Abstract The consumption of ayahuasca, a brew prepared from the decoction of two Amazon plants, has increased worldwide in the last decades. This fact raised questions about the safety in its oral administration. In this sense, information concerning the chemical composition of ayahuasca is essential to find a comprehensive reply. Therefore, the aim of this study consisted of determining the elemental composition of ready-to-consume ayahuasca samples produced in Brazil, in order...
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Abstract Objectives Implants with a triangular neck were recently introduced to limit peri‐implant bone loss. The primary objective of this randomized controlled trial was to compare peri‐implant bone changes of circular versus triangular cross‐section neck implants 1‐year after loading. The secondary objectives were to assess buccal hard tissue thickness changes, Pink Esthetic Score (PES) and patient satisfaction. Material and methods Thirty four patients requiring replacement of the...
Thu Jun 04, 2020 18:56
Publication date: September 2020Source: Clinical Neurology and Neurosurgery, Volume 196Author(s): Alba Scerrati, Stefania Labanti, Giorgio Lofrese, Lorenzo Mongardi, Michele Alessandro Cavallo, Luca Ricciardi, Pasquale De Bonis
Thu Jun 04, 2020 19:28
Abstract Background Treatment of patients with head and neck cancer can result in disrupted mastication. To measure masticatory performance in people with compromised mastication, the Mixing Ability Test (MAT) was developed. Objective In this study, the reliability of the MAT was evaluated in patients with head and neck cancer and healthy controls. Methods Thirty‐four patients with head and neck cancer and 42 healthy controls performed the MAT twice on the same day. To assess reliability,...
Thu Jun 04, 2020 11:51
Σε 15 ανέρχονται τα νέα εργαστηριακά επιβεβαιωμένα κρούσματα κορωνοϊού στη χώρα μας από τις 2 Ιουνίου, σύμφωνα με την ανακοίνωση του Εθνικού Οργανισμού Δημόσιας Υγείας (ΕΟΔΥ). Η σύγκριση γίνεται με την προηγούμενη ανακοίνωση του ΕΟΔΥ, την περασμένη Τρίτη. Σημειώνεται ότι -εκτός εκτάκτων περιπτώσεων- οι ανακοινώσεις θα γίνονται πλέον κάθε Πέμπτη. Ο συνολικός αριθμός των κρουσμάτων ανέρχεται σε 2.952 (ημερήσια μεταβολή +0.5%), εκ των οποίων 55.2% άνδρες. Από το σύνολο των 2952 κρουσμάτων, 652 (22.1%)...
Thu Jun 04, 2020 18:17
Πιστεύετε ότι έχετε κάποιο σκοπό στη ζωή σας, έναν νόημα ή έναν τελικό στόχο; Αν όχι, σκέφτεστε πως στο μάλλον θα τον ανακαλύψετε; Πριν δώσετε απάντηση, έχετε σκεφτεί αν κάτι τέτοιο θα μπορούσε να επηρεάσει τη συνολική σας ευημερία; Πρόσφατη έρευνα που δημοσιεύτηκε στο The Journal of Clinical Psychiatry έχει μια ενδιαφέρουσα απάντηση. Ερευνητές από το Πανεπιστήμιο του Χάρβαρντ ζήτησαν σε 1.042 ενήλικες, μέσης ηλικίας 65 ετών, να συμπληρώσουν ερωτηματολόγια σχετικά με το νόημα στη ζωή τους και κατόπιν...
Thu Jun 04, 2020 09:45
Μια μελέτη που διεξήχθη στο Σίδνεϊ κατά τη διάρκεια του πρώτου επιδημικού κύματος του COVID-19 στην Αυστραλία διαπίστωσε συσχέτιση μεταξύ χαμηλότερης υγρασίας και αύξησης των κρουσμάτων. Συγκεκριμένα, οι ερευνητές ανακάλυψαν ότι η μείωση της υγρασίας κατά 1% θα μπορούσε να αυξήσει τον αριθμό των περιπτώσεων COVID-19 κατά 6%. Η έρευνα με επικεφαλής τον καθηγητή Michael Ward στο Πανεπιστήμιο του Σίδνεϊ, και δύο ερευνητές από το συνεργαζόμενο Fudan University School of Public Health της Σαγκάης, είναι...
Thu Jun 04, 2020 08:00
Publication date: Available online 3 June 2020Source: Clinical NeurophysiologyAuthor(s): Saman Zafar, Padmaja Kandula
Thu Jun 04, 2020 19:20
Publication date: Available online 3 June 2020Source: Clinical NeurophysiologyAuthor(s): Yasuo Terao, Shun-ichi Matsuda, Hiroyuki Ishiura, Shoji Tsuji, Tomotaka Yamamoto, Hideki Fukuda, Yoshikazu Ugawa
Thu Jun 04, 2020 19:20
Publication date: Available online 3 June 2020Source: Clinical NeurophysiologyAuthor(s): Davide Rossi Sebastiano, Laura Tassi, Dunja Duran, Elisa Visani, Francesca Gozzo, Francesco Cardinale, Lino Nobili, Angelo Del Sole, Annalisa Rubino, Sara Dotta, Elena Schiaffi, Rita Garbelli, Silvana Franceschetti, Roberto Spreafico, Ferruccio Panzica
Thu Jun 04, 2020 19:20
Publication date: Available online 3 June 2020Source: Clinical NeurophysiologyAuthor(s): Mamede de Carvalho
Thu Jun 04, 2020 19:20
Publication date: Available online 3 June 2020Source: Revue des Maladies RespiratoiresAuthor(s): A. David, P. Gerardin, A. Payet
Thu Jun 04, 2020 19:18
200 years ago Ørsted laid the foundation of electromagnetism in his famous experiment deflecting a magnetic needle in the electrical field of a platinum wire. For this he used his own Cu‐Zn trough battery, which was among the best then available, but 21 years later it was surpassed by the coal‐zinc battery invented by Bunsen, which became highly successful and acclaimed. That year, 1841, Bunsen made his first direct contact with Scandinavia when he visited Berzelius in Stockholm, Palmstedt in Gothenburg,...
Thu Jun 04, 2020 18:55
N ‐glycosylation may affect the safety and efficacy of biopharmaceuticals and is thus monitored during manufacturing. Mass spectrometry of the intact protein is increasingly used to reveal co‐existing glycosylation variants. However, quantification of N ‐glycoforms via this approach may be biased by single hexose residues as introduced by glycation or O ‐glycosylation. Here, we describe a simple strategy to reveal actual N ‐glycoform abundances of therapeutic antibodies, involving experimental...
Thu Jun 04, 2020 18:41
Bio‐polyols conversion : A series of 3D porous self‐supported NHC‐iridium coordination polymers were prepared and could function as recyclable solid molecular catalysts for dehydrogenation of bio‐polyols to lactic acid with excellent activity and selectivity due to the synergistic participation of the Ba2+ and hydroxide ions, as well as the blockage of unwanted pathways by adding methanol. Abstract The global demand for lactic acid (LA) is increasing due to its successful application as monomer...
Thu Jun 04, 2020 18:31
A catalytic method for the site‐ and enantioselective synthesis of functionalized arenes through intermolecular hydroarylation of 1,3‐dienes with aryl pinacolato boronates is reported. The reactions are promoted by 5.0 mol % of a phosphoramidite–Ni complex in ethanol, affording enantioenriched products in up to >95:5 rr and 99:1 er. Mechanistic studies indicate that Ni–allyl formation is irreversible and related to the nature of the arylboronate. Abstract A catalytic method for the site‐selective...
Thu Jun 04, 2020 18:28
Well I'll B : Activation of the radical‐inactive pinacol alkylboronic esters through a simple transesterification process provides access to highly reactive radical precursors that can be involved in a broad range of radical chain reactions involving C−X, C−C and C−H bonds. Merging this process with the unique and rich chemistry of boronic esters holds tremendous potential for synthetic applications. Abstract The generation of carbon‐centered radicals from air‐sensitive organoboron compounds...
Thu Jun 04, 2020 18:28
Reagents that introduce the CH2F group into organic molecules operate via electrophilic, nucleophilic, or radical routes. New stable, easy to handle, and efficient reagents for fluoromethylation provide access to organic CH2F derivatives of academic interest and industrial importance. While CH2F transfer to heteroatoms is straightforward, carbon fluoromethylation still remains a challenge. Abstract The introduction of a monofluoromethyl moiety has undoubtedly become a very important area of...
Thu Jun 04, 2020 18:27
A cascade reaction has been designed for the synthesis of spirocyclic pyrrolines from nitrones and arynes. A key feature of this transformation is an unusual dearomative [3,3′]‐sigmatropic rearrangement of a heterocyclic intermediate that results in a spirocyclization. This modular approach provides access to three‐dimensionally‐defined pyrrolines and pyrrolidines with opportunities for divergent derivatization. Abstract A dearomative [3,3′]‐sigmatropic rearrangement that converts N‐alkenylbenzisoxazolines...
Thu Jun 04, 2020 18:27
“In a spare hour, I walk my dog … My favorite time of day is when I enjoy my walks in the garden … ” Find out more about Xiaohua Liu in her Author Profile.
Thu Jun 04, 2020 18:27
The right white light : The ternary organic metal halide hybrid (HMTA)4PbMn0.69Sn0.31Br8 contains three distinct metal halide species comprising emissions to cover the blue, green, and red spectral regions (the different colors in the picture represent unit cells of single‐component metal halide crystals with HMTA+). The multicomponent single‐crystalline material exhibited warm‐white to cool‐white emissions at appropriate excitation wavelengths. Abstract Zero‐dimensional (0D) organic metal...
Thu Jun 04, 2020 18:26
Thin film : A homogeneous MXene film actuator with both hydrophilicity and high electrical conductivity was fabricated by a vacuum‐assisted filtration process. The film is highly moisture‐sensitive and can undergo a considerable amount of deformation. The high‐performance MXene film actuator makes it applicable to flexible excavators, electrical switches, and other fields, applications that are difficult to achieve by using other 2D materials directly. Abstract MXene (Ti3C2Tx ) is a new 2D...
Thu Jun 04, 2020 18:26
In the (hydra)zone : A palladium‐catalyzed formal hydroalkylation of alkynes with hydrazones has been realized. The reaction proceeds with high regio‐ and stereoselectivity to form (Z )‐alkene through a palladium‐hydride species. Abstract We have developed an unprecedented Pd‐catalyzed formal hydroalkylation of alkynes with hydrazones, which are generated in situ from naturally abundant aldehydes, as both alkylation reagents and hydrogen donors. The hydroalkylation proceeds with high regio‐...
Thu Jun 04, 2020 18:25
Metalloenzyme catalysis : Through the use of cryoreduction and annealing, a method of studying electron transfer in redox active metalloenzymes is developed. Combined with electron paramagnetic resonance spectroscopy, active states in the catalytic cycle of the copper containing nitrite reductases are probed. Abstract Redox active metalloenzymes catalyse a range of biochemical processes essential for life. However, due to their complex reaction mechanisms, and often, their poor optical signals,...
Thu Jun 04, 2020 18:25
Inverse Vulcanized Polymers with Shape Memory, Enhanced Mechanical Properties, and Vitrimer Behavior
Functional sulfur : The synthesis of sulfur‐polymers with significantly improved mechanical properties and controlled performance is reported. In the process a linear pre‐polymer containing hydroxyl functional group is crosslinked by difunctional isocyanate secondary crosslinkers. Control of hardness, flexibility, solubility and function of the material is demonstrated. Abstract The invention of inverse vulcanization provides great opportunities for generating functional polymers directly from...
Thu Jun 04, 2020 12:50
The discovery of a new low‐barrier two‐step solid reaction pathway for Li‐Se chemistry is reported. The finding has enabled a highly compact Se electrode (2.35 gSe cm−3) with a record‐breaking Se content (80 wt %), and high Se loading (8 mg cm−2), as well as a superhigh volumetric energy density of up to 2502 Wh L−1, surpassing that of LiCoO2. Abstract For Li‐Se batteries, ether‐ and carbonate‐based electrolytes are commonly used. However, because of the “shuttle effect” of the highly dissoluble...
Thu Jun 04, 2020 12:49
Less is more : Take one chiral ligand from a standard paddlewheel dirhodium tetracarboxylate complex out and replace it by acetamidate and you switch on reactivity and harness outstanding enantioselectivity in cyclopropanations with α‐stannylated‐α‐diazoesters. Even though the products contain a tert ‐alkylstannane moiety, “stereoretentive” Stille cross coupling is shown to be possible. Abstract The heteroleptic dirhodium paddlewheel catalyst 7 with a chiral carboxylate/acetamidate ligand...
Thu Jun 04, 2020 12:48
The atoms went in one by one : Atomically mixed AuPt, AuPd, PtPd, AuPdPt nanoalloys are prepared by the solid solvent method via single‐atom level manipulation. The supported nanoalloys/CeO2 with ultra‐low noble metal content exhibit remarkable catalytic performance towards CO oxidation at room temperature and robust thermostability. Abstract Synthesis of well‐defined atomically mixed alloy nanoparticles on desired substrates is an ultimate goal for their practical application. Herein we report...
Thu Jun 04, 2020 12:45
Ultrafast near‐infrared laser pulses stimulate reversible blue shift of the absorption band of photochromic‐free MOFs with rates up to hundreds of s−1. This optical switching can be applied for MOF‐based communication devices allowing the remote modulation of the intensities of initial photoluminescence and the visible light passing through the MOFs. Abstract We demonstrate herein an all‐optical switch based on stimuli‐responsive and photochromic‐free metal–organic framework (HKUST‐1). Ultrafast...
Thu Jun 04, 2020 12:42
A novel N‐hetero‐Rh(I)‐metallacyclic silanone has been synthesized. This silanone, showing an extremely large dimerization energy (ΔG = +86.2 kcal/mol), displays considerable stability and persists in solution up to 60 °C. Above 120 °C, an intramolecular C(sp3)‐H insertion occurs slowly over a period of two weeks leading to the bicyclic silanol. The exceptional stability of the silanone, related to the unusual electronic and steric effects of Rh(I)‐substituent, should allow for a more profound study...
Thu Jun 04, 2020 13:52
Molecular flip‐flop : By pulsing the tip voltage in a scanning tunneling microscope, individual molecules in a monolayer of a polyaromatic salt can be switched reversibly from a bright (0) to a dark (1) state, at room temperature and outside of a vacuum. The information density of this single‐molecule binary memory can reach up to 41 terabits per cm2. Abstract Reported here is a molecular dipole that self‐assembles into highly ordered patterns at the liquid‐solid interface, and it can be switched...
Thu Jun 04, 2020 13:52
C−H bond activation and free internal rotation: The infrared spectrum of the monohydrated adamantane cation reveals the hydration‐induced activation of its acidic C−H bond. Despite the strong CH⋅⋅⋅O ionic hydrogen bond in this prototypical reaction intermediate, the water ligand undergoes essentially free internal rotation because of weak angular anisotropy of the intermolecular bond. Abstract Diamondoid cations are reactive intermediates in their functionalization reactions in polar solution....
Thu Jun 04, 2020 13:52
Diversity Oriented Clicking (DOC) is a unified click chemistry approach for the synthesis of diverse lead‐like structures. We showcase DOC through the application of novel highly activated 2‐Substituted‐Alkynyl‐1‐Sulfonyl Fluorides (SASFs) hubs in combination with a range of selective and robust click‐cycloaddition, to deliver an unprecedented SuFExable library of functional biologically active lead‐structures. Abstract Diversity Oriented Clicking (DOC) is a unified click‐approach for the...
Thu Jun 04, 2020 13:52
Perovskite with new properties : A room‐temperature ferroelectric 2D metal–halide double perovskite, (CPA)4AgBiBr8, exhibits a notable spontaneous polarization of 3.2 μC cm−2 and a Curie temperature of 305 K. Its 2D alternating array of inorganic perovskite frameworks and organic cations endows it with a large mobility‐lifetime product (≈ 1.0×10−3 cm2 V−1) for detecting X‐ray photons. Abstract Although two‐dimensional (2D) metal–halide double perovskites display versatile physical properties...
Thu Jun 04, 2020 12:41
Silver connection : The assembly of two Au25(PET)18 monomers bridged by two Ag atoms generates the Ag2Au50(PET)36 dimer with distinct optical, electronic, and catalytic properties. This study provides a feasible strategy to precisely modulate the assembly of metal nanoclusters with controllable structure and properties. Abstract The assembly of atomically precise metal nanoclusters offers exciting opportunities to gain fundamental insights into the hierarchical assembly of nanoparticles. However,...
Thu Jun 04, 2020 12:41
The highly stereoselective synthesis of 1,1′‐disaccharides was achieved by using glycosyl 1,2‐diols and glycosyl donors in the presence of a tricyclic borinic acid catalyst. The complexation between the diol and the catalyst is crucial for the activation of the glycosyl donors and the cis configuration of the product, whereas the anomeric stereochemistry of the glycosyl donor depends on the employed glycosyl donor. Abstract The highly stereoselective synthesis of 1,1′‐disaccharides was achieved...
Thu Jun 04, 2020 12:40
Playing the OBO : Oxoborane carbamate and carboxylate analogues result from the in situ trapping of [BO2]− produced by elimination of 2,3‐dimethyl‐2‐butene from a magnesium pinacolatoboryl anion. Abstract Oxoborane carbamate and carboxylate analogues result from the in situ trapping of [BO2]− produced by elimination of 2,3‐dimethyl‐2‐butene from a pinacolatoboryl anion.
Thu Jun 04, 2020 12:40
Dual‐functionalized crescent microgels are designed and constructed by incorporating different functions within a single particle. These microgels are used for selectively capturing and killing cancer cells based on their high affinity to the lung cancer cells and local generation of high concentration of H2O2. It provides a novel strategy to create synergy in one unit for selective cancer chemotherapy. Abstract In cancer therapy, the selective targeting of cancer cells while avoiding side...
Thu Jun 04, 2020 12:39
The spongian trio : The first total syntheses of three unusual norrisolide‐type rearranged spongian diterpenes, cheloviolene C, seconorrisolide B, and seconorrisolide C, have been accomplished via a common intermediate through late‐stage ring‐scissoring. The synthesis features a Wolff ring contraction for the synthesis of the trans ‐hydrindane system, and a crucial retro Diels–Alder reaction/intramolecular ene cyclization for the rapid stereoselective construction of the furo[2,3‐b]furan system....
Thu Jun 04, 2020 12:39
Chiral Cu x Co y S nanoparticles were developed to selectively induce apoptosis of senescent cells using both an alternating magnetic field and near infrared light. Photon‐induced cellular redox and mechanical damage of the cellular skeleton lead to a much shorter treatment time and higher efficiency. The developed strategy was successfully used to remove senescent cells in vivo. Abstract In the present study, chiral Cux Coy S nanoparticles (NPs) were...
Thu Jun 04, 2020 12:38
POM‐incorporated CoO ultrathin nanowires (CoO UNWs) were fabricated by a facile solvothermal method. The UNWs with and without POM incorporation both present superior photocatalysis activities towards syngas production compared with nanowire bundle. Mechanistic studies indicate that size, structure, and composition all contribute to the high performance. Abstract Utilizing sustainable energy for chemical activation of small molecules, such as CO2, to produce important chemical feedstocks is...
Thu Jun 04, 2020 12:38
Thu Jun 04, 2020 12:38
Heteroatom‐stabilized transition‐metal carbene complexes are useful building blocks for organic synthesis, but their catalytic generation from substrates with common functional groups is still challenging. In their Communication (DOI: https://doi.org/10.1002/anie.20200271010.1002/anie.202002710), F. Kakiuchi and co‐workers report a novel hydroaminative cyclization of enynes with secondary amines catalyzed by phosphine‐quinolinolato rhodium complexes to form cyclic enamines via catalytic construction...
Thu Jun 04, 2020 12:37
Haloesterifications using easily obtainable alkenes and carboxylic acids have unique industrial benefits. The first general catalytic asymmetric iodoesterification of simple alkenes was achieved by T. Arai et al. in their Communication (DOI: https://doi.org/10.1002/anie.20200388610.1002/anie.202003886) by using a dinuclear zinc‐3,3′‐(R,S,S )‐bis(aminoimino)binaphthoxide (di‐Zn) complex. The picture represents a harmonizing quartet of metal ionic bond, hydrogen bond, halogen bond, and π–π stacking,...
Thu Jun 04, 2020 12:35
Cya round : Refactoring through promoter engineering enabled heterologous expression of the biosynthetic gene cluster of cyanogramide. Gene inactivation and feeding experiments revealed a concise cyanogramide biosynthetic pathway. Biochemical characterization of the P450 enzyme CyaH indicated an unusual skeletal rearrangement reaction for spirooxindole formation. Abstract Cyanogramide (1 ) from the marine actinomycete Actinoalloteichus cyanogriseus WH1‐2216‐6 features a unique spirooxindole...
Thu Jun 04, 2020 12:34
“The most important future application of my research is making environmentally benign tyres … My favorite way to spend a holiday is climbing a mountain … ” Find out more about Dongmei Cui in her Author Profile.
Thu Jun 04, 2020 12:30
It's a D‐all ! The first catalyst‐free and chemical‐reductant‐free deuteration of alkene and alkynes was achieved through an electrochemical approach with graphite felt electrodes and deuterated water in an undivided cell under neutral conditions. Up to 99 % D incorporation and 91 % yield can be obtained, and the method is compatible with electron‐rich alkenes, heterocycles, epoxides, and protecting groups. A series of deuterated pharmaceutical compounds was prepared. Abstract We report a method...
Thu Jun 04, 2020 12:30
The total synthesis of three topologically different natural products not only illustrated the power of a newly developed TiCl3‐mediated reductive cyclization methodology, but also provided mechanistic insight on the key 1,2‐migration process associated with the domino process. Abstract 2,3,3‐Trisubstituted indolenine constitutes an integral part of many biologically important monoterpene indole alkaloids. We report herein an unprecedented access to this skeleton by a TiCl3‐mediated reductive...
Thu Jun 04, 2020 12:29
Giving perovskite the edge : The influence of intercalating ligands on crystal and electronic structures of reduced‐dimensional (RD) perovskite have been investigated. A destabilized aromatic group, such as thiophene, effectively tailors the band‐edge electronic states and improves charge carrier mobilities. RD perovskite photovoltaics with thiophene‐based ligands show improved performance compared to devices using conventional intercalating cations. Abstract The insertion of large organic...
Thu Jun 04, 2020 12:29
Not just a phase : A dianionic phase‐transfer catalyst enables fluorinative dearomatization of 2‐naphthols with Selectfluor to afford the fluorinated naphthalenone derivatives in good yield and with high enantioselectivity. This reaction, which is compatible with a range of functional groups, is the first example of catalytic asymmetric fluorination of 2‐naphthols. Abstract A linked dicarboxylate phase‐transfer catalyst enables smooth asymmetric dearomative fluorination of 2‐naphthols with...
Thu Jun 04, 2020 12:29
Solid‐state fluorescence : A strategy for designing solid‐state fluorescent materials based on the tuning of their molecular packing mode by regioisomerization is proposed. Changing the molecular packing from a long‐range cofacial mode to a discrete cross packing, an ACQ‐to‐AIE transformation can be realized, achieving highly bright solid‐state materials. Abstract The traditional design strategies for highly bright solid‐state luminescent materials rely on weakening the intermolecular π–π interactions,...
Thu Jun 04, 2020 12:28
A diverse group of homoleptic uranium–methyl complexes is presented. The addition of MeLi to UCl4 at low temperature yields an unprecedented homoleptic uranium–methyl dimer. Overall this complex as well as several other monomeric uranium–alkyl complexes demonstrate the rich coordination and electronic structure and bonding of homoleptic uranium–alkyl complexes with sterically unencumbered alkyl substituents. Abstract Homoleptic σ‐bonded uranium–alkyl complexes have been a synthetic target...
Thu Jun 04, 2020 12:27
3D‐MoS2 sponge features a controllable appearance, hydrophobic surface, metal active sites, and multidimensional electron transport pathways. These sponges are more conducive to the circulation of iron ions in advanced oxidation processes (AOPs), the degradation of aromatic organic pollutants, and the recovery of catalyst. Abstract 3D‐MoS2 can adsorb organic molecules and provide multidimensional electron transport pathways, implying a potential application for environment remediation. Here,...
Thu Jun 04, 2020 12:27
A potential strategy for the rapid discovery of anti‐viral therapeutic agents is delineated by J. Dash et al. in their Communication (DOI: https://doi.org/10.1002/anie.20200346110.1002/anie.202003461). HIV‐1 TAR RNA promotes azide–alkyne cycloaddition to generate a new class of triazole‐linked thiazole peptidomimetics as the RNA's own binders.
Thu Jun 04, 2020 12:27
Mn2+ complexes are more biocompatible alternatives to Gd3+‐based MRI agents, and 52Mn is an emerging radionuclide for positron emission tomography. Both applications require highly inert chelates which, given the labile nature of Mn2+, remains a challenge. In their Research Article (DOI: https://doi.org/10.1002/anie.20200368510.1002/anie.202003685), L. Charbonnière, É. Tóth and co‐workers demonstrate that a strongly preorganized 2,4‐pyridyl‐disubstituted bispidol ligand provides exceptional kinetic...
Thu Jun 04, 2020 12:27
Catching cells with DNA : A conceptually new strategy is proposed for engineering a microfluidic chip using sub‐10 nm three‐dimensional DNA structures (TDNs) with a pendant aptamer at the top vertex (ApTDN‐Chip). At the microfluidic nanointerface, the improvement of effective recognition by the aptamers is ascribed to the more ordered nano‐topography. Abstract Microfluidic chips with nano‐scale structures have shown great potential, but the fabrication and cost issues restrict their application....
Thu Jun 04, 2020 12:22
We report a molecular investigation of cobalt phthalocyanine (CoPc) catalyzed CO 2 reduction reaction by electrochemical scanning tunneling microscopy (ECSTM). An ordered adlayer of CoPc is prepared on Au(111). Approximately 14% of the adsorbed species appear with high contrast in CO 2 purged electrolyte environment. The ECSTM experiments indicate the proportion of high contrast species correlated with the reduction of Co II Pc (~‐0.2 V). The high contrast species is ascribed to CoPc‐CO 2...
Thu Jun 04, 2020 12:19
Aqueous zinc (Zn) battery has been considered as a promising candidate for grid‐scale energy storage. However, their cycle stability is generally limited by the structure collapse of cathode materials and the dendrite formation coupled with undesired hydrogen evolution on Zn anode. Here we propose a Zn‐organic battery, which involves a phenanthrenequinone macrocyclic trimer (PQ‐MCT) cathode, a Zn foil anode and a nonaqueous electrolyte of N, N‐dimethylformamide (DMF) solution containing Zn2+.The...
Thu Jun 04, 2020 12:09
Trade off : With a trade off between active‐site exposure and structural stability, a 3D ordered mesoporous (3DOM) structured Sn‐Ti‐O material achieves cathodic energy conversion efficiency (EEca) as high as 71.5 % over 200 hours for electrochemical conversion of CO2 into CO. It benefits from an electron density reconfiguration at the Sn‐Ti‐O interface and a local alkaline environment to improve CO selectivity and stabilize lattice oxygen atoms. Abstract Simultaneously improving energy efficiency...
Wed Jun 03, 2020 22:59
Although DNA nanotechnology has spawned a broad variety of biomedical nanostructures over the last decade, these DNA nanostructures often suffer from limited stability and considerable immunogenicity. This Review introduces various biomedical applications of DNA nanostructures, describes the challenges imposed on the DNA nanostructures by the physiological environment, and discusses possible solutions to these challenges. Abstract DNA nanotechnology holds substantial promise for future biomedical...
Wed Jun 03, 2020 22:58
Enantiomeric discrimination is achieved by tip‐enhanced Raman scattering (TERS) using a silver tip chemically modified by an achiral para ‐mercaptopyridine ( p MPY) probe molecule. Differences in the relative intensities of the p MPY spectra were monitored for three pairs of enantiomers containing hydroxyl (–OH) and/or amino (–NH 2 ) groups. The N: or N + –H functionality of the p MPY‐modified tip participates in hydrogen bond interactions with a particular molecular orientation of each...
Wed Jun 03, 2020 22:58
Dynamic duo : This Review discusses novel types of water‐compatible dynamic covalent bonds for the self‐assembly of metal‐free organic molecules based on either acylhydrazone or oxime chemistry. Recent progress in the design, synthesis, and characterization in water of complex molecules with well‐defined three‐dimensional architectures, the self‐assembly of which is based on this dynamic approach, is summarized here. Abstract Imine synthesis has enjoyed a long history as the dynamic covalent...
Wed Jun 03, 2020 22:57
Concise syntheses of (−)‐minovincine and (−)‐aspidofractinine were achieved using easily available and inexpensive reagents and catalyst. A key element of the strategy was the use of a sequence of cascade reactions to rapidly construct the penta‐ and hexacyclic frameworks. To streamline the synthetic routes, the steric effect was used to secure various chemo‐ and regioselective transformations. Abstract We report 8‐step syntheses of (−)‐minovincine and (−)‐aspidofractinine using easily available...
Wed Jun 03, 2020 22:57
Three supramolecular strategies to control reactivity within nanospaces are presented. These nano‐environments may: 1) restrict substrate conformation and enforce preorganization; 2) allow for stabilization of transition state; or 3) incorporate with the requisite active site or an additional catalyst. The synergistic effects may result in rather large rate accelerations and high selectivity. Abstract Nanospaces are ubiquitous in the realm of biological systems and are of significant interest...
Wed Jun 03, 2020 22:48
Active nickel : Activation of white phosphorus (P4) by N‐heterocyclic carbene nickel(0) complexes affords binary nickel phosphorus cluster compounds. Both the degradation of P4 to P1 and P3 units and the aggregation to P5 and P8 moieties has been observed. The structures of the resulting Ni3P4, Ni3P6, and Ni3P8 clusters can be understood with the Wade–Mingos electron‐counting rules. Abstract The reaction of zerovalent nickel compounds with white phosphorus (P4) is a barely explored route to...
Wed Jun 03, 2020 22:48
Served on a (golden) tray ! A highly reactive and electron‐rich (alkyl)(amino)carbene (CAAC) derivative was deposited on a surface, and its binding mode and ordering were investigated for the first time. Mobile CAAC‐Au species were found that form islands on the surface. These results open the door for more on‐surface studies of the highly relevant class of CAACs. Abstract The structural properties and binding motif of a strongly σ‐electron‐donating N‐heterocyclic carbene have been investigated...
Wed Jun 03, 2020 22:47
In the second segment of a tripartite essay, we move from a sketch of the artificial intelligence debate to examples of AI in action, both in chemistry and society. Impressive, scary, and funny, these abound. Yet, moral decisions are hardly to be left to a computer. And causes are deeper than correlations. We do try to give voice to the opposing view of an optimistic, limitless future of AI in chemistry. And return to fuss. Abstract In the second part of this Essay, we leave philosophy, and...
Wed Jun 03, 2020 22:46
Substrate‐induced switching : A FeII spin‐crossover molecule at the interface with metals switches from a high‐spin to low‐spin state with visible light. This result is the complete opposite of what is known for the bulk materials. Therefore, for spin‐crossover compounds, the interface matters. Abstract Light‐induced spin‐state switching is one of the most attractive properties of spin‐crossover materials. In bulk, low‐spin (LS) to high‐spin (HS) conversion via the light‐induced excited spin‐state...
Wed Jun 03, 2020 22:45
Properly aligned : Residual dipolar couplings and residual chemical shift anisotropies can be acquired from natural products without special sample preparation using magnetically induced alignment. On the basis of two examples—the novel natural product gymnochrome G and the alkaloid strychnine—these data, together with the predicted alignment, yield the correct configuration with high certainty. Abstract Anisotropic NMR has gained increasing popularity to determine the structure and specifically...
Wed Jun 03, 2020 22:44
Super‐carbon‐chain compounds : Gibbosols A and B, obtained from the South China Sea dinoflagellate Amphidinium gibbosum , are stereochemically challenging, flexible super‐carbon‐chain compounds. A combined chemical, spectroscopic, and computational approach was successfully employed to establish the absolute configurations of thirty‐seven stereogenic carbon centers within these structurally intriguing marine natural products. Abstract Marine dinoflagellates produce remarkable organic molecules,...
Wed Jun 03, 2020 22:44
Selective targeting of closely related members of the cyclin‐dependent kinase family remains difficult. Here, a heterobifunctional degrader molecule, TMX‐2172, is described. Dual degradation of CDK2 and CDK5 in OVCAR8 cells is achieved by reducing the binding affinity of the pyrimidine kinase inhibitor for CDK4, CDK6, CDK7, and CDK9, and by differential recognition between CDK2 and CDK1 mediated by the E3 ligase cereblon. Abstract Cyclin‐dependent kinase 2 (CDK2) is a potential therapeutic...
Wed Jun 03, 2020 21:59
The Diels–Alder reactions of 1,3,5‐cycloheptatriene (CHT) and cyclooctatetraene (COT) with the dienophiles maleic anhydride and 4‐phenyl‐1,2,4‐triazoline‐3,5‐dione (PTAD) have been examined with density functional theory. Zwitterionic intermediates were not found in the [4+2] cycloadditions of both CHT or COT with PTAD, while [2+2+2] cycloadditions, as an alternative path to the Diels–Alder products, are highly disfavored. Abstract Rolf Huisgen explored the Diels–Alder reactions of 1,3,5‐cycloheptatriene...
Wed Jun 03, 2020 21:59
Solid switch ! A photoresponsive N‐heterocyclic carbene (NHC) has been synthesized that combines the excellent photophysical properties of arylazopyrazoles (AAPs) with an NHC that acts as a robust surface anchor (AAP‐BIMe). Thermally stable self‐assembled monolayers on gold were formed and photoswitching resulted in reversible alterations of the surface energy (i.e. wettability), the surface potential (i.e. work function), and the conductance (i.e. resistance). Abstract A novel photoresponsive...
Wed Jun 03, 2020 21:58
Chemical reduction of a benzo‐fused double [7]helicene ( 1 ) with two alkali metals, K and Rb, provided access to three different reduced states of 1 . The doubly‐reduced helicene 1 2− has been characterized by single‐crystal X‐ray diffraction as a solvent‐separated ion triplet with two potassium counterions. The triply‐ and tetra‐reduced helicenes, 1 3− and 1 4− , have been crystallized together in an equimolar ratio and both form the contact‐ion complexes with two Rb + ions each,...
Wed Jun 03, 2020 21:58
A Pt‐S‐mediated biosensor platform was demonstrated to avoid biothiol interference. High‐fidelity signals were recorded by AuNP@Pt‐S, with capability to completely discriminate diseased target cells even in a mixed‐cells system, while the AuNP‐S sensor could not. Compared to the previous methods involving changing ligands, this example solves the thiol interference problem by changing AuNP surface composition. Abstract The Au−S bond is the classic way to functionalize gold nanoparticles (AuNPs)....
Wed Jun 03, 2020 21:49
Ray of light : In‐situ X‐ray absorption spectroscopy methods for electrochemical tests have been developed to follow the changes of electron configurations and geometric local structures of metal oxides during electrocatalysis. This Minireview gives a brief introduction to recent progress in understanding catalytic mechanisms of perovskite and pyrochlore oxides by using this method. Abstract Metal oxides are some of the most promising candidates as electrocatalysts for electrical‐energy‐storage...
Wed Jun 03, 2020 21:49
The development of transition metal oxides (TMOs)‐based bifunctional catalysts toward efficient overall water splitting through delicate control of composition and structure is a challenging task. Herein, we report rational design and controllable fabrication of unique heterostructured inter‐doped ruthenium‐cobalt oxide ((Ru‐Co)O x ) hollow nanosheet arrays on carbon cloth. Benefiting from the desirable compositional and structural advantages of more exposed active sites, optimized electronic structure,...
Wed Jun 03, 2020 20:32
Radical Ring‐Opening polymerization (rROP) of Cyclic Ketene Acetals (CKAs) combines the advantages of both ring‐opening polymerization and radical polymerization thereby allowing the robust production of polyesters coupled with the mild polymerization conditions of a radical process. rROP was recently rejuvenated by the possibility to copolymerize CKAs with classic vinyl monomers leading to the insertion of cleavable functionality into a vinyl‐based copolymer backbone and thus imparting (bio)degradability....
Wed Jun 03, 2020 20:30
This article describes a synthetic approach to a new structurally diverse family of π‐expanded diketopyrrolopyrroles (DPPs). These red‐emissive dyes, based on a previously unknown skeleton, can be easily synthesized via a three‐step strategy involving the preparation of diketopyrrolopyrrole followed by N‐arylation and subsequent intramolecular palladium‐catalyzed direct arylation. A careful selection of the aryl substituents on DPP gives access to a π‐extended DPP derivative with intense fluorescence...
Wed Jun 03, 2020 20:02
A difluoromethyl group (CF 2 H) is considered to be a lipophilic and metabolically stable bioisostere of an amino (NH 2 ) group. Therefore, methods that can rapidly convert an NH 2 group into a CF 2 H group would be of great value to medicinal chemistry. We report herein an efficient Cu‐catalyzed approach for the conversion of alkyl pyridinium salts, which can be readily synthesized from the corresponding alkyl amines, to their alkyl difluoromethane analogues. This protocol tolerates a broad...
Wed Jun 03, 2020 18:35
Water electrolysis is a promising strategy for high‐purity hydrogen production but restrained by the high electricity cost. Developing an oxygen evolution reaction (OER) electrocatalyst with excellent activity and low price is indispensable for reducing water electrolysis cost. The modulation of electronic structure of catalysts can be an efficient strategy to boost their activities. Herein, the oxygen vacancies of defective iron‐cobalt oxide (FeCoO x ‐Vo) nanosheets are modified by the homogeneously...
Wed Jun 03, 2020 18:31
“3‐Point annulations”, or ‘‘phenalenannulations” transform a benzene ring directly into a substituted pyrene by “wrapping” two new cycles around the perimeter of the central ring at three consecutive carbon atoms. This efficient, modular, and general method for p‐extension opens access to non‐ symmetric pyrenes and their expanded analogues. Potentially, this approach can convert any aromatic ring bearing a ‐CH 2 Br or a –CHO group into a pyrene moiety. Depending upon the workup choices, the process...
Wed Jun 03, 2020 17:09
The challenge of quantitatively forming self‐assembled hetero‐dimers without other equilibrium by‐products is overcome through self‐sorting favored by the introduction of designed shape‐complementary moieties. Such a supramolecular strategy based on CB[8]‐directed dimerization is further applied to generate hetero‐chromophore dimers quantitatively, leading to efficient energy transfer (> 85 %) upon photoexcitation.
Wed Jun 03, 2020 17:09
This study explores a new mode of contortion in perylene diimides where the molecule is bent, like a bow along its long axis. We synthesize these bowed PDIs through a facile 4‐fold Suzuki macrocyclization with aromatic linkers and a tetraborylated perylene diimide that introduces strain and results in a bowed structure. By ‐altering the strings of the bow, the degree of bending can be controlled from flat to highly bent. Through spectroscopy and quantum chemical calculations, we demonstrate that...
Wed Jun 03, 2020 17:08
Inspired by natural photosynthesis, biocatalytic photoelectrochemical (PEC) platforms are gaining prominence for the conversion of solar energy into useful chemicals by combining redox biocatalysis and photoelectrocatalysis. Here, we report a dual biocatalytic PEC platform consisting of a molybdeneum (Mo)‐doped BiVO4 (Mo:BiVO4) photoanode and an inverse opal ITO (IO‐ITO) cathode that gives rise to the coupling of peroxygenase and ene‐reductase‐mediated catalysis, respectively. In the PEC cell, the...
Wed Jun 03, 2020 17:04
It is promising and challenging to manipulate the electronic structures and functions of materials utilizing both metal‐to‐metal charge transfer (MMCT) and spin‐crossover (SCO) to tune the valence and spin states of metal ions. Here, metallocyanate building block is utilized to link with a ferrous−triazole moiety and generates a mixed‐valence complex {[(Tp 4‐Me )Fe III (CN) 3 ] 9 [Fe II 4 (trz‐ph) 6 ]}⋅[Ph 3 PMe] 2 ⋅[(Tp 4‐Me )Fe III (CN) 3 ] ( 1 ; trz‐ph = 4‐phenyl‐4H‐1,2,4‐tirazole)....
Wed Jun 03, 2020 17:04
A highly enantioselective isothiourea‐catalyzed acylative kinetic resolution (KR) of acyclic tertiary alcohols has been developed. Selectivity factors of up to 200 were achieved for the KR of tertiary alcohols bearing an adjacent ester substituent, with both reaction conversion and enantioselectivity found to be sensitive to the steric and electronic environment at the stereogenic tertiary carbinol centre. For more sterically‐congested alcohols, the use of a recently‐developed isoselenourea catalyst...
Wed Jun 03, 2020 15:42
It takes two : Microscopic and mesoscopic dual postsynthetic modifications of metal–organic frameworks introduced hierarchical porosity while converting C−H bonds into C−C bonds (see picture). Owing to the proximity to the open Co sites, the introduced functional group could effectively prevent or enhance the adsorption of guest molecules. Abstract We report the dual postsynthetic modification (PSM) of a metal–organic framework (MOF) involving the microscopic conversion of C−H bonds into C−C...
Wed Jun 03, 2020 14:52
Bismuth doping reduces charge‐transfer resistance, creates a strained surface, and optimizes the d‐band center of porous Nix Biy aerogels. The optimum benefits of the amorphous structure and abundant superficial oxygenated species are real ized in a Ni97Bi3 aerogel, which demonstrates unprecedented electrocatalytic performance in methanol oxidation with both high activity and durability. Abstract Low‐cost, non‐noble‐metal electrocatalysts are required for direct methanol fuel cells, but...
Wed Jun 03, 2020 14:48
Sonodynamic therapy : A MOF‐derived sonosensitizer (DHMS) with oxygen generation and multimodal imaging ability was prepared for augmented sonodynamic cancer therapy. DHMS showed a high reactive oxygen species generation ability under ultrasound irradiation to effectively inhibit tumor growth, benefitting from the Mn contained in DHMS, which could improve the electron–hole separation. Abstract The high reactive oxygen species (ROS) generation ability and simple construction of sonosensitizer...
Wed Jun 03, 2020 14:48
Hybrid AIEgen and biological tumor‐exocytosed exosomes nanovesicles (DES) were combined with photodynamic therapy (PDT) in tumor vessel normalization therapy. DES enhance tumor tissue penetration of AIEgens significantly. Dexamethasone (DEX) was used to normalize vascular function within the tumor microenvironment, thereby reducing local hypoxia and enhancing the PDT effect of DES. Key: aggregation‐induced emission luminogens (AIEgens), photosensitizer (DCPy). Abstract The development of novel...
Wed Jun 03, 2020 14:48
Macrocycles in action : A chiral macrocycle‐enabled counteranion trapping strategy was demonstrated for boosting highly efficient and selective catalysis. Just 1 mol % of the designer macrocycle can promote excellent conversion and up to 99 % ee in combination with 1 mol % achiral acid, which is inactive alone. Abstract The tight binding enabled by tailor‐made macrocycles can be manipulated for tuning the catalysis process. In parallel to well‐developed crown ether‐based cation‐binding catalysis,...
Wed Jun 03, 2020 14:48
A Glycan Array‐Based Assay for the Identification and Characterization of Plant Glycosyltransferases
Express and screen : A high‐throughput assay based on the application of azido‐functionalized sugar nucleotide donors on a synthetic glycan array for screening heterologously expressed plant glycosyltransferases was developed. The opportunity to express and screen large numbers of glycosyltransferases instead of rationally selected candidates will markedly accelerate the elucidation of plant cell wall biosynthetic pathways. Abstract Growing plants with modified cell wall compositions is a promising...
Wed Jun 03, 2020 14:47
The preparation of unique, non‐functionalized terpenes remains challenging. The strategic use of a minimal number of functional groups, coupled with retrosynthetic planning based on the use of a guiding all‐carbon quaternary center to forge three additional such centers, fueled by some unique C−C bond forming steps, can afford an expeditious, 17‐step total synthesis of the unique angular triquinane natural product (+)‐waihoensene. Abstract The four contiguous all‐carbon quaternary centers...
Wed Jun 03, 2020 14:47
Conductive and water soluble : A new π‐conjugated polyelectrolyte is synthesized from an insulating hydrophobic precursor made via ring‐opening metathesis polymerization. Anionic poly(cyclopentadienylene vinylene) can be made with a variety of side chains, is conductive and non‐toxic, and can easily be formulated into conductive hydrogels due to its high water‐solubility. Abstract The use of π‐conjugated polymers (CPs) in conductive hydrogels remains challenging due to the water‐insoluble nature...
Wed Jun 03, 2020 14:47
Simplifying matters : Three imine‐based metal complexes, having no overlap in terms of their compositions, have been simultaneously generated from the self‐sorting of a constitutional dynamic library containing three amines, three aldehydes, and three metal salts. The mechanism and the driving forces underlying the self‐sorting process have been examined. Abstract Three imine‐based metal complexes, having no overlap in terms of their compositions, have been simultaneously generated from the...
Wed Jun 03, 2020 14:45
The efficient catalytic disproportionation of formic acid to methanol is enabled by shutting down the dehydrogenation of formic acid by using a cycle that involves recyclable silylformates and ruthenium‐based catalysts. The procedure enables the formation of methanol in yields of up to 77 % isolated product. Abstract A novel strategy to prepare methanol from formic acid without an external reductant is presented. The overall process described herein consists of the disproportionation of silyl...
Wed Jun 03, 2020 14:45
The interplay between lead vacancy and water rationalizes the positive and negative effects of water on the charge carrier lifetimes in the organic–inorganic perovskite MAPbI3. The obtained results provide a theoretical understanding of how the complex charge dynamics in perovskites are affected by defects and water. Abstract The perovskite CH3NH3PbI3 excited‐state lifetimes exhibit conflicting experimental results under humid environments. Using ab initio nonadiabatic (NA) molecular dynamics,...
Wed Jun 03, 2020 14:45
Elastic organic crystals have attracted considerable attention as next‐generation flexible smart materials. However, the detailed information on both molecular packing change and macroscopic mechanical crystal deformations upon applied stress are still insufficient. Here we report that fluorescent single crystals of 9,10‐dibromoanthracene are elastically bendable and stretchable, which allows a detailed investigation of the deformation behavior. We clearly observed a Poisson’s effect for the crystal,...
Wed Jun 03, 2020 12:01
Freeze, don't move : A transformation of fluxional into configurationally stable axially chiral N‐arylpyrroles was achieved through a highly atroposelective electrophilic aromatic substitution catalyzed by a chiral‐at‐metal rhodium Lewis acid, with follow‐up transformations leading to structurally diverse axially chiral N‐arylpyrroles. Abstract A transformation of fluxional into configurationally stable axially chiral N‐arylpyrroles was achieved with a highly atroposelective electrophilic aromatic...
Wed Jun 03, 2020 11:05
Modular Synthesis of Furans with up to Four Different Substituents by a trans‐Carboboration Strategy
As you like it : Propargyl alcohols can be transformed in a single step into 3‐borylated‐2,4,5‐triarylated furans by an efficient trans ‐carboboration/cyclization/dehydration cascade. A subsequent Suzuki coupling allows a fourth substituent of choice to be introduced. The modularity of the method is unrivaled in that it allows four different substituents to be introduced in a programmable manner and hence all isomers of the multiply arylated furan to be attained. Abstract Propargyl alcohols,...
Wed Jun 03, 2020 11:05
Atomic force microscopy was used to reshape, resize and relocate single‐crystal microwaveguides in order to attain spatial control over their light output. Using an AFM cantilever tip, acicular microcrystals of three N ‐benzylideneanilines were bent to an arbitrary angle, sliced out from a bundle into individual crystals, cut into shorter crystals of arbitrary length, and moved across and above a solid surface. Abstract Flexible organic single crystals are evolving as new materials for optical...
Wed Jun 03, 2020 11:05
Forcing a rearrangement : In situ monitoring of the mechanochemical [1,2]‐intramolecular phenyl migration in benzil was accomplished by a combination of real‐time analytical techniques and temperature sensing. The mechanochemical rearrangement occurs suddenly after an induction time, without detectable intermediates. Abstract Recent progress in the field of mechanochemistry has expanded the discovery of mechanically induced chemical transformations to several areas of science. However, a general...
Wed Jun 03, 2020 11:00
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