werden können. Nun verwenden wir eine optimierte Reinigungsmethode und präsentieren Kryo‐EM‐Strukturen des Bam‐Komplexes mit Darobactin 9 (D9), welche als Basis für die biotechnologische Herstellung von zwanzig neuen Darobactinen, einschließlich halogenierter Analoga, dient. Das neu entwickelte Darobactin 22 bindet enger an BamA und übertrifft das bereits hohe Aktivitätsprofil von D9 gegen klinisch relevante Krankheitserreger, wie Carbapenem‐resistente Acinetobacter baumannii, um das bis zu 32‐fache, ohne erkennbare Anzeichen von Toxizität.
β‐ and γ‐C(sp3)−H Heteroarylation of Free Carboxylic Acids: A Modular Synthetic Platform for Diverse Quaternary Carbon Centers
Authors: Meng Guangrong , Hu Liang , Tomanik Martin , Yu Jin‐Quan 
Published: October 2022

AbstractPdII‐catalyzed C(sp3)−H activation of free carboxylic acids represents a significant advance from conventional cyclopalladation initiated reactions. However, developing a modular synthetic platform for diverse quaternary and tertiary carbon centers based on this reactivity, two challenges remain to be addressed: mono‐selectivity in each consecutive C−H functionalization step; compatibility with heteroatoms. While the exclusive mono‐selectivity was achieved by β‐lactonization/nucleophilic attack, the latter limitation remains to be overcome. Herein, we report the PdII‐catalyzed β‐ and γ‐C(sp3)−H heteroarylation of free carboxylic acids using pyridine‐pyridone ligands capable of overcoming these limitations. A sequence of three consecutive C(sp3)−H activation reactions of pivalic acid provides an unique platform for constructing diverse quaternary carbon centers containing heteroaryls which could serve as an enabling tool for escaping the flat land in medicinal chemistry.
Identification of Cysteine 270 as a Novel Site for Allosteric Modulators of SARS‐CoV‐2 Papain‐Like Protease**
Authors: Hu Hangchen , Wang Qian , Su Haixia , Shao Qiang , Zhao Wenfeng , Chen Guofeng , Li Minjun , Xu Yechun 
Published: October 2022

AbstractThe coronavirus papain‐like protease (PLpro) plays an important role in the proteolytic processing of viral polyproteins and the dysregulation of the host immune response, providing a promising therapeutic target. However, the development of inhibitors against severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) PLpro is challenging owing to the restricted S1/S2 sites in the substrate binding pocket. Here we report the discovery of two activators of SARS‐CoV‐2 PLpro and the identification of the unique residue, cysteine 270 (C270), as an allosteric and covalent regulatory site for the activators. This site is also specifically modified by glutathione, resulting in protease activation. Furthermore, a compound was found to allosterically inhibit the protease activity by covalent binding to C270. Together, these results elucidate an unrevealed molecular mechanism for allosteric modulation of SARS‐CoV‐2 PLpro and provid a novel site for allosteric inhibitors design.
Selective Synthesis of Oligosaccharides by Mechanochemical Hydrolysis of Chitin over a Carbon‐Based Catalyst
Authors: Kobayashi Hirokazu , Suzuki Yusuke , Sagawa Takuya , Saito Makoto , Fukuoka Atsushi 
Published: October 2022

AbstractOligosaccharides possess fascinating functions that are applicable in a variety of fields, such as agriculture. However, the selective synthesis of oligosaccharides, especially chitin‐oligosaccharides, has remained a challenge. Chitin‐oligosaccharides activate the plant immune system, enabling crops to withstand pathogens without harmful agrichemicals. Here, we demonstrate the conversion of chitin to chitin‐oligosaccharides using a carbon catalyst with weak acid sites and mechanical milling. The catalyst produces chitin‐oligosaccharides with up to 94 % selectivity in good yields. Monte‐Carlo simulations indicate that our system preferentially hydrolyzes larger chitin molecules over oligomers, thus providing the desired high selectivity. This unique kinetics is in contrast to the fact that typical catalytic systems rapidly hydrolyze oligomers to monomers. Unlike other materials carbons more strongly adsorb large polysaccharides than small oligomers, which is suitable for the selective synthesis of small oligosaccharides.
A Nanocomposite of Bismuth Clusters and Bi2O2CO3 Sheets for Highly Efficient Electrocatalytic Reduction of CO2 to Formate
Authors: Lin Li , He Xiaoyang , Zhang Xia‐Guang , Ma Wenchao , Zhang Biao , Wei Diye , Xie Shunji , Zhang Qinghong , Yi Xiaodong , Wang Ye 
Published: October 2022

AbstractThe renewable‐electricity‐driven CO2 reduction to formic acid would contribute to establishing a carbon‐neutral society. The current catalyst suffers from limited activity and stability under high selectivity and the ambiguous nature of active sites. Herein, we report a powerful Bi2S3‐derived catalyst that demonstrates a current density of 2.0 A cm−2 with a formate Faradaic efficiency of 93 % at −0.95 V versus the reversible hydrogen electrode. The energy conversion efficiency and single‐pass yield of formate reach 80 % and 67 %, respectively, and the durability reaches 100 h at an industrial‐relevant current density. Pure formic acid with a concentration of 3.5 mol L−1 has been produced continuously. Our operando spectroscopic and theoretical studies reveal the dynamic evolution of the catalyst into a nanocomposite composed of Bi0 clusters and Bi2O2CO3 nanosheets and the pivotal role of Bi0−Bi2O2CO3 interface in CO2 activation and conversion.
Combined Bioinformatics and Combinatorial Chemistry Tools to Locate Drug‐Able Anti‐TB Phytochemicals: A Cost‐Effective Platform for Natural Product‐Based Drug Discovery
Authors: Swain Shasank S. , Hussain Tahziba 
Published: October 2022

AbstractBased on extensive experimental studies, a huge number of phytochemicals showed potential activity against tuberculosis (TB) at a lower minimum inhibitory concentration (MIC) and fewer toxicity profiles. However, these promising drugs have not been able to convert from ′lead′ to ′mainstream′ due to inadequate drug‐ability profiles. Thus, early drug‐prospective analyses are required at the primary stage to accelerate natural‐product‐based drug discovery with limited resources and time. In the present study, we have selected seventy‐three potential anti‐TB phytochemicals (MIC value ≤10 μg/mL) and assessed the drug‐ability profiles using bioinformatics and combinatorial chemistry tools, systematically. Primarily, the molecular docking study was done against two putative drug targets, catalase‐peroxidase enzyme (katG) and RNA polymerase subunit‐β (rpoB) of Mycobacterium tuberculosis (Mtb) using AutoDock 4.2 software. Further, assessed the drug‐ability score from Molsoft, toxicity profiles from ProTox, pharmacokinetics from SwisADME, hierarchical cluster analysis (HCA) by ChemMine tools and frontier molecular orbitals (FMOs) with Avogadro and structural activity relationships (SAR) analysis with ChemDraw 18.0 software. Above analyses indicated that, lower MIC exhibited anti‐TB phytochemicals, abietane, 12‐demethylmulticaulin exhibited poor docking and drug‐ability scores, while tiliacorinine, 2‐nortiliacorinine showed higher binding energy and drug‐ability profiles. Overall, tiliacorinine, 2‐nortiliacorinine, 7α‐acetoxy‐6β‐hydroxyroyleanone (AHR), (2S)‐naringenin and isovachhalcone were found as the most active and drug‐able anti‐TB candidates from 73 candidates. Phytochemicals are always a vital source of mainstream drugs, but the MIC value of a phytochemical is not sufficient for it to be promoted. An ideal drug‐ability profile is therefore essential for achieving clinical success, where advanced bioinformatics tools help to assess and analyse that profile. Additionally, several natural pharmacophores found in existing anti‐TB drugs in SAR analyses also provide crucial information for developing potential anti‐TB drug. As a conclusion, combined bioinformatics and combinatorial chemistry are the most effective strategies to locate potent‐cum‐drug‐able candidates in the current drug‐development module.
Oxygen On‐Demand: Understanding the Oxygen Reduction Reaction (ORR) Performance Enhancement of Conductive Polymer Films upon Modification with ZIF‐8 MOF
Authors: López Federico C. D. , Bertoni Andrés I. , Allegretto Juan A. , Marmisollé Waldemar A. , Azzaroni Omar , Rafti Matías , Grumelli Doris 
Published: October 2022

AbstractRecent developments surrounding the oxygen reduction reaction (ORR) focus on low‐cost alternatives to materials used in traditional electrodes, e. g. Pt. To accumulate competitive advantages, these non‐traditional electrodes often consist of multiple functional coating layers. Considering that each layer can potentially alter the reaction mechanism, thus changing its technological value, it becomes relevant to study how a particular electrode architecture impacts on the considered reaction pathway. From kinetic studies with rotating disk electrodes (RDE) it was found that, for Au electrodes coated with the conductive polymer P(ABA−ANI), either bare or modified with ZIF‐8 (MOF) microcrystals, the ORR occurs (at neutral pH) via an associative pathway, involving a two‐electron transfer process and H2O2 production. Although ZIF‐8 lacks catalytic activity towards the ORR, its passive role as an in situ O2 reservoir not only enhanced the measured current response, but also extended the region of electrochemical potential under kinetic control.
Heterogeneous catalyzed isomerization of turpentine oil by ordered mesoporous materials like M41S structures
Authors: Borges de Sousa Leonardo , Speranza Jessica T. , Condotta Rodrigo , Cella Rodrigo 
Published: October 2022

AbstractHerein, the synthesis of a structure with a porous system similar to that of molecular sieves, MCM‐41 and 48 types, with the incorporation of heteroatoms in their synthesis, is reported. The catalytic activity of these materials was tested in the isomerization reaction of turpentine oil to obtain camphene. The best results were obtained with Zn‐Al‐Si‐MCM, a mesoporous material, with a conversion of up to 96% and selectivities of 31% and 22% to camphene and 4‐carene, respectively, both of which are bicyclic products. The recycling of the catalyst was also tested, and after three cycles, no significant loss of activity was observed.
QoS aware routing protocol using robust spatial gabriel graph based clustering scheme for ad hoc network
Authors: Sugitha George , Sivakumar Thimmakkondu Babuji , Hasan Hussain Shahul Hameed 
Published: October 2022

SummaryMANET (mobile ad hoc network) comprises of a set of wireless mobile node connected in a self‐healing and self‐configured network devoid of any fixed infrastructure. The cognitive radio (CR) in the MANET system has been developed for addressing the spectrum congestion issue. However, the existing techniques failed to solves the complex convex problem of channel assignment. To address this issue, the proposed protocol is designed. In the proposed scheme, both primary user (PU) and secondary user (SU) are clustered initially based on the graph theory process. After that, in each cluster, formation of robust spatial Gabriel graph (RS‐GG) takes place at which the neighboring nodes are predicted by estimating the weighted end‐to‐end delay. Once the multi path decision‐making condition is satisfied, the route path is established, and the communication takes place based on QoS constraint. This can lead to the enhancement of PDR, network connectivity maintenance and network lifetime. The performance analysis of the proposed methods is carried out for PDR, control overheads, energy consumption, and End‐to‐End delay and the analysis is compared with existing protocols to prove the effectiveness of proposed design. The simulation outcomes illustrate that the suggested strategy performs well and improves the data transmission.
Bipolar disorders and narcissism: Diagnostic concerns, conceptual commonalities and potential antecedents
Authors: Nagel Madeline G. , Marcus David K. , Zeigler‐Hill Virgil 
Published: October 2022

AbstractNarcissistic personality disorder (NPD) and the manic and hypomanic episodes found in the bipolar disorders are characterized by grandiosity. It is possible that this shared grandiosity is a ‘homologous structure’ or reflects a superficial similarity between two disparate conditions. It is, however, possible that NPD and the bipolar disorders are more closely related than implied by their segregation into the separate superordinate categories of personality disorders and mood disorders. Whereas narcissism is considered to be a life‐course, stable trait and the bipolar disorders are characterized by episodes of mania and depression, there is considerable research indicating that narcissism may be linked to mood instability (including depression) and bipolar disorder may have a pervasive personality component (i.e., hypomanic personality). Utilizing dimensional models of psychopathology, the current review examined the evidence linking narcissism and the bipolar disorders and suggests that considerable overlap may exist in the domains associated with reward‐seeking, harm avoidance and social functioning.
Hydrogen and Halogen Bonding to Au(I) Fluorido Complexes
Authors: Rachor Simon G. , Müller Robert , Kaupp Martin , Braun Thomas 
Published: October 2022

AbstractThe hydrogen bonding in the Au(I) complex [Au(F ⋅ HF)(SPhos)] (SPhos=dicyclohexyl(2’,6’‐dimethoxy[1,1’‐biphenyl]‐2‐yl)phosphane) (1 a ⋅ HF) has been analysed by IR and NMR measurements, revealing the formation of an unsymmetrical bifluoride moiety. The data are in excellent agreement with DFT calculations. Comparisons to analogous complexes bearing NHC (NHC=N‐heterocyclic carbene) ligands demonstrated a comparable bonding situation. The identity of the halogen bond in the compound [Au(F ⋅ IC6F5)(SPhos)] (1 a ⋅ IC6F5) in CD2Cl2has been estimated, and van't Hoff data for the equilibrium between [Au(F)(SPhos)] (1 a) and IC6F5with [Au(F ⋅ IC6F5)(SPhos)] are ΔH0=−8.1(3) kJ mol−1and ΔS0=−36(1) J (mol K)−1. The latter are also in agreement with DFT calculations. For all calculations, comparisons between an explicit and implicit solvent model were drawn. Single crystal X‐ray diffraction studies were performed for [Au(F ⋅ 2IC6F5)(BrettPhos)] ⋅ 2IC6F5(BrettPhos=2‐(dicyclohexylphosphino)‐3,6‐dimethoxy‐2’,4’,6’‐triisopropyl‐1,1’‐biphenyl) (1 b ⋅ 4IC6F5) demonstrating the presence of halogen bonds to Au(I) fluorido complexes in the solid state.
Enhancing the Performance of Piezoelectric Wind Energy Harvester Using Curve‐Shaped Attachments on the Bluff Body
Authors: Poudel Prakash , Sharma Saurav , Ansari M. N. M. , Vaish Rahul , Kumar Rajeev , Ibrahim Sobhy M. , Thomas P. , Bowen Chris 
Published: October 2022

AbstractThis paper presents a piezoelectric wind energy harvester that operates by a galloping mechanism with different shaped attachments attached to a bluff body. A comparison is made between harvesters that consist of different shaped attachments on a bluff body; these include triangular, circular, square, Y‐shaped, and curve‐shaped attachments. Simulation of the pressure field and the velocity field variation around the different shaped bluff bodies is performed and it is found that a high pressure difference creates a high lift force on the bluff body with curve‐shaped attachments. A theoretical model based on a galloping mechanism is presented, which is verified by experiments. It is observed that the proposed harvester with curve‐shaped attachments provides the best performance, where the harvester with a curve‐shaped attachments provides the highest voltage and power output compared to the other shaped harvesters examined in this study. This paper provides a new concept for improving the power performance of the piezoelectric wind energy harvesters with modifications made on the bluff body.
Endocannabinoid signaling in the central nervous system
Authors: Martinez Ramirez César E. , Ruiz‐Pérez Gonzalo , Stollenwerk Todd M. , Behlke Christina , Doherty Ashley , Hillard Cecilia J. 
Published: October 2022

AbstractIt is hard to overestimate the influence of the endocannabinoid signaling (ECS) system on central nervous system (CNS) function. In the 40 years since cannabinoids were found to trigger specific cell signaling cascades, studies of the ECS system continue to cause amazement, surprise, and confusion! CB1 cannabinoid receptors are expressed widely in the CNS and regulate cell–cell communication via effects on the release of both neurotransmitters and gliotransmitters. CB2 cannabinoid receptors are difficult to detect in the CNS but seem to “punch above their weight” as compounds targeting these receptors have significant effects on inflammatory state and behavior. Positive and negative allosteric modulators for both receptors have been identified and examined in preclinical studies. Concentrations of the endocannabinoid ligands, N‐arachidonoylethanolamine and 2‐arachidonoylglycerol (2‐AG), are regulated by a combination of enzymatic synthesis and degradation and inhibitors of these processes are available and making their way into clinical trials. Importantly, ECS regulates many essential brain functions, including regulation of reward, anxiety, inflammation, motor control, and cellular development. While the field is on the cusp of preclinical discoveries providing impactful clinical and therapeutic insights into many CNS disorders, there is still much to be learned about this remarkable and versatile modulatory system.
A subset of OPCs do not express Olig2 during development which can be increased in the adult by brain injuries and complex motor learning
Authors: Fang Li‐Pao , Liu Qing , Meyer Erika , Welle Anna , Huang Wenhui , Scheller Anja , Kirchhoff Frank , Bai Xianshu 
Published: October 2022

AbstractOligodendrocyte precursor cells (OPCs) are uniformly distributed in the mammalian brain; however, their function is rather heterogeneous in respect to their origin, location, receptor/channel expression and age. The basic helix–loop–helix transcription factor Olig2 is expressed in all OPCs as a pivotal determinant of their differentiation. Here, we identified a subset (2%–26%) of OPCs lacking Olig2 in various brain regions including cortex, corpus callosum, CA1 and dentate gyrus. These Olig2 negative (Olig2neg) OPCs were enriched in the juvenile brain and decreased subsequently with age, being rarely detectable in the adult brain. However, the loss of this population was not due to apoptosis or microglia‐dependent phagocytosis. Unlike Olig2pos OPCs, these subset cells were rarely labeled for the mitotic marker Ki67. And, accordingly, BrdU was incorporated only by a three‐day long‐term labeling but not by a 2‐hour short pulse, suggesting these cells do not proliferate any more but were derived from proliferating OPCs. The Olig2neg OPCs exhibited a less complex morphology than Olig2pos ones. Olig2neg OPCs preferentially remain in a precursor stage rather than differentiating into highly branched oligodendrocytes. Changing the adjacent brain environment, for example, by acute injuries or by complex motor learning tasks, stimulated the transition of Olig2pos OPCs to Olig2neg cells in the adult. Taken together, our results demonstrate that OPCs transiently suppress Olig2 upon changes of the brain activity.
Self‐deception: Distorted metacognitive process in ambiguous contexts
Authors: Mei Dongmei , Ke Zijun , Li Zhihao , Zhang Wenjian , Gao Dingguo , Yin Lijun 
Published: October 2022

AbstractAs one of the commonly used folk psychological concepts, self‐deception has been intensively discussed yet is short of solid ground from cognitive neuroscience. Self‐deception is a biased cognitive process of information to obtain or maintain a false belief that could be both self‐enhancing or self‐diminishing. Study 1 (N = 152) captured self‐deception by adopting a modified numerical discrimination task that provided cheating opportunities, quantifying errors in predicting future performance (via item‐response theory model), and measuring the belief of how good they are at solving the task (i.e., self‐efficacy belief). By examining whether self‐efficacy belief is based upon actual ability (true belief) or prediction errors (false belief), Study 1 showed that self‐deception occurred in the effortless (easier access to answer cues) rather than effortful (harder access to answer cues) cheating opportunity conditions, suggesting high ambiguity in attributions facilitates self‐deception. Studies 2 and 3 probed the neural source of self‐deception, linking self‐deception with the metacognitive process. Both studies replicated behavioral results from Study 1. Study 2 (ERP study; N = 55) found that the amplitude of frontal slow wave significantly differed between participants with positive/self‐enhancing and negative/self‐diminishing self‐deceiving tendencies in incorrect predictions while remaining similar in correct predictions. Study 3 (functional magnetic resonance imaging study; N = 33) identified self‐deceiving associated activity in the anterior medial prefrontal cortex and showed that effortless cheating context increased cheating behaviors that further facilitated self‐deception. Our findings suggest self‐deception is a false belief associated with a distorted metacognitive mental process that requires ambiguity in attributions of behaviors.
Measuring brain beats: Cardiac‐aligned fast functional magnetic resonance imaging signals
Authors: Hermes Dora , Wu Hua , Kerr Adam B. , Wandell Brian A. 
Published: October 2022

AbstractBlood and cerebrospinal fluid (CSF) pulse and flow throughout the brain, driven by the cardiac cycle. These fluid dynamics, which are essential to healthy brain function, are characterized by several noninvasive magnetic resonance imaging (MRI) methods. Recent developments in fast MRI, specifically simultaneous multislice acquisition methods, provide a new opportunity to rapidly and broadly assess cardiac‐driven flow, including CSF spaces, surface vessels and parenchymal vessels. We use these techniques to assess blood and CSF flow dynamics in brief (3.5 min) scans on a conventional 3 T MRI scanner in five subjects. Cardiac pulses are measured with a photoplethysmography (PPG) on the index finger, along with functional MRI (fMRI) signals in the brain. We, retrospectively, align the fMRI signals to the heartbeat. Highly reliable cardiac‐gated fMRI temporal signals are observed in CSF and blood on the timescale of one heartbeat (test–retest reliability within subjects R2 > 50%). In blood vessels, a local minimum is observed following systole. In CSF spaces, the ventricles and subarachnoid spaces have a local maximum following systole instead. Slower resting‐state scans with slice timing, retrospectively, aligned to the cardiac pulse, reveal similar cardiac‐gated responses. The cardiac‐gated measurements estimate the amplitude and phase of fMRI pulsations in the CSF relative to those in the arteries, an estimate of the local intracranial impedance. Cardiac aligned fMRI signals can provide new insights about fluid dynamics or diagnostics for diseases where these dynamics are important.