Πέμπτη 15 Αυγούστου 2019


Tardive Dyskinesia: Treatment Update
Abstract Purpose of Review Tardive dyskinesia (TD) is caused by exposure to medications with dopamine antagonism, mainly antipsychotics. It often distresses individuals, physically and emotionally and affects their quality of life. We evaluated peer-reviewed recently published articles with a goal of providing a critically appraised update on the latest advancements in this field. ...
Current Neurology and Neuroscience Reports
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Remote photonic sensing of cerebral hemodynamic changes via temporal spatial analysis of acoustic vibrations
Abstract A novel photonic method for remote monitoring of task‐related hemodynamic changes in human brain activation is presented. Physiological processes associated with neural activity, such as nano‐vibrations due to blood flow and tissue oxygenation in the brain, are detected by remote sensing of nano acoustic vibrations using temporal spatial analysis of defocused self‐interference random patterns. Temporal nanometric changes of the speckle pattern due to visual task‐induced hemodynamic responses...
Journal of Biophotonics
8h
Video‐assisted parathyroid gland mapping with autofocusing
Preservation of the parathyroid gland (PTG) in neck endocrine surgery is an important for regulating the amount of calcium in the blood and within the bones. Localization of the PTG has been attempted using various methods such as ultrasound, sestamibi, CT, MRI, and ICG fluorescence imaging. These methods cannot be used during surgery, have high sensitivity, or have PTG specificity. However, autofluorescence technique has shown high sensitivity and does not require exogenous contrast. In this study,...
Journal of Biophotonics
1d
Access to Aryl‐Naphthaquinone Atropisomers via Phosphine‐Catalyzed Atroposelective (4+2) Annulations of δ‐Acetoxy Allenoates with 2‐Hydroxyquinone Derivatives
Although asymmetric phosphine catalysis is a powerful tool for the construction of various chiral carbon centers, its synthetic potential toward enantioenriched atropisomer has not been explored yet. Herein, we report a phosphine‐catalyzed highly atroposelective (4+2) annulation of δ‐acetoxy allenoate and 2‐hydroxyquinone derivative, which provides expedient access to aryl‐naphthaquinone atropisomers via the de novo construction of benzene ring. The two functions of catalyst, tertiary phosphine...
Angewandte Chemie International Edition
8h
Exceeding Metal Capacity in Sandwich Complexes: Ligand‐unsupported Docking of Extra Metal Moieties at Edges of a Metal Sheet Sandwich Complex
The ligand‐unsupported accommodation of extra metal moieties in a sandwich complex is reported. Although it has been considered that the metal‐capacity of a metal sheet sandwich complex is strictly limited by the size of cyclic unsaturated hydrocarbon ligands, we found that the M‐M edge bonds in a metal sheet sandwich complex provide a ligand‐unsupported docking site for extra metal moieties, allowing expansion of metal‐capacity in sandwich complexes. The metal sheet sandwich complex [Pd₄(µ₄‐C₈H₈)(µ₄‐C₉H₉)]+,...
Angewandte Chemie International Edition
8h
High Precision Size Recognition and Separation in Synthetic 1D Nanochannels
Covalent organic frameworks (COFs) allow elaborate manufacture of ordered one‐dimensional channels in the crystal. While this makes designing by topology diagram particularly attractive as a tool for assembling straight pores to facilitate mass transport, molecular recognition has been so far inaccessible. We define a superlattice of COFs, by engineering channels with persistent triangular shape and discrete pore size. We observe a size recognition regime that is different from the characteristic...
Angewandte Chemie International Edition
8h
Reversible Formation of a Light‐responsive Catalyst by Utilizing Intermolecular Cooperative Effects
A photo‐responsive system where structure formation is coupled to catalytic activity is presented. The observed catalytic activity is reliant on intermolecular cooperative effects that are present when amphiphiles assemble into vesicular structures. Photo‐responsive units within the amphiphilic pre‐catalysts allow for switching between assembled and disassembled states, thereby modulating the catalytic activity. The ability to reversibly form cooperative catalysts within a dynamic self‐assembled...
Angewandte Chemie International Edition
8h
Insertion of CO2 Mediated by a (Xantphos)NiI–Alkyl Species
Gathering support: The incorporation of CO2 into organometallic and organic molecules represents a sustainable way to prepare carboxylates. Demonstrated herein is that the direct reduction of (tBu‐Xantphos)NiIIBr2 by Zn affords NiI species. (tBu‐Xantphos)NiI‐Me and (tBu‐Xantphos)NiI‐Et complexes undergo fast insertion of CO2 at 22 °C, providing experimental support for the proposed mechanisms of Ni‐catalyzed carboxylation reactions. Abstract The incorporation of CO2 into organometallic and...
Angewandte Chemie International Edition
22h
Conformational Re‐engineering of Porphyrins as Receptors with Switchable N–H···X‐type Binding Modes
The selectivity and functional variability of porphyrin cofactors are typically based on substrate binding of metalloporphyrins wherein the pyrrole nitrogen units only serve to chelate the metal ions. Yet, using the free base porphyrin inner core system for other functions is possible through conformational engineering. As a first step towards porphyrin ‘enzyme‐like’ active centers, a structural and spectroscopic study of substrate binding to the inner core porphyrin system shows that a highly saddle...
Angewandte Chemie International Edition
22h
Synthesis and Utility of a Neptunium(III) Hydrocarbyl Complex
To extend organoactinide chemistry beyond uranium, we report the first structurally characterized transuranic hydrocarbyl complex, Np[η4‐Me2NC(H)C6H5]3, 1, from reaction of NpCl4(DME)2 with four equivalents of K[Me2NC(H)C6H5]. Unlike the U(III) species, the neptunium analogue can be used to access other Np(III) complexes. The reaction of 1 with three equivalents of HE2C(2,6‐Mes2‐C6H3), E = O, S, yields [(2,6‐Mes2‐C6H3)CE2]3Np(THF)2, maintaining the trivalent oxidation state.
Angewandte Chemie International Edition
22h
In operando visualization of the electrochemical formation of liquid polybromide microdroplets
Zn/Br flow batteries are one of the promising technologies for stationary energy storage. Bromine complexing agents have been used to form phase‐separated liquid polybromide charging products. However, dynamic and microscopic understanding of the nucleation and growth of the polybromides on the electrode is limited due to the beam‐sensitivity and complexity of polybromides and their surrounding electrolytes. In this communication, we report an in operando platform composed of dark field light microscopy...
Angewandte Chemie International Edition
22h
Conformational Spin Switching and Spin‐Selective Hydrogenation of a Magnetically Bistable Carbene
The control of the spin states of molecules opens the path to tuning selectivity in chemical reactions and to developing novel magnetically switchable materials. 3‐Methoxy‐9‐fluorenylidene is a carbene that is generated in cryogenic matrices both in its lowest energy singlet and triplet states, and the ratio of these states can be shifted by selective irradiation. The interconversion of the nearly degenerate spin states is induced by a conformational change of the methoxy group: switching the methoxy...
Angewandte Chemie International Edition
22h
NHC‐Coordinated Diphosphene Stabilized Gold(I) Hydride and its Reversible Conversion to Gold(I) Formate with CO2
An NHC‐coordinated diphosphene is employed as ligand for the synthesis of a hydrocarbon‐soluble monomeric Au(I) hydride, which readily adds CO2 at room temperature yielding the corresponding Au(I) formate. The reversible reaction can be expedited by the addition of NHC, which induces β ‐hydride shift and the removal of CO2 from equilibrium through the formation of an NHC‐CO2 adduct. The Au(I) formate is alternatively formed by dehydrogenative coupling of the Au(I) hydride with formic acid (HCO2H),...
Angewandte Chemie International Edition
22h
Molecular Design Strategy for Ordered Mesoporous Stoichiometric Metal Oxide
Although the construction of ordered mesoporous materials has achieved great processes, it is still a challenge to synthesize ordered mesoporous stoichiometric metal oxides via the co‐assembly method. Herein, we develop a molecular design strategy to construct ordered mesoporous Ti3+‐doped Li4Ti5O12 nanocrystal frameworks (OM‐Ti3+‐Li4Ti5O12) via the stoichiometric cationic coordination assembly process. Ti4+/Li+‐Citrate chelate is designed as a new molecular precursor, in which the citrate can not...
Angewandte Chemie International Edition
22h
Cooperative Tertiary Amine/Chiral Iridium Complex Catalyzed Asymmetric [4+3] and [3+3] Annulation Reactions
Asymmetric reactions merging organocatalysis and metal catalysis significantly broaden the organic synthesis. Nevertheless, the accomplishment of stereoselective annulations combining two types of dipole species, independently generated from the activations of organocatalysts and metal complexes, still remains as a challenging task. Here we report that Morita−Baylis−Hillman carbonates from isatins and carbamate‐functionalized allyl carbonates could be chemoselectively activated by achiral Lewis basic...
Angewandte Chemie International Edition
22h
DNA origami nanoplate‐based emulsion with designed nanopore function
Bio‐inspired functional microcapsules have attracted increasing attention in many fields from physical/chemical science to artificial cell engineering. Although the particle‐stabilised microcapsules are advantageous for their stability and functionalisation potential, versatile methods for their designable functionalisation are desired to expand their possibilities. This study reports a water‐in‐oil microdroplet stabilised with amphiphilised DNA origami nanoplates. By utilising DNA nanotechnology,...
Angewandte Chemie International Edition
22h
Crystal structure of a NIR‐emitting DNA‐stabilized Ag16 nanocluster
In the last 15 years, scientists have used DNA as a scaffold to stabilize small, atomically monodisperse silver nanoclusters. These DNA‐templated nanoclusters have attracted a lot of attention due to their intriguing photophysical properties. Here, we describe the crystal structure of a DNA‐encapsulated, near‐infrared emitting Ag16 nanocluster (DNA‐Ag16NC) determined by X‐ray analysis. The asymmetric unit of the crystal contains two DNA‐Ag16NCs and the crystal packing between DNA‐Ag16NCs is promoted...
Angewandte Chemie International Edition
22h
A Fluorescent LCK Inhibitor that Exhibits Diagnostic Changes in Emission Upon Binding the Kinase Enzyme
The development of a fluorescent LCK inhibitor that exhibits favourable solvatochromic properties upon binding the kinase enzyme is described. Fluorescent properties were realised through the inclusion of a Prodan‐derived fluorophore into the pharmacophore of the ATP‐competitive kinase inhibitor. Fluorescence titration experiments exemplify the solvatochromic properties of the inhibitor, in which dramatic increase in emission intensity and hypsochromic shift in emission maxima are clearly observed...
Angewandte Chemie International Edition
22h
Quantitative Synthesis of Temperature‐responsive Polymersomes by Multiblock Polymerization
The current challenge for polymersomes is to prepare amphiphilic block polymers with not only well‐defined molecular weight, but also precisely high‐order multiblock structure in terms of the distribution of monomeric units along the chain. Here, we describe a synthesis of temperature‐responsive polymersomes with precisely defined membrane structures using high‐precision amphiphilic multiblock polymer via aqueous single electron transfer living radical polymerization (SET‐LRP) in which poly(ethylene...
Angewandte Chemie International Edition
22h
Observation of the Low‐Frequency Spectrum of the Water Dimer as a Sensitive Test of the Water Dimer Potential and Dipole Moment Surfaces
The intermolecular modes of the water dimer in the frequency region from 70 to 550 cm−1 were recorded. Observed bands were assigned to donor torsion, acceptor wag, acceptor twist, intermolecular stretch, donor torsion overtone, and in‐plane and out‐of‐plane vibrational modes. This data provides a test for water potentials and dipole moment surfaces. Calculations of the IR spectrum are presented using molecular dynamics approaches. Abstract Using the helium nanodroplet isolation setup at the...
Angewandte Chemie International Edition
22h
Copper‐Catalyzed Asymmetric Annulation Reactions of Carbenes with 2‐Iminyl‐ or 2‐Acyl‐Substituted Phenols: Convenient Access to Enantioenriched 2,3‐Dihydrobenzofurans
Full circle: A Cu‐catalyzed enantioselective annulation of aryldiazoacetates with 2‐iminyl‐ or 2‐acyl‐substituted phenols has been developed to prepare enantioenriched 2,3‐dihydrobenzofurans. In this reaction, the Cu catalyst first induces carbene formation, and then functions as a Lewis acid to activate the electrophile and control the diastereo‐ and enantioselectivity. Abstract We have developed a method for the highly diastereo‐ and enantioselective construction of 2,3‐dihydrobenzofurans...
Angewandte Chemie International Edition
22h
Coordination Assisted Distal C−H Alkylation of Fused Heterocycles
Distal C−H alkylation (C‐5 of quinoline and thiazole, C‐7 of benzothiazole and benzoxazole) of heterocycles is reported. Upon complexation with heterocyclic substrate, nitrile DG in template directs the metal catalyst towards close vicinity of the specific distal C−H bond of the heterocycles. The hypothesized pathway has been supported by various X‐ray crystallographically characterized intermediates. Abstract Distal C−H bond functionalization of heterocycles remained extremely challenging...
Angewandte Chemie International Edition
22h
Channel‐Rich RuCu Nanosheets for pH‐Universal Overall Water Splitting Electrocatalysis
Channel rich RuCu nanosheets (NSs) have been successfully prepared and applied as a highly active and stable bifunctional electrocatalyst for the oxygen evolution reaction, hydrogen evolution reaction, as well as overall water splitting. This system is one of the best electrocatalysts reported to date. Abstract Channel‐rich RuCu snowflake‐like nanosheets (NSs) composed of crystallized Ru and amorphous Cu were used as efficient electrocatalysts for oxygen evolution reaction (OER), hydrogen evolution...
Angewandte Chemie International Edition
22h
Structural and Computational Analysis of 2‐Halogeno‐Glycosyl Cations in the Presence of a Superacid: An Expansive Platform
Influential halogens: Halogen substitution effects on the conformation of superacid‐generated glucosyl, galactosyl, and mannosyl cations are described. The 2‐bromo derivatives display intramolecular stabilization of the glycosyl cations. Introducing an electron‐withdrawing fluorine atom at C2 influences the oxocarbenium ion reactivity in a superacid, with quenching by weakly coordinating SbF6− anions. Abstract An expansive NMR‐based structural analysis of elusive glycosyl cations derived from...
Angewandte Chemie International Edition
22h
A Promising Carbon/g‐C3N4 Composite Negative Electrode for a Long‐Life Sodium‐Ion Battery
Flatland composites: Low‐cost carbon/graphitic carbon nitride (C/g‐C3N4) composites can be used as the negative electrode for a long‐life sodium‐ion battery. Abstract 2D graphitic carbon nitride (g‐C3N4) nanosheets are a promising negative electrode candidate for sodium‐ion batteries (NIBs) owing to its easy scalability, low cost, chemical stability, and potentially high rate capability. However, intrinsic g‐C3N4 exhibits poor electronic conductivity, low reversible Na‐storage capacity, and...
Angewandte Chemie International Edition
22h
Topotactic Synthesis of Phosphabenzene‐Functionalized Porous Organic Polymers: Efficient Ligands in CO2 Conversion
Top of the POPs: A topotactical two‐step synthetic pathway has been developed for the preparation of porous phosphabenzene‐functionalized polymers under metal‐free conditions. These porous organic polymers (POPs) exhibit high CO2 uptake capacity and act as efficient heterogeneous catalysts for amine formylation when doped with a small amount of ruthenium. Abstract Progress toward the preparation of porous organic polymers (POPs) with task‐specific functionalities has been exceedingly slow—especially...
Angewandte Chemie International Edition
22h
The Kirkendall Effect for Engineering Oxygen Vacancy of Hollow Co3O4 Nanoparticles toward High‐Performance Portable Zinc–Air Batteries
Controllable oxygen vacancy defects were introduced into the hollow Co3O4 nanoparticles through the regulation of nanoscale Kirkendall effect. This dramatically enhanced the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activities, leading to superior Zn–air battery performance. Abstract Structure and defect control are widely accepted effective strategies to manipulate the activity and stability of catalysts. On a freestanding hierarchically porous carbon microstructure,...
Angewandte Chemie International Edition
22h
Spectroscopic Characterization of an Eight‐Iron Nitrogenase Cofactor Precursor That Lacks the “9th Sulfur”
Nitrogenase catalyzes the reduction of N2 to NH₄+ at its cofactor site. Designated the M‐cluster, this [MoFe₇S₉C(R‐homocitrate)] cofactor is synthesized via transformation of a [Fe₄S₄] cluster pair into an [Fe₈S₉C] precursor (designated the L‐cluster) prior to insertion of Mo and homocitrate. Here we report the characterization of an eight‐iron cofactor precursor (designated the L*‐cluster), which is proposed to have a composition of [Fe₈S₈C] and lack the “9th sulfur” in the belt region of the L‐cluster....
Angewandte Chemie International Edition
22h
Enabling Superior Electrochemical Properties for Highly Efficient Potassium Storage via Impregnating Ultrafine Sb Nanocrystals within Nanochannel‐Containing Carbon Nanofibers
Antimony (Sb)‐based nanocomposites have emerged as an attractive class of anode materials for batteries as they exhibit large theoretical capacity and impressive working voltage. However, the tardy potassium ion diffusion characteristic, unstable Sb/electrolyte interphase, and huge volume variation pose a grand challenge that hinder the practical use of Sb‐based anodes for potassium‐ion batteries (PIBs). Herein, we report a simple yet robust strategy for uniformly impregnating ultrasmall Sb nanocrystals...
Angewandte Chemie International Edition
1d
GDCh Science Forum Chemistry 2019
Angewandte Chemie International Edition
1d
Defect‐Rich Graphene Nanomesh Produced by Thermal Exfoliation of Metal–Organic Frameworks for the Oxygen Reduction Reaction
Mesh‐merized: A nitrogen‐doped graphene nanomesh was simply prepared by thermal exfoliation of crystal‐ and shape‐modified metal–organic frameworks. The ultrathin, nitrogen‐doped graphene nanomesh obtained with high porosity and defect‐rich graphene edges, shows an unprecedented catalytic activity for oxygen reduction reaction (ORR) in acid electrolytes. Abstract Although graphene nanomesh is an attractive 2D carbon material, general synthetic routes to produce functional graphene nanomesh...
Angewandte Chemie International Edition
1d
Synthesis of Indolines and Derivatives by Aza‐Heck Cyclization
An aza‐Heck cyclization that allows the preparation of indoline scaffolds is described. Using N‐hydroxy anilines as electrophiles, which can be easily accessed from the corresponding nitroarenes, this method provides indolines bearing pendant functionality and complex ring topologies. Abstract For the first time, an aza‐Heck cyclization that allows the preparation of indoline scaffolds is described. Using N‐hydroxy anilines as electrophiles, which can be easily accessed from the corresponding...
Angewandte Chemie International Edition
1d
An Unprecedented Cyclization Mechanism in the Biosynthesis of Carbazole Alkaloids in Streptomyces
Magnificent seven: The total biosynthetic pathway of the carbazole alkaloid carquinostatin A (CQS) was established through biochemical characterization of seven CQS biosynthetic gene products CqsB1–7. The crystal structure of CqsB2, which catalyzes the cyclization step, provides mechanistic insights into the intricate reactions involved in the enzymatic synthesis of carbazoles. Abstract Carquinostatin A (CQS), a potent neuroprotective substance, is a unique carbazole alkaloid with both an ortho‐quinone...
Angewandte Chemie International Edition
1d
Ni‐Catalyzed Conversion of Enol Triflates to Alkenyl Halides
A Ni‐catalyzed halogenation of enol triflates was developed that enables the synthesis of a broad range of alkenyl iodides, bromides, and chlorides under mild reaction conditions. The reaction utilizes inexpensive, bench stable Ni(OAc)2·4H2O as a pre‐catalyst and proceeds at room temperature in the presence of sub‐stoichiometric Zn and either cod or DMAP.
Angewandte Chemie International Edition
1d
Photo‐switchable phase separation and oligonucleotide trafficking in DNA coacervate micro‐droplets
Coacervate micro‐droplets produced by liquid‐liquid phase separation have been used as synthetic protocells that mimic the dynamical organization of membrane‐free organelles in living systems. Achieving spatiotemporal control over droplet condensation and disassembly remains challenging. Herein, we describe the formation and photo‐switchable behaviour of light‐responsive coacervate droplets prepared from mixtures of double‐stranded DNA and an azobenzene cation. The droplets disassemble and reassemble...
Angewandte Chemie International Edition
1d
Copper‐mediated selenazolidine deprotection enables one‐pot chemical synthesis of challenging proteins
While chemical protein synthesis (CPS) has granted access to challenging proteins, synthesis of longer proteins is often limited by low abundance or non‐strategic placement of cysteine (Cys) residues, essential for native chemical ligations (NCL), as well as multiple purification and isolation steps. Selective deselenization and one‐pot CPS serve as key technologies to circumvent these issues. Herein, we describe the one‐pot total synthesis of human thiosulfate: glutathione sulfurtransferase (TSTD1),...
Angewandte Chemie International Edition
1d
Building a Bridge from Papermaking to Solar Fuels
Black liquor, an industrial waste product of papermaking, is primarily used as a low‐grade combustible energy source. Despite its high lignin content, the potential utility of black liquor as a feedstock in products manufacturing, remains to be exploited. Demonstrated here in is the use of black liquor as a primary feed‐stock for synthesizing graphene quantum dots that exhibit both up‐conversion and photoluminescence when excited using visible/near‐infrared radiation, thereby enabling the photosensitization...
Angewandte Chemie International Edition
1d
A Metallaphotoredox Strategy for the Cross‐Electrophile Coupling of Alpha‐Chloro Carbonyls with Aryl Halides
Here, we demonstrate that a metallaphotoredox‐catalyzed cross‐electrophile coupling mechanism provides a unified method for the alpha‐arylation of diverse activated alkyl chlorides, including alpha‐chloroketones, alpha‐chloroesters, alpha‐chloroamides, alpha‐chlorocarboxylic acids, and benzylic chlorides. This strategy, which is effective for a wide range of aryl bromide coupling partners, is predicated upon a halogen atom abstraction/nickel radical‐capture mechanism that is generically successful...
Angewandte Chemie International Edition
1d
Nanoemulsion with Porphyrin Shell for Cancer Theranostics
A nanoemulsion with a porphyrin shell (NewPS) is created by the self‐assembly of porphyrin salt around an oil core. The NewPS has ~100 nm spherical structure with excellent colloidal stability against radical changes in temperature, mechanical agitation, pH and in serum. The NewPS system is amenable to different porphyrin salts (mono‐sodium or tris‐sodium salt) and oils (low or high density), and is capable of co‐loading with chemotherapeutics (paclitaxel). The porphyrin salt shell is essential for...
Angewandte Chemie International Edition
1d

Stereoelectronic Effects in Ligand Design: Enantioselective Rhodium‐Catalyzed Hydrogenation of Aliphatic Cyclic Tetrasubstituted Enamides and Concise Synthesis of (R)‐Tofacitinib
The conformationally defined, electron‐rich, C 2‐symmetric, P‐chiral ligand ArcPhos was designed by taking advantage of stereoelectronic effects. With the Rh‐ArcPhos catalyst, excellent enantioselectivities and high turnovers were achieved in the asymmetric hydrogenation of aliphatic carbocyclic and heterocyclic tetrasubstituted enamides. Abstract We herein report the development of a conformationally defined, electron‐rich, C 2‐symmetric, P‐chiral bisphosphorus ligand, ArcPhos, by taking...
Angewandte Chemie International Edition
1d
Internal Nucleophilic Catalyst Mediated Cyclisation/Ring Expansion Cascades for the Synthesis of Medium‐Sized Lactones and Lactams
Two‐step process: A strategy for the synthesis of medium‐sized lactones and lactams from linear precursors is described in which an amine acts as an internal nucleophilic catalyst to facilitate a cyclisation/ring expansion cascade. This method obviates the need for high‐dilution conditions and enables medium‐sized ring biaryl scaffolds to be prepared with full control of atroposelectivity by point‐to‐axial chirality transfer. Abstract A strategy for the synthesis of medium‐sized lactones and...
Angewandte Chemie International Edition
1d
2D Monoelemental Germanene Quantum Dots: Synthesis as Robust Photothermal Agents for Photonic Cancer Nanomedicine
A facile, top‐down, liquid‐exfoliation approach to produce ultra‐small germanene quantum dots (GeQDs) is presented. 2D GeQDs are robust photothermal therapeutic (PTT) agents and can be used for hyperpyrexia ablation of tumors guided by multimodal (photoacoustic, PA; NIR fluorescence, FL; photothermal, PT) imaging. Abstract As a new family member of the emerging two‐dimensional (2D) monoelemental materials (Xenes), germanene has shown promising advantages over the prototypical 2D Xenes, such...
Angewandte Chemie International Edition
1d
The Unexplored World of Cycloalkene–Water Complexes: Primary and Assisting Interactions Unraveled by Experimental and Computational Spectroscopy
The intermolecular interactions in cycloalkene–water adducts were computationally characterized, thus demonstrating that the primary O−H⋅⋅⋅πC=C hydrogen bond is dominated by the electrostatic interaction. A deeper investigation by means of a joint rotational spectroscopy/state‐of‐the‐art quantum chemistry approach also led to the determination of an accurate semi‐experimental equilibrium structure for the cyclopentene adduct.
Angewandte Chemie International Edition
1d
Enhanced Raman Scattering by ZnO Superstructures: Synergistic Effect of Charge Transfer and Mie Resonances
Supersize Mie: A remarkable enhancement of Raman scattering is achieved by submicrometer‐sized spherical ZnO superstructures by a synergistic effect of charge‐transfer and Mie resonances. Abstract A remarkable enhancement of Raman scattering is achieved by submicrometer‐sized spherical ZnO superstructures. The secondary superstructures of ZnO particles with a uniform diameter in the range of 220–490 nm was formed by aggregating ca. 13 nm primary single crystallites. By engineering the superstructure...
Angewandte Chemie International Edition
1d
Chemical Synthesis at Surfaces with an Atomic Precision: Taming Complexity and Perfection
Scanning probe microscopies (SPM) are powerful tools to study structure and dynamics of molecules at surfaces and interfaces as well as to precisely manipulate atoms and molecules by applying external force, by inelastic electron tunneling, or by means of an electric field. The rapid development of these SPM manipulation modes made it possible to achieve a fine control over fundamental processes in physics of interfaces and on chemical reactivity, such as adsorption, diffusion, bond formation and...
Angewandte Chemie International Edition
1d
Squaramate‐Modified Nucleotides and DNA for Specific Cross‐Linking with Lysine‐Containing Peptides and Proteins
A squaramate–dNTP building block was prepared and used for the enzymatic synthesis of reactive DNA for cross‐linking with amines, peptides, and proteins, without the need for an external reagent. This could be used to label DNA and to identify and study DNA‐binding proteins. Abstract Squaramate‐linked 2′‐deoxycytidine 5′‐O‐triphosphate was synthesized and found to be good substrate for KOD XL DNA polymerase in primer extension or PCR synthesis of modified DNA. The resulting squaramate‐linked...
Angewandte Chemie International Edition
1d
Synthesis of Polyethylene with In‐Chain α,β‐Unsaturated Ketone and Isolated Ketone Units: Pd‐Catalyzed Ring‐Opening Copolymerization of Cyclopropenone with Ethylene
Daisy chain: A C3 polar monomer unit was successfully incorporated into a polyethylene chain for the first time by the Pd‐catalyzed copolymerization of cyclopropenones with ethylene. A polyethylene‐containing α,β‐unsaturated ketone unit in the chain was obtained, possibly by coordination‐insertion of the carbonyl group and ring opening of the strained three‐membered cyclopropenone ring. Under different reaction conditions an isolated ketone structure was afforded as the major carbonyl unit, and was...
Angewandte Chemie International Edition
1d
Fulminating Gold and Silver
The painting Explosion in the alchemist's laboratory by Justus van Bentum (1670–1727) might depict a detonation of fulminating gold, giving off ruby‐red fumes. The Essay describes the history of preparation and uses of fulminating gold and silver from the late 1500s onward. Abstract This Essay deals with the fascinating and highly explosive compounds fulminating gold and fulminating silver, which are easily made by treatment of gold dissolved in aqua regia with ammonia, and by reaction of...
Angewandte Chemie International Edition
1d
Dirac Nodal Arc Semimetal PtSn4: An Ideal Platform for Understanding Surface Properties and Catalysis for Hydrogen Evolution
Putting the tin into plaTINum: The Dirac semimetal PtSn4 has a two‐dimensional layered structure. Intrinsic and stable surface states are found in the Pt layer of the PtSn4 single crystal. The p orbitals of Pt atoms of these robust surface states can deliver electrons efficiently for hydrogen reduction. PtSn4 thus acts as a benchmark electrocatalyst for hydrogen evolution. Abstract Conductivity, carrier mobility, and a suitable Gibbs free energy are important criteria that determine the performance...
Angewandte Chemie International Edition
1d
O−O Bond Formation and Liberation of Dioxygen Mediated by N5‐Coordinate Non‐Heme Iron(IV) Complexes
The O−O bond is efficiently formed and dioxygen stoichiometrically released in the reaction of non‐heme oxoiron(IV) complexes with meta‐chloroperbenzoic acid. High‐valent iron(IV) is identified as a resting state. It is suggested to be activated towards O–O coupling through concerted inner‐sphere transfer of an electron and a hydroxyl anion. Abstract Formation of the O−O bond is considered the critical step in oxidative water cleavage to produce dioxygen. High‐valent metal complexes with terminal...
Angewandte Chemie International Edition
1d
Strigolactones: Plant Hormones with Promising Features
A rich field: The recently discovered class of plant hormones, the strigolactones, display unprecedented biological activity. Their use however is not without challenges: the synthesis of strigolactones is complicated and designing the desired activity a difficult task. This Minireview describes the current state of knowledge about the strigolactones and how synthetic analogs can be developed that can potentially contribute to the development of a sustainable agriculture. Abstract Almost 80 years...
Angewandte Chemie International Edition
1d
Cysteine SH and Glutamate COOH Contributions to [NiFe] Hydrogenase Proton Transfer Revealed by Highly Sensitive FTIR Spectroscopy
Catalytic contributions: Protonated Cys546‐SH, H‐bonded Glu34‐COOH, and ordered water frequencies were observed for the Ni‐C, Ni‐L, and Ni‐SIa states of [NiFe] hydrogenase, showing that the organized proton transfer pathway during the catalytic reaction is regulated by the H‐bond network of Cys546, Glu34, and an ordered water molecule. Abstract A [NiFe] hydrogenase (H2ase) is a proton‐coupled electron transfer enzyme that catalyses reversible H2 oxidation; however, its fundamental proton transfer...
Angewandte Chemie International Edition
1d
Rapid Identification of Halogen Bonds in Co‐Crystalline Powders via 127I Nuclear Quadrupole Resonance Spectroscopy
127 I can show you the bond: 127I NQR spectroscopy is established as a rapid probe of iodine–nitrogen halogen‐bond formation in a series of 1,4‐diiodobenzene co‐crystalline powders. The method is cross‐validated through testing on two previously unknown co‐crystals, demonstrating its predictive power. DFT computations reveal the origins of the observed spectral shifts. Abstract 127I nuclear quadrupole resonance (NQR) spectroscopy is established as a rapid and robust method to indicate the...
Angewandte Chemie International Edition
1d
Asymmetric Catalytic Formal 1,4‐Allylation of β,γ‐Unsaturated α‐Ketoesters: Allylboration/Oxy‐Cope Rearrangement
A highly efficient catalytic asymmetric allylboration/oxy‐Cope rearrangement reaction sequence of β,γ‐unsaturated α‐ketoesters with allylboronic acids has been realized by employing a NiII/N,N′‐dioxide complex as the catalyst. This transformation provides a facile and rapid route to formal allyl conjugate addition products, chiral γ‐allyl‐α‐ketoesters, with good results. Abstract A highly enantioselective formal conjugate allyl addition of allylboronic acids to β,γ‐unsaturated α‐ketoesters...
Angewandte Chemie International Edition
1d
Case 25-2019: A 41-Year-Old Pregnant Woman with Abdominal Pain
Presentation of Case. Dr. Madhukar S. Patel (Surgery): A 41-year-old pregnant woman was seen in the emergency department of this hospital at 36 weeks 3 days of gestation because of abdominal pain. Six and a half months before this evaluation, when the patient was at her initial routine prenatal…
The New England Journal of Medicine: Search Results in Surgery
9h
Statewide Implementation of Postoperative Opioid Prescribing Guidelines
To the Editor: Opioids are widely overprescribed after surgery. Leftover medication is often diverted into the community, contributing to the opioid epidemic. The lack of evidence on which to base prescribing practices after surgery may hinder efforts to reduce overprescribing. In this study, we…
The New England Journal of Medicine: Search Results in Surgery
9h
[ASAP] Three-Dimensional Tetrathiafulvalene-Based Covalent Organic Frameworks for Tunable Electrical Conductivity
Journal of the American Chemical SocietyDOI: 10.1021/jacs.9b06908
Journal of the American Chemical Society: Latest Articles (ACS Publications)
9h
[ASAP] Nitrogen Bridged Diazocines: Photochromes Switching within the Near-Infrared Region with High Quantum Yields in Organic Solvents and in Water
Journal of the American Chemical SocietyDOI: 10.1021/jacs.9b06104
Journal of the American Chemical Society: Latest Articles (ACS Publications)
9h
[ASAP] MftD Catalyzes the Formation of a Biologically Active Redox Center in the Biosynthesis of the Ribosomally Synthesized and Post-translationally Modified Redox Cofactor Mycofactocin
Journal of the American Chemical SocietyDOI: 10.1021/jacs.9b06102
Journal of the American Chemical Society: Latest Articles (ACS Publications)
9h

[ASAP] Localized Electronic Structure of Nitrogenase FeMoco Revealed by Selenium K-Edge High Resolution X-ray Absorption Spectroscopy
Journal of the American Chemical SocietyDOI: 10.1021/jacs.9b06988
Journal of the American Chemical Society: Latest Articles (ACS Publications)
9h
[ASAP] Iodonitrene in Action: Direct Transformation of Amino Acids into Terminal Diazirines and <sup>15</sup>N<sub>2</sub>-Diazirines and Their Application as Hyperpolarized Markers
Journal of the American Chemical SocietyDOI: 10.1021/jacs.9b07035
Journal of the American Chemical Society: Latest Articles (ACS Publications)
9h
[ASAP] In Situ Construction of a Cs<sub>2</sub>SnI<sub>6</sub> Perovskite Nanocrystal/SnS<sub>2</sub> Nanosheet Heterojunction with Boosted Interfacial Charge Transfer
Journal of the American Chemical SocietyDOI: 10.1021/jacs.9b04482
Journal of the American Chemical Society: Latest Articles (ACS Publications)
9h
[ASAP] The Photoaddition of a Psoralen to DNA Proceeds via the Triplet State
Journal of the American Chemical SocietyDOI: 10.1021/jacs.9b06521
Journal of the American Chemical Society: Latest Articles (ACS Publications)
9h
[ASAP] Quantum Effects on H<sub>2</sub> Diffusion in Zeolite RHO: Inverse Kinetic Isotope Effect for Sieving
Journal of the American Chemical SocietyDOI: 10.1021/jacs.9b06506
Journal of the American Chemical Society: Latest Articles (ACS Publications)
13h
[ASAP] In Situ Small-Angle X-ray Scattering Studies During Reversible Addition–Fragmentation Chain Transfer Aqueous Emulsion Polymerization
Journal of the American Chemical SocietyDOI: 10.1021/jacs.9b06788
Journal of the American Chemical Society: Latest Articles (ACS Publications)
13h
[ASAP] Ligand-Induced Surface Charge Density Modulation Generates Local Type-II Band Alignment in Reduced-Dimensional Perovskites
Journal of the American Chemical SocietyDOI: 10.1021/jacs.9b04801
Journal of the American Chemical Society: Latest Articles (ACS Publications)
13h
[ASAP] Role of the Carboxylate in Enzyme-Catalyzed Decarboxylation of Orotidine 5'-Monophosphate: Transition State Stabilization Dominates Over Ground State Destabilization
Journal of the American Chemical SocietyDOI: 10.1021/jacs.9b04823
Journal of the American Chemical Society: Latest Articles (ACS Publications)
13h
[ASAP] Anisotropic Polyoxometalate Cages Assembled via Layers of Heteroanion Templates
Journal of the American Chemical SocietyDOI: 10.1021/jacs.9b04533
Journal of the American Chemical Society: Latest Articles (ACS Publications)
1d
[ASAP] C–N Cross-Couplings for Site-Selective Late-Stage Diversification via Aryl Sulfonium Salts
Journal of the American Chemical SocietyDOI: 10.1021/jacs.9b07323
Journal of the American Chemical Society: Latest Articles (ACS Publications)
1d
[ASAP] The Role of Protein Thermodynamics and Primary Structure in Fibrillogenesis of Variable Domains from Immunoglobulin Light Chains
Journal of the American Chemical SocietyDOI: 10.1021/jacs.9b05499
Journal of the American Chemical Society: Latest Articles (ACS Publications)
1d
[ASAP] Monitoring DNA–Ligand Interactions in Living Human Cells Using NMR Spectroscopy
Journal of the American Chemical SocietyDOI: 10.1021/jacs.9b03031
Journal of the American Chemical Society: Latest Articles (ACS Publications)
1d
[ASAP] Cyclic Sulfenyl Thiocarbamates Release Carbonyl Sulfide and Hydrogen Sulfide Independently in Thiol-Promoted Pathways
Journal of the American Chemical SocietyDOI: 10.1021/jacs.9b06319
Journal of the American Chemical Society: Latest Articles (ACS Publications)
1d
[ASAP] Rationalizing the Hot-Carrier-Mediated Reaction Mechanisms and Kinetics for Ammonia Decomposition on Ruthenium-Doped Copper Nanoparticles
Journal of the American Chemical SocietyDOI: 10.1021/jacs.9b06804
Journal of the American Chemical Society: Latest Articles (ACS Publications)
1d
[ASAP] Iron(III) Speciation Observed at Aqueous and Glycerol Surfaces: Vibrational Sum Frequency and X-ray
Journal of the American Chemical SocietyDOI: 10.1021/jacs.9b05231
Journal of the American Chemical Society: Latest Articles (ACS Publications)
1d
Medium Preparation for the Cultivation of Microorganisms under Strictly Anaerobic/Anoxic Conditions
As obligate anaerobic organisms are unable to grow upon oxygen exposure, the use of anaerobic culturing techniques is indispensable. Here, we demonstrate a simple and effective method to cultivate a mixed culture derived from a biogas plant from media preparation to gas and volatile fatty acid quantification.
JoVE: Journal of Visualized Experiments
10h
Photodeposition of Pd onto Colloidal Au Nanorods by Surface Plasmon Excitation
A protocol for anisotropic photodeposition of Pd onto aqueously-suspended Au nanorods via localized surface plasmon excitation is presented.
JoVE: Journal of Visualized Experiments
10h
Structured Motor Rehabilitation After Selective Nerve Transfers
Here, we present a protocol for the motor rehabilitation of patients with severe nerve injuries and selective nerve transfer surgery. It aims at restoring the motor function proposing several stages in patient education, early-stage therapy after surgery and interventions for rehabilitation after successful re-innervation of the nerve’s target.
JoVE: Journal of Visualized Experiments
10h
A Human Peripheral Blood Mononuclear Cell (PBMC) Engrafted Humanized Xenograft Model for Translational Immuno-oncology (I-O) Research
We describe a human peripheral blood mononuclear cell (PBMC) — based humanized xenograft mouse model for translational immuno-oncology research. This protocol could serve as a general guideline for establishing and characterizing similar models for I-O therapy assessment.
JoVE: Journal of Visualized Experiments
11h
Isolation and Quantification of Zika Virus from Multiple Organs in a Mouse
The goal of the protocol is to demonstrate the techniques used to investigate viral disease by isolating and quantifying Zika virus, from multiple organs in a mouse following infection.
JoVE: Journal of Visualized Experiments
11h

Navigating MARRVEL, a Web-Based Tool that Integrates Human Genomics and Model Organism Genetics Information
Here, we present a protocol to access and analyze many human and model organism databases efficiently. This protocol demonstrates the use of MARRVEL to analyze candidate disease-causing variants identified from next-generation sequencing efforts.
JoVE: Journal of Visualized Experiments
12h
A Positioning Device for the Placement of Mice During Intranasal siRNA Delivery to the Central Nervous System
Here, we present a protocol using a mouse positioning device that enables the appropriate placement of mice for the intranasal administration of a brain-targeting peptide-siRNA formulation enabling effective gene silencing in the central nervous system.
JoVE: Journal of Visualized Experiments
12h
Advanced Diffusion Imaging in The Hippocampus of Rats with Mild Traumatic Brain Injury
The overall goal of this procedure is to obtain quantitative microstructural information of the hippocampus in a rat with mild traumatic brain injury. This is done using an advanced diffusion-weighted magnetic resonance imaging protocol and region-of-interest based analysis of parametric diffusion maps.
JoVE: Journal of Visualized Experiments
1d
A Luciferase-fluorescent Reporter Influenza Virus for Live Imaging and Quantification of Viral Infection
Influenza A viruses (IAVs) are contagious respiratory pathogens that cause annual epidemics and occasional pandemics. Here, we describe a protocol to track viral infections in vivo using a novel recombinant luciferase and fluorescence-expressing bi-reporter IAV (BIRFLU). This approach provides researchers with an excellent tool to study IAV in vivo.
JoVE: Journal of Visualized Experiments
1d
Semi-automatic PD-L1 Characterization and Enumeration of Circulating Tumor Cells from Non-small Cell Lung Cancer Patients by Immunofluorescence
The characterization of circulating tumor cells (CTCs) is a popular topic in translational research. This protocol describes a semi-automatic immunofluorescence (IF) assay for PD-L1 characterization and enumeration of CTCs in non-small cell lung cancer (NSCLC) patient samples.
JoVE: Journal of Visualized Experiments
1d
In Vivo Imaging and Quantitation of the Host Angiogenic Response in Zebrafish Tumor Xenografts
The aim of this method is to generate an in vivo model of tumor angiogenesis by xenografting mammalian tumor cells into a zebrafish embryo that has fluorescently-labelled blood vessels. By imaging the xenograft and associated vessels, a quantitative measurement of the angiogenic response can be obtained.
JoVE: Journal of Visualized Experiments
1d
Ultrasonography of the Adult Male Urinary Tract for Urinary Functional Testing
We describe the use of high frequency ultrasound with contrast imaging as a method to measure bladder volume, bladder wall thickness, urine velocity, void volume, void duration, and urethral diameter. This strategy can be used to assess voiding dysfunction and treatment efficacy in various mouse models of lower urinary tract dysfunction (LUTD).
JoVE: Journal of Visualized Experiments
1d
Isolation and Culture of Primary Aortic Endothelial Cells from Miniature Pigs
An effective enzymatic method for isolation of primary porcine aortic endothelial cells (pAECs) from miniature pigs is described. The isolated primary pAECs can be used to investigate the immune and coagulation response in xenotransplantation.
JoVE: Journal of Visualized Experiments
1d
Biosynthesis of a Flavonol from a Flavanone by Establishing a One-pot Bienzymatic Cascade
The derivation of a flavonol is crucial for its application in healthcare and the food industry. Here, we provide a detailed protocol for the biosynthesis of a flavonol from a flavanone and discuss the crucial steps and its advantages over other approaches.
JoVE: Journal of Visualized Experiments
1d
Statewide Implementation of Postoperative Opioid Prescribing Guidelines
To the Editor: Opioids are widely overprescribed after surgery. Leftover medication is often diverted into the community, contributing to the opioid epidemic. The lack of evidence on which to base prescribing practices after surgery may hinder efforts to reduce overprescribing. In this study, we…
The New England Journal of Medicine: Search Results in Health Policy and Reform
10h
Time to Reevaluate U.S. Mifepristone Restrictions
In September 2000, the Food and Drug Administration (FDA) — of which one of us was commissioner at the time — approved mifepristone, one of two medications used to end early unwanted pregnancies. At that time, because of limited clinical trial data from the United States, the FDA simultaneously…
The New England Journal of Medicine: Search Results in Health Policy and Reform
10h
The "All of Us" Research Program
Longitudinal cohort studies have improved human health by characterizing natural histories of diseases, identifying their risk factors, and revealing new biomarkers. Advances in genomics and biosensors have set the stage for refined taxonomies of disease, which may help to guide prognosis, improve…
The New England Journal of Medicine: Search Results in Health Policy and Reform
10h
Eculizumab in Aquaporin-4–Positive Neuromyelitis Optica Spectrum Disorder
Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune, inflammatory disorder of the central nervous system that has a prevalence of 0.5 to 10 persons (predominantly women) per 100,000 population. It is characterized mainly by recurrent optic neuritis and myelitis, and such attacks are…
The New England Journal of Medicine: Neurology\Neurosurgery
10h
Statewide Implementation of Postoperative Opioid Prescribing Guidelines
To the Editor: Opioids are widely overprescribed after surgery. Leftover medication is often diverted into the community, contributing to the opioid epidemic. The lack of evidence on which to base prescribing practices after surgery may hinder efforts to reduce overprescribing. In this study, we…
The New England Journal of Medicine: Neurology\Neurosurgery
10h
Case 25-2019: A 41-Year-Old Pregnant Woman with Abdominal Pain
Presentation of Case. Dr. Madhukar S. Patel (Surgery): A 41-year-old pregnant woman was seen in the emergency department of this hospital at 36 weeks 3 days of gestation because of abdominal pain. Six and a half months before this evaluation, when the patient was at her initial routine prenatal…
The New England Journal of Medicine: Search Results in Emergency Medicine
11h
Mike’s Labels
Mike is a homeless chronic alcoholic. I know this because I wrote his label right here on his medical record. The first sentence, variations of which appear hundreds of times in his file, reads, "53-year-old homeless male, chronic alcoholic, presenting here via ambulance after being picked up…
The New England Journal of Medicine: Search Results in Emergency Medicine
11h
Cholesterol Crystal Embolization after Transcatheter Aortic-Valve Replacement
Figure 1.
The New England Journal of Medicine: Search Results in Primary Care\Hospitalist\Clinical Practice
11h
Warm Autoimmune Hemolytic Anemia
Foreword. This Journal feature begins with a case vignette highlighting a common clinical problem. Evidence supporting various strategies is then presented, followed by a review of formal guidelines, when they exist. The article ends with the author’s clinical recommendations. Stage. A 61-year-old…
The New England Journal of Medicine: Search Results in Primary Care\Hospitalist\Clinical Practice
11h
Mike’s Labels
Mike is a homeless chronic alcoholic. I know this because I wrote his label right here on his medical record. The first sentence, variations of which appear hundreds of times in his file, reads, "53-year-old homeless male, chronic alcoholic, presenting here via ambulance after being picked up…
The New England Journal of Medicine: Search Results in Primary Care\Hospitalist\Clinical Practice
11h
Case 25-2019: A 41-Year-Old Pregnant Woman with Abdominal Pain
Presentation of Case. Dr. Madhukar S. Patel (Surgery): A 41-year-old pregnant woman was seen in the emergency department of this hospital at 36 weeks 3 days of gestation because of abdominal pain. Six and a half months before this evaluation, when the patient was at her initial routine prenatal…
The New England Journal of Medicine: Search Results in Primary Care\Hospitalist\Clinical Practice
11h

Time to Reevaluate U.S. Mifepristone Restrictions
In September 2000, the Food and Drug Administration (FDA) — of which one of us was commissioner at the time — approved mifepristone, one of two medications used to end early unwanted pregnancies. At that time, because of limited clinical trial data from the United States, the FDA simultaneously…
The New England Journal of Medicine: Search Results in Primary Care\Hospitalist\Clinical Practice
11h
Placenta Percreta Involving Maternal Bladder
Figure 1.
The New England Journal of Medicine: Search Results in Primary Care\Hospitalist\Clinical Practice
11h
Recognition for Discoveries in DNA Repair
Recombination between homologous chromosomes is essential for successful meiosis. It drives genetic diversity in germline cells and provides the necessary scaffolding for accurate, balanced segregation of the parental chromosomes into meiotic products. However, its importance in somatic cells has…
The New England Journal of Medicine: Cancer, Genetics
11h
Hippocampal sharp-wave ripples linked to visual 

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