bluuebunny/crossref_metadata_2025_split huggingface dataset:
Verbesserter Zugang zu organisch löslichen Di‐ und Tetrafluoridochlorat(I/III)‐Salzen
Authors: Pröhm P. , Schmid J. R. , Sonnenberg K. , Voßnacker P. , Steinhauer S. , Schattenberg C. J. , Müller R. , Kaupp M. , Riedel S. 
Published: May 2020

AbstractEs wird über eine einfache Eintopfsynthese für Tetraalkylammoniumtetrafluoridochlorat(III), [kat][ClF4] ([kat]=[NEt3Me]+, [NEt4]+), im Gramm‐Maßstab berichtet. In Acetonitril wird ein Chloridsalz bei tiefen Temperaturen mit verdünntem Fluor umgesetzt. Das Zwischenprodukt dieser Reaktion, [ClF2]−, wird zum ersten Mal strukturell charakterisiert. Mögliche Anwendungen des [ClF4]−‐Salzes werden durch folgende Reaktionen eruiert: Diphenyldisulfid, Ph2S2, wird in Pentafluorsulfanylbenzol, PhSF5, überführt, sowie die CN‐Gruppen in Acetonitril und in Tetracyanoborat ([B(CN)4]−) in CF3‐Gruppen. Eine Reaktion mit Kohlenstoffmonoxid, CO, führt zu Fluorphosgen, COF2. Elementares Gold löst sich unter Bildung des Tetrafluoridoaurates, [AuF4]−.
Cobalt Single‐Atom Catalysts with High Stability for Selective Dehydrogenation of Formic Acid
Authors: Li Xiang , Surkus Annette‐Enrica , Rabeah Jabor , Anwar Muhammad , Dastigir Sarim , Junge Henrik , Brückner Angelika , Beller Matthias 
Published: May 2020

AbstractMetal–organic framework (MOF)‐derived Co‐N‐C catalysts with isolated single cobalt atoms have been synthesized and compared with cobalt nanoparticles for formic acid dehydrogenation. The atomically dispersed Co‐N‐C catalyst achieves superior activity, better acid resistance, and improved long‐term stability compared with nanoparticles synthesized by a similar route. High‐angle annular dark‐field–scanning transmission electron microscopy, X‐ray photoelectron spectroscopy, electron paramagnetic resonance, and X‐ray absorption fine structure characterizations reveal the formation of CoIINx centers as active sites. The optimal low‐cost catalyst is a promising candidate for liquid H2 generation.
Synthesis, crystal structures, fluorescence, electrochemiluminescent properties, and Hirshfeld surface analysis of four Cu/Mn Schiff‐basecomplexes
Authors: Zeng Yumei , Zhang Haiyang , Zhang Yujie , Ji Fanghua , Liang Jinlu , Zhang Shuhua 
Published: May 2020

AbstractFour new complexes [Cu(L1)2]n (1), [Mn(L1)2]n (2), [Cu(L2)2]n (3), [Mn(L2)2]n (4, HL1 = 2‐(((4H‐1,2,4‐triazol‐4‐yl)imino)methyl)‐4,6‐dichlorophenol; HL2 = 2‐(((4H‐1,2,4‐triazol‐4‐yl)imino)methyl)‐4,6‐dibromophenol) were synthesized by microreaction bottle method. Complexes 1 and 3 and 2 and 4 are isomorphous heterostructures having the same molecular structure. The structures of 1–4 were characterized using single X‐ray diffraction, Fourier‐transform infrared spectroscopy, powder X‐ray diffraction, and thermogravimetric analysis, and their potential applications were analyzed by detecting their fluorescence and electrochemical luminescence (ECL). Hirshfeld surface analysis indicates that X···H (X = Br, Cl) interactions play a crucial role in stabilizing the self‐assembly process of 1–4, which show highly intense ECL in N,N‐dimethylformamide solution and high thermal stability.
CDC20 inhibitor Apcin inhibits embryo implantation in vivo and in vitro
Authors: Guo Chuanjia , Kong Fandou , Lv Yunyi , Gao Na , Xiu Xiaoxin , Sun Xiaojing 
Published: May 2020

AbstractFor successful implantation, endometrial receptivity must be established. The high expression of CDC20 in many kinds of malignant tumours has been reported, and it is related to the occurrence and development of tumours. According to these functions, we think that CDC20 may also play important roles in the process of embryo implantation. To prove our hypothesis, we observed the distribution and expression of CDC20 in mouse and human early pregnancy. The effect of E2 and/or P4 on the expression of CDC20 in human endometrial cells was detected by Western blot. To further explore whether CDC20 is an important factor in adhesion and proliferation. The results showed that the expression of CDC20 in the uterus and menstrual cycle of early pregnant mice was spatiotemporal. E2 can promote the expression of CDC20. On the contrary, P4 and E2 + P4 inhibited the expression of CDC20. We also detected the proliferation and adhesion of human endometrial cells. We found that the inhibition of CDC20 with its inhibitor Apcin could reduce the adhesion rate and proliferation ability to RL95‐2 and HEC‐1A cells, respectively. Inhibiting CDC20 by Apcin could interfere the embryo implantation of mouse. It is suggested that CDC20 may play an important role in the process of embryo implantation.Significance of the studyEmbryo implantation is an extremely complex and delicate process, including identification, localisation, adhesion and invasion between embryo and endometrium. Studies have shown the process of embryo implantation is very similar to that of tumour invasion. CDC20 is a cancer‐promoting factor. We found CDC20 is spatially and spatially expressed in mouse and human menstrual cycles and is regulated by oestrogen and progesterone. Apcin can inhibit the adhesion of JAR cells and embryo implantation of mouse. CDC20 may provide a new way to improve the success rate of assisted reproduction.
Biocatalytic Alkylation Cascades: Recent Advances and Future Opportunities for Late‐Stage Functionalization
Authors: McKean Iain J. W. , Hoskisson Paul A. , Burley Glenn A. 
Published: May 2020

AbstractThis Concept article describes the latest developments in the emerging area of late‐stage biocatalytic alkylation. Central to these developments is the ability to efficiently prepare S‐adenosyl methionine (SAM) cofactor analogues and couple this with enzymatic alkyl transfer. Recent developments in the enzymatic synthesis of SAM cofactor analogues are summarized first, followed by their application as alkyl transfer agents catalyzed by methyltransferases (MTases). Second, innovative methods to regenerate SAM cofactors by enzymatic cascades is reported. Finally, future opportunities towards establishing a generalized platform for late‐stage alkylation are described.
Left ventricular pacing induced polymorphic ventricular tachycardia via the adaptive left ventricle pacing algorithm
Authors: Khalil Fouad , Del‐Carpio Munoz Freddy , Deshmukh Abhishek , Killu Ammar M. 
Published: May 2020

AbstractProviders should be aware of the possibility of cardiac resynchronization therapy‐related proarrhythmia which could be life‐threatening. His‐bundle pacing may serve as an alternative, more physiological, option in the management as it preserves the normal sequence of depolarization from the septum to the lateral wall, and from endocardium to epicardium.
Syntheses of Pt‐Ni Hollow Nanoalloy for Hydrogen Generation from Catalytic Hydrolysis of Ammonia Borane
Authors: Li Zhao , Pei Qijun , Yu Yang , Jing Zijun , Wang Jintao , He Teng 
Published: May 2020

AbstractEfficient bimetallic nano‐catalysts consisting of both noble metals and non‐noble metals, are highly desired for the development of new hydrogen storage materials. In this work, supported Pt−Ni nanoalloys with hollow structures were successfully synthesized using galvanic replacement method and exhibited excellent catalytic activity with a turnover frequency as high as 302.3 molH2 ⋅ molmetal−1 ⋅ min−1 for the hydrolysis of ammonia borane. The chemical composition and structure of the alloy can be rationally controlled by the synthetic conditions, which further tune the catalytic activities of hydrogen evolution.
Activity‐Directed Synthesis of Inhibitors of the p53/hDM2 Protein–Protein Interaction
Authors: Green Adam I. , Hobor Fruzsina , Tinworth Christopher P. , Warriner Stuart , Wilson Andrew J. , Nelson Adam 
Published: May 2020

AbstractProtein–protein interactions (PPIs) provide a rich source of potential targets for drug discovery and biomedical science research. However, the identification of structural‐diverse starting points for discovery of PPI inhibitors remains a significant challenge. Activity‐directed synthesis (ADS), a function‐driven discovery approach, was harnessed in the discovery of the p53/hDM2 PPI. Over two rounds of ADS, 346 microscale reactions were performed, with prioritisation on the basis of the activity of the resulting product mixtures. Four distinct and novel series of PPI inhibitors were discovered that, through biophysical characterisation, were shown to have promising ligand efficiencies. It was thus shown that ADS can facilitate ligand discovery for a target that does not have a defined small‐molecule binding site, and can provide distinctive starting points for the discovery of PPI inhibitors.
Triquinoline‐ versus Fullerene‐Based Cycloparaphenylene Ionic Complexes: Comparison of Photoinduced Charge‐Shift Reactions
Authors: Stasyuk Anton J. , Stasyuk Olga A. , Solà Miquel , Voityuk Alexander A. 
Published: May 2020

AbstractA triquinoline cationic moiety (TQ⋅H+) has recently been designed as a novel molecular unit for supramolecular chemistry. In addition to some useful features, TQ⋅H+ has strong electron‐acceptor properties, which renders the molecular cation a unique element in nanochemistry. TQ⋅H+ is found to form complexes with coronene (COR) and cycloparaphenylene (CPP). In this work, we report a computational study of photoinduced electron transfer in supramolecular complexes TQ⋅H+‐COR, TQ⋅H+⊂[12]CPP and (TQ⋅H+‐COR)⊂[12]CPP. The electron‐transfer rates are estimated by using the semi‐classical approach. The results are compared with the data previously obtained for a structurally similar inclusion complex Li+@C60⊂[10]CPP. In particular, we found a red solvatochromic shift for charge‐shift bands in the TQ⋅H+‐complexes unlike a blueshift showed by Li+@C60⊂[10]CPP. This distinction is explored in terms of electronic and structural features of the systems.
Synthesis of Chiral MOF‐74 Frameworks by Post‐Synthetic Modification by Using an Amino Acid
Authors: Gheorghe Andreea , Strudwick Benjamin , Dawson Daniel M. , Ashbrook Sharon E. , Woutersen Sander , Dubbeldam David , Tanase Stefania 
Published: May 2020

AbstractThe synthesis of chiral metal–organic frameworks (MOFs) is highly relevant for asymmetric heterogenous catalysis, yet very challenging. Chiral MOFs with MOF‐74 topology were synthesised by using post‐synthetic modification with proline. Vibrational circular dichroism studies demonstrate that proline is the source of chirality. The solvents used in the synthesis play a key role in tuning the loading of proline and its interaction with the MOF‐74 framework. In N,N′‐dimethylformamide, proline coordinates monodentate to the Zn2+ ions within the MOF‐74 framework, whereas it is only weakly bound to the framework when using methanol as solvent. Introducing chirality within the MOF‐74 framework also leads to the formation of defects, with both the organic linker and metal ions missing from the framework. The formation of defects combined with the coordination of DMF and proline within the framework leads to a pore blocking effect. This is confirmed by adsorption studies and testing of the chiral MOFs in the asymmetric aldol reaction between acetone and para‐nitrobenzaldehyde.
Di‐ and Tetracyano‐Substituted Pyrene‐Fused Pyrazaacenes: Aggregation in the Solid State
Authors: Ueberricke Lucas , Ciubotaru Ioana , Ghalami Farhad , Mildner Felix , Rominger Frank , Elstner Marcus , Mastalerz Michael 
Published: May 2020

AbstractFive di‐ and tetracyano‐substituted pyrene‐fused pyrazaacenes were synthesized and studied as potential electron acceptors in the solid state. Single crystals of all compounds were grown and the crystal packing studied by DFT calculations (transfer integrals and reorganization energies) to get insight into possible use for semiconducting charge transport.
Isothermal crystallization of PLA: Nucleation density and growth rates of α and α' phases
Authors: Foglia Fabiana , De Meo Annarita , Iozzino Valentina , Volpe Valentina , Pantani Roberto 
Published: May 2020

AbstractFrom a technological point of view, poly(lactic acid) (PLA) is one of the most important polymers produced from renewable sources, due to its versatility, relatively acceptable processability, and low cost. However, a significant limitation exists in its slow crystallization kinetics, which results in amorphous products having low mechanical properties and thermal resistance. For this reason, quantitative knowledge of the phenomenon of crystallization kinetics is fundamental. In this work, the crystallization kinetics in quiescent conditions of a commercial grade of PLA was analyzed in terms of nucleation and growth rates by direct morphological observations at different crystallization temperatures (Tc) and by calorimetric analysis in isothermal and non‐isothermal conditions. The optical analysis showed a spherulitic morphology with radial growth of the lamellae. The analysis of the growth rate evidenced the α/α'‐crystals polymorphism with a transition temperature of ~120°C. Based on experimental observation, the crystallization kinetics of the two crystalline phases were assessed.
On the Formation of the Popcorn Flavorant 2,3‐Butanedione (CH3COCOCH3) in Acetaldehyde‐Containing Interstellar Ices
Authors: Kleimeier N. Fabian , Turner Andrew M. , Fortenberry Ryan C. , Kaiser Ralf I. 
Published: May 2020

AbstractAcetaldehyde (CH3CHO) is ubiquitous throughout the interstellar medium and has been observed in cold molecular clouds, star forming regions, and in meteorites such as Murchison. As the simplest methyl‐bearing aldehyde, acetaldehyde constitutes a critical precursor to prebiotic molecules such as the sugar deoxyribose and amino acids via the Strecker synthesis. In this study, we reveal the first laboratory detection of 2,3‐butanedione (diacetyl, CH3COCOCH3) – a butter and popcorn flavorant – synthesized within acetaldehyde‐based interstellar analog ices exposed to ionizing radiation at 5 K. Detailed isotopic substitution experiments combined with tunable vacuum ultraviolet (VUV) photoionization of the subliming molecules demonstrate that 2,3‐butanedione is formed predominantly via the barrier‐less radical–radical reaction of two acetyl radicals (CH3ĊO). These processes are of fundamental importance for a detailed understanding of how complex organic molecules (COMs) are synthesized in deep space thus constraining the molecular structures and complexity of molecules forming in extraterrestrial ices containing acetaldehyde through a vigorous galactic cosmic ray driven non‐equilibrium chemistry.
Retracted: Building a richer understanding of diversity through causally consistent evenness measures
Authors: Pierson Kawika 
Published: May 2020

AbstractCausally consistent evenness measures can only be changed when the populations they refer to change. This novel property is deeply important for making causal inferences, and yet every prominent evenness measure is not causally consistent. This paper proposes a family of causally consistent evenness measures, and while any evenness measure can be made to be causally consistent, the family I introduce has the added benefit of a straightforward interpretation as a percentage evenness. I go on to illustrate the performance of these measures, and demonstrate the importance of causal consistency not only for causal inference but also for correctly reflecting the evenness of ecological communities. I also present several alternative transformations of my preferred measures, which work to address potential critiques in advance, communicate evenness to nontechnical audiences, and connect my work to more familiar ecological indicators.
A Novel Fullerene‐Pyrrole‐Pyrrole‐3‐Carboxylic Acid Nanocomposite Modified Molecularly Imprinted Impedimetric Sensor for Dopamine Determination in Urine
Authors: Ertuğrul Uygun Hilmiye Deniz , Demir M. Nalan 
Published: May 2020

AbstractIn this study, we designed an electrochemical impedance based sensor by using molecularly imprinted fullerene modified pyrrole‐pyrrole‐3‐carboxylic acid copolymers on screen printed carbon electrode to monitor dopamine in real urine samples. All modifications were characterized by electrochemical impedance spectroscopy (EIS) and Scanning Electron Microscopy (SEM). Performance parameters of the developed sensor system were determined by calibration curve performed between 25 ng/mL and 250 ng/mL (R2= 0.9939). LOD and LOQ were 8.77 ng/mL and 26.6 ng/mL, respectively. The developed sensor method was compared with ELISA. The regression analysis between ELISA and the sensor analysis showed good correlation with R2= 0.979
Body Composition of Very Low‐Birth‐Weight Infants Fed Fortified Human Milk: A Pilot Study
Authors: McNelis Kera , Liu Chunyan , Ehrlich Shelley , Fields Christopher , Fields Trayce , Poindexter Brenda 
Published: May 2020

AbstractBackgroundAlthough donor milk is increasingly fed to preterm infants, the resultant quality of growth and body composition is unknown. The aim of this pilot study was to describe the body composition of very low‐birth‐weight infants fed human milk in the neonatal intensive care unit and explore the association between the proportion of donor human milk intake and fat‐free and fat mass deposition.MethodsBody composition of 30 preterm infants fed maternal and donor human milk was measured by air displacement plethysmography. Regression models were developed to associate each parameter of body composition with the proportion of donor milk intake and other explanatory variables.ResultsThe proportion of donor milk intake was negatively associated with body fat percentage (P= .01). Fat‐free massz‐scores ranged from −4.6 to 1.11 (meanz‐score of −0.95, 17th percentile).ConclusionDonor human milk intake is negatively associated with body fat percentage in this pilot study of very low‐birth‐weight preterm infants.
Designing for effective controlled release in agricultural products: new insights into the complex nature of the polymer–active agent relationship and implications for use
Authors: Levett Ian , Liao Minjie , Pratt Chris , Redding Matthew , Laycock Bronwyn , Pratt Steven 
Published: May 2020

AbstractBACKGROUNDVarious active chemical agents, such as soil microbial inhibitors, are commonly applied to agricultural landscapes to optimize plant yields or minimize unwanted chemical transformations. Dicyandiamide (DCD) is a common nitrification inhibitor. However, it rapidly decomposes under warm and wet conditions, losing effectiveness in the process. Blending DCD with an encapsulating polymer matrix could help overcome this challenge and slow its release. Here, we encapsulated DCD in a biodegradable matrix of poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) and investigated the effects of DCD crystal size and loading rates on release rates.RESULTSThree DCD crystal size fractions (0–106, 106–250 and 250–420 μm) were blended with PHBV at 200, 400, 600 and 800 gkg−1 loadings through extrusion processing and release kinetics were studied in water over 8 weeks. For loadings ≥ 600 g kg−1, more than 95% release was reached within the first 7 days. By contrast, at 200 g kg−1 loading only 10%, 36% and 57% of the DCD was mobilized after 8 weeks in water for 0 to 106 μm, 106 to 250 μm and 250 to 420 μm crystal size fractions, respectively.CONCLUSIONThe lower percolation threshold for this combination of materials lies between 200 and 400 g kg−1 DCD loading. The grind size fraction of DCD significantly affects the quantity of burst release from the surface of the pellet, particularly below the lower percolation threshold. The results presented here are likely translatable to the encapsulation and release of other crystalline materials from hydrophobic polymer matrices used in controlled release formulations, such as fertilizers, herbicides and pesticides. © 2020 Society of Chemical Industry
Effects of infrared freeze drying on volatile profile, FTIR molecular structure profile and nutritional properties of edible rose flower (Rosa rugosa flower)
Authors: Qiu Liqing , Zhang Min , Bhandari Bhesh , Wang Bin 
Published: May 2020

AbstractBACKGROUNDInfrared freeze drying (IRFD) utilizes infrared radiation as a novel heating source in freeze drying (FD), leading to high‐quality dehydrated products and less drying time. The present study aimed to investigate the effects of IRFD on the drying characteristics (drying time and energy consumption), volatiles, physical structure and nutritional properties of Rosa rugosa flower. In addition, freeze drying (FD) and hot air drying (HAD) were also evaluated in a comparison with the IFRD drying method with respect to product quality parameters.RESULTSFifty‐six volatile compounds were identified in fresh samples, whereas 53, 51 and 46 volatile compounds were identified in FD, IRFD and HAD samples, respectively. FD and IRFD were relatively more effective than HAD for better retention of volatile compounds of Rosa rugose flower. E‐nose analysis also exhibited similar flavor properties in FD and IRFD samples. The molecular structure properties of FD and IRFD samples measured by FTIR spectroscopy were also similar. As for nutritional properties, HAD dramatically (P < 0.05) reduced the nutritional values of R. rugosa flower after drying. The content of vitamin C (from 14.83 to 12.15 mg 100 g–1), flavonoids (from 478.00 to 333.33 mg 100 g–1) and anthocyanins (from 220.70 to 196.90 mg 100 g–1) in R. rugosa flower is well retained by IRFD and no significant difference (P < 0.05) was observed between FD and IRFD samples.CONCLUSIONIRFD was found to be effective in retaining the aroma, structure and nutrition of R. rugosa flower, as well as demonstrating a lower energy consumption and shorter drying time. © 2020 Society of Chemical Industry
Evaluation of convective storms using spaceborne radars over the Indo‐Gangetic Plains and western coast of India
Authors: Mangla Rohit , Indu J. , Lakshmi Venkataraman 
Published: May 2020

AbstractMonsoonal convective systems are examined using four years (2014–2017) of radar reflectivity data from the Precipitation Features (PFs) database of the Global Precipitation Measurement (GPM) Microwave Imager (GMI) and Dual Precipitation Radar (DPR). The study classifies the cumulonimbus tower (PF‐CbT) at 12 km, and intense convective clouds at both 3 km (PF‐ICC3) and 8 km (PF‐ICC8) based on PFs' reflectivity threshold at a reference height over the Indo‐Gangetic Plains (IGP) and Indian Western coastal (WG) region, including the Arabian Sea and the Western Ghats. Results show that the regional variations are more enhanced for the PF‐ICC3 clouds with high occurrence over the IGP region. In the mixed‐phase regime, the median maximum reflectivity is greater for all cloud types over the IGP region. The occurrences of 20 and 40 dBZ echo the top height > 5 km is higher in the IGP region, indicating the deep and intense convection. The aerosol–cloud interaction is examined for warm and mixed‐phase clouds. The vertical structure of aerosols shows the suppression of warm rainfall over the IGP region. However, rainfall intensity increases in mixed‐phase clouds because of the dominancy of ice processes. The significant positive (negative) correlation is observed between the echo top height and aerosol concentrations over the IGP (WG) region. The value of the novel findings clearly states the region‐specific demand for a closer examination of the radar reflectivity–aerosol interaction on regime‐dependent clouds over the IGP region as well as contrasts against other regions for similar and contrasting cloud–aerosol‐radiation interactions.