bluuebunny/crossref_metadata_2025_split huggingface dataset:
NMR Spectroscopic Characterization of the C‐Mannose Conformation in a Thrombospondin Repeat Using a Selective Labeling Approach
Authors: Jonker Hendrik R. A. , Saxena Krishna , Shcherbakova Aleksandra , Tiemann Birgit , Bakker Hans , Schwalbe Harald 
Published: August 2020

AbstractDespite the great interest in glycoproteins, structural information reporting on conformation and dynamics of the sugar moieties are limited. We present a new biochemical method to express proteins with glycans that are selectively labeled with NMR‐active nuclei. We report on the incorporation of 13C‐labeled mannose in the C‐mannosylated UNC‐5 thrombospondin repeat. The conformational landscape of the C‐mannose sugar puckers attached to tryptophan residues of UNC‐5 is characterized by interconversion between the canonical 1C4 state and the B03 / 1S3 state. This flexibility may be essential for protein folding and stabilization. We foresee that this versatile tool to produce proteins with selectively labeled C‐mannose can be applied and adjusted to other systems and modifications and potentially paves a way to advance glycoprotein research by unravelling the dynamical and conformational properties of glycan structures and their interactions.
Enzyme‐Inspired Room‐Temperature Lithium–Oxygen Chemistry via Reversible Cleavage and Formation of Dioxygen Bonds
Authors: Wang Chengyi , Zhang Zihe , Liu Weiwei , Zhang Qinming , Wang Xin‐Gai , Xie Zhaojun , Zhou Zhen 
Published: August 2020

AbstractLi‐O2 batteries are promising energy storage systems due to their ultra‐high theoretical capacity. However, most Li‐O2 batteries are based on the reduction/oxidation of Li2O2 and involve highly reactive superoxide and peroxide species that would cause serious degradation of cathodes, especially carbon‐based materials. It is important to explore lithium‐oxygen reactions and find new Li‐O2 chemistry which can restrict or even avoid the negative influence of superoxide/peroxide species. Here, inspired by enzyme‐catalyzed oxygen reduction/oxidation reactions, we introduce a copper(I) complex 3 N‐CuI (3 N=1,4,7‐trimethyl‐1,4,7‐triazacyclononane) to Li‐O2 batteries and successfully modulate the reaction pathway to a moderate one on reversible cleavage/formation of O−O bonds. This work demonstrates that the reaction pathways of Li‐O2 batteries could be modulated by introducing an appropriate soluble catalyst, which is another powerful choice to construct better Li‐O2 batteries.
Congenital diaphragmatic hernia and maternal dietary nutrient pathways and diet quality
Authors: Carmichael Suzan L. , Ma Chen , Witte John S. , Yang Wei , Rasmussen Sonja A. , Brunelli Luca , Nestoridi Eirini , Shaw Gary M. , Feldkamp Marcia L. ,   National Birth Defects Prevention Study
Published: August 2020

AbstractIntroductionWe examined the association of congenital diaphragmatic hernia (CDH) with maternal dietary intake, using semi‐Bayes hierarchical models and principal components analysis to consider intake of nutrients that contribute to one‐carbon metabolism and oxidative stress pathways, and a diet quality index.MethodsWe included data on 825 cases and 11,108 nonmalformed controls born from 1997–2011 whose mother participated in the National Birth Defects Prevention Study (NBDPS), a multisite, population‐based case–control study. Exposure data were from maternal telephone interviews, which included a food frequency questionnaire. Adjusted odds ratios (aOR) and 95% confidence intervals (CI) were generated from logistic regression models that included nutritional factors as continuous variables and were adjusted for maternal energy intake, race–ethnicity, parity, and vitamin supplement intake.ResultsIn the semi‐Bayes hierarchical model that included all nutrients and confounders, riboflavin was the only nutrient for which the 95% CI excluded 1.0; the aOR for a 1 SD increase was 0.83. The aORs were 0.79 (95% CI 0.69–0.91) for the one‐carbon metabolism pathway score, 0.90 (95% CI 0.80–1.01) for oxidative stress, and 0.85 (95% CI 0.77–0.93) for diet quality (the aORs correspond to a 1 SD increase).ConclusionsThe findings from this study provide some support for the hypothesis that better prepregnancy nutrition is associated with reduced risk for CDH. These results provide etiologic clues but should be interpreted with caution given the novelty of the investigation.
Polycomb Repressive Complexes in Hox Gene Regulation: Silencing and Beyond
Authors: Gentile Claudia , Kmita Marie 
Published: August 2020

AbstractThe coordinated expression of the Hox gene family encoding transcription factors is critical for proper embryonic development and patterning. Major efforts have thus been dedicated to understanding mechanisms controlling Hox expression. In addition to the temporal and spatial sequential activation of Hox genes, proper embryonic development requires that Hox genes get differentially silenced in a cell‐type specific manner as development proceeds. Factors contributing to Hox silencing include the polycomb repressive complexes (PRCs), which control gene expression through epigenetic modifications. This review focuses on PRC‐dependent regulation of the Hox genes and is aimed at integrating the growing complexity of PRC functional properties in the context of Hox regulation. In particular, mechanisms underlying PRC binding dynamics as well as a series of studies that have revealed the impact of PRC on the 3D organization of the genome is discussed, which has a significant role on Hox regulation during development.
Recent Advances in the Construction of Flexible Sensors for Biomedical Applications
Authors: Zhou Nan , Liu Tianjiao , Wen Bianying , Gong Coucong , Wei Gang , Su Zhiqiang 
Published: August 2020

AbstractThe fabrication of flexible sensors is a potential way to promote the progress of modern social science and technology due to their wide applications in high‐performance electronic equipment and devices. Flexible sensors based on organic materials combine the unique advantages of flexibility and low cost, increasing interest in healthcare monitoring, treatment, and human–machine interfaces. Advances in materials science and biotechnology have rapidly accelerated the development of bio‐integrated multifunctional sensors and devices. Due to their excellent mechanical and electrical properties, many types of functional materials provided benefits for the construction of various sensors with improved flexibility and stretchability. In this review, recent advance in the fabrication of flexible sensors by using functional nanomaterials including nanoparticles, carbon materials, metal‐organic materials, and polymers is presented. In addition, the potential biomedical applications of the fabricated flexible sensors for detecting gas molecules signals, small molecules, DNA/RNA, proteins, others are introduced and discussed.
Superficial anorectal abscess resembling a lipoma: A case report
Authors: Kogo Hideki , Takasaki Hideaki , Sakata Yoshinori , Nakamura Yoshiharu , Yoshida Hiroshi 
Published: August 2020

AbstractPerianal abscesses exist in various forms depending on the location. Clinical examination and endorectal ultrasound (EUS) may be useful for the diagnosis of anal tumor.
Determination of Configuration and Conformation of a Reserpine Derivative with Seven Stereogenic Centers Using Molecular Dynamics with RDC‐Derived Tensorial Constraints**
Authors: Sager Emine , Tzvetkova Pavleta , Gossert Alvar D. , Piechon Philippe , Luy Burkhard 
Published: August 2020

AbstractNMR‐based determination of the configuration of complex molecules containing many stereocenters is often not possible using traditional NOE data and coupling patterns. Making use of residual dipolar couplings (RDCs), we were able to determine the relative configuration of a natural product containing seven stereocenters, including a chiral amine lacking direct RDC data. To identify the correct relative configuration out of 32 possible ones, experimental RDCs were used in three different approaches for data interpretation: by fitting experimental data based singular value decomposition (SVD) using a single alignment tensor and either (i) a single conformer or (ii) multiple conformers, or alternatively (iii) using molecular dynamics simulations with tensorial orientational constraints (MDOC). Even though in all three approaches one and the same configuration could be selected and clear discrimination between possible configurations was achieved, the experimental data was not fully satisfied by the methods based on single tensor approaches. While these two approaches are faster, only MDOC is able to fully reproduce experimental results, as the obtained conformational ensemble adequately covers the conformational space necessary to describe the molecule with inherent flexibility.
Dynamics of Hydrogen Bonding in Three‐Component Nanorotors
Authors: Biswas Pronay Kumar , Goswami Abir , Saha Suchismita , Schmittel Michael 
Published: August 2020

AbstractThe dynamics of hydrogen bonding do not only play an important role in many biochemical processes but also in Nature's multicomponent machines. Here, a three‐component nanorotor is presented where both the self‐assembly and rotational dynamics are guided by hydrogen bonding. In the rate‐limiting step of the rotational exchange, two phenolic O‐H–N,N(phenanthroline) hydrogen bonds are cleaved, a process that was followed by variable‐temperature 1H NMR spectroscopy. Activation data (ΔG≠298=46.7 kJ mol−1 at 298 K, ΔH≠=55.3 kJ mol−1, and ΔS≠=28.8 J mol−1 K−1) were determined, furnishing a rotational exchange frequency of k298=40.0 kHz. Fully reversible disassembly/assembly of the nanorotor was achieved by addition of 5.0 equivalents of trifluoroacetic acid (TFA)/1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) over three cycles.
Stabilization of Linear C3 by Two Donor Ligands: A Theoretical Study of L‐C3‐L (L=PPh3, NHCMe, cAACMe)**
Authors: Gorantla Sai Manoj N. V. T. , Pan Sudip , Mondal Kartik Chandra , Frenking Gernot 
Published: August 2020

AbstractQuantum chemical studies using density functional theory and ab initio methods have been carried out for the molecules L‐C3‐L with L=PPh3 (1), NHCMe (2, NHC=N‐heterocyclic carbene), and cAACMe (3, cAAC=cyclic (alkyl)(amino) carbene). The calculations predict that 1 and 2 have equilibrium geometries where the ligands are bonded with rather acute bonding angles at the linear C3 moiety. The phosphine adduct 1 has a synclinal (gauche) conformation whereas 2 exhibits a trans conformation of the ligands. In contrast, the compound 3 possesses a nearly linear arrangement of the carbene ligands at the C3 fragment. The bond dissociation energies of the ligands have the order 1<2<3. The bonding analysis using charge and energy decomposition methods suggests that 3 is best described as a cumulene with electron‐sharing double bonds between neutral fragments (cAACMe)2 and C3 in the respective electronic quintet state yielding (cAACMe)=C3=(cAACMe). In contrast, 1 and 2 possess electron‐sharing and dative bonds between positively charged ligands [(PPh3)2]+ or [(NHCMe)2]+ and negatively charged [C3]− fragments in the respective doublet state.
Mimicking Photosystem I with a Transmembrane Light Harvester and Energy Transfer‐Induced Photoreduction in Phospholipid Bilayers
Authors: Pannwitz Andrea , Saaring Holden , Beztsinna Nataliia , Li Xinmeng , Siegler Maxime A. , Bonnet Sylvestre 
Published: August 2020

AbstractPhotosystem I (PS I) is a transmembrane protein that assembles perpendicular to the membrane, and performs light harvesting, energy transfer, and electron transfer to a final, water‐soluble electron acceptor. We present here a supramolecular model of it formed by a bicationic oligofluorene 12+ bound to the bisanionic photoredox catalyst eosin Y (EY2−) in phospholipid bilayers. According to confocal microscopy, molecular modeling, and time dependent density functional theory calculations, 12+ prefers to align perpendicularly to the lipid bilayer. In presence of EY2−, a strong complex is formed (Ka=2.1±0.1×106 m−1), which upon excitation of 12+ leads to efficient energy transfer to EY2−. Follow‐up electron transfer from the excited state of EY2− to the water‐soluble electron donor EDTA was shown via UV–Vis absorption spectroscopy. Overall, controlled self‐assembly and photochemistry within the membrane provides an unprecedented yet simple synthetic functional mimic of PS I.
The Critical Role of Passive Permeability in Designing Successful Drugs
Authors: Di Li , Artursson Per , Avdeef Alex , Benet Leslie Z. , Houston J. Brian , Kansy Manfred , Kerns Edward H. , Lennernäs Hans , Smith Dennis A. , Sugano Kiyohiko 
Published: August 2020

AbstractPassive permeability is a key property in drug disposition and delivery. It is critical for gastrointestinal absorption, brain penetration, renal reabsorption, defining clearance mechanisms and drug‐drug interactions. Passive diffusion rate is translatable across tissues and animal species, while the extent of absorption is dependent on drug properties, as well as in vivo physiology/pathophysiology. Design principles have been developed to guide medicinal chemistry to enhance absorption, which combine the balance of aqueous solubility, permeability and the sometimes unfavorable compound characteristic demanded by the target. Permeability assays have been implemented that enable rapid development of structure‐permeability relationships for absorption improvement. Future advances in assay development to reduce nonspecific binding and improve mass balance will enable more accurately measurement of passive permeability. Design principles that integrate potency, selectivity, passive permeability and other ADMET properties facilitate rapid advancement of successful drug candidates to patients.
Crystal Structures and Phosphorescent Properties of Group 14 Dipyridinometalloles and Their Copper Complexes
Authors: Ohshita Joji , Yamaji Kosuke , Adachi Yohei 
Published: August 2020

AbstractWe recently reported dipyridinosilole (DPyS) and dipyridinogermole (DPyG) as π‐conjugated units that show low‐temperature phosphorescence. A copper complex of DPyG shows solid‐state phosphorescence at room temperature. In this work, we prepared diphenyldipyridinostannole (DPySn1). Its optical and electrochemical properties were investigated and compared with those of DPyS1 and DPyG1 with the same phenyl substituents. DPySn1 showed the most red‐shifted phosphorescence at 520 nm at 77 K in the solid‐state, which is likely due to the intermolecular Sn‐pyridine interaction that was confirmed by single‐crystal X‐ray diffraction. Copper complexes of DPyS1 and DPySn1 were also prepared and it was found that the phosphorescence of these dipyridinometallole‐copper complex solids was red‐shifted in the order of DPySn1−Cu (617 nm)<DPyG1−Cu (624 nm)<DPyS1−Cu (645 nm). Single‐crystal X‐ray diffraction studies were performed for DPyS1−Cu and DPySn1−Cu complexes. DPyS1−Cu showed a double‐chained polymeric ladder‐like structure with Cu4I4 cluster units and DPySn1−Cu possessed a single chain polymeric structure with Cu2I2 units, analogous to DPyG1−Cu.
Cytotoxicity of dental disclosing solution on gingival epithelial cells in vitro
Authors: Jung Im‐hee , Yeon Kyeong Ho , Song Hwi Rin , Hwang Young Sun 
Published: August 2020

AbstractObjectiveColoring dental biofilm and plaque with a dental disclosing solution is visually effective in dental treatment and oral hygiene education. Despite continuous reports of the risk of the product ingredients, dental disclosing solution are widely used in dentistry. However, the cytotoxic mechanism of dental disclosing solution is not known. Here we elucidated the tissue dyeing range and investigated the cytotoxic mechanism of dental disclosing solution.Materials and methodsGingival epithelial cells and mouse head and neck tissue were stained with dental disclosing solution. Changes in the cell cycle distribution by the dental disclosing solution treatment were analyzed. A deoxynucleotidyl transferase dUTP nick and labeling (TUNEL) assay was performed to examine the apoptotic features of the gingival epithelial cells.ResultsDental disclosing solution stained the chromosome strongly, as well as both the hard and soft tissue of the mouse head and neck. The results of flow cytometric analysis and TUNEL analyses revealed that the cytotoxicity associated with dental disclosing solution was related to the induction of apoptosis. However, the staining of porcine skin by dental disclosing solution was not easily removed, even with a wide range of pH solutions.ConclusionsThese results suggest that dental disclosing solution had strong cytotoxicity and safer alternatives are needed.
Robust Solid‐Electrolyte Interphase Enables Near‐Theoretical Capacity of Graphite Battery Anode at 0.2 C in Propylene Carbonate‐Based Electrolyte
Authors: Han Jisoo , Chung Gyeong Jun , Song Seung‐Wan 
Published: August 2020

AbstractThe formation of a robust solid‐electrolyte interphase (SEI) layer at the surface of a graphite anode by electrolyte control is a key technology for high‐performance lithium‐ion batteries. Although propylene carbonate (PC) offers a lower melting point than ethylene carbonate, its combination with the graphite anode without additive is a worse choice, owing to co‐intercalation of PC and Li+ ion into graphite, exfoliation of graphene sheets, and death of the battery. This study reports a graphite anode with an unprecedentedly high initial coulombic efficiency of 94 %, close to theoretical capacity, and excellent capacity retention of 99 % after 100 cycles in a PC‐based electrolyte system, even at an unusually high rate of 0.2 C, which is generally attainable only at a very low rate of below 0.05 C in commercial electrolyte. The SEI stabilization for a graphite anode in PC‐based electrolyte provides a new avenue for high‐energy and high‐performance batteries in widened range of working temperatures. A strong correlation between anode‐electrolyte interfacial stabilization and highly reversible cycling performance is clearly demonstrated.
Comparative node selection‐based localization technique for wireless sensor networks: A bilateration approach
Authors: Tabassum Nikhath , Devanagavi Geetha D. , Biradar Rajashekhar C. , Lazarescu Mihai T. 
Published: August 2020

SummaryWireless sensor networks find extensive applications, such as environmental and smart city monitoring, structural health, and target location. To be useful, most sensor data must be localized. We propose a node localization technique based on bilateration comparison (BACL) for dense networks, which considers two reference nodes to determine the unknown position of a third node. The mirror positions resulted from bilateration are resolved by comparing their coordinates with the coordinates of the reference nodes. Additionally, we use network clustering to further refine the location of the nodes. We show that BACL has several advantages over Energy Aware Co‐operative Localization (EACL) and Underwater Recursive Position Estimation (URPE): (1) BACL uses bilateration (needs only two reference nodes) instead of trilateration (that needs three reference nodes), (2) BACL needs reference (anchor) nodes only on the field periphery, and (3) BACL needs substantially less communication and computation. Through simulation, we show that BACL localization accuracy, as root mean square error, improves by 53% that of URPE and by 40% that of EACL. We also explore the BACL localization error when the anchor nodes are placed on one or multiple sides of a rectangular field, as a trade‐off between localization accuracy and network deployment effort. Best accuracy is achieved using anchors on all field sides, but we show that localization refinement using node clustering and anchor nodes only on one side of the field has comparable localization accuracy with anchor nodes on two sides but without clustering.
Pioneer use of gene expression programming for predicting seasonal streamflow in Australia using large scale climate drivers
Authors: Esha Rijwana , Imteaz Monzur Alam 
Published: August 2020

AbstractThis paper presents development of an artificial intelligence (AI)‐based model, genetic expression programming (GEP) to predict long‐term streamflow using large‐scale climate drivers as predictors. GEP is chosen over artificial neural networks (ANNs) model, as ANN is a black‐box model, whereas GEP is able to explain the developed forecast models with mathematical expressions. As a case study, 12 streamflow measuring stations were selected from four different regions of New South Wales (NSW) in eastern Australia. A number of climate indices, Pacific Decadal Oscillation (PDO), Indian Ocean Dipole (IOD), El Nino Southern Oscillation (ENSO) and ENSO Modoki index (EMI), were selected as candidate predictors based on the findings of some preliminary studies. Higher predictabilities of the GEP‐based models are evident from the Pearson correlation (r) values ranging between 0.57 and 0.97, which are mostly about twice the values achieved by multiple linear regression (MLR) models in the preliminary study. Performances of the developed models were assessed using standard statistical measures such as root relative squared error (RRSE), relative absolute error (RAE), root mean square error (RMSE), mean absolute error (MAE), Nash–Sutcliffe efficiency (NSE) and Pearson correlation (r) values. The developed models are able to predict spring streamflow up to 5 months in advance with significantly high correlation values.
Mobile containers in human cognitive evolution studies: Understudied and underrepresented
Authors: Langley Michelle C. , Suddendorf Thomas 
Published: August 2020

AbstractMobile carrying devices—slings, bags, boxes, containers, etc.—are a ubiquitous tool form among recent human communities. So ingrained are they to our present lifeways that the fundamental relationship between mobile containers and foresight is easily overlooked, resulting in their significance in the study of human cognitive development being largely unrecognized. Exactly when this game‐changing innovation appeared and became an essential component of the human toolkit is currently unknown. Taphonomic processes are obviously a significant factor in this situation; however, we argue that these devices have also not received the attention that they deserve from human evolution researchers. Here we discuss what the current archeological evidence is for Pleistocene‐aged mobile containers and outline the various lines of evidence that they provide for the origins and development of human cognitive and cultural behavior.
A novel seed dispersal mode ofApostasia nipponicacould provide some clues to the early evolution of the seed dispersal system in Orchidaceae
Authors: Suetsugu Kenji 
Published: August 2020

AbstractDespite being one of the most diverse families, scant attention has been paid to the seed dispersal system in Orchidaceae, owing to the widely accepted notion that wind dispersal is the dominant strategy. However, the indehiscent fruits, with seeds immersed in fleshy tissue, evoke the possibility of endozoochory in Apostasioideae, the earliest diverging lineage of orchids. In the present study, I investigated the seed dispersal system of Apostasia nipponica by direct observation, time-lapse photography, and investigation of the viability of seeds passing through the digestive tract of orthopterans. This study revealed a previously undocumented seed dispersal system in A. nipponica, in which the cricket, Eulandrevus ivani, and the camel cricket, Diestrammena yakumontana, consume the fruit and defecate viable seeds. Orthopterans are rarely considered seed dispersers, but the gross fruit morphology and pigmentation patterns of some Apostasia species parallel those seen in A. nipponica, suggesting that similar seed dispersal systems could be widespread among Apostasia species. Whether seed dispersal by orthopteran frugivores is common in Apostasioideae warrants further investigation.