bluuebunny/crossref_metadata_2025 huggingface dataset:
Heterotrimetallic Mixed‐Valent Molecular Precursors Containing Periodic Table Neighbors: Assignment of Metal Positions and Oxidation States
Authors: Han Haixiang , Carozza Jesse C. , Colliton Audra P. , Zhang Yuxuan , Wei Zheng , Filatov Alexander S. , Chen Yu‐Sheng , Alkan Melisa , Rogachev Andrey Yu. , Dikarev Evgeny V.
Published: March 2020

A known trinuclear structure was used to design the heterobimetallic mixed‐valent, mixed‐ligand molecule [CoII(hfac)3−Na−CoIII(acac)3] (1). This was used as a template structure to develop heterotrimetallic molecules [CoII(hfac)3−Na−FeIII(acac)3] (2) and [NiII(hfac)3−Na−CoIII(acac)3] (3) via isovalent site‐specific substitution at either of the cobalt positions. Diffraction methods, synchrotron resonant diffraction, and multiple‐wavelength anomalous diffraction were applied beyond simple structural investigation to provide an unambiguous assignment of the positions and oxidation states for the periodic table neighbors in the heterometallic assemblies. Molecules of 2 and 3 are true heterotrimetallic rather than a statistical mixture of two heterobimetallic counterparts. Trinuclear platform 1 exhibits flexibility in accommodating a variety of di‐ and trivalent metals, which can be further utilized in the design of molecular precursors for the NaMM′O4 functional oxide materials.
Long‐Lived Circularly Polarized Phosphorescence in Helicene‐NHC Rhenium(I) Complexes: The Influence of Helicene, Halogen, and Stereochemistry on Emission Properties
Authors: Gauthier Etienne S. , Abella Laura , Hellou Nora , Darquié Benoît , Caytan Elsa , Roisnel Thierry , Vanthuyne Nicolas , Favereau Ludovic , Srebro‐Hooper Monika , Williams J. A. Gareth , Autschbach Jochen , Crassous Jeanne
Published: March 2020

The first enantiopure chiral‐at‐rhenium complexes of the form fac‐ReX(CO)3(:C^N) have been prepared, where :C^N is a helicene‐N‐heterocyclic carbene (NHC) ligand and X=Cl or I. These have complexes show strong changes in the emission characteristics, notably strongly enhanced phosphorescence lifetimes (reaching 0.7 ms) and increased circularly polarized emission (CPL) activity, as compared to their parent chiral models lacking the helicene unit. The halogen along with its position within the dissymmetric stereochemical environment strongly affect the photophysics of the complexes, particularly the phosphorescence quantum yield and lifetime. These results give fresh insight into fine tuning of photophysical and chiroptical properties of Re‐NHC systems.
Bi3+‐Er3+ and Bi3+‐Yb3+ Codoped Cs2AgInCl6 Double Perovskite Near‐Infrared Emitters
Authors: Arfin Habibul , Kaur Jagjit , Sheikh Tariq , Chakraborty Sudip , Nag Angshuman
Published: March 2020

Bi3+ and lanthanide ions have been codoped in metal oxides as optical sensitizers and emitters. But such codoping is not known in typical semiconductors such as Si, GaAs, and CdSe. Metal halide perovskite with coordination number 6 provides an opportunity to codope Bi3+ and lanthanide ions. Codoping of Bi3+ and Ln3+ (Ln=Er and Yb) in Cs2AgInCl6 double perovskite is presented. Bi3+‐Er3+ codoped Cs2AgInCl6 shows Er3+ f‐electron emission at 1540 nm (suitable for low‐loss optical communication). Bi3+ codoping decreases the excitation (absorption) energy, such that the samples can be excited with ca. 370 nm light. At that excitation, Bi3+‐Er3+ codoped Cs2AgInCl6 shows ca. 45 times higher emission intensity compared to the Er3+ doped Cs2AgInCl6. Similar results are also observed in Bi3+‐Yb3+ codoped sample emitting at 994 nm. A combination of temperature‐dependent (5.7 K to 423 K) photoluminescence and calculations is used to understand the optical sensitization and emission processes.
A Transannular Polyene Tetracyclization for Rapid Construction of the Pimarane Framework
Authors: Feilner Julian M. , Wurst Klaus , Magauer Thomas
Published: March 2020

Polyene cyclizations are one of the most powerful and fascinating chemical transformations to rapidly generate molecular complexity. However, cyclizations employing heteroatom‐substituted polyenes are rare. Described here is the tetracyclization of a dual nucleophilic aryl enol ether involving an unprecedented transannular endo‐termination step. In this transformation, five stereocenters, two of which are quaternary, four carbon–carbon bonds, and four six‐membered rings are formed from a readily available cyclization precursor. The realization of this cyclization enabled short synthetic access to the tricyclic diterpenoid pimara‐15‐en‐3α‐8α‐diol.
Elective Termination of Pregnancy in Autoimmune Rheumatic Diseases: Experience From Two Databases
Authors: Lockshin Michael D. , Guerra Marta , Salmon Jane E.
Published: March 2020

Objective

To provide reference data regarding the frequency and safety of elective termination of pregnancy in women with autoimmune rheumatic diseases followed up in 2 referral databases.

Methods

Two large databases, one from an autoimmune rheumatic disease referral clinical practice with a known interest in pregnancy (the Barbara Volcker Center for Women and Rheumatic Disease [BVC]), and one from an observational study of systemic lupus erythematosus– and antiphospholipid antibody–associated pregnancies (Predictors of Pregnancy Outcome: Biomarkers in Antiphospholipid Antibody Syndrome and Systemic Lupus Erythematosus [PROMISSE]), were interrogated for histories of prior elective termination of pregnancy and complications related to incident pregnancy termination.

Results

Of women who had had prior pregnancies, 21.7% of 1,307 in the BVC database and 25.3% of 297 in the PROMISSE database gave histories of 1–5 prior elective terminations of pregnancy; BVC patients reported no flares or hospitalizable complications due to pregnancy termination. Of 674 incident pregnancies, termination for fetal or maternal reasons was recommended for 15 (2%); of these, 2 fetuses died before the procedure was carried out and 1 woman declined termination and, though gravely ill, successfully delivered. She died of cardiomyopathy 3 years later.

Conclusion

Many patients with autoimmune rheumatic disease undergo elective termination of pregnancy; few report complications. In medically indicated termination of pregnancy, there are no adverse signals of unusual complications or disease flare.
An Alternative Method for Anatomy Training: Immersive Virtual Reality
Authors: Kurul Ramazan , Ögün Muhammed Nur , Neriman Narin Ayşe , Avci Şebnem , Yazgan Beyza
Published: March 2020

The aim of this study was to investigate the effect of immersive three‐dimensional (3D) interactive virtual reality (VR) on anatomy training in undergraduate physical therapy students. A total of 72 students were included in the study. The students were randomized into control (n = 36) and VR (n = 36) group according to the Kolb Learning Style Inventory, sex, and Purdue Spatial Visualization Test Rotations (PSVT‐R). Each student completed a pre‐intervention and post‐intervention test, consisting of 15 multiple‐choice questions. There was no significant difference between the two groups in terms of age, sex, Kolb Learning Style Inventory distribution, and the PSVT‐R (P > 0.05). The post‐test scores were significantly higher compared to pre‐test scores in both the VR group (P < 0.001) and the control group (P < 0.001). The difference between the pre‐test and post‐test results was found to be significantly higher in favor of the VR group (P < 0.001). In this study, anatomy training with a 3D immersive VR system was found to be beneficial. These results suggest that VR systems can be used as an alternative method to the conventional anatomy training approach for health students.
A Long‐Cycling Aqueous Zinc‐Ion Pouch Cell: NASICON‐Type Material and Surface Modification
Authors: Zhang Xianghua , Chen Haoliang , Liu Weiling , Xiao Ni , Zhang Qi , Rui Xianhong , Huang Shaoming
Published: March 2020

Aqueous zinc‐ion batteries (ZIBs) have become the highest potential energy storage system for large‐scale applications owing to the high specific capacity, good safety and low cost. In this work, a NASICON‐type Na3V2(PO4)3 cathode modified by a uniform carbon layer (NVP/C) has been synthesized via a facile solid‐state method and exhibited significantly improved electrochemical performance when working in an aqueous ZIB. Specifically, the NVP/C cathode shows an excellent rate capacity (e. g., 48 mAh g−1 at 1.0 A g−1). Good cycle stability is also achieved (e. g., showing a capacity retention of 88% after 2000 cycles at 1.0 A g−1). Furthermore, the Zn2+ (de)intercalation mechanism in the NVP cathode has been determined by various ex‐situ techniques. In addition, a Zn||NVP/C pouch cell has been assembled, delivering a high capacity of 89 mAhg−1 at 0.2 A g−1 and exhibiting a superior long cycling stability.
Preparation of Hierarchical Cube‐on‐plate Metal Phosphides as Bifunctional Electrocatalysts for Overall Water Splitting
Authors: Ma Jizhen , Wang Yueqing , Pan Wei , Zhang Jintao
Published: March 2020

To rationally design efficient and cost‐effective electrocatalysts, a simple but efficient strategy has been developed to directly anchor prussian blue analogue (PBA) nanocubes on cobalt hydroxide nanoplates (PBA@Co(OH)2) via the in‐situ interfacial precipitation process. Subsequently, the thermal treatment in the presence of sodium hydrogen phosphite enabled the successful transition into metal phosphides with the hierarchical cube‐on‐plate structure. When used as electrocatalytsts, the obtained bimetal phosphides exhibited good bifunctional electrocatalytic activities for hydrogen and oxygen evolution reactions with good long‐term stability. Thus, an enhanced performance for overall water splitting can be achieved, which could be ascribed to the hierarchical structure and favorable composition of as‐prepared bimetal phosphide for rapid electron and mass transfer. The present study demonstrates a favorable approach to modulate the composition and structure of metal phosphide for enhancing the electrocatalytic ability toward water splitting.
The record‐breaking heat wave of June 2019 in Central Europe
Authors: Xu Peiqiang , Wang Lin , Liu Yuyun , Chen Wen , Huang Ping
Published: March 2020

After being hit by several devastating heat waves in recent years, Europe experienced an exceptionally hot June in 2019 again. This June is the hottest one on record over Central Europe both in a monthly‐mean sense and in terms of the number of extremely hot days. The above‐normal hot condition is caused by an anomalous long‐lasting anticyclone in the upper troposphere, which advects warm air from the Sahel and Mediterranean region and enhances incoming solar radiation and surface turbulent fluxes. The anomalous anticyclone results from an unusually‐intensified British‐Baikal Corridor (BBC) pattern and a synoptic Rossby wave breaking (RWB) event over Europe. Three sub‐monthly heat waves are observed in the month. The first two are associated with the BBC pattern, and the third is related to the combination of the previous BBC pattern activity and the RWB event.
Simultaneous quantification of abemaciclib and letrozole in rat plasma: method development, validation and pharmacokinetic application
Authors: Dhakne Pooja , Sahu Amit Kumar , Sharma Manish Kumar , Sengupta Pinaki
Published: March 2020

Treatment through a combination of drugs involving cyclin D‐dependent kinase inhibitors like abemaciclib and aromatase inhibitor like letrozole proved to be a potential therapeutic regimen and first‐line treatment in estrogen receptor‐positive breast cancer. In this study, we developed a simple and simultaneous RP‐HPLC bioanalytical method for quantifying abemaciclib and letrozole in rat plasma. Abemaciclib and letrozole were separated on Zorbax Eclipse C18 column employing a gradient elution method comprising 10 mM ammonium acetate (pH 5) and acetonitrile as mobile phase. The method was found to have acceptable selectivity, accuracy (97.20–118.17%), precision (1.10–9.39%) and stability in the validation experiment performed as per the US Food and Drug Administration guidelines. The method sensitivity was low at a concentration level of 100 ng/ml. The applicability of the method has been verified through a single‐dose oral pharmacokinetic study in rat. The developed method will be useful to quantitate the analytes in rat plasma samples of different preclinical studies including their pharmacokinetic drug–drug interactions in the future. To date, no method has been reported for the quantification of abemaciclib and letrozole simultaneously in any type of biological matrices. Therefore, this study makes a definite significant contribution in the field of bioanalytical research.
LC–MS/MS method for the determination of erianin in rat plasma: Application to a pharmacokinetic study
Authors: Yi Xunfei , Lan Xiaopeng
Published: March 2020

Erianin is one of the bibenzyl ingredients isolated from Dctidrobium chrysotoxum Lindl. In recent years, erianin has attracted attention owing to its antitumor activity. In this study, an LC–MS/MS method was established to measure erianin in rat plasma. Gigantol was used as the internal standard. A Waters Acquity UPLC BEH C18 column was employed for chromatographic separation. The mobile phase consisted of water containing 0.1% formic acid and acetonitrile with a gradient elution at the flow rate of 0.4 ml/min. Selective reaction monitoring mode was used for quantitative analysis of erianin in positive electrospray ionization. In the concentration range of 0.1–1200 ng/ml, erianin in rat plasma was linear with correlation coefficient >0.999. The lowest limit of quantification was 0.1 ng/ml. The intra‐ and inter‐day RSDs were <9.69%, while the RE was in the range of −8.59–11.24%. The mean recovery was >85.37%. Erianin was stable in rat plasma after storage under certain conditions. The validated method was demonstrated to be selective, sensitive and reliable, and has been successfully applied to pharmacokinetic study of erianin in rat plasma. Erianin was rapidly eliminated from rat plasma with a short half‐life (〜1.5 h) and low oral bioavailability (8.7%).
The chemical profile of active fraction of Kalimeris indica and its quantitative analysis
Authors: Huang Wenping , Wen Zhiqi , Wang Qi , Chen Renhao , Li Zhifeng , Feng Yulin , Yang Shilin
Published: March 2020

Kalimeris indica (L) Sch‐Bip is a medicinal plant used by the Miao ethnic group in the Guizhou province of China. It is widely used as a fresh vegetable to treat colds, diarrhea and gastric ulcers. However, few studies have been conducted on the mechanism of its effect on colds, and its quality control. The anticomplement and antitussive activities of different polar extracts of K. indica were evaluated. Fifty‐nine compounds, mainly including phenols and flavonoids, were identified in K. indica extract by ultra‐high‐performance liquid chromatography quadrupole time‐of‐flight tandem mass spectrometry. A method was established through ultra‐high‐performance liquid chromatography with a photodiode array to simultaneously determine the anticomplement and antitussive activity of five compounds in K. indica combining chemical identification with chemometrics for discrimination and quality assessment. Also, 3,5‐dicaffeoylquinic acid and 4,5‐dicaffeoylquinic acid exhibited significantly higher anticomplementary activity than the other three compounds. The quantitative data were further analyzed by principal component analysis and orthogonal partial least‐squares discriminant analysis. Heatmap visualization was conducted to clarify the distribution of the major compounds in different geographical origins. Screening pharmacological activities by a combination of chemometrics and chemical identification might be an effective method for the quality control of K. indica.
Customized allogeneic bone grafts for maxillary horizontal augmentation: A 5‐year follow‐up radiographic and histologic evaluation
Authors: Kloss Frank Rudolf , Offermanns Vincent , Donkiewicz Phil , Kloss‐Brandstätter Anita
Published: March 2020

We report the histological evaluation of an individualized allogeneic bone block 5 years after alveolar ridge augmentation. The biopsy showed a well‐vascularized lamellar bone with fatty incorporations without any avital allograft remnants. The presence of osteocytes, lining cells, macrophages, and blood vessels indicated a healthy and vital bone tissue.
Nanobody‐Ferritin Conjugate for Targeted Photodynamic Therapy
Authors: Liu Manman , Zhu Yang , Wu Tiantian , Cheng Junjie , Liu Yangzhong
Published: March 2020

Ferritin is an iron‐storage protein nanocage that is assembled from 24 subunits. The hollow cavity of ferritin enables its encapsulation of various therapeutic agents; therefore, ferritin has been intensively investigated for drug delivery. The use of antibody‐ferritin conjugates provides an effective approach for targeted drug delivery. However, the complicated preparation and limited protein stability hamper wide applications of this system. Herein, we designed a novel nanobody‐ferritin platform (Nb‐Ftn) for targeted drug delivery. The site‐specific conjugation between nanobody and ferritin is achieved by transglutaminase‐catalyzed protein ligation. This ligation strategy allows the Nb conjugation after drug loading in ferritin, which avoids deactivation of the nanobody under the harsh pH environment required for drug encapsulation. To verify the tumor targeting of this Nb‐Ftn platform, a photodynamic reagent, manganese phthalocyanine (MnPc), was loaded into the ferritin cavity, and an anti‐EGFR nanobody was conjugated to the surface of the ferritin. The ferritin nanocage can encapsulate about 82 MnPc molecules. This MnPc@Nb‐Ftn conjugate can be efficiently internalized by EGFR positive A431 cancer cells, but not by EGFR negative MCF‐7 cells. Upon 730 nm laser irradiation, MnPc@Nb‐Ftn selectively killed EGFR positive A431 cells by generating reactive oxygen species (ROS), whereas no obvious damage was observed on MCF‐7 cells. Given that ferritin can be used for encapsulation of various therapeutic agents, this work provides a strategy for facile construction of nanobody‐ferritin for targeted drug delivery.
Synergistic Biophysical Techniques Reveal Structural Mechanisms of Engineered Cationic Antimicrobial Peptides in Lipid Model Membranes
Authors: Heinrich Frank , Salyapongse Aria , Kumagai Akari , Dupuy Fernando G. , Shukla Karpur , Penk Anja , Huster Daniel , Ernst Robert K. , Pavlova Anna , Gumbart James C. , Deslouches Berthony , Di Y. Peter , Tristram‐Nagle Stephanie
Published: March 2020

In the quest for new antibiotics, two novel engineered cationic antimicrobial peptides (eCAPs) have been rationally designed. WLBU2 and D8 (all 8 valines are the d‐enantiomer) efficiently kill both Gram‐negative and ‐positive bacteria, but WLBU2 is toxic and D8 nontoxic to eukaryotic cells. We explore protein secondary structure, location of peptides in six lipid model membranes, changes in membrane structure and pore evidence. We suggest that protein secondary structure is not a critical determinant of bactericidal activity, but that membrane thinning and dual location of WLBU2 and D8 in the membrane headgroup and hydrocarbon region may be important. While neither peptide thins the Gram‐negative lipopolysaccharide outer membrane model, both locate deep into its hydrocarbon region where they are primed for self‐promoted uptake into the periplasm. The partially α‐helical secondary structure of WLBU2 in a red blood cell (RBC) membrane model containing 50 % cholesterol, could play a role in destabilizing this RBC membrane model causing pore formation that is not observed with the D8 random coil, which correlates with RBC hemolysis caused by WLBU2 but not by D8.
Chemical Perturbation of Oncogenic Protein Folding: from the Prediction of Locally Unstable Structures to the Design of Disruptors of Hsp90–Client Interactions
Authors: Paladino Antonella , Woodford Mark R. , Backe Sarah J. , Sager Rebecca A. , Kancherla Priyanka , Daneshvar Michael A. , Chen Victor Z. , Bourboulia Dimitra , Ahanin Elham F. , Prodromou Chrisostomos , Bergamaschi Greta , Strada Alessandro , Cretich Marina , Gori Alessandro , Veronesi Marina , Bandiera Tiziano , Vanna Renzo , Bratslavsky Gennady , Serapian Stefano A. , Mollapour Mehdi , Colombo Giorgio
Published: March 2020

Protein folding quality control in cells requires the activity of a class of proteins known as molecular chaperones. Heat shock protein‐90 (Hsp90), a multidomain ATP driven molecular machine, is a prime representative of this family of proteins. Interactions between Hsp90, its co‐chaperones, and client proteins have been shown to be important in facilitating the correct folding and activation of clients. Hsp90 levels and functions are elevated in tumor cells. Here, we computationally predict the regions on the native structures of clients c‐Abl, c‐Src, Cdk4, B‐Raf and Glucocorticoid Receptor, that have the highest probability of undergoing local unfolding, despite being ordered in their native structures. Such regions represent potential ideal interaction points with the Hsp90‐system. We synthesize mimics spanning these regions and confirm their interaction with partners of the Hsp90 complex (Hsp90, Cdc37 and Aha1) by Nuclear Magnetic Resonance (NMR). Designed mimics selectively disrupt the association of their respective clients with the Hsp90 machinery, leaving unrelated clients unperturbed and causing apoptosis in cancer cells. Overall, selective targeting of Hsp90 protein–protein interactions is achieved without causing indiscriminate degradation of all clients, setting the stage for the development of therapeutics based on specific chaperone:client perturbation.
Rational Construction of 2D Fe3O4@Carbon Core–Shell Nanosheets as Advanced Anode Materials for High‐Performance Lithium‐Ion Half/Full Cells
Authors: Qu Dongyang , Sun Zhonghui , Xu Jianan , Song Zhongqian , Kong Huijun , Zhao Bolin , Dong Xiandui , Niu Li
Published: March 2020

Transition metal oxides have vastly limited practical application as electrode materials for lithium‐ion batteries (LIBs) due to their rapid capacity decay. Here, a versatile strategy to mitigate the volume expansion and low conductivity of Fe3O4 by coating a thin carbon layer on the surface of Fe3O4 nanosheets (NSs) was employed. Owing to the 2D core–shell structure, the Fe3O4@C NSs exhibit significantly improved rate performance and cycle capability compared with bare Fe3O4 NSs. After 200 cycles, the discharge capacity at 0.5 A g−1 was 963 mA h g−1 (93 % retained). Moreover, the reaction mechanism of lithium storage was studied in detail by ex situ XRD and HRTEM. When coupled with a commercial LiFePO4 cathode, the resulting full cell retains a capacity of 133 mA h g−1 after 100 cycles at 0.1 A g−1, which demonstrates its superior energy storage performance. This work provides guidance for constructing 2D metal oxide/carbon composites with high performance and low cost for the field of energy storage.
Isoleucine Residues Determine Chiral Discrimination of Odorant‐Binding Protein
Authors: Zaremska Valeriia , Tan Jiajun , Lim Sierin , Knoll Wolfgang , Pelosi Paolo
Published: March 2020

Enzymes, receptors, and carrier proteins discriminate between enantiomers of natural and synthetic chemicals. Whereas the structural details of this phenomenon have been investigated in enzymes and receptors, much less is known for carrier proteins of hydrophobic ligands, particularly concerning the contribution of asymmetric centers in the side chains of amino acids to chirally selective binding. Working with a pig odorant‐binding protein, we have found that the replacement of either one or both isoleucine residues in the binding pocket by leucines abolishes discrimination of menthol and carvone enantiomers. The results indicate that isoleucines are crucial for chiral discrimination of hydrophobic ligands, and that asymmetry in the side chain may be as important as the overall asymmetry of the protein. The results provide suggestions and guidelines for improving chiral selectivity of binding proteins and enzymes, with consequent applications in the production of enantiomerically pure drugs.
Spin Crossover and Long‐Lived Excited States in a Reduced Molecular Ruby
Authors: Becker Patrick M. , Förster Christoph , Carrella Luca M. , Boden Pit , Hunger David , van Slageren Joris , Gerhards Markus , Rentschler Eva , Heinze Katja
Published: March 2020

The chromium(III) complex [CrIII(ddpd)2]3+ (molecular ruby; ddpd=N,N′‐dimethyl‐N,N′‐dipyridine‐2‐yl‐pyridine‐2,6‐diamine) is reduced to the genuine chromium(II) complex [CrII(ddpd)2]2+ with d4 electron configuration. This reduced molecular ruby represents one of the very few chromium(II) complexes showing spin crossover (SCO). The reversible SCO is gradual with T1/2 around room temperature. The low‐spin and high‐spin chromium(II) isomers exhibit distinct spectroscopic and structural properties (UV/Vis/NIR, IR, EPR spectroscopies, single‐crystal XRD). Excitation of [CrII(ddpd)2]2+ with UV light at 20 and 290 K generates electronically excited states with microsecond lifetimes. This initial study on the unique reduced molecular ruby paves the way for thermally and photochemically switchable magnetic systems based on chromium complexes complementing the well‐established iron(II) SCO systems.
Resolution, structures, and vibrational circular dichroism of helicoidal trinickel and tricobalt paddlewheel complexes
Authors: Cortijo Miguel , Valentín‐Pérez Ángela , Rosa Patrick , Daugey Nicolas , Buffeteau Thierry , Hillard Elizabeth A.
Published: March 2020

It has been recently shown that enantiomers of the helicoidal paddlewheel complex [Co3(dpa)4(CH3CN)2]2+ (dpa = the anion of 2,2′‐dipyridylamine) can be resolved using the chiral [As2(tartrate)2]2− anion (AsT) and that these complexes demonstrate a strong chiroptical response in the ultraviolet‐visible and X‐ray energy regions. Here we report that the nickel congener, [Ni3(dpa)4(CH3CN)2]2+, can likewise be resolved using AsT. Depending on the stereochemistry of the enantiopure AsT anion, one or the other of the trinickel enantiomers crystallize from CH3CN and diethyl ether in space group P4212 as the (NBu4)2[Ni3(dpa)4(CH3CN)2](AsT)2·[solvent] salt. After resolution, the AsT salts were converted into the PF6− salts by anion exchange, with retention of the chirality of the trinickel complex. The enantiopure [Ni3(dpa)4(CH3CN)2](PF6)2·2CH3CN and [Co3(dpa)4(CH3CN)2](PF6)2·CH3CN·C4H10O compounds crystallize in space groups C2 and P21, respectively. Both the Ni(II) and Co(II) complex cations are stable towards racemization in CH3CN. Vibrational circular dichroism (VCD) data obtained in CD3CN demonstrate the expected mirror image spectra for the enantiomers, the observed peaks arising from the dpa ligand. The VCD response is significant, with Δε values up to 6 Lmol−1 cm−1 and vibrational dissymmetry factors on the order of 10−3. Density functional theory calculations well reproduce the experimental spectra, showing little difference between the peak position, sign, and intensity in the VCD for the cobalt and nickel complexes. These results suggest that VCD enhancement of these peaks is unlikely, and their remarkable intensity may be due to their rigid helicoidal structure.
Yicathins B and C and Analogues: Total Synthesis, Lipophilicity and Biological Activities
Authors: Loureiro Daniela R. P. , Magalhães Álvaro F. , Soares José X. , Pinto Joana , Azevedo Carlos M. G. , Vieira Sara , Henriques Ana , Ferreira Helena , Neves Nuno , Bousbaa Hassan , Reis Salette , Afonso Carlos M. M. , Pinto Madalena M. M.
Published: March 2020

Natural products have always been an important source of new hits and leads in drug discovery, with the marine environment being regarded as a significant source of novel and exquisite bioactive compounds. Yicathins B and C are two marine‐derived xanthones that have shown antibacterial and antifungal activity. Herein, the total synthesis of these yicathins and six novel analogues is reported for the first time. As marine natural products tend to have very lipophilic scaffolds, the lipophilicity of yicathins and their analogues was evaluated in the classical octanol/water system and a biomimetic model‐based system. As the xanthonic nucleus is a “privileged structure”, other biological activities were evaluated, namely antitumor and anti‐inflammatory activities. An interesting anti‐inflammatory activity was identified for yicathin analogues that paves the way for the design of dual activity (anti‐infective and anti‐inflammatory) marine‐inspired xanthone derivatives.
Shape Similarity by Fractal Dimensionality: An Application in the de novo Design of (−)‐Englerin A Mimetics
Authors: Friedrich Lukas , Byrne Ryan , Treder Aaron , Singh Inderjeet , Bauer Christoph , Gudermann Thomas , Mederos y Schnitzler Michael , Storch Ursula , Schneider Gisbert
Published: March 2020

Molecular shape and pharmacological function are interconnected. To capture shape, the fractal dimensionality concept was employed, providing a natural similarity measure for the virtual screening of de novo generated small molecules mimicking the structurally complex natural product (−)‐englerin A. Two of the top‐ranking designs were synthesized and tested for their ability to modulate transient receptor potential (TRP) cation channels which are cellular targets of (−)‐englerin A. Intracellular calcium assays and electrophysiological whole‐cell measurements of TRPC4 and TRPM8 channels revealed potent inhibitory effects of one of the computer‐generated compounds. Four derivatives of this identified hit compound had comparable effects on TRPC4 and TRPM8. The results of this study corroborate the use of fractal dimensionality as an innovative shape‐based molecular representation for molecular scaffold‐hopping.
Rethinking the 10‐pack‐year rule for favorable human papillomavirus–associated oropharynx carcinoma: A multi‐institution analysis
Authors: Broughman James R. , Xiong David D. , Moeller Benjamin J. , Contrera Kevin J. , Prendes Brandon L. , Lamarre Eric D. , Ku Jamie A. , Burkey Brian B. , Woody Neil M. , Joshi Nikhil P. , Adelstein David J. , Geiger Jessica L. , Frenkel Catherine H. , Milas Zvonimir L. , Brickman Daniel S. , Sumrall Ashley L. , Carrizosa Daniel R. , Greskovich John F. , Koyfman Shlomo A. , Ward Matthew C.
Published: March 2020

Background

De‐intensified treatment strategies for early human papillomavirus–positive (HPV+) oropharynx cancer (OPC) rely on selecting patients with an excellent prognosis. The criterion for enrollment in current de‐intensification trials is ≤10 pack‐years. More nuance to the pack‐year criteria may expand enrollment, improve patient outcomes, and prevent overtreatment. It was hypothesized that patients with more than 10 pack‐years may experience favorable outcomes if smoking cessation has been achieved.

Methods

From an institutional review board–approved database, patients with HPV+ oropharyngeal squamous carcinoma treated definitively with radiation with or without chemotherapy were retrospectively identified. Patients with a history of smoking who were eligible for national de‐intensification trials were included (cT1‐2N1‐2b or T3N0‐2b [American Joint Committee on Cancer, seventh edition]). Cox regression with penalized smoothing splines was used to evaluate nonlinear effects of cessation. Recursive partitioning analysis (RPA) was used to objectively search for relationships between the 2 colinear variables (pack‐years and time since cessation).

Results

Among 330 patients meeting the inclusion criteria, 130 (40%) were never smokers, 139 (42%) were former smokers, and 61 (18%) were current smokers. With standard therapy, all former smokers achieved a progression‐free survival (PFS) rate higher than 91%, regardless of pack‐year exposure. Nonlinear Cox regression demonstrated that more recent cessation was associated with significantly worse PFS even among those with ≤20 pack‐years. RPA demonstrated that only current smokers experienced a 2‐year PFS rate lower than 91%; former smokers, regardless of pack‐years, experienced a 2‐year PFS rate higher than 91%.

Conclusions

The 10‐pack‐year rule may not apply to all early HPV+ OPCs, particularly for former smokers. Future randomized de‐intensification trials should consider a broader and more nuanced approach until the predictive role of smoking status is established.
Serous cavity fluids: Momentum, molecules, markers… and more!
Authors: Siddiqui Momin T.
Published: March 2020

Current practice trends in serous fluid cytology have resulted in the initiation of a new reporting system. This article highlights the reporting, processing, and role of theranostics and immunocytochemistry in serous fluid cytology.
Exploiting Polythiophenyl‐Triazine‐Based Conjugated Microporous Polymer with Superior Lithium‐Storage Performance
Authors: Ren Shi‐Bin , Ma Wenyan , Zhang Chong , Chen Lei , Wang Kai , Li Rong‐Rong , Shen Mao , Han De‐Man , Chen Yuxiang , Jiang Jia‐Xing
Published: March 2020

Conjugated microporous polymers (CMPs) have been heralded as promising energy‐storage materials with advantages such as chemical flexibility, porous structure, and environmentally friendliness. Herein, a novel conjugated microporous polymer was synthesized by integrating triazine, thiophene, and benzothiadiazole into a polymer skeleton, and the Li+‐storage performance for the as‐synthesized polymer anode in Li‐ion batteries (LIBs) was investigated. Benefiting from the inherent large surface area, plentiful redox‐active units, and hierarchical porous structure, the polymer anode delivered a high Li+ storage capacity up to 1599 mAh g−1 at a current rate of 50 mA g−1 with an excellent rate behavior (363 mAh g−1 at 5 A g−1) and a long‐term cyclability of 326 mAh g−1 over 1500 cycles at 5 A g−1, implying that the newly developed polymer anode offers a great prospect for next‐generation LIBs.
Ordered‐Mesoporous‐Carbon‐Confined Pb/PbO Composites: Superior Electrocatalysts for CO2 Reduction
Authors: Huang Xin , Song Jinliang , Wu Haoran , Xie Chao , Hua Manli , Hu Yue , Han Buxing
Published: March 2020

CO2 electroreduction has gained significant interest. However, fabricating cost‐effective nonprecious‐metal electrocatalysts that can selectively convert CO2 to a specific product remains highly challenging. Herein, Pb‐based materials consisting of Pb0 and PbO confined in ordered mesoporous carbon (OMC) (Pb/PbO@OMC) were constructed for CO2 electroreduction to CO. Interestingly, the activity and selectivity of the Pb/PbO@OMC varied with the molar ratio of Pb0/PbO. The material calcined at 800 °C (Pb/PbO@OMC‐800) with a Pb0/PbO ratio of 0.58 provided the best result with CO as the only carbon‐based product, and the Faradaic efficiency of CO reached 98.3 % at a high current density of 41.3 mA cm−2. Detailed studies indicated that Pb0, PbO, and OMC co‐operated well to enhance the performance of Pb/PbO@OMC‐800, which mainly originated from the good interface between Pb0 and PbO, higher electrochemical active surface area, and faster electron transfer to form the CO2⋅− intermediate.
Infant emotion regulation and cortisol response during the first 2 years of life: Association with maternal parenting profiles
Authors: Wu Qiong , Feng Xin
Published: March 2020

This study investigated the prospective associations among emotion expression, behavioral regulation, and cortisol responses in relation to different maternal parenting behaviors during the first 2 years of the infant's life, among a sample of low‐income families. Participants included 1,141 mother–child pairs, assessed when the infants were 6, 15, and 24 months old. Maternal parenting behaviors were observed at the 6‐month assessment, whereas infant emotion expression, orienting toward mothers, and cortisol responses were measured using a series of emotion‐eliciting tasks at all time points. A latent profile analysis revealed four maternal parenting profiles: Detached, Intrusive, Average, and Engaged. Furthermore, a multiple‐group path model revealed distinct patterns of emotion development for infants within different maternal parenting groups. Among children with Engaged and Average mothers, orienting behaviors tended to predict less negative emotion and cortisol responses, which was associated with more future orienting behaviors. Conversely, among children with Intrusive and Detached mothers, orienting behaviors tended to predict more negative emotion and cortisol responses, which predicted less future orienting behaviors. Findings of this study enhance current understanding of how different profiles of maternal parenting behaviors impact infant emotional development in poverty, with significant implications for intervention programs targeting early mother–infant interactions.
Zonulin as a potential putative biomarker of risk for shared type 1 diabetes and celiac disease autoimmunity
Authors: Wood Heickman Lauren K. , DeBoer Mark D. , Fasano Alessio
Published: March 2020

The incidence of type 1 diabetes (T1D) is increasing annually, in addition to other childhood‐onset autoimmune diseases. This review is inspired by recent strides in research defining the pathophysiology of autoimmunity in celiac disease, a disease that has significant genetic overlap with T1D. Population genetic studies have demonstrated an increased proportion of newly diagnosed young children with T1D also have a higher genetic risk of celiac disease, suggesting that shared environmental risk factors are driving the incidence of both diseases. The small intestine barrier forms a tightly regulated interface of the immune system with the outside world and largely controls the mucosal immune response to non‐self‐antigens, dictating the balance between tolerance and immune response. Zonulin is the only known physiological modulator of the intercellular tight junctions, important in antigen trafficking, and therefore, is a key player in regulation of the mucosal immune response. While usually tightly controlled, when the zonulin pathway is dysregulated by changes in microbiome composition and function, antigen trafficking control is lost, leading to loss of mucosal tolerance in genetically susceptible individuals. The tenant of this hypothesis is that loss of tolerance would not occur if the zonulin‐dependent intestinal barrier function is restored, thereby preventing the influence of environmental triggers in individuals genetically susceptible to autoimmunity. This review outlines the current research and a structured hypothesis on how a dysregulated small intestinal epithelial barrier, a “leaky gut,” may be important in the pathogenesis of autoimmunity in certain individuals at risk of both T1D and celiac disease.
Gut dysbiosis and heart failure: navigating the universe within
Authors: Madan Shivank , Mehra Mandeep R.
Published: March 2020

Alternations in gut microbial composition (i.e. loss of microbial diversity or ‘gut dysbiosis’) have been associated with heart failure with reduced ejection fraction (HFrEF). It has also been suggested that increased chronic low‐level inflammation and immune system dysregulation seen in patients with HFrEF could be related to gut dysbiosis and increased intestinal permeability. Hence, the concept of modulating gut microbial composition with the goal of reducing systemic inflammation and controlling HFrEF progression has generated a substantial interest in the scientific community. However, several challenges to the gut dysbiosis theory remain as the exact gut microbial composition in HFrEF patients in these studies is not the same and a common microbiome linked to HFrEF is not yet established. With the advances in culture independent sequencing techniques it has also become evident that the gut microbiome may be much more diverse than previously believed. Further, various ‘omic’ technologies have enabled us to appreciate the potential role of gut microbial metabolites in various physiological processes in the host. Hence, identification of specific gut microbial metabolites may offer an alternative approach at solving this gut microbiome‐HFrEF puzzle. In the current review, we evaluate the concept of gut symbiosis, the potential role of gut dysbiosis in systemic inflammation and HFrEF, and finally highlight the challenges faced by the gut dysbiosis theory in HFrEF and provide a framework for the possible solutions.
Sites of Electron Transfer Reactivity in Organometallic Compounds
Authors: Kaim Wolfgang
Published: March 2020

Three essentially different sites are identified for redox activity in organometallic compounds: The metal, the organometallic (C‐bonded) ligand(s), and potentially noninnocent co‐ligands. Typical reactivity patterns resulting from either of these alternatives will be pointed out by means of representative examples, possibly involving unusual metal oxidation states, carbon‐centered radicals, or ligand redox systems.
Metal Catalysis with Microwaves in Organic Synthesis: a Personal Account
Authors: Petricci Elena , Cini Elena , Taddei Maurizio
Published: March 2020

In the last 25 years, the influence of microwave (MW) irradiation in chemical synthesis has intrigued chemists for the exceptional results obtained in shortening reaction times. Inspired by recent papers that demonstrate the existence of a non‐thermal effect in some MW assisted reactions, we examine herein a series of reactions catalysed by homogeneous and heterogeneous metals occurring under MW irradiation. The review contains examples of hydroformylation, hydrogenation (including enantioselective versions with 98 % ee), hydrogenolysis, hydrogen transfer and borrowing hydrogen reactions carried out under MWs and metal catalysis. An increase in the influence of MW irradiation was often observed in reactions performed with heterogeneous catalysts such as Pd/C. In these cases, a “microwave catalysis” can be possible. The increase in the (apparent) reaction rate requires the contribution of MW irradiation that modifies the catalyst surface, driving the reaction progress as occurring in other kinds of catalysis.
Electrochemistry of Novel Phthalocyanines Bearing 1,2,4 Triazole Groups
Authors: Akyüz Duygu , Demirbaş Ümit , Akçay Hakkı Türker , Menteşe Emre , Koca Atıf , Kantekin Halit
Published: March 2020

The phthalonitrile (3) and triazole substituted metallo phthalocyanines (MPc) (4–7) were prepared. The novel compounds were characterized with spectroscopic data. Electrochemical analyses of metallophthalocyanines (4–7) bearing triazole substituents were performed to investigate redox activity of phthalocyanines (Pcs) ring. While incorporation of Ni2+ and Cu2+ cations in the Pc core only influenced peak positions of Pc ring processes, Co2+ and Cl1−Fe3+ cations of CoPc and FePc gave extra redox couples to the Pc based ones. Releasing the axial Cl1− anion on Fe3+ cation of FePc during the reduction reactions complicated the redox responses. Redox reactions of Co2+ and Fe3+ metal centers also considerable influenced spectral and color responses of these complexes.
Review trends and expectations for international higher education
Authors: Dennis Marguerite J.
Published: March 2020

What did we learn about American international higher education in 2019? We learned:
Load balancing approach for heterogeneous 2‐tiered wireless sensor networks
Authors: Zafer Mostefa , Senouci Mustapha Reda , Aissani Mohamed
Published: March 2020

This article addresses the problem of managing power consumption in a heterogeneous Wireless Sensor Network (WSN), composed of Sensor Nodes (SNs), Relay Nodes (RNs), and a Collector Node (CN). The aim is to extend the lifetime of RNs that actively participate in data routing. The proposed approach consists in creating, from the dense initial topology, several 2‐tiered subtopologies, linking the SNs to the CN, without having common RNs. The simultaneous exploitation of these subtopologies in the data routing from the SNs to the CN constitutes a load balancing solution for the considered WSN. Obtained simulation results demonstrate the effectiveness of the proposed approach in extending the lifetime of the
RNs.
CFD assisted investigation of mechanical juice extraction from cassava leaves and characterization of the products
Authors: Latif Sajid , Romuli Sebastian , Barati Ziba , Müller Joachim
Published: March 2020

Cassava is grown because of its starchy roots, but the leaves being rich in protein are mostly underutilized. For protein recovery, mechanical juice extraction from cassava leaves and the extraction process was evaluated using computational fluid dynamics (CFD) simulation. The influence of input variables such as nozzle diameter and rotational speed of the screw was investigated in relation to process efficiency. The highest green juice extraction yield (81.0%) from cassava leaves and dry matter of press cake (61.3%) were achieved by using 4 mm nozzle diameter and 18 rpm screw speed. The protein content of the cassava leaves, press cake, juice sediment, and juice supernatant was found to be 31.5%, 27.7%, 26.2%, and 12.4%, respectively. The crude protein, cellulose, hemicellulose, lignin, and total phenolic content mainly accumulated in the press cake. The screw pressing concentrated the amino acids in the press cake and the juice sediment.
Skewness and index futures return
Authors: Jondeau Eric , Wang Xuewu , Yan Zhipeng , Zhang Qunzi
Published: March 2020

In this paper, we show that the individual skewness, defined as the average of monthly skewness across firms, performs very well at predicting the return of S&P 500 index futures. This result holds after controlling for the liquidity risk or for the current business cycle conditions. We also find that individual skewness performs very well at predicting index futures returns out‐of‐sample.
Medial temporal lobe regions mediate complex visual discriminations for both objects and scenes: A process‐based view
Authors: Lawrence Ashley V. , Cardoza Jose , Ryan Lee
Published: March 2020

Debate continues regarding the role of medial temporal lobe regions in object and scene processing. Considerable evidence indicates that the perirhinal cortex (PRC) plays an important role in the perception of objects—namely, in disambiguating complex objects that share conjunctions of features. These findings support a content‐specific view of medial temporal lobe functioning in which PRC is critically important for processing complex objects, while the parahippocampal cortex (PHC) and hippocampus (HC) may be selectively engaged during scene processing. However, emerging evidence from both animal and human studies suggest that the PRC is sensitive to spatial configural information as well as object information. In this fMRI study, we observed preliminary evidence for BOLD activation in the PRC during a complex visual discrimination task for objects and scenes, as well as robust activation for both stimulus types in PHC and HC. The results are discussed in light of a recent process‐based model of medial temporal lobe functioning.
Role of cellular, molecular and tumor microenvironment in hepatocellular carcinoma: Possible targets and future directions in the regorafenib era
Authors: Juengpanich Sarun , Topatana Win , Lu Chen , Staiculescu Daniel , Li Shijie , Cao Jiasheng , Lin Jiacheng , Hu Jiahao , Chen Mingyu , Chen Jiang , Cai Xiujun
Published: March 2020

Hepatocellular carcinoma (HCC) remains as one of the major causes of cancer‐related mortality, despite the recent development of new therapeutic options. Regorafenib, an oral multikinase inhibitor, is the first systemic therapy that has a survival benefit for patients with advanced HCC that have a poor response to sorafenib. Even though regorafenib has been approved by the FDA, the clinical trial for regorafenib treatment does not show significant improvement in overall survival. The impaired efficacy of regorafenib caused by various resistance mechanisms, including epithelial–mesenchymal transitions, inflammation, angiogenesis, hypoxia, oxidative stress, fibrosis and autophagy, still needs to be resolved. In this review, we provide insight on regorafenib microenvironmental, molecular and cellular mechanisms and interactions in HCC treatment. The aim of this review is to help physicians select patients that would obtain the maximal benefits from regorafenib in HCC therapy.