bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tunable Synchronicity of Molecular Valence Tautomerism with Macroscopic Solid‐Liquid Transition by Molecular Lattice Engineering
Authors: Chida Mayumi , Takahashi Satoru , Konishi Ryunosuke , Matsumoto Takeshi , Nakada Akinobu , Wakizaka Masanori , Kosaka Wataru , Miyasaka Hitoshi , Chang Ho‐Chol 
Published: September 2021

AbstractThe combination of a cobalt‐dioxolene core that exhibits valence tautomerism (VT) with pyridine‐3,5‐dicarboxylic acid functionalized with chains bearing two, four, or six oxyethylene units led to new complexes ConEGEspy (n = 2, 4, and 6). These complexes commonly form violet crystals of the low‐spin (ls)‐[CoIII(nEGEspy)2(3,6‐DTBSQ)(3,6‐DTBCat)] (ls‐[CoIII], 3,6‐DTBSQ = 3,6‐di‐tert‐butyl semiquinonato, 3,6‐DTBCat = 3,6‐di‐tert‐butyl catecholato). Interestingly, violet crystals of Co2EGEspy in the ls‐[CoIII] transitioned into a green liquid, accompanied by an almost complete VT shift (94 %) to the high‐spin (hs)‐[CoII(nEGEspy)2(3,6‐DTBSQ)2] (hs‐[CoII]) upon melting. In contrast, violet crystals of Co4EGEspy and Co6EGEspy in the ls‐[CoIII] exhibited partial VT (33 %) and only a 9.3 % VT shift after melting, respectively. These data demonstrate the tunability of the synchronicity of the molecular VT and macroscopic solid‐liquid transitions by optimizing the tethered chains, thus establishing a new strategy for coupling bistable molecules with the macroscopic world.
Amine‐Directed Palladium‐Catalyzed C−H Halogenation of Phenylalanine Derivatives
Authors: Ville Alexia , Annibaletto Julien , Coufourier Sébastien , Hoarau Christophe , Tamion Rodolphe , Journot Guillaume , Schneider Cédric , Brière Jean‐François 
Published: September 2021

AbstractInvited for the cover of this issue are Jean‐François Brière, Cédric Schneider, Guillaume Journot and co‐workers from the COBRA laboratory and Oril Industrie (Normandy, France). The image shows the progression from questioning how to easily and regioselectively introduce halogen atoms to amino acids to the discovery of a catalytic functional‐group‐directed C−H halogenation of phenylalanine derivatives. Read the full text of the article at 10.1002/chem.202102411.
Liquid‐Phase Cyclohexene Oxidation with O2 over Spray‐Flame‐Synthesized La1−xSrxCoO3 Perovskite Nanoparticles
Authors: Büker Julia , Alkan Baris , Chabbra Sonia , Kochetov Nikolai , Falk Tobias , Schnegg Alexander , Schulz Christof , Wiggers Hartmut , Muhler Martin , Peng Baoxiang 
Published: September 2021

AbstractLa1−xSrxCoO3 (x=0, 0.1, 0.2, 0.3, 0.4) nanoparticles were prepared by spray‐flame synthesis and applied in the liquid‐phase oxidation of cyclohexene with molecular O2 as oxidant under mild conditions. The catalysts were systematically characterized by state‐of‐the‐art techniques. With increasing Sr content, the concentration of surface oxygen vacancy defects increases, which is beneficial for cyclohexene oxidation, but the surface concentration of less active Co2+ was also increased. However, Co2+ cations have a superior activity towards peroxide decomposition, which also plays an important role in cyclohexene oxidation. A Sr doping of 20 at. % was found to be the optimum in terms of activity and product selectivity. The catalyst also showed excellent reusability over three catalytic runs; this can be attributed to its highly stable particle size and morphology. Kinetic investigations revealed first‐order reaction kinetics for temperatures between 60 and 100 °C and an apparent activation energy of 68 kJ mol−1 for cyclohexene oxidation. Moreover, the reaction was not affected by the applied O2 pressure in the range from 10 to 20 bar. In situ attenuated total reflection infrared spectroscopy was used to monitor the conversion of cyclohexene and the formation of reaction products including the key intermediate cyclohex‐2‐ene‐1‐hydroperoxide; spin trap electron paramagnetic resonance spectroscopy provided strong evidence for a radical reaction pathway by identifying the cyclohexenyl alkoxyl radical.
Pyrimidyn‐Based Dynamin Inhibitors as Novel Cytotoxic Agents
Authors: Odell Luke R. , Chau Ngoc , Russell Cecilia C. , Young Kelly A. , Gilbert Jayne , Robinson Phillip J. , Sakoff Jennette A. , McCluskey Adam 
Published: September 2021

AbstractFive focused libraries of pyrimidine‐based dynamin GTPase inhibitors, in total 69 compounds were synthesised, and their dynamin inhibition and broad‐spectrum cytotoxicity examined. Dynamin plays a crucial role in mitosis, and as such inhibition of dynamin was expected to broadly correlate with the observed cytotoxicity. The pyrimidines synthesised ranged from mono‐substituted to trisubstituted. The highest levels of dynamin inhibition were noted with di‐ and tri‐ substituted pyrimidines, especially those with pendent amino alkyl chains. Short chains and simple heterocyclic rings reduced dynamin activity. There were three levels of dynamin activity noted: 1–10, 10–25 and 25–60 μM. Screening of these compounds in a panel of cancer cell lines: SW480 (colon), HT29 (colon), SMA (spontaneous murine astrocytoma), MCF‐7 (breast), BE2‐C (glioblastoma), SJ‐G2 (neuroblastoma), MIA (pancreas), A2780 (ovarian), A431 (skin), H460 (lung), U87 (glioblastoma) and DU145 (prostate) cell lines reveal a good correlation between the observed dynamin inhibition and the observed cytotoxicity. The most active analogues (31 a,b) developed returned average GI50 values of 1.0 and 0.78 μM across the twelve cell lines examined. These active analogues were: N2‐(3‐dimethylaminopropyl)‐N4‐dodecyl‐6‐methylpyrimidine‐2,4‐diamine (31 a) and N4‐(3‐dimethylaminopropyl)‐N2‐dodecyl‐6‐methylpyrimidine‐2,4‐diamine (31 b).
Development of an image‐based measurement system for human facial skin colour
Authors: He Ruili , Xiao Kaida , Pointer Michael , Bressler Yoav , Liu Zhen , Lu Yan 
Published: September 2021

AbstractIn this study, an image‐based measurement system was developed for human facial skin colour, involving the development of a digital imaging system, collection of facial skin colour from 60 human subjects, generation of different colour characterization models, and performance evaluation. The factors that affect facial skin colour characterization, including different training datasets (two colour charts and the collected facial skin colour dataset), mathematical mapping methods (linear transformation, polynomial regression, root‐polynomial regression and neural network) and camera image formats (JPG and RAW), were investigated and quantified not only by the conventional method of CIELAB colour difference, but also two newly introduced measures, facial colour contrast and skin colour gamut. The results indicate that the RAW image format for camera digital signals gave a more stable performance than the JPG format images, and the higher order polynomial regression with good predictive accuracy in terms of CIELAB colour difference did not perform well for the whole facial image. It is suggested to evaluate the model performance using the colour of both specific facial positions and the overall facial skin colour. Our comparative analysis in this study provides useful guidance for determining the colour characterization model for facial skin.
Efficient parallel algorithms for dynamic closeness‐ and betweenness centrality
Authors: Regunta Sai Charan , Tondomker Sai Harsh , Shukla Kshitij , Kothapalli Kishore 
Published: September 2021

AbstractFinding the centrality measures of nodes in a graph is a problem of fundamental importance due to various applications from social networks, biological networks, and transportation networks. Given the large size of such graphs, it is natural to use parallelism as a recourse. Several studies show how to compute the various centrality measures of nodes in a graph on parallel architectures, including multi‐core systems and GPUs. However, as these graphs evolve and change, it is pertinent to study how to update the centrality measures on changes to the underlying graph. In this article, we show novel parallel algorithms for updating the betweenness‐ and closeness‐centrality values of nodes in a dynamic graph. Our algorithms process a batch of updates in parallel by extending the approach of handling a single update for betweenness‐ and closeness‐centrality. For the latter, we also introduce techniques based on traversals of the block‐cut tree of a graph. Besides, our algorithms incorporate mechanisms to exploit the structural properties of graphs for enhanced performance. We implement our algorithms on two parallel architectures: an Intel 24‐core CPU and an Nvidia Tesla V100 GPU. To the best of our knowledge, we are the first to show GPU algorithms for the above two problems. In addition, we conduct detailed experiments to study the impact of various parameters associated with our algorithms and their implementation. Our results on a collection of real‐world graphs indicate that our algorithms achieve a significant speedup over corresponding state‐of‐the‐art algorithms.
Azulene Bridged π‐Distorted Chromophores: The Influence of Structural Symmetry on Optoelectrochemical and Photovoltaic Parameters
Authors: Raheem Abbasriyaludeen Abdul , Murugan Palanichamy , Shanmugam Ramasamy , Praveen Chandrasekar 
Published: September 2021

AbstractConjugated chromophores possessing π‐twisted functionality such as tetracyanobutadiene (TCBD) have emerged as promising active layer materials for organic photovoltaics (OPVs). In this study, we disclose the synthesis of two azulenyl chromophores containing one and two TCBD groups. The symmetrical and unsymmetrical structural characteristics of these molecules inflict dissimilar optoelectronic and electrochemical properties. Based on molar absorptivity, aggregation behavior, HOMO‐LUMO energies and other quantum chemical parameters, the symmetrical molecule (TATC2) appears to be a better non‐fullerene acceptor (NFA) compared to its unsymmetrical counterpart (TATC1). For instance, higher absorptivity and deeper HOMO‐LUMO levels for TATC2 (23950 M−1 cm−1; −6.01 eV/−3.86 eV) over TATC1 (12200 M1 cm−1; −5.46 eV/−3.64 eV) was observed. Validating this structure‐property relationship on solar cell prototypes exhibited higher photovoltaic parameters (VOC=0.54 V, FF=0.48, JSC=6.42 mA/cm2) for TATC2 than TATC1 (VOC=0.47 V, FF=0.38, JSC=5.77 mA/cm2). Though the device parameters are not high, this work uncovers the intrinsic properties of azulene‐tethered twisted chromophores as potential π‐semiconductor choice for NFA solar cells. In particular, this report explores the utility of azulene‐based π‐twisted semiconductors as acceptor material for OPVs with cell efficiencies of 1.70 and 1.04 % for TATC2 and TATC1 respectively.
Estimating phase error using a Hilbert transform‐based time‐domain technique
Authors: Al‐Ali Abdulwadood A. , Elwakil Ahmed S. , Maundy Brent J. , Allagui Anis , Elamien Mohamed B. 
Published: September 2021

SummaryMeasuring phase noise in oscillators is crucial in communication systems, vibration analysis, and frequency synthesizers. Traditionally, this measurement is done in frequency domain by estimating the ratio of the power density at an offset frequency from the carrier to the power of the carrier signal. This approach is hardware intensive and dependent on the the offset frequency, for which there exists no standard. Here, we propose an alternative method to quantify phase noise but in the time domain in the form of a root‐mean‐square true phase angle deviation. This is done using a self‐created reference signal and by applying the Hilbert transform to generate a complex analytic signal from the real time‐domain data sequence. This enables the computation of instantaneous metrics such as phase noise. Simulations and experimental results are provided to validate the proposed technique. In addition, its relationship to the origin of phase noise is mathematically explained.
High‐efficiency LC‐S compensated wireless power transfer charging converter for implantable pacemakers
Authors: Cetin Sevilay , Demirci Yunus Emre 
Published: September 2021

AbstractThis paper deals with wireless power transfer (WPT) based on magnetic coupling resonance in order to delivery power to a cardiac pacemaker from the outside of the body. The high‐efficiency power delivery, implantation, and safety are key parameters for a WPT system, designed for active implantable medical devices. Therefore, this paper is focused on high‐efficiency power transfer, implantation, and safety issues. For the wireless charging of the pacemaker, the LC‐S compensation topology is presented and designed based on high‐efficiency power delivery. The resonant components of the LC‐S compensation topology were extracted in order to ensure that WPT converter operates at resonance frequency. The operation of the presented WPT charging converter is validated by a prototype operating at 300‐kHz operation frequency. At 4.2 V output voltage and 0.45 A output current, the WPT efficiency of the prototype is measured as 82.39%. Finally, the safety evaluation of the proposed WPT converter is also discussed based on reference values presented in the literature.
Endoscopic ultrasound‐guided choledochoduodenostomy without fistula dilation using a stent with a 5.9‐Fr delivery system: Comparison to a conventional procedure with fistula dilation
Authors: Koga Takehiko , Hijioka Susumu , Nagashio Yosikuni , Ohba Akihiro , Maruki Yuta , Yoshinari Motohiro , Hisada Yuya , Harai Shota , Kitamura Hidetoshi , Maehara Kosuke , Murashima Yumi , Kawasaki Yuki , Kawahara Shun , Takeshita Kotaro , Yamada Natsumi , Satake Tomoyuki , Kondo Shunsuke , Morizane Chigusa , Ueno Hideki , Okusaka Takuji , Saito Yutaka 
Published: September 2021

AbstractObjectivesTo evaluate the feasibility and safety of endoscopic ultrasound‐guided choledochoduodenostomy (EUS‐CDS) without fistula dilation using a novel self‐expandable metal stent (SEMS).MethodsThis retrospective study examined patients who underwent EUS‐CDS for malignant distal biliary obstruction between October 2017 and May 2021 at the National Cancer Center, Japan. The primary outcome was a technical success without fistula dilation. Secondary outcomes were the overall technical success, clinical success, adverse events (AEs), procedure time, recurrent biliary obstruction (RBO), and time to RBO (TRBO).ResultsForty‐one patients were enrolled; 31 patients underwent EUS‐CDS with fistula dilation using a conventional SEMS with 7.5–8.5‐Fr delivery system (conventional SEMS group), and 10 patients underwent EUS‐CDS without fistula dilation using the novel SEMS with a 5.9‐Fr delivery system (novel SEMS group). In the novel SEMS group, the rate of technical success without fistula dilation was 90%. There were no differences in overall technical success (100% vs. 97%, p = 1.00), clinical success (80% vs. 90%, p = 0.58), and overall AEs (10% vs. 23%, p = 0.65) rates between the novel and conventional SEMS groups. In the novel SEMS group, no early AEs were observed and no bile leakage into the abdominal cavity was observed on the computed tomography scan after the procedure. The median procedure time was significantly shorter in the novel SEMS group (17 min vs. 24 min, p = 0.03). RBO and median TRBO did not differ between the 2 groups.ConclusionsEUS‐CDS without fistula dilation using the novel SEMS with a 5.9‐Fr delivery system is technically feasible, straightforward, quick, and safe.
The forestecology R package for fitting and assessing neighborhood models of the effect of interspecific competition on the growth of trees
Authors: Kim Albert Y. , Allen David N. , Couch Simon P. 
Published: September 2021

Abstract

Neighborhood competition models are powerful tools to measure the effect of interspecific competition. Statistical methods to ease the application of these models are currently lacking.

We present the forestecology package providing methods to (a) specify neighborhood competition models, (b) evaluate the effect of competitor species identity using permutation tests, and (cs) measure model performance using spatial cross‐validation. Following Allen and Kim (PLoS One, 15, 2020, e0229930), we implement a Bayesian linear regression neighborhood competition model.

We demonstrate the package's functionality using data from the Smithsonian Conservation Biology Institute's large forest dynamics plot, part of the ForestGEO global network of research sites. Given ForestGEO’s data collection protocols and data formatting standards, the package was designed with cross‐site compatibility in mind. We highlight the importance of spatial cross‐validation when interpreting model results.

The package features (a) tidyverse‐like structure whereby verb‐named functions can be modularly “piped” in sequence, (b) functions with standardized inputs/outputs of simple features sf package class, and (c) an S3 object‐oriented implementation of the Bayesian linear regression model. These three facts allow for clear articulation of all the steps in the sequence of analysis and easy wrangling and visualization of the geospatial data. Furthermore, while the package only has Bayesian linear regression implemented, the package was designed with extensibility to other methods in mind.
Reversible Stereoisomer‐Specific Cotton Effect of the Ligand Field Transitions at a Copper(II) Binding Site of the Prion Protein
Authors: Rivillas‐Acevedo Lina , Grande‐Aztatzi Rafael , Juaristi Eusebio , Vela Alberto , Quintanar Liliana 
Published: September 2021

AbstractThe prion protein (PrP) is a metal binding protein that plays multifunctional roles in the brain and it is associated with spongiform encephalopathy disorders, a group of neurodegenerative infectious diseases. PrP can bind six copper ions at its N‐terminal region, one of the binding sites involving His96. Copper(II) ions bind to His96 forming two coordination modes at physiological pH: a 3N1O species involving the His imidazole group, two deprotonated amides (from His96 and Thr95) and one backbone carbonyl oxygen; and a 4N coordination mode where the oxygen‐based ligand is replaced by a third deprotonated amide (from Gly94). In this study, synthetic PrP fragments 92–99 were used to evaluate the impact of different substitutions at positions 94 and 95 of the sequence in the Cotton effect of the ligand field transitions for the 4N species, as studied by circular dichroism (CD) spectroscopy. Specifically, the T95A substitution had no impact, while the G94A substitution yields a change in the sign of the ligand field transitions, which can be reverted when substituting Gly94 by the stereoisomer D‐Ala. The electronic structure of the Cu(II)‐PrP(92–96) complex and its variants was studied, while time‐dependent density functional theory (TD‐DFT) calculations provided a prediction of the CD spectra in the ligand field region that is consistent with observed experimental results. Furthermore, the calculated CD spectra for other Cu(II)‐PrP(92–96) complexes with substitutions (alkyls and halides) at position 94 indicate that the complexes with L‐stereoisomers displays the opposite Cotton effect as compared to their D‐stereoisomer counterparts. Our analysis indicates this impact in the Cotton effect is a consequence of the geometric distortion that the nearly square planar 4N Cu(II)‐PrP(92–99) complex suffers when an L‐substituent is placed in position 94; the distortion from planarity is reversed by the D‐stereoisomer substitution. Overall, this study provides insights into the origin of the Cotton effect of the ligand field transitions of nearly square planar Cu(II)‐peptide complexes.
Risk factors for depression and anxiety in painful and painless diabetic polyneuropathy: A multicentre observational cross‐sectional study
Authors: Kec David , Rajdova Aneta , Raputova Jana , Adamova Blanka , Srotova Iva , Nekvapilova Eva Kralickova , Michalcakova Radka Neuzilova , Horakova Magda , Belobradkova Jana , Olsovsky Jindrich , Weber Pavel , Hajas Gabriel , Kaiserova Michaela , Mazanec Radim , Potockova Veronika , Ehler Edvard , Forgac Martin , Birklein Frank , Üçeyler Nurcan , Sommer Claudia , Bednarik Josef , Vlckova Eva 
Published: September 2021

AbstractBackgroundDespite the high prevalence of depression and anxiety in chronic pain conditions, current knowledge concerning emotional distress among painful diabetic polyneuropathy (pDSPN) and other diabetes mellitus (DM) sufferers is limited.MethodsThis observational multicentre cohort study employed the Hospital Anxiety and Depression Scale, the Beck Depression Inventory II and the State‐Trait Anxiety Inventory to assess symptoms of depression and anxiety in several groups with diabetes, as well as in a control group. The study cohort included 347 pDSPN patients aged 63.4 years (median), 55.9% males; 311 pain‐free diabetic polyneuropathy (nDSPN) patients aged 63.7 years, 57.9% males; 50 diabetes mellitus (DM) patients without polyneuropathy aged 61.5 years, 44.0% males; and 71 healthy controls (HC) aged 63.0 years, 42.3% males. The roles played in emotional distress were explored in terms of the biological, the clinical (diabetes‐, neuropathy‐ and pain‐related), the socio‐economic and the cognitive factors (catastrophizing).ResultsThe study disclosed a significantly higher prevalence of the symptoms of depression and anxiety not only in pDSPN (46.7% and 60.7%, respectively), but also in patients with nDSPN (24.4% and 44.4%) and DM without polyneuropathy (22.0% and 30.0%) compared with HCs (7.0% and 14.1%, p < 0.001). Multiple regression analysis demonstrated the severity of pain and neuropathy, catastrophic thinking, type 2 DM, lower age and female sex as independent contributors to depression and anxiety.ConclusionsIn addition to the severity of neuropathic pain and its cognitive processing, the severity of diabetic polyneuropathy and demographic factors are key independent contributors to emotional distress in diabetic individuals.SignificanceIn large cohorts of well‐defined painless and painful diabetic polyneuropathy patients and diabetic subjects without polyneuropathy, we found a high prevalence of the symptoms of depression and anxiety, mainly in painful individuals. We have confirmed neuropathic pain, its severity and cognitive processing (pain catastrophizing) as dominant risk factors for depression and anxiety. Furthermore, some demographic factors (lower age, female sex), type 2 diabetes mellitus and severity of diabetic polyneuropathy were newly identified as important contributors to emotional distress independent of pain.