bluuebunny/crossref_metadata_2025_split huggingface dataset:
Visible‐Light Catalyzed [1+2+2] Cycloaddition Reactions Enabled by the Formation of Methylene Nitrones
Authors: Guo Jing , Xie Ying , Zeng Wen‐Tian , Wu Qiao‐Lei , Weng Jiang , Lu Gui 
Published: September 2020

AbstractNitrones are key intermediates in organic synthesis. Herein, we report the first photo‐redox synthesis of methylene nitrone intermediates from nitroarenes and arylamines. The highly reactive methylene nitrones are in situ trapped by alkenes to afford various isoxazolidines. This three‐component reaction features the use of N,N‐dimethylanilines or N‐aryl glycines as C1 building blocks, which allow for the one‐pot formal [1+2+2] cycloaddition from simple starting materials. A wide range of useful isoxazolidines can be obtained under mild conditions with moderate to good yields. Mechanistic investigations support the formation of methylene nitrone via selective N−CH3 bond cleavage and methylene transfer.magnified image
Solvent‐Controlled Hydrogenation of 2’‐Hydroxychalcones: A Simple Solution to the Total Synthesis of Bussealins
Authors: Soto Martín , Soengas Raquel G. , Rodríguez‐Solla Humberto 
Published: September 2020

AbstractA solvent‐controlled hydrogenation of 2’‐hydroxychalcones to selectively obtain different hydrogenation products is herein reported. Thus, hydrogenation of 2’‐hydroxychalcones using EtOH as solvent provided the corresponding 1,3‐diarylpropanes in excellent yields. On the contrary, when the hydrogenation was performed in DCM, the corresponding dihydrochalcones were isolated. Switching the reaction solvent to n‐BuOH/H2O (1:1), afforded 1,3‐diarylpropanols from moderate to good yields. The methodology here reported offers a straightforward, simple and cost‐effective method for the preparation of a wide variety of 2’‐hydroxy‐1,3‐diarylpropanes derivatives, and was also applied to the preparation of natural Bussealins C and D.magnified image
A Convenient FeCl3‐Mediated Synthesis of 5‐Trifluoromethyl‐1,2,4‐triazoles from Trifluoroacetimidoyl Chlorides and Hydrazides
Authors: Du Shiying , Wang Le‐Cheng , Yang Zuguang , Chen Zhengkai , Wu Xiao‐Feng 
Published: September 2020

AbstractA low cost FeCl3‐mediated cascade annulation of trifluoroacetimidoyl chlorides and hydrazides for the efficient synthesis of 5‐trifluoromethyl‐1,2,4‐triazoles has been developed. The transformation proceeds through a cascade base‐promoted intermolecular C−N bond formation and FeCl3‐mediated intramolecular dehydration sequence under mild conditions. The protocol exhibits many notable features and can be readily scaled up to gram scale.magnified image
Comparison of 5‐year postoperative outcomes after Billroth I and Roux‐en‐Y reconstruction following distal gastrectomy for gastric cancer: Results from a multi‐institutional randomized controlled trial
Authors: Kimura Yutaka , Mikami Jota , Yamasaki Makoto , Hirao Motohiro , Imamura Hiroshi , Fujita Junya , Takeno Atsushi , Matsuyama Jin , Kishi Kentaro , Hirao Takafumi , Fukunaga Hiroki , Demura Koichi , Kurokawa Yukinori , Takiguchi Shuji , Eguchi Hidetoshi , Doki Yuichiro 
Published: September 2020

AbstractAimWe previously reported in a randomized controlled trial that Billroth I and Roux‐en‐Y reconstructions were generally equivalent regarding body weight change and nutritional status 1 year after distal gastrectomy for gastric cancer. We describe the long‐term follow‐up data 5 years after distal gastrectomy.MethodsWe analyzed consecutive gastric cancer patients who were randomly assigned to undergo Billroth I or Roux‐en‐Y reconstruction after distal gastrectomy. We evaluated body weight change, nutritional status, late complications, quality of life (QOL) using the European Organization for Research and Treatment of Cancer Core QOL Questionnaire, and dysfunction using the Dysfunction After Upper Gastrointestinal Surgery for Cancer, 5 years after surgery.ResultsA total of 228 patients (Billroth I = 105; Roux‐en‐Y = 123) were eligible for efficacy analyses in this study. Body weight loss 5 years after surgery did not differ significantly between the Billroth I and Roux‐en‐Y groups (10.0% ± 7.9% and 9.6% ± 8.4%, respectively; P = .70). There were no significant differences in other aspects of nutritional status between the two groups. Reflux esophagitis occurred in 19.0% of the patients in the Billroth I group vs 4.9% in the Roux‐en‐Y group (P = .002). Regarding QOL, Billroth I was significantly inferior to Roux‐en‐Y on the diarrhea scale (Billroth I: 28.6, Roux‐en‐Y: 16.0; P = .047). Regarding dysfunction, no score differed significantly between the two groups.ConclusionsBillroth I and Roux‐en‐Y reconstructions were generally equivalent regarding body weight change, nutritional status, and QOL 5 years after distal gastrectomy, although Roux‐en‐Y more effectively prevented reflux esophagitis and diarrhea.
The prognostic value of additional copies of 1q21 in multiple myeloma depends on the primary genetic event
Authors: Locher Maurus , Steurer Michael , Jukic Emina , Keller Markus A. , Fresser Friedrich , Ruepp Carmen , Wöll Ewald , Verdorfer Irmgard , Gastl Günther , Willenbacher Wolfgang , Weger Roman , Nachbaur David , Wolf Dominik , Gunsilius Eberhard , Zschocke Johannes , Steiner Normann 
Published: September 2020

AbstractHyperdiploidy (HRD) and specific immunoglobulin heavy locus (IGH) translocations are primary chromosomal abnormalities (CA) in multiple myeloma (MM). In this retrospective study of 794 MM patients we aimed to investigate clinical features and common CA including gain(1q) in separate subgroups defined by primary CA. In the entire group, we confirmed that gain(1q) was associated with short time to next treatment and adverse overall survival (OS). The impact was worse for four or more copies of 1q21 as compared to three copies. However, in a subgroup of patients with clonal gain(11q) and without known primary IGH translocations (CG11q), already three copies of 1q21 were associated with a poor outcome; in the absence of gain(1q), patients in this subgroup had a remarkably long median OS of more than nine years. These cases were associated with HRD, coexpression of CD56 and CD117, male gender, and IgG subtype. In non‐CG11q patients, four or more copies of 1q21 (but not three copies) had a significant adverse impact on outcome. Several associations with CA and clinical findings were observed for the defined subgroups. As an example, we found a predominance of early tetraploidy, plasma cell leukemia, and female gender in the t(14;16) subgroup. Our results underscore the importance of subgrouping in MM.
Super‐Enhancement Focusing of Teflon Spheres
Authors: Yue Liyang , Wang Zengbo , Yan Bing , Monks James N. , Joya Yasir , Dhama Rakesh , Minin Oleg V. , Minin Igor V. 
Published: September 2020

AbstractA Teflon (polytetrafluoroethylene) sphere can be used as a focusing lens in the applications of imaging and sensing due to its low‐loss property in the terahertz band. Herein, field intensities and focusing parameters are analytically calculated for Teflon spheres at different low‐loss levels and then a super‐enhancement focusing effect in the spheres with particular size parameters was discovered, which can stimulate about 4000 times stronger field intensity than that for incident radiation as well as the great potential of overcoming diffraction limit despite high sensitivity to the magnitude of Teflon loss. A subsequent analysis of scattering amplitudes proves that the strong scattering of a single‐order mode in the internal electric or magnetic field is the main factor causing this phenomenon.
Structural Basis for α‐Helix Mimicry and Inhibition of Protein–Protein Interactions with Oligourea Foldamers
Authors: Cussol Léonie , Mauran‐Ambrosino Laura , Buratto Jérémie , Belorusova Anna Y , Neuville Maxime , Osz Judit , Fribourg Sébastien , Fremaux Juliette , Dolain Christel , Goudreau Sébastien R. , Rochel Natacha , Guichard Gilles 
Published: September 2020

AbstractEfficient optimization of a peptide lead into a drug candidate frequently needs further transformation to augment properties such as bioavailability. Among the different options, foldamers, which are sequence‐based oligomers with precise folded conformation, have emerged as a promising technology. We introduce oligourea foldamers to reduce the peptide character of inhibitors of protein–protein interactions (PPI). However, the precise design of such mimics is currently limited by the lack of structural information on how these foldamers adapt to protein surfaces. We report a collection of X‐ray structures of peptide–oligourea hybrids in complex with ubiquitin ligase MDM2 and vitamin D receptor and show how such hybrid oligomers can be designed to bind with high affinity to protein targets. This work should enable the generation of more effective foldamer‐based disruptors of PPIs in the context of peptide lead optimization.
A Synthetic Method for Site‐Specific Functionalized Polypeptides: Metal‐Free, Highly Active, and Selective at Room Temperature
Authors: Zhao Wei , Lv Yanfeng , Li Ji , Feng Zihao , Ni Yonghao , Hadjichristidis Nikos 
Published: September 2020

AbstractFunctionalized polypeptides have attracted tremendous interest in recent years and found many stimulating applications owing to their tunable physicochemical characteristics including hydrophilicity and stimuli‐responsive behavior. The development of new strategies to produce these polymers without metallic contaminants is crucial for their applications in high‐value and sensitive domains, such as biomedical, microelectronic, food‐packaging, and personal beauty care fields. Herein, a highly efficient strategy to access well‐defined site‐specific functionalized polypeptides is developed by combining Michael reaction with hydrogen‐bonding organocatalytic ROP of NCA. A library of chain‐end and chain‐middle functionalized polypeptides (14 examples) with predesigned molecular weights and low polydispersities are readily prepared with this approach. Specifically, the whole synthetic process is metal‐free, fulfilling high activity and selectivity at room temperature.
Amine–Boranes as Transfer Hydrogenation and Hydrogenation Reagents: A Mechanistic Perspective
Authors: Lau Samantha , Gasperini Danila , Webster Ruth L. 
Published: September 2020

AbstractTransfer hydrogenation (TH) has historically been dominated by Meerwein–Ponndorf–Verley (MPV) reactions. However, with growing interest in amine–boranes, not least ammonia–borane (H3N⋅BH3), as potential hydrogen storage materials, these compounds have also started to emerge as an alternative reagent in TH reactions. In this Review we discuss TH chemistry using H3N⋅BH3 and their analogues (amine–boranes and metal amidoboranes) as sacrificial hydrogen donors. Three distinct pathways were considered: 1) classical TH, 2) nonclassical TH, and 3) hydrogenation. Simple experimental mechanistic probes can be employed to distinguish which pathway is operating and computational analysis can corroborate or discount mechanisms. We find that the pathway in operation can be perturbed by changing the temperature, solvent, amine–borane, or even the substrate used in the system, and subsequently assignment of the mechanism can become nontrivial.
Clathrate XI K58Zn122Sb207: A New Branch on the Clathrate Family Tree
Authors: Cox Tori , Gvozdetskyi Volodymyr , Bertolami Mark , Lee Shannon , Shipley Kristian , Lebedev Oleg I. , Zaikina Julia V. 
Published: September 2020

AbstractThe compositional screening of K‐Zn‐Sb ternary system aided by machine learning, rapid exploratory synthesis using KH salt‐like precursor and in situ powder X‐ray diffraction yielded a novel clathrate type XI K58Zn122Sb207. This clathrate consists of a 3D Zn‐Sb framework hosting K+ ions inside polyhedral cages, some of which are reminiscent of known clathrate types while others are unique to this structure type. The complex non‐centrosymmetric structure in the tetragonal space group
was solved by means of single crystal X‐ray diffraction as a 6‐component twin due to pseudocubic symmetry and further confirmed by high‐resolution synchrotron powder X‐ray diffraction and state‐of‐the‐art scanning transmission electron microscopy. The electron‐precise composition of this clathrate yields narrow‐gap p‐type semiconductor with extraordinarily low thermal conductivity due to displacement or “rattling” of K cations inside oversized cages and as well as to twinning, stacking faults and antiphase boundary defects.
Isolierbare Silicium‐basierte Polykationen mit Lewis‐Superacidität
Authors: Hermannsdorfer André , Driess Matthias 
Published: September 2020

AbstractMolekulare Silicium‐Polykationen des Typs R2Si2+ und RSi3+ (R=H, organische Gruppe) sind Lewis‐Supersäuren und bisher in kondensierter Phase unbekannt. Wir berichten über die Synthese einer Reihe isolierbarer Terpyridinkomplexe von R2Si2+ und RSi3+, [R2Si(terpy)]2+ (R=Ph 12+; R2=C12H8 22+, (CH2)3 32+) und [RSi(terpy)]3+ (R=Ph 43+, C6H11 53+, m‐Xylyl 63+) in Form ihrer Triflat‐Salze. Die Stabilisierung dieser Spezies wird durch höhere Koordination erreicht, was aber niedrigere Fluoridionenaffinitäten (FIA) zur Folge hat. Trotzdem bleibt ein signifikantes Maß an Lewis‐Superacidität erhalten, wie durch Berechnungen und Experimente bestätigt wird. Die Komplexe aktivieren C(sp3)‐F‐Bindungen, was anhand der Fluoridabstraktion von 1‐Fluoradamantan (AdF) und der katalytischen Hydrodefluorierung von AdF demonstriert wird. Weiterhin veranschaulicht die Bildung der kristallinen Addukte [2(F)]+ und [5(H)]2+ die hohe Reaktivität gegenüber Fluorid‐ und Hydriddonoren.
Super‐Resolution Spatial Proximity Detection with Proximity‐PAINT
Authors: Schueder Florian , Lara‐Gutiérrez Juanita , Haas Daniel , Beckwith Kai Sandvold , Yin Peng , Ellenberg Jan , Jungmann Ralf 
Published: September 2020

AbstractVisualizing the functional interactions of biomolecules such as proteins and nucleic acids is key to understanding cellular life on the molecular scale. Spatial proximity is often used as a proxy for the direct interaction of biomolecules. However, current techniques to visualize spatial proximity are either limited by spatial resolution, dynamic range, or lack of single‐molecule sensitivity. Here, we introduce Proximity‐PAINT (pPAINT), a variation of the super‐resolution microscopy technique DNA‐PAINT. pPAINT uses a split‐docking‐site configuration to detect spatial proximity with high sensitivity, low false‐positive rates, and tunable detection distances. We benchmark and optimize pPAINT using designer DNA nanostructures and demonstrate its cellular applicability by visualizing the spatial proximity of alpha‐ and beta‐tubulin in microtubules using super‐resolution detection.
Liquid‐Free All‐Solid‐State Zinc Batteries and Encapsulation‐Free Flexible Batteries Enabled by In Situ Constructed Polymer Electrolyte
Authors: Ma Longtao , Chen Shengmei , Li Xinliang , Chen Ao , Dong Binbin , Zhi Chunyi 
Published: September 2020

AbstractZn batteries are usually considered as safe aqueous systems that are promising for flexible batteries. On the other hand, any liquids, including water, being encapsulated in a deformable battery may result in problems. Developing completely liquid‐free all‐solid‐state Zn batteries needs high‐quality solid‐state electrolytes (SSEs). Herein, we demonstrate in situ polymerized amorphous solid poly(1,3‐dioxolane) electrolytes, which show high Zn ion conductivity of 19.6 mS cm−1 at room temperature, low interfacial impedance, highly reversible Zn plating/stripping over 1800 h cycles, uniform and dendrite‐free Zn deposition, and non‐dry properties. The in‐plane interdigital‐structure device with the electrolyte completely exposed to the open atmosphere can be operated stably for over 30 days almost without weight loss or electrochemical performance decay. Furthermore, the sandwich‐structure device can normally operate over 40 min under exposure to fire. Meanwhile, the interfacial impedance and the capacity using in situ‐formed solid polymer electrolytes (SPEs) remain almost unchanged after various bending tests, a key criterion for flexible/wearable devices. Our study demonstrates an approach for SSEs that fulfill the requirement of no liquid and mechanical robustness for practical solid‐state Zn batteries.
Genetic diversity, population structure, and historical demography of a highly vagile and human‐impacted seabird in the Pacific Ocean: The red‐tailed tropicbird, Phaethon rubricauda
Authors: Varela Andrea I. , Brokordt Katherina , Ismar‐Rebitz Stefanie M.H. , Gaskin Chris P. , Carlile Nicholas , O'Dwyer Terence , Adams Josh , VanderWerf Eric A. , Luna‐Jorquera Guillermo 
Published: September 2020

Abstract

Many seabird breeding colonies have recovered from heavy anthropogenic disturbance after conservation actions. The widely distributed red‐tailed tropicbird, Phaethon rubricauda, was used as a model species to assess potential anthropogenic impacts on the genetic diversity of breeding colonies in the Pacific Ocean.
Cytochrome c oxidase subunit I and control region sequences analyses were conducted across the range of the species in the Pacific Ocean. The study sites were at islands without human‐related disturbance (non‐impacted islands) and with human‐related disturbance (impacted islands). We hypothesized that (i) breeding colonies of the red‐tailed tropicbird on impacted islands have lower genetic diversity compared with colonies on non‐impacted islands, and (ii) breeding colonies of the red‐tailed tropicbird show significant fine and broad‐scale genetic structure across the Pacific Ocean. Bayesian skyline analyses were conducted to infer past changes in population sizes.
Genetic diversity was similar between impacted and non‐impacted islands. There was significant broad‐scale genetic structure among colonies separated by over 6,000 km, but a lack of significant fine‐scale genetic structure within Australasia and Hawai'i, although a significant level of differentiation was found within Chile with ΦST analyses. Skyline analyses showed that effective population sizes remained relatively constant through time, but experienced either a slight decrease or the end of an expansion event through the last 1,000 years. These changes may be related to the arrival of humans on Pacific islands.
Impacted islands may have received immigrants from other relatively close islands, buffering the loss of genetic diversity. However, it is also possible that colonies have retained ancestral variation or that a large effective population size coupled with a long generation time (13 years) has prevented the loss of genetic diversity in human‐impacted islands. Future research using higher‐resolution markers is needed to resolve the population genetic structure of the red‐tailed tropicbird in an ecological time‐scale.
Experimentelle Untersuchungen zur Verstärkung von Brückenfahrbahnplatten mit Textilbeton
Authors: Adam Viviane , Bielak Jan , Will Norbert , Hegger Josef 
Published: September 2020

AbstractEtwa die Hälfte der Straßenbrücken in Deutschland wurde vor 1985 gebaut. Als Folge des gestiegenen Verkehrsaufkommens und strengerer normativer Anforderungen kann der Tragfähigkeitsnachweis durch eine Brückennachrechnung häufig nicht erbracht werden. Durch eine gezielte Tragwerksverstärkung lässt sich die Restnutzungsdauer verlängern, was eine erweiterte Planungsphase und Entzerrung der Baumaßnahmen von Ersatzneubauten ermöglicht. Am Institut für Massivbau (IMB) der RWTH Aachen wurden Versuche zur Ermittlung des Biege‐ und Querkraftverstärkungspotenzials einer Querschnittsergänzung der Brückenfahrbahnplatte mit Carbonbeton durchgeführt. Im vorliegenden Beitrag werden 17 Bauteilversuche an Fahrbahnplattenstreifen vorgestellt (verstärkte Versuchskörper und unverstärkte Referenzen). Dabei erfolgte ein Großteil der Versuche mit statischer Belastung, zwei Tastversuche wurden zyklisch beansprucht.
Copulation Song inDrosophila: Do Females Sing to Change Male Ejaculate Allocation and Incite Postcopulatory Mate Choice?
Authors: Kerwin Peter , von Philipsborn Anne C. 
Published: September 2020

AbstractDrosophilamales sing a courtship song to achieve copulations with females. Females were recently found to sing a distinct song during copulation, which depends on male seminal fluid transfer and delays female remating. Here, it is hypothesized that female copulation song is a signal directed at the copulating male and changes ejaculate allocation. This may alter female remating and sperm usage, and thereby affect postcopulatory mate choice. Mechanisms of how female copulation song is elicited, how males respond to copulation song, and how remating is modulated, are considered. The potential adaptive value of female signaling during copulation is discussed with reference to vertebrate copulation calls and their proposed function in eliciting mate guarding. Female copulation song may be widespread within theDrosophilagenus. This newly discovered behavior opens many interesting avenues for future research, including investigation of how sexually dimorphic neuronal circuits mediate communication between nervous system and reproductive organs.
Dynamics of microbial competition, commensalism, and cooperation and its implications for coculture and microbiome engineering
Authors: Xu Peng 
Published: September 2020

AbstractMicrobial consortium is a complex adaptive system with higher‐order dynamic characteristics that are not present by individual members. To accurately predict the social interactions, we formulate a set of unstructured kinetic models to quantitatively capture the dynamic interactions of multiple microbial species. By introducing an interaction coefficient, we analytically derived the steady‐state solutions for the interacting species and the substrate‐depleting profile in the chemostat. We analyzed the stability of the possible coexisting states defined by competition, parasitism, amensalism, commensalism, and cooperation. Our model predicts that only parasitism, commensalism, and cooperation could lead to stable coexisting states. We also determined the optimal social interaction criteria of microbial coculture when sequential metabolic reactions are compartmentalized into two distinct species. Coupled with Luedeking–Piret and Michaelis–Menten equations, accumulation of metabolic intermediates in one species and formation of end‐product in another species could be derived and assessed. We discovered that parasitism consortia disfavor the bioconversion of intermediate to final product; and commensalism consortia could efficiently convert metabolic intermediates to final product and maintain metabolic homeostasis with a broad range of operational conditions (i.e., dilution rates); whereas cooperative consortia leads to highly nonlinear pattern of precursor accumulation and end‐product formation. The underlying dynamics and emergent properties of microbial consortia may provide critical knowledge for us to understand ecological coexisting states, engineer efficient bioconversion process, deliver effective gut therapeutics as well as elucidate probiotic‐pathogen or tumor‐host interactions in general.