bluuebunny/crossref_metadata_2025_split huggingface dataset:
Singlet Biradical Versus Triplet Biradical/Zwitterion Characteristics in Isomers of C6−C5−C6−C7−C6‐Fused Pentacyclic Aromatic Hydrocarbons Revealed through Reactivity Patterns
Authors: Zhen Cian‐Jhe , Lu Shu‐Feng , Lin Min‐Hwa , Wu Jay‐Tai , Chao Ito , Lin Chih‐Hsiu 
Published: October 2021

AbstractAmong various polycyclic aromatic hydrocarbons, C6−C5−C6−C7−C6 fused pentacyclic aromatic hydrocarbons have the unique potential to adopt quinonoid, zwitterion, singlet, or triplet biradical electronic configurations. Two such hybrid structures between pentacene and azulene were synthesized and their ground state electronic configurations were deduced from the reactivity patterns they exhibit respectively. Compound 6, where the radicaloid carbons are linked through a para‐phenylene, forms a head‐to‐head dimer like a singlet biradical. In contrast, isomer 7, where the para‐linkage was switched to meta, reacts readily with oxygen which resembles the reactivity of a triplet state. The oxidized intermediate(s) then undergoes rearrangement to furnish the C6−C5−C6−C6−C6 ring contraction product 13. Cation 14, the protonated form of 7, was synthesized, which implies 7 also reacts like a zwitterion. It was revealed the oxidative rearrangement takes place even with mesityl dibenzotropylium cation despite its perceived aromaticity. DFT calculations confirm the most stable forms of 6 and 7 are singlet and triplet diradical, which is consistent with the observed reactivity of respective molecules.
In Vitro and In Vivo Sequestration of Methamphetamine by a Sulfated Acyclic CB[n]‐Type Receptor
Authors: Brockett Adam T. , Deng Chunlin , Shuster Michael , Perera Suvenika , DiMaggio Delaney , Cheng Ming , Murkli Steven , Briken Volker , Roesch Matthew R. , Isaacs Lyle 
Published: October 2021

AbstractWe report the synthesis of two new acyclic sulfated acyclic CB[n]‐type receptors (TriM0 and Me4TetM0) and investigations of their binding properties toward a panel of drugs of abuse (1–13) by a combination of 1H NMR spectroscopy and isothermal titration calorimetry. TetM0 is the most potent receptor with Ka≥106 M−1 toward methamphetamine, fentanyl, MDMA and mephedrone. TetM0 is not cytotoxic toward HepG2 and HEK 293 cells below 100 μM according to MTS metabolic and adenylate kinase release assays and is well tolerated in vivo when dosed at 46 mg kg−1. TetM0 does not inhibit the hERG ion channel and is not mutagenic based on the Ames fluctuation test. Finally, in vivo efficacy studies show that the hyperlocomotion of mice treated with methamphetamine can be greatly reduced by treatment with TetM0 up to 5 minutes later. TetM0 has potential as a broad spectrum in vivo sequestrant for drugs of abuse.
Cyclodimers and Cyclotrimers of 2,3 ‐Bisalkynylated Anthracenes, Phenazines and Diazatetracenes
Authors: Maier Steffen , Hippchen Nikolai , Rominger Frank , Freudenberg Jan , Bunz Uwe H. F. 
Published: October 2021

AbstractThe synthesis of novel (N−)acene‐based cyclooligomers is reported. Glaser‐Hay coupling of the bisethynylated monomers results in cyclodimers and cyclotrimers that are separable by column and gel‐permeation chromatographies. For the diazatetracene, the use of sec‐butyl‐silylethynyl groups is necessary to achieve solubility. Diazatetracene‐based cyclodimers and cyclotrimers were used as semiconductors in thin‐film transistors. Although their optoelectronic properties are quite similar, their electron mobilities in proof‐of‐concept thin‐film transistors differ by an order of magnitude.
Breaking Symmetry Relaxes Structural and Magnetic Restraints, Suppressing QTM in Enantiopure Butterfly Fe2Dy2 SMMs**
Authors: Baniodeh Amer , Wagner Danny , Peng Yan , Kaemmerer Hagen , Leblanc Nicolas , Bräse Stefan , Naubron Jean‐Valére , Anson Christopher E. , Powell Annie K. 
Published: October 2021

AbstractThe {Fe2Dy2} butterfly systems can show single molecule magnet (SMM) behaviour, the nature of which depends on details of the electronic structure, as previously demonstrated for the [Fe2Dy2(μ3‐OH)2(Me‐teaH)2(O2CPh)6] compound, where the [N,N‐bis‐(2‐hydroxyethyl)‐amino]‐2‐propanol (Me‐teaH3) ligand is usually used in its racemic form. Here, we describe the consequences for the SMM properties by using enantiopure versions of this ligand and present the first homochiral 3d/4 f SMM, which could only be obtained for the S enantiomer of the ligand for [Fe2Dy2(μ3‐OH)2(Me‐teaH)2(O2CPh)6] since the R enantiomer underwent significant racemisation. To investigate this further, we prepared the [Fe2Dy2(μ3‐OH)2(Me‐teaH)2(O2CPh)4(NO3)2] version, which could be obtained as the RS‐, R‐ and S‐compounds. Remarkably, the enantiopure versions show enhanced slow relaxation of magnetisation. The use of the enantiomerically pure ligand suppresses QTM, leading to the conclusion that use of enantiopure ligands is a “gamechanger” by breaking the cluster symmetry and altering the intimate details of the coordination cluster's molecular structure.
Early palliative care is associated with less intense care in children dying with cancer in Alabama: A retrospective, single‐site study
Authors: Davis Elizabeth S. , Martinez Isaac , Hurst Garrett , Bhatia Smita , Johnston Emily E. 
Published: October 2021

BackgroundRegional studies show that children with cancer receive medically intense end‐of‐life (EOL) care, but EOL care patterns, including palliative care utilization in Alabama, remain unknown.MethodsThis was a retrospective study of 233 children (0‐19 years) who received cancer‐directed therapy at Children's of Alabama and died from 2010 through 2019. Rates and disparities in palliative care utilization and the association between palliative care and intense EOL care, death location, and hospice were examined.ResultsThe median death age was 11 years; 62% were non‐Hispanic White. Forty‐one percent had a non–central nervous system (CNS) solid tumor. Fifty‐eight percent received palliative care, and 36% received early palliative care (≥30 days before death). Children without relapsed/refractory disease were less likely to receive palliative care than those who had relapsed/refractory disease (adjusted odds ratio [aOR], 0.2; 95% confidence interval [CI], 0.1‐0.7). Children with CNS tumors and hematologic malignancies were less likely to have early palliative care (aOR for CNS tumors, 0.4; 95% CI, 0.2‐0.7; aOR for hematologic malignancies, 0.3; 95% CI, 0.2‐0.7) than children with non‐CNS solid tumors. Late palliative care (vs none) was associated with more medically intense care (aOR, 3.3; 95% CI, 1.4‐7.8) and hospital death (aOR, 4.8; 95% CI, 1.9‐11.6). Early palliative care (vs none) was associated with more hospice enrollment (aOR, 3.4; 95% CI, 1.5‐7.6) but not medically intense care (aOR, 1.3; 95% CI, 0.6‐2.9) or hospital death (aOR, 1.8; 95% CI, 0.8‐3.7).ConclusionsFifty‐eight percent of children dying of cancer in Alabama receive palliative care, but EOL care varies with the receipt and timing (early vs late) of palliative care. Whether this variation reflects differences in child and family preferences or systemic factors (eg, hospice access) remains unknown.
Anion‐Dependent Outstanding Luminescence Enhancement of Eu(D‐facam)3 Upon Coexistence With the Tetramethylammonium Cation
Authors: Li Ziying , Minami Haruki , Nakamura Kazuki , Kobayashi Norihisa 
Published: October 2021

AbstractThe effect of a series of tetramethylammonium salts with different counter anions on the photophysical properties of a chiral Eu(III) complex (Eu(D‐facam)3) was investigated. Anion‐dependent luminescence of the Eu(III) complex was observed, and particularly in the presence of acetate ions, an outstanding luminescence enhancement (>300 times) and induced circularly polarized luminescence (glum=−0.63) were obtained. The energy transfer process was then evaluated using key photophysical parameters, and it was found that the sensitisation efficiency of the Eu(III) complex significantly increased in the presence of tetramethylammonium acetate (TMAOAc). The interactions between Eu(D‐facam)3 and TMAOAc were confirmed by luminescence analysis, circular dichroism spectroscopy, Fourier transform infrared spectroscopy and mass spectral measurements.
Visualization of the Skeletal Muscle Stem Cell Niche in Fiber Bundles
Authors: Schüler Svenja C. , Dumontier Simon , Rigaux Jonathan , Bentzinger C. Florian 
Published: October 2021

AbstractSkeletal muscle stem cells (MuSCs) reside in a complex niche composed of the muscle fiber plasma membrane and the laminin‐rich basal lamina surrounded by the microvasculature, as well as different supportive cell types such as fibro‐adipogenic progenitors residing in the interstitial extracellular matrix. Within the first few hours after tissue damage, MuSCs undergo cytoskeletal rearrangements and transcriptional changes that prime the cells for activation. Due to their time‐consuming nature, enzymatic methods for liberation of single muscle fibers with fully quiescent MuSCs are challenging. Moreover, during enzymatic digestion, important niche components including the microvasculature and the collagenous interstitial matrix are destroyed. Here, we provide a method for the visualization of MuSCs on muscle fibers in their intact niche. Our method relies on mechanical teasing of fiber bundles from fixed skeletal muscles. We demonstrate that teased muscle fiber bundles allow the investigator to capture a representative snapshot of the MuSC niche in skeletal muscle, and outline how stem cell morphology and different microenvironmental components can be visualized. © 2021 The Authors. Current Protocols published by Wiley Periodicals LLC.Basic Protocol 1: Isolation of fiber bundlesBasic Protocol 2: Immunofluorescence staining of MuSCs on fiber bundlesSupport Protocol: Preparation of Sylgard dishes
Tailoring Quantum Dot Sizes for Optimal Photoinduced Catalytic Activation of Nitrogenase
Authors: Meirovich Matan M. , Bachar Oren , Nandi Ramesh , Amdursky Nadav , Yehezkeli Omer 
Published: October 2021

AbstractMany efforts have been directed towards elucidating the nitrogenase structure, its biocatalytic activity, and methods to artificially activate it by external stimuli. Here, we investigated how semiconductor nanoparticles (NPs) with sizes ranging between 2.3–3.5 nm form nano‐biohybrids with the nitrogenase enzyme and enable its photoinduced biocatalytic activity. We examined two homogenously synthesized quantum dots (QDs), CdS, CdSe, and two nitrogenase variants, the wild‐type and a cysteine‐mutated. We show that the cysteine‐mutated variant does not enhance the hydrogen generation amounts, as compared with the wild type. Nevertheless, we show that the 2.3 nm‐sized CdSe NPs facilitate an eightfold increase compared with larger CdSe NPs. The obtained results were investigated using electrochemical techniques, transmission electron microscopy, and further confirmed by time‐resolved spectroscopic measurements, which allow us to determine the electron tranfer rate constant (kET) of the different configurations.
Direct Synthesis of 5‐Methylfurfural from d‐Fructose by Iodide‐Mediated Transfer Hydrogenation
Authors: Xu Jianwang , Miao Xinge , Liu Lei , Wang Yantao , Yang Weiran 
Published: October 2021

AbstractHerein, a robust catalytic system was developed for the green synthesis of 5‐methylfurfural (5‐MF) by iodide‐mediated transfer hydrogenation. Around 50 % of 5‐MF was yielded from d‐fructose within 7.5 min using NaI as the catalyst and formic acid as both the hydrogen source and co‐catalyst. The catalytic system was used for six consecutive cycles without any decrease in the yield. Various starch and raw biomass could be used as promising starting materials for 5‐MF synthesis with moderate yields, and the productivity of 5‐MF from corn starch reached 103 mmol gcat−1 h−1, which is comparable with the best result from l‐rhamnose. Moreover, the co‐production of 5‐MF and furfural from raw biomass makes this methodology more competitive than other routes.
Broadband dielectric resonator antenna with dual‐frequency circularly polarized response for WLAN and WiMAX applications
Authors: Sharma Anand , Dwivedi Ajay Kumar , Narayaswamy Nagesh Kallollu , Gupta Ashish , Tripathi Devendra Kumar 
Published: October 2021

AbstractIn this paper, a moon‐shaped aperture‐coupled ring‐shaped dielectric resonator antenna (DRA) is suggested, realized, and tested. The L‐shaped microstrip line is designed to stimulate the aperture. Vital characteristics of the proposed radiator are as follows: (a) Broadband DRA with dual‐frequency circular polarized (CP) response is realized by the mixture of
and
mode in‐ring DRA; (b) wide impedance bandwidth is attained with the help of dropping the effective permittivity of radiating structure by converting cylindrical shape into a ring shape. To test the practical feasibility, the proposed antenna design is fabricated and tested inside the anechoic chamber. Practical outcomes confirm that the proposed antenna works over the frequency range of 2.44–3.66 GHz along with supporting dual CP waves within the operating range, i.e., 2.44–2.64 and 3.4–3.65 GHz respectively. Broadsided (θ = 00 and ϕ = 00) RHCP radiation pattern makes the proposed antenna design applicable for IEEE 802.15.4 wireless sensor network (2.5 GHz) and WiMAX (3.5 GHz).
Impacts of environmental stress on resistance and resilience of algal‐associated bacterial communities
Authors: Morrissey Kathryn Lee , Iveša Ljiljana , Delva Soria , D'Hondt Sofie , Willems Anne , De Clerck Olivier 
Published: October 2021

AbstractAlgal‐associated bacteria are fundamental to the ecological success of marine green macroalgae such as Caulerpa. The resistance and resilience of algal‐associated microbiota to environmental stress can promote algal health and genetic adaptation to changing environments. The composition of bacterial communities has been shown to be unique to algal morphological niches. Therefore, the level of response to various environmental perturbations may in fact be different for each niche‐specific community. Factorial in situ experiments were set up to investigate the effect of nutrient enrichment and temperature stress on the bacterial communities associated with Caulerpa cylindracea. Bacteria were characterized using the 16S rRNA gene, and the community compositions were compared between different parts of the algal thallus (endo‐, epi‐, and rhizomicrobiome). Resistance and resilience were calculated to further understand the changes of microbial composition in response to perturbations. The results of this study provide evidence that nutrient enrichment has a significant influence on the taxonomic and functional structure of the epimicrobiota, with a low community resistance index observed for both. Temperature and nutrient stress had a significant effect on the rhizomicrobiota taxonomic composition, exhibiting the lowest overall resistance to change. The functional performance of the rhizomicrobiota had low resilience to the combination of stressors, indicating potential additive effects. Interestingly, the endomicrobiota had the highest overall resistance, yet the lowest overall resilience to environmental stress. This further contributes to our understanding of algal microbiome dynamics in response to environmental changes.
Static environments with limited resources select for multiple foraging strategies rather than conformity
Authors: Borofsky Talia M. , Feldman Marcus W. 
Published: October 2021

AbstractSocial learning and conformity, or positive frequency‐biased transmission, are important components of the evolution of culture and group identities in animals and humans. Previous theoretical work on the evolution of social learning and conformity when environmental states change found that conformity evolves for a large range of environmental conditions. However, the foraging environment can affect the adaptive benefits of social learning and conformity. Conformity can cause a population to focus mainly on one resource while ignoring other available resources, which can incite competition if the first resource is limited. We study the evolution of social learning and frequency‐biased transmission in a limited‐resource environment using a replicator model of a forager population feeding on two resources in which foragers set their resource preferences during an early learning stage. In sharp contrast with previous models, anti‐conformity, or negative frequency‐biased transmission, rather than conformity, evolves from a population of non‐conformists under most environmental conditions. Numerical simulations suggest that both social learning and conformity cause the foragers to favor one resource over the other even though the resources provide the same benefit to foragers. Resource limitation favors anti‐conformity because anti‐conformity tends to force both resources to be exploited equally. Similarly, depletion of resources selects against social learning. However, increasing social learning is adaptive when independent discovery of foraging cues is difficult because it increases the rate at which individuals learn to find food. Consequently, in an environment with difficult‐to‐learn food cues, increased social learning is more likely to evolve. However, social learning does not emerge from a population of individual learners. Our results show that competition and consumer‐resource interactions can alter the evolutionary course of social learning and transmission bias. As there are many examples of conformity in the animal kingdom, and especially in humans, future studies should explore what extensions of the model would allow conformity to first evolve.
Extensive aquatic subsidies lead to territorial breakdown and high density of an apex predator
Authors: Eriksson Charlotte E. , Kantek Daniel L. Z. , Miyazaki Selma S. , Morato Ronaldo G. , dos Santos‐Filho Manoel , Ruprecht Joel S. , Peres Carlos A. , Levi Taal 
Published: October 2021

AbstractEnergetic subsidies between terrestrial and aquatic ecosystems can strongly influence food webs and population dynamics. Our objective was to study how aquatic subsidies affected jaguar (Panthera onca) diet, sociality, and population density in a seasonally flooded protected area in the Brazilian Pantanal. The diet (n = 138 scats) was dominated by fish (46%) and aquatic reptiles (55%), representing the first jaguar population known to feed extensively on fish and to minimally consume mammals (11%). These aquatic subsidies supported the highest jaguar population density estimate to date (12.4 jaguars/100 km²) derived from camera traps (8,065 trap nights) and GPS collars (n = 13). Contrary to their mostly solitary behavior elsewhere, we documented social interactions previously unobserved between same‐sex adults including cooperative fishing, co‐traveling, and play. Our study demonstrates that aquatic subsidies, frequently described in omnivores, can also transform the ecology and behavior of obligate carnivores.
Features of myocardial injury detected by cardiac magnetic resonance in a patient with desmin‐related restrictive cardiomyopathy
Authors: Chen Zixian , Li Rui , Wang Yongxiang , Cao Liang , Lin Chen , Liu Feng , Hu Rui , Nan Jiang , Zhuang Xin , Lu Xiande , Nan Guangxian , Hu Guocui , Xue Jingmei , Zhang Yaping , Xiao Jing , Yao Yali , Guo Shunlin , Lei Junqiang 
Published: October 2021

AbstractMyocardial fibrosis detected by cardiac magnetic resonance (CMR) has been reported in patients with desmin‐related myopathy, although its characteristics remain unclear. Here, we describe a case of desmin‐related restrictive cardiomyopathy wherein CMR imaging revealed myocardial oedema, ischaemia, and fibrosis in the left ventricle; the different types and processes of myocardial injury were detected by CMR. Middle wall left ventricular enhancement may be a feature of late gadolinium enhancement, and the lateral wall is often involved in cases of myocardial injury. CMR is useful for the early detection of cardiac involvement and the prediction of prognosis in patients diagnosed with desmin‐related myopathy.
Rb3Er4Cu5Te10: Exploring the Frontier between Polar Intermetallics and Zintl‐Phases via Experimental and Quantumchemical Approaches
Authors: Gladisch Fabian C. , van Leusen Jan , Passia Marco T. , Kögerler Paul , Steinberg Simon 
Published: October 2021

AbstractThe tailored design of solid‐state materials requires a proper understanding of their respective electronic structures. In order to rationalize the relationships between crystal structures and electronic structures in intermetallic compounds, the Zintl‐Klemm concept has been frequently employed. Yet, the frontier between the valence‐electron concentrations (e/a) of the Zintl‐ and the polar intermetallic phases has remained unclear to date. To shed some light on this frontier, we explored the electronic structure of the quaternary compound Rb3Er4Cu5Te10. To this effect, the crystal structure of this telluride, which was obtained as pure phase from high‐temperature reactions, was determined by means of X‐ray diffraction experiments for the very first time. In addition, the magnetic properties of the Rb3Er4Cu5Te10 were also determined in order to explore the erbium 4 f states in more detail.
Synthesis of Polycyclic Indolines by Utilizing a Reduction/Cyclization Cascade Reaction
Authors: Zhang Jingyu , Xia Wei , Qu Meilin , Huda Saskia , Ward Jas S. , Rissanen Kari , Albrecht Markus 
Published: October 2021

AbstractSubsequent reduction and dearomatizing cyclization reactions open up an entry into the synthesis of novel N‐fused polycyclic indolines. The dearomatizing cyclization as key step of the sequence proceeds well with Cu(OTf)2 or TfOH as catalyst. At elevated temperature reduction of nitro‐substituted precursors with iron under acidic conditions affords a broad variety of polycyclic indolines directly in a two‐step cascade reaction in good to excellent yields. Using the developed protocol, the alkaloids tryptanthrin and phaitanthrin C have been prepared.
Advances in mass spectrometry‐based glycoproteomics: An update covering the period 2017–2021
Authors: Gutierrez‐Reyes Cristian D. , Jiang Peilin , Atashi Mojgan , Bennett Andrew , Yu Aiying , Peng Wenjing , Zhong Jieqiang , Mechref Yehia 
Published: October 2021

AbstractProtein glycosylation is one of the most common posttranslational modifications, and plays an essential role in a wide range of biological processes such as immune response, intercellular signaling, inflammation, host–pathogen interaction, and protein stability. Glycoproteomics is a proteomics subfield dedicated to identifying and characterizing the glycans and glycoproteins in a given cell or tissue. Aberrant glycosylation has been associated with various diseases such as Alzheimer's disease, viral infections, inflammation, immune deficiencies, congenital disorders, and cancers. However, glycoproteomic analysis remains challenging because of the low abundance, site‐specific heterogeneity, and poor ionization efficiency of glycopeptides during LC–MS analyses. Therefore, the development of sensitive and accurate approaches to efficiently characterize protein glycosylation is crucial. Methods such as metabolic labeling, enrichment, and derivatization of glycopeptides, coupled with different mass spectrometry techniques and bioinformatics tools, have been developed to achieve sophisticated levels of quantitative and qualitative analyses of glycoproteins. This review attempts to update the recent developments in the field of glycoproteomics reported between 2017 and 2021.