bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cyclic Heterometallic Interactions formed from a Flexible Tripeptide Complex Showing Effective Antiferromagnetic Spin Coupling
Authors: Miyake Ryosuke , Suganuma Eri , Kimura Shun , Mori Hirotoshi , Okabayashi Jun , Kusamoto Tetsuro 
Published: November 2020

AbstractDeveloping tunable motifs for heterometallic interactions should be beneficial for fabricating functional materials based on cooperative electronic communications between metal centers. Reported here is the efficient formation of cyclic heterometallic interactions from a complex containing an artificial tripeptide with metal binding sites on its main chain and side chains. X‐ray structural analysis and X‐ray absorption spectroscopy revealed that the cyclic metal–metal arrangements arise from the amide groups connecting four square‐planar CuII centers and four octahedral NiII centers in a cyclic manner. UV/Vis spectral studies suggested that this efficient formation was achieved by the selective formation of the square‐planar CuII centers and a crystallization process. Magnetic measurements using SQUID clarified that the cyclic complex represented the S=2 spin state at low temperatures due to effective antiferromagnetic interactions between the NiII and CuII centers.
C−H Activation by an Iron‐Nitrido Bis‐Pocket Porphyrin Species
Authors: Wang Hai‐Xu , Wu Liangliang , Zheng Bin , Du Lili , To Wai‐Pong , Ko Cheng‐Hoi , Phillips David Lee , Che Chi‐Ming 
Published: November 2020

AbstractHigh‐valent iron‐nitrido species are nitrogen analogues of iron‐oxo species which are versatile reagents for C−H oxidation. Nonetheless, C−H activation by iron‐nitrido species has been scarcely explored, as this is often hampered by their instability and short lifetime in solutions. Herein, the hydrogen atom transfer (HAT) reactivity of an Fe porphyrin nitrido species (2 c) toward C−H substrates was studied in solutions at room temperature, which was achieved by nanosecond laser flash photolysis (LFP) of its FeIII‐azido precursor (1 c) supported by a bulky bis‐pocket porphyrin ligand. C−H bonds with bond dissociation enthalpies (BDEs) of up to ≈84 kcal mol−1 could be activated, and the second‐order rate constants (k2) are on the order of 102–104 s−1 m−1. The Fe‐amido product formed after HAT could further release ammonia upon protonation.
Observing Single‐Atom Catalytic Sites During Reactions with Electrospray Ionization Mass Spectrometry
Authors: Hülsey Max J. , Sun Geng , Sautet Philippe , Yan Ning 
Published: November 2020

AbstractSingle‐atom catalysts (SACs) have become a prominent theme in heterogeneous catalysis, not least because of the potential fundamental insight into active sites. The desired level of understanding, however, is prohibited due to the inhomogeneity of most supported SACs and the lack of suitable tools for structure–activity correlation studies with atomic resolution. Herein, we describe the potency of electrospray ionization mass spectrometry (ESI‐MS) to study molecularly defined SACs supported on polyoxometalates in catalytic reactions. We identified the exact composition of active sites and their evolution in the catalytic cycle during CO and alcohol oxidation reactions performed in the liquid phase. Critical information on metal‐dependent reaction mechanisms, the key intermediates, the dynamics of active sites and even the stepwise activation barriers were obtained, which would be challenging to gather via prevailingly adopted techniques in SAC research. DFT calculations revealed intricate details of the reaction mechanisms, and strong synergies between ESI‐MS defined SAC sites and electronic structure theory calculations become apparent.
Activation of Aptamers with Gain of Function by Small‐Molecule‐Clipping of Intramolecular Motifs
Authors: Huang Mengjiao , Li Tingyu , Xu Yuanfeng , Wei Xinyu , Song Jia , Lin Bingqian , Zhu Zhi , Song Yanling , Yang Chaoyong 
Published: November 2020

AbstractClick reactions have the advantages of high reactivity, excellent orthogonality, and synthetic accessibility. Inspired by click reactions, we propose the concept of “clipped aptamers”, whose binding affinity is regulated by the “clip”‐like specific interaction between a synthetic DNA‐mismatch‐binding small molecule (molecular glue, Z‐NCTS) and the preset CGG/CGG sequences in nucleic acid sequences. In this study, we investigated a Z‐NCTS‐mediated de novo selection of clipped aptamers against epithelial cell adhesion molecule. The generated clipped aptamers can achieve the efficient transition from a binding‐inactive state to an active state by clipping of Z‐NCTS with two CGG sites, which otherwise would not hybridize. The experimental and simulation results showed that the clipped aptamer had ideal binding thermodynamics and the ability to regulate cellular adhesion. Because of this superior activated mechanism and structural diversity, clipped aptamers hold great potential in biosensing, imaging, conditional gene‐ and cellular behavior‐regulation, and drug delivery.
Ethanol‐free extraction of resveratrol and its glycoside from Japanese knotweed rhizome by liquefied dimethyl ether without pretreatments
Authors: Kanda Hideki , Oishi Kazuma , Machmudah Siti , Wahyudiono  , Goto Motonobu 
Published: November 2020

AbstractHerein, we carried out the extraction of polyphenol resveratrol and its glycoside (piceid) from raw Japanese knotweed via a simple method, employing dimethyl ether (DME) as the solvent. With DME extraction, the conventional drying and cell wall disruption steps can be left out. As a result, more resveratrol and piceid were obtained in DME extraction than in conventional ethanol extraction. Because the Hansen solubility parameters of DME are closer to ethanol than to water, it allowed us to extract resveratrol and piceid from raw Japanese knotweed, unlike water. Simultaneously, 83.5% of the initial water and 213 mg/g dry of organic extracts were extracted from raw Japanese knotweed. As DME extraction does not involve drying and grinding of the decomposed antioxidants, it is highly suitable for extracting antioxidants.
Altered functional connectivity of the amygdala and its subregions in typhoon‐related post‐traumatic stress disorder
Authors: Liu Tao , Ke Jun , Qi Rongfeng , Zhang Li , Zhang Zhiqiang , Xu Qiang , Zhong Yuan , Lu Guangming , Chen Feng 
Published: November 2020

AbstractBackgroundNew evidence suggests that the centromedial amygdala (CMA) and the basolateral amygdala (BLA) play different roles in threat processing. Our study aimed to investigate the effects of trauma and post‐traumatic stress disorder (PTSD) on the functional connectivity (FC) of the amygdala and its subregions.MethodsTwenty‐seven patients with typhoon‐related PTSD, 33 trauma‐exposed controls (TEC), and 30 healthy controls (HC) were scanned with a 3‐Tesla magnetic resonance imaging scanner. The FCs of the BLA, the CMA, and the amygdala as a whole were examined using a seed‐based approach, and then, the analysis of variance was used to compare the groups.ResultsWe demonstrated that the BLA had a stronger connectivity with the prefrontal cortices (PFCs) and angular gyrus in the PTSD group than in the TEC group. Additionally, compared with the PTSD and the HC groups, the TEC group exhibited decreased and increased BLA FC with the ventromedial PFC and postcentral gyrus (PoCG), respectively. Furthermore, the PTSD group showed abnormal FC between the salience network and default‐mode network, as well as the executive control network. Compared with the HC group, the TEC group and the PTSD group both showed decreased BLA FC with the superior temporal gyrus (STG). Finally, the FCs between the bilateral amygdala (as a whole) and the vmPFC, and between the BLA and the vmPFC have a negative correlation with the severity of PTSD.ConclusionsDecreased BLA‐vmPFC FC and increased BLA‐PoCG FC may reflect PTSD resilience factors. Trauma leads to decreased connectivity between the BLA and the STG, which could be further aggravated by PTSD.
Perspectives, fears and expectations of patients with gynaecological cancers during the COVID‐19 pandemic: A Pan‐European study of the European Network of Gynaecological Cancer Advocacy Groups (ENGAGe)
Authors: Gultekin Murat , Ak Sertac , Ayhan Ali , Strojna Aleksandra , Pletnev Andrei , Fagotti Anna , Perrone Anna Myriam , Erzeneoglu B. Emre , Temiz B. Esat , Lemley Birthe , Soyak Burcu , Hughes Cathy , Cibula David , Haidopoulos Dimitrios , Brennan Donal , Cola Edoardo , van der Steen‐Banasik Elzbieta , Urkmez Esra , Akilli Huseyin , Zapardiel Ignacio , Tóth Icó , Sehouli Jalid , Zalewski Kamil , Bahremand Kiarash , Chiva Luis , Mirza Mansoor Raza , Papageorgiou Maria , Zoltan Novak , Adámková Petra , Morice Philippe , Garrido‐Mallach Sonia , Akgor Utku , Theodoulidis Vasilis , Arik Zafer , Steffensen Karina D. , Fotopoulou Christina 
Published: November 2020

AbstractBackgroundThe impact of the COVID‐19 pandemic on European gynaecological cancer patients under active treatment or follow‐up has not been documented. We sought to capture the patient perceptions of the COVID‐19 implications and the worldwide imposed treatment modifications.MethodsA patient survey was conducted in 16 European countries, using a new COVID‐19‐related questionnaire, developed by ENGAGe and the Hospital Anxiety & Depression Scale questionnaire (HADS). The survey was promoted by national patient advocacy groups and charitable organisations.FindingsWe collected 1388 forms; 592 online and 796 hard‐copy (May, 2020). We excluded 137 due to missing data. Median patients’ age was 55 years (range: 18–89), 54.7% had ovarian cancer and 15.5% were preoperative. Even though 73.2% of patients named cancer as a risk factor for COVID‐19, only 17.5% were more afraid of COVID‐19 than their cancer condition, with advanced age (>70 years) as the only significant risk factor for that. Overall, 71% were concerned about cancer progression if their treatment/follow‐up was cancelled/postponed. Most patients (64%) had their care continued as planned, but 72.3% (n = 892) said that they received no information around overall COVID‐19 infection rates of patients and staff, testing or measures taken in their treating hospital. Mean HADS Anxiety and Depression Scores were 8.8 (range: 5.3–12) and 8.1 (range: 3.8–13.4), respectively. Multivariate analysis identified high HADS‐depression scores, having experienced modifications of care due to the pandemic and concern about not being able to visit their doctor as independent predictors of patients’ anxiety.InterpretationGynaecological cancer patients expressed significant anxiety about progression of their disease due to modifications of care related to the COVID‐19 pandemic and wished to pursue their treatment as planned despite the associated risks. Healthcare professionals should take this into consideration when making decisions that impact patients care in times of crisis and to develop initiatives to improve patients’ communication and education.
Concomitant septal myectomy and mitral valve repair in a child with Noonan syndrome
Authors: Doi Toshio , Toritsuka Daisuke , Higashida Akihiko , Yokoyama Shigeki , Fukahara Kazuaki , Yoshimura Naoki 
Published: November 2020

AbstractWe successfully performed concomitant septal myectomy and mitral valve repair in a child with Noonan syndrome.
Steady‐State Electrocatalytic Activity Evaluation with the Redox Competition Mode of Scanning Electrochemical Microscopy: A Gold Probe and a Boron‐Doped Diamond Substrate
Authors: Henrotte Olivier , Boudet Alice , Limani Ndrina , Bergonzo Philippe , Zribi Bacem , Scorsone Emmanuel , Jousselme Bruno , Cornut Renaud 
Published: November 2020

AbstractIn the current context of energetic transition, investigations of alternative complex systems require tools such as scanning electrochemical microscopy (SECM), offering interesting opportunities as an electroanalytical technique to evaluate innovative catalysts. Herein, we demonstrate how a judicious choice of probe and substrate materials opens up improved performances to achieve steady‐state measurements for oxygen reduction reaction (ORR) catalytic activity detection through redox competition scanning electrochemical microscopy (RC‐SECM). On the probe side, we show that using gold enhances the stability of the local oxygen concentration detection in comparison to the regularly used platinum one. On the substrate side, we evaluate boron‐doped diamond as an appealing alternative to classical support substrate, that shows a low ORR activity, high stability and very good reusability. This work introduces an alternative approach for quantitative measurements with SECM, improving measurement ease, comfort and reproducibility, thus paving the way towards standardized benchmarking and numerical simulation‐based parameter extraction.
In Vitro and In Vivo Sequestration of Phencyclidine by Me4Cucurbit[8]uril**
Authors: Murkli Steven , Klemm Jared , Brockett Adam T. , Shuster Michael , Briken Volker , Roesch Matthew R. , Isaacs Lyle 
Published: November 2020

AbstractWe report investigations of the use of cucurbit[8]uril (CB[8]) macrocycles as an antidote to counteract the in vivo biological effects of phencyclidine. We investigate the binding of CB[8] and its derivative Me4CB[8] toward ten drugs of abuse (3–9, 12–14) by a combination of 1H NMR spectroscopy and isothermal titration calorimetry in phosphate buffered water. We find that the cavity of CB[8] and Me4CB[8] are able to encapsulate the 1‐amino‐1‐aryl‐cyclohexane ring system of phencyclidine (PCP) and ketamine as well as the morphinan skeleton of morphine and hydromorphone with Kd values ≤50 nm. In vitro cytotoxicity (MTS metabolic and adenylate kinase cell death assays in HEK293 and HEPG2 cells) and in vivo maximum tolerated dose studies (Swiss Webster mice) which were performed for Me4CB[8] indicated good tolerability. The tightest host⋅guest pair (Me4CB[8]⋅PCP; Kd=2 nm) was advanced to in vivo efficacy studies. The results of open field tests demonstrate that pretreatment of mice with Me4CB[8] prevents subsequent hyperlocomotion induction by PCP and also that treatment of animals previously dosed with PCP with Me4CB[8] significantly reduces the locomotion levels.
Inversion Symmetry Breaking in Order–Disorder Transitions of Globular Ligands Coordinating to Cobalt(II) and Nickel(II) Bisacetylacetonato Complexes During Heating
Authors: Hoshino Norihisa , Akutagawa Tomoyuki 
Published: November 2020

AbstractUnexpected inversion‐symmetry breaking was observed in the order–disorder phase transitions of [M(acac)2(abco)2] (1; M=Co2+, 2; Ni2+, acac−=2,4‐pentanedionato, abco=1‐azabicyclo‐[2.2.2]‐octane=quinuclidine) during heating. The isostructural, transition‐free complexes [M(acac)2(cabco)2] (3; M=Co2+, 4; Ni2+, cabco=3‐chloro‐1‐azabicyclo‐[2.2.2]‐octane=3‐chloroquinuclidine) were also studied for comparison. Complexes 1 and 2 crystallized in ordered phases in the centrosymmetric I2/m space group at 100 K, whereas they crystallized in disordered phases in the non‐symmetric I2 space group at 300 K. The 60° step rotation disordering of the abco ligands was observed in the electron density maps of 1 and 2, which was consistent with the transition enthalpies estimated by differential scanning calorimetry (DSC). Gradual phase transitions were observed for 1 and 2 by DSC and powder X‐ray diffraction (PXRD) at approximately 225 K. The inversion‐symmetry disordering was likely induced by the local pseudo‐symmetry of the abco ligands, increasing from trigonal to hexagonal and the increased steric repulsion pathways among them.
A Novel Thermocell System Using Proton Solvation Entropy
Authors: Kobayashi Takashi , Yamada Teppei , Tadokoro Makoto , Kimizuka Nobuo 
Published: November 2020

AbstractThe entropy change associated with proton‐coupled electron transfer (PCET) reactions significantly enhance the Seebeck coefficient (Se) of thermocells. A redox pair of [Ru(Hxim)6]2+/3+ (Him=imidazole, x=0≈1) releases three protons in their one‐electron redox reactions in thermocells, which gave a remarkably high Se of −3.7 mV K−1 as confirmed by temperature‐dependent square wave voltammetry. The value of Se is proportional to the redox reaction entropy (ΔSrc), which increased with the number of dissociating protons. This result demonstrates the utility of PCET reaction toward efficient thermoelectric conversion.
Feng Ligand: Privileged Chiral Ligand in Asymmetric Catalysis
Authors: Wang Ming‐Yang , Li Wei 
Published: November 2020

AbstractCatalysts and ligands possessing the great ability to tolerate over a wide range of mechanistically unrelated reactions are remarked as "privileged", which are rather scarce but extremely meaningful in asymmetric catalysis. Feng and co‐workers have developed a library of conformationally flexible, C2‐symmetric N,N'‐dioxide amide compounds with original design and featured structure (named as Feng ligand now). They were initially reported as chiral organocatalysts in 2005 and have been further developed as a new class of privileged chiral ligands since 2006. Tremendous success, including versatile coordination chemistry with plenty of metal sources (main‐group metals, transition metals, and rare‐earth metals), a truly broad scope of asymmetric reactions (more than 50 types), diverse areas of catalysis (organocatalysis, Lewis‐acid catalysis, bimetallic relay catalysis, and photocatalysis), numerous synthetic applications of bioactive compounds, has been achieved using Feng N,N'‐dioxide. Besides, they demonstrate that chiral ligands with conformationally flexible property can offer excellent chiral environment as well, which challenges the conventional idea preferring rigid structures in the design of chiral ligands. Herein, we briefly introduced the discovery of Feng ligand and the millstones during the development. We also covered the successful applications of Feng ligand by other scientists as well as novel chiral ligands inspired by them.
Numerical analysis of nanoparticle transport and deposition in a cynomolgus monkey nasal passage
Authors: Dong Jingliang , Ma Jiawei , Tian Lin , Inthavong Kiao , Ito Kazuhide , Tu Jiyuan 
Published: November 2020

AbstractEnvironmental exposure to toxic agents is commonly encountered by occupational and residential populations. However, in vivo exposure data in human subjects is limited by measurement and ethical restrictions. Monkey represents a suitable surrogate for human exposure studies, but the particle transport and deposition features in monkey airways are still not well understood. As a response to this research challenge, this paper presents a virtual exposure study that numerically investigated the nanoparticle transport process through a realistic cynomolgus monkey nasal airway. Particles with size of 1 nm to 1 μm were considered and the transport process was modelled by the Lagrangian discrete phase model. Overall and local deposition as well as particle dispersion along the airway were examined by using a variety of non‐dimensional parameters including combined diffusion parameter, deposition enhancement factor and particle flux enhancement factor. Consistent deposition patterns were observed in present and literature nasal models. Most particles tended to pass the nasal airway through certain spatial regions, including the middle section of the nasal valve, the lower half of the middle coronal plane, and the central regions of the choana. While naturally inhaled nanoparticles can hardly be delivered to the olfactory region as it is located apart from the mainstream with high particle flux. Research findings provide insight into nanoparticle inhalation exposure characteristics in the monkey airway and can contribute in formulating data extrapolation schemes between monkey and human airways.
Analysis of hemodynamic changes from aneurysm inception to large sizes
Authors: Salimi Ashkezari Seyedeh Fatemeh , Mut Fernando , Chung Bong Jae , Robertson Anne M. , Frösen Juhana , Cebral Juan R. 
Published: November 2020

AbstractWhile previous studies have identified many risk factors for the progression and rupture of cerebral aneurysms, the changes in aneurysm flow characteristics during its evolution are not fully understood. This work analyzes the changes in the aneurysm hemodynamic environment from its initial development to later stages when the aneurysm has substantially enlarged. A total of 88 aneurysms at four locations were studied with image based computational fluid dynamics (CFD). Two synthetic sequences representing the aneurysm geometry at three earlier stages were generated by shrinking the aneurysm sac while keeping the neck fixed or shrinking the neck simultaneously. The flow conditions were then quantitatively compared between these two modes of evolution. As aneurysms enlarged, the inflow rate increased in growing neck sequences, but decreased in fixed neck sequences. The inflow jet became more concentrated in both sequences. The mean aneurysm flow velocity and wall shear stress decreased in both sequences, but they decreased faster in enlarging aneurysms if the neck was fixed. Additionally, the intra‐aneurysmal flows became more complex and more unstable, wall shear stress distribution became more oscillatory, and the area under low wall shear stress increased for both sequences. The evolution of flow characteristics of aneurysms with fixed and growing necks are different. The observed trends suggest that fixed neck aneurysms may evolve towards a flow environment characteristic of stable aneurysms faster than aneurysms with growing necks, which could also evolve towards a more disfavorable environment.
Social rumor detection based on multilayer transformer encoding blocks
Authors: Lin Lijun , Chen Zhiyun 
Published: November 2020

AbstractThe propagation of rumors on social media has been identified as a critical problem in recent years that causes social panic or economic turmoil (to some extent), thereby giving rise to the need for faster identification. With the advancements in deep learning, researches based on neural networks become popular. Most of the existing methods extensively adopt recurrent neural networks (RNNs), such as gated recurrent unit and long short‐term memory. This results in a significant degradation in the concurrency performance of the models, implying an increased consumption of time and resources. This study proposes a model with multilayer transformer encoding blocks for detecting rumors. The self‐attention mechanism in the transformer encoding blocks provides better concurrency to the proposed model and improves its performance. The proposed model performs faster executions using less or no recurrences in comparison to other models based on RNNs. Experiments on two real social datasets verified that our model could achieve significantly better results than baseline methods. The accuracy rate increased by 1.1% and 2.2% on the Weibo and PHEME datasets, respectively. In comparison to the methods that use RNNs as a feature extractor, the training duration in the proposed model was reduced by 16% and 70% in Weibo and PHEME, respectively.