JoVE: Journal of Visualized Experiments
- In Vivo Optical Calcium Imaging of Learning-Induced Synaptic Plasticity in Drosophila melanogasterHere we present a protocol with which pre- and/or postsynaptic calcium can be visualized in the context of Drosophila learning and memory. In vivo calcium imaging using synaptically localized calcium sensors is combined with a classical olfactory conditioning paradigm such that the synaptic plasticity underlying this type of associative learning may be determined.
- DNA Sequence Recognition by DNA Primase Using High-Throughput Primase ProfilingProtein binding microarray (PBM) experiments combined with biochemical assays link the binding and catalytic properties of DNA primase, an enzyme that synthesizes RNA primers on template DNA. This method, designated as high-throughput primase profiling (HTPP), can be used to reveal DNA-binding patterns of a variety of enzymes.
Journal of the American Chemical Society: Latest Articles (ACS Publications)
- [ASAP] Spotlights on Recent <italic toggle="yes">JACS</italic> PublicationsJournal of the American Chemical SocietyDOI: 10.1021/jacs.9b10779
- [ASAP] Unveiling Electronic Properties in Metal–Phthalocyanine-Based Pyrazine-Linked Conjugated Two-Dimensional Covalent Organic FrameworksJournal of the American Chemical SocietyDOI: 10.1021/jacs.9b07644
- [ASAP] Evaluation of Structure–Function Relationships of Aggregation-Induced Emission Luminogens for Simultaneous Dual Applications of Specific Discrimination and Efficient Photodynamic Killing of Gram-Positive BacteriaJournal of the American Chemical SocietyDOI: 10.1021/jacs.9b07162
- [ASAP] In Situ Methods for Identifying Reactive Surface Intermediates during Hydrogenolysis Reactions: C–O Bond Cleavage on Nanoparticles of Nickel and Nickel PhosphidesJournal of the American Chemical SocietyDOI: 10.1021/jacs.9b06112
- [ASAP] Phosphaaluminirenes: Synthons for Main Group HeterocyclesJournal of the American Chemical SocietyDOI: 10.1021/jacs.9b09330
- [ASAP] Ni-Catalyzed Asymmetric Allylation of Secondary Phosphine OxidesJournal of the American Chemical SocietyDOI: 10.1021/jacs.9b08734
- [ASAP] Cyclohexyl-Fused, Spirobiindane-Derived, Phosphine-Catalyzed Synthesis of Tricyclic ?-Lactams and Kinetic Resolution of ?-Substituted AllenoatesJournal of the American Chemical SocietyDOI: 10.1021/jacs.9b07418
- [ASAP] Revealing the Effects of the Non-solvent on the Ligand Shell of Nanoparticles and Their CrystallizationJournal of the American Chemical SocietyDOI: 10.1021/jacs.9b06010
- [ASAP] Understanding Chemoselectivity in Proton-Coupled Electron Transfer: A Kinetic Study of Amide and Thiol ActivationJournal of the American Chemical SocietyDOI: 10.1021/jacs.9b08398
- [ASAP] An Emerging Molecular Design Approach to Heavy-Atom-Free Photosensitizers for Enhanced Photodynamic Therapy under HypoxiaJournal of the American Chemical SocietyDOI: 10.1021/jacs.9b09220
- [ASAP] Dibenzo[<italic toggle="yes">hi</italic>,<italic toggle="yes">st</italic>]ovalene as Highly Luminescent Nanographene: Efficient Synthesis via Photochemical Cyclodehydroiodination, Optoelectronic Properties, and Single-Molecule SpectroscopyJournal of the American Chemical SocietyDOI: 10.1021/jacs.9b08320
- [ASAP] The Optimal Electronic Structure for High-Mobility 2D Semiconductors: Exceptionally High Hole Mobility in 2D AntimonyJournal of the American Chemical SocietyDOI: 10.1021/jacs.9b05923
- [ASAP] Reversible Polymerization-like Kinetics for Programmable Self-Assembly of DNA-Encoded Nanoparticles with Limited ValenceJournal of the American Chemical SocietyDOI: 10.1021/jacs.9b07919
- [ASAP] Direct Growth of Highly Strained Pt Islands on Branched Ni Nanoparticles for Improved Hydrogen Evolution Reaction ActivityJournal of the American Chemical SocietyDOI: 10.1021/jacs.9b07659
- [ASAP] Insights into Reaction Intermediates to Predict Synthetic Pathways for Shape-Controlled Metal NanocrystalsJournal of the American Chemical SocietyDOI: 10.1021/jacs.9b06267
- [ASAP] [{(PhSn)<sub>3</sub>SnS<sub>6</sub>}{(MCp)<sub>3</sub>S<sub>4</sub>}] (M = W, Mo): Minimal Molecular Models of the Covalent Attachment of Metal Chalcogenide Clusters on Doped Transition Metal Dichalcogenide LayersJournal of the American Chemical SocietyDOI: 10.1021/jacs.9b09209
- [ASAP] Water/Oxygen Circulation-Based Biophotoelectrochemical System for Solar Energy Storage and ReleaseJournal of the American Chemical SocietyDOI: 10.1021/jacs.9b08046
Journal of Voice
- Perceived Control, Voice Handicap, and Barriers to Voice TherapyTo characterize the associations of perceived control with voice outcomes and self-reported likelihood of attending voice therapy using a national practice-based research network.
Medgadget
- 3D Microenvironments to Grow Brain Tumors in LabClinical researchers are constantly thwarted by the inability to quickly and easily try new therapies in tumors and other disease targets. Tumors within the brain are particularly hard to study because of the difficulty with access and the incredible fragility of nearby tissues. Researchers at Tufts University have just developed a way to create an environment that closely mimics that of the brain and were able to grow pediatric and adult tumors
- Gore CARDIOFORM ASD Cleared in Europe for Atrial Septal DefectsGore won the European CE Mark for its GORE CARDIOFORM ASD Occluder, a device designed for percutaneous, transcatheter closure of ostium secundum atrial defects (ASDs). The occluder recently completed a clinical study involving 125 patients with ASD, ranging from 2 to 84 years of age, all of whom were successfully implanted with the GORE CARDIOFORM ASD and maintained closure six months later. The device is made of two discs that make conta
- Epica SeeFactorCT3 Multi-Modality System Wins FDA ClearanceEpica, a company based in San Clemente, California, won FDA clearance for its SeeFactorCT3 system that combines computed tomography (CT), fluoroscopy, and digitial radiography (DR) into a single device. It is intended for use in diagnostic, interventional, and intraoperative procedures mostly involving the head, neck, and extremities. As such, it is expected to be used by a variety of surgeons, dentists, and imaging specialists. Th
- Electrified Graphene Filters Kill All Pathogens and Their ByproductsPathogenic bacteria are usually the culprits responsible for the spread of nosocomial infections, but there are other sources of disease in hospitals, including viruses, fungi, their spores, prions, and endotoxins produced by bacteria. Existing methods and standards usually involve two filter beds being used within hospitals’ ventilation systems. These have to be replaced on a regular basis, and though these filters trap pathogens and som
- Soft Robotic Glove for Hand Grasp RehabAll sorts of conditions, including muscular dystrophy, ALS, and partial spinal cord injury, result in patients losing their ability to confidently grasp objects with their hands. Regaining this important capability is usually a priority, as it is one of the biggest impediments to living a normal life. Now, researchers at Harvard’s Wyss Institute have developed and are clinically testing a soft robotic glove that helps to restore hand funct
- Nobel Prize in Physiology or Medicine 2019 Announced for Cell Oxygen RegulationTwo Americans and an English knight have won this year’s Nobel Prize in Physiology or Medicine for their discovery of how cells detect how much oxygen is available to them and the mechanism that regulates how they adapt to changes in oxygen levels. The Nobel Laureates: William G. Kaelin Jr., Sir Peter J. Ratcliffe and Gregg L. Semenza While the scientific community recognized the importance of oxygen for animal cells a very long tim
- Red Light Activated Cancer Drug Improves Treatment in MiceResearchers from the City University of Hong Kong have developed a new, controllable cancer drug called phorbiplatin that only becomes active and potent after red light stimulation. Their work demonstrates that in the dark the cancer drug does not have substantial toxicity, but the drug is able to substantially reduce tumor size when activated by red light. One day, this technology may be used to improve cancer treatment and reduce its side effec
Angewandte Chemie International Edition
- In‐Situ Nanostructuring and Stabilization of Polycrystalline Copper by an Organic Salt Additive Promotes Electrocatalytic CO2 Reduction to EthyleneCatalytic cubes: An efficient method for nanostructuring copper electrodes using N,N′‐ethylene‐phenanthrolinium dibromide as a molecular additive is reported. Using such Cu electrodes in electrochemical CO2 reduction produces C≥2 products with selectivities up to 70 % for more than 40 h without significant change in the surface morphology. Abstract Bridging homogeneous molecular systems with heterogeneous catalysts is a promising approach f
- In‐Operando Mapping of pH Distribution in Electrochemical ProcessesSpatially and temporally resolved pH in an electrochemical system was obtained by laser scanning confocal microscopy. A combination of pH sensitive dyes was used to extend the dynamic pH range. This approach can be used to investigate the reaction products and transport phenomena in aqueous electrochemical systems. Abstract In aqueous electrochemical processes, the pH evolves spatially and temporally, and often dictates the process performa
- Accessing Difluoromethylated and Trifluoromethylated cis‐Cycloalkanes and Saturated Heterocycles: Preferential Hydrogen Addition to the Substitution Sites for DearomatizationAdd‐ons: The preferential addition of hydrogen to the substitution sites of difluoromethylated and trifluoromethylated arenes and heteroarenes for dearomative reduction is described. This strategy enables the rapid and diastereoselective synthesis of cis‐difluoromethylated and cis‐trifluoromethylated cycloalkanes and saturated heterocycles, as well as the construction of all‐cis multiply trifluoromethylated cyclic aliphatic compounds with a defin
- Water‐Induced Growth of High‐Oriented Mesoporous Graphitic Carbon Nanospring for Fast K‐ion Adsorption/Intercalation StorageHere, high‐oriented mesoporous graphitic carbon nanospring (OGCS) with graphitic layers that are perpendicular to the axis is prepared by hydrothermal treatment of epoxy resin at 500 ℃ and followed by annealing at 1400 ℃. It is demonstrated that the water plays an important role in not only forming graphitic carbon nanospring with high [002] orientation and a large amount of active edge‐plane sites, but also contributing to the generation of me
- Nucleophile Coordination Enabled Regioselectivity in Palladium‐Catalyzed Asymmetric Allylic C−H AlkylationBranching out: Palladium‐chiral phosphoramidite catalysis is used for an unprecedented branched‐selective asymmetric allylic C−H alkylation by using 2‐acylimidazoles as model coordinating nucleophiles. Density‐functional theory calculations suggest an unusual inner‐sphere mechanism for the carbon–carbon bond‐forming process. Abstract Branched selectivity in asymmetric allylic C−H alkylation is enabled by using 2‐acylimidazoles as nucleophil
- Selective CO2 Electroreduction to Ethylene and Multicarbon Alcohols via Electrolyte‐Driven NanostructuringElectrolyte‐driven nanostructuring can be used to synthesize highly selective Cu catalysts for CO2 electroreduction to multicarbon products (80 % Faradaic efficiency). Operando spectroscopy measurements showed that apart from enhanced roughness from the pre‐treatment, the subsurface oxygen and Cu+ species and the adsorbed halides favor C−C coupling, leading to high selectivity for ethylene, ethanol, and n‐propanol. Abstract Production of mu
- Revealing an Interconnected Interfacial Layer in Solid‐State Polymer Sodium BatteriesThrough preparation of a composite Na/C metal anode, an effective approach is introduced that constructs a strong chemical connection between the composite anode and the PEO based polymer electrolyte. This interconnected interface environment results in ultralong cycle life of Na‐metal polymer batteries, reaching a capacity retention of over 80 % after 5 000 cycles. Abstract Replacing the commonly used nonaqueous liquid electrolytes in rech
- Palladium(0)‐Catalyzed Directed syn‐1,2‐Carboboration and ‐Silylation: Alkene Scope, Applications in Dearomatization, and Stereocontrol by a Chiral AuxiliaryAlkene functionalization: A method to affect syn‐1,2‐carboboration and ‐silylation of alkenes and heterocycles via Pd0/PdII catalysis is described. Strategic use of a chiral directing group allows for stereocontrol in the key 1,2‐migratory insertion step. Abstract We report the development of palladium(0)‐catalyzed syn‐selective 1,2‐carboboration and ‐silylation reactions of alkenes containing cleavable directing groups. With B2pin2 or PhMe
- Alkali Metal Arenides as a Universal Synthetic Tool for Layered 2D Germanene Modification2D materials: A new methodology in germanene chemistry is presented using germanane (Ge6H6) as a stable and easily accessible starting material for effective synthesis of novel germanene derivatives. Abstract The rediscovery of graphene in 2004 has started an enormous chase in the research of 2D materials. A new family of layered 2D materials consisting of the 14th group elements beyond carbon has already been reported. Here, a new methodol
- “Direct Mechanocatalysis” – Palladium as Milling Media and Catalyst in the Mechanochemical Suzuki PolymerizationThe milling ball is the catalyst. We introduce a palladium‐catalyzed reaction inside a ball mill making catalyst powders, ligands, and solvents obsolete. We present a facile and highly sustainable synthesis concept for palladium‐catalyzed C‐C‐coupling reactions, showcased for the Suzuki‐Miyaura polymerization of 4‑bromophenylboronic acid towards poly( para ‐phenylene). Surprisingly, we even observe one of the highest degrees of polymerization (
- Topochemical Synthesis of Two‐Dimensional Transition Metal Phosphides Using Phosphorene TemplatesTransition metal phosphides (TMPs) have emerged as a fascinating class of narrow‐gap semiconductors and electrocatalysts. However, they are intrinsic non‐layered materials that cannot be delaminated into two‐dimensional (2D) sheets. Here, we demonstrate a general bottom‐up topochemical strategy to synthesize a series of 2D TMPs (e.g. Co 2 P, Ni 12 P 5 and Co x Fe 2‐x P) using phosphorene sheets as the phosphorous precursor and 2D templa
- Catalytic Enantioselective Methylene C(sp3)–H Amidation of 8‐Alkylquinolines Using Cp*RhIII/Chiral Carboxylic Acid SystemThe catalytic enantioselective directed methylene C(sp 3 )–H amidation reactions of 8‐alkylquinolines using a Cp*Rh III /chiral carboxylic acid (CCA) hybrid catalytic system is described. A binaphthyl‐based chiral carboxylic acid efficiently differentiates between the enantiotopic methylene C–H bonds, which leads to the formation of C–N bonds in good enantioselectivity.
- Vapor‐phase linker exchange of the metal‐organic framework ZIF‐8: a solvent‐free approach to post‐synthetic modificationZeolitic imidazolate frameworks (ZIFs) are a sub‐class of metal‐organic frameworks (MOFs). Although generally stable, ZIFs can undergo post‐synthetic linker exchange (PSLE) in solution under mild conditions. Here we present a novel, solvent‐free approach to post‐synthetic linker exchange through exposure to linker vapor.
- Effect of temperature on the nucleation and growth of precious metal nanocrystalsUnderstanding the effect of physical parameters ( e.g. temperature) on crystallisation dynamics is of paramount importance for the synthesis of nanocrystals of well‐defined sizes and geometries. However, imaging nucleation and growth is an experimental challenge owing to the resolution required and the kinetics involved. Here, using an aberration‐corrected transmission electron microscope, we report the fabrication of precious metal nanocrystal
- Insight into Tri‐coordinated Aluminium Species on Ethanol‐to‐Olefin Conversion over ZSM‐5 ZeolitesEthylene, a key chemical in the synthesis of plastics, fibres, rubbers, solvents and many other necessary chemicals , is produced from petroleum‐ and coal‐based industrial chemical processes. Commercial bioethanol is a renewable low‐cost feedstock that can be readily converted into ethylene by dehydration process using solid acids, such as Brønsted acidic H‐ZSM‐5 zeolites, and thus it is an ideal candidate to replace petroleum and coal for the
- Enantioselective Dearomatization of Indoles via an Azoalkene‐enabled (3+2) Reaction: Facile Access to PyrroloindolinesAn enantioselective dearomatization of indoles via an organocatalytic (3+2) reaction has been established. The reaction made use of simple indole derivatives as substrates, and was empowered by the utilization of azoalkenes as a reaction partner. A wide range of pyrroloindolines containing an all‐carbon quaternary stereogenic center were readily prepared in high yields and with excellent enantioselectivities.
- High‐Throughput Ligand Screening Enables the Enantioselective Conjugate Borylation of Cyclobutenones to Access Synthetically Versatile Tertiary CyclobutylboronatesCyclobutane rings are important in medicinal chemistry, yet few enantioselective methods exist to access this scaffold. In particular, cyclobutylboronates are receiving increasing attention in the literature due to the synthetic versatility of alkylboronic esters and the increasing role of boronic acids in drug discovery. Herein, a conjugate borylation of α‐alkyl,β‐aryl/alkyl cyclobutenones is developed leading to the first synthesis of enantioen
- The Reactions of Carbon Monoxide with Silyl and Silenyl Lithium. Synthesis and Isolation of the First Stable Bis‐Silyl Ketyl Radical and 1‐Silaallenolate LithiumReactions of carbon monoxide (CO) with tBu2MeSiLi and (E)‐(tBu2MeSi)(tBuMe2Si)C=Si(SiMetBu2)Li·2THF (4) were studied both experimentally and computationally. Reaction of tBu2MeSiLi with CO in hexane yields the first stable bis‐silyl ketyl biradical [(tBu2MeSi)2COLi]•2 (3). Reaction of 4 with CO yields selectively and quantitatively the first reported 1‐silaallenolate, (tBu2MeSi)(tBuMe2Si)C=C=Si(SiMetBu2)OLi·THF (5). Both 3 and 5 were characterize
- Atomic‐Scale Visualization of the Stepwise Metal‐Mediated Dehalogenative Cycloaddition Reaction Pathways: Competition between Radicals and Organometallic IntermediatesDehalogenative cycloaddition reaction is a powerful strategy to generate new ring scaffolds with π‐conjugated features on a surface, and thus holds great promise toward atomically precise electronic devices or nanomaterials. The ortho‐dihalo‐substitution provides a good strategy to realize cycloaddition. However, the limited understanding of intermediate states involved hinders mechanistic exploration for further precise design and optimization o
- Photo‐energy conversion and storage in an aprotic Li‐O2 batteryLi‐O 2 batteries have attracted extensive interest in recent years. However, the intrinsic high overpotentials of Li 2 O 2 formation and oxidation lead to large voltage hysteresis in the discharge and charge processes, plaguing the development of Li‐O 2 batteries. Herein, we report a photo‐involved Li‐O 2 battery with carbon nitride (C 3 N 4 ) as a bifunctional photocatalyst to accelerate both oxygen reduction and evolution reaction
- Concise Synthesis of Open‐cage Fullerenes for Oxygen DeliveryOpen‐cage fullerenes with a 19‐membered orifice were prepared in 3 steps from C 60 . The key step for cage‐opening is aniline mediated ring expansion of a fullerene‐mixed peroxide with a ketolactone moiety on the orifice. Release of ring strain on the spherical fullerene cage served as the main driving force for the efficient cage‐opening sequence. Encapsulation of oxygen could be achieved at room temperature under moderate pressure (50 atm) an
- Organoplatinum‐Substituted Polyoxometalate Inhibits β‐amyloid Aggregation for Alzheimer’s TherapyAggregated β‐amyloid (Aβ) is widely considered as a key factor in triggering progressive loss of neuronal function in Alzheimer's disease (AD), so targeting and inhibiting Aβ aggregation has been broadly recognized as an efficient therapeutic strategy for curing AD. Herein, we designed and prepared an organic platinum‐substituted polyoxometalate, (Me 4 N) 3 [PW 11 O 40 (SiC 3 H 6 NH 2 ) 2 PtCl 2 ] (abbreviated as Pt II ‐PW 11 ) for inh
- Super‐Resolution Microscopy Reveals Shape and Distribution of Dislocations in Single Crystal NanocompositesWith their potential to offer new properties, single crystals containing nanoparticles provide an attractive class of nanocomposite materials. However, to fully profit from these, it is essential that we can characterise their 3D structures, identifying the locations of individual nanoparticles, and the defects present within the host crystals. Using calcite crystals containing quantum dots as a model system, we here use 3D stochastic optical rec
- Self‐Assembly of Hybrid Oxidant POM@Cu‐BTC for Enhanced Efficiency and Long‐time Stability of Perovskite Solar CellsThe controllable oxidation of Spiro‐OMeTAD and improving stability of hole transport materials (HTMs) layer are crucial for good performance and stability of perovskite solar cells (PSCs). Herein, we report an efficient hybrid polyoxometalate@metal‐organic framework (POM@MOF) material –[Cu2(BTC)4/3(H2O)2]6[H3PMo12O40]2 or POM@Cu‐BTC – for oxidation of Spiro‐OMeTAD with Li‐TFSI and TBP. When POM@Cu‐BTC is introduced to the HTM layer as dopant, the
- Self‐Healable Solid Polymeric Electrolytes for Stable and Flexible Lithium Metal BatteriesThe key issue holding back the applications of the solid polymeric electrolytes in high‐energy density lithium metal batteries is the contradictory requirements of high ion conductivity and mechanical stability. In this work, self‐healable solid polymeric electrolytes (SHSPEs) with rigid‐flexible backbones and high ion conductivity are synthesized by a facile condensation polymerization approach. The all solid Li metal full batteries based on the
- Facet‐Dependent On‐surface Reactions in Growth of CdSe NanoplateletsFacet‐dependent on‐surface reactions are systematically studied on zinc‐blende CdSe nanoplatelets with atomically‐flat {001} basal facets and small yet non‐polar side facets. The on‐surface half‐reactions between the surface Se sites and Cd carboxylates in the solution is qualitatively the same as those on the spheroidal counterparts. Conversely, the on‐surface half‐reactions between the surface Cd sites and the activated Se precursors in solutio
- Synthesis of Indomorphan Pseudo‐Natural Product Inhibitors of Glucose Transporters GLUT‐1 and ‐3Combination therapy: Indomorphan pseudo‐natural products (pseudo‐NPs) have been synthesized that combine biosynthetically unrelated indole and morphan alkaloid fragments. This new glucose uptake inhibitor chemotype selectively targets and upregulates the glucose transporters GLUT‐1 and GLUT‐3 and inhibits the growth of cancer cells. Abstract Bioactive compound design based on natural product (NP) structure may be limited because of partial
- Employing Aryl‐Linked Bis‐mesoionic Carbenes as a Pincer‐Type Platform to Access Ambient‐Stable Palladium(IV) ComplexesPalladium(IV) tris(halido) complexes supported by aryl‐bridged bis‐mesoionic carbenes show unusual stability under ambient conditions. The synthesis, solid‐state structures, and reactivity of the complexes are presented and investigated. Abstract The study of palladium(IV) species has great implications for PdII/PdIV‐mediated catalysis. However, most of the PdIV complexes rapidly decompose under ambient conditions, which makes the isolation
- Photochemical Asymmetric Nickel‐Catalyzed Acyl Cross‐CouplingLight it up: Photochemical enantioselective nickel‐catalyzed cross‐coupling reactions are difficult to implement. A visible‐light‐mediated strategy is reported that couples anhydrides 2 and 4‐alkyl dihydropyridines 1 (DHPs) to afford enantioenriched α‐amino and α‐aryl ketones under mild conditions. The chemistry, which does not require exogenous photocatalysts, is triggered by the direct excitation of DHPs, which generate radicals while facilitat
- Shengqian Ma“My biggest motivation is to make something that can be utilized in people's daily life or industry. My worst nightmare is having to go back to high school and take the National College Entrance Examination again …” Find out more about Shengqian Ma in his Author Profile.
- Dong‐Pyo Kim“My biggest motivation is the happiness that comes from scientific discussions. For me, science is a tool of good communication in friendship, irrespective of age, language, or culture. Guaranteed to make me laugh is finding similarities in human nature and science …” Find out more about Dong‐Pyo Kim in his Author Profile.
- Electronic Tuning of Mixed Quinoidal‐Aromatic Conjugated Polyelectrolytes via Direct Ionic SubstitutionWe introduce the direct ionic substitution strategy of generating strongly electron‐accepting ionic motifs and showcase its utility by synthesizing and characterizing a series of ionic azaquinodimethane (iAQM) compounds. The facile introduction of cationic substituents onto the quinoidal para‐azaquinodimethane (AQM) core gives rise to a strongly electron‐accepting building block, which can be readily employed in the synthesis of ionic small molec
- High‐throughput bioassays using “dip‐and‐go” multiplexed electrospray mass spectrometryA multiplexed system based on inductive nanoelectrospray mass spectrometry (nESI‐MS) has been developed for high‐throughput screening (HTS) bioassays. This system combines inductive nESI and field amplification micro‐electrophoresis to achieve a “dip‐and‐go” sample loading and purification strategy that enables nESI‐MS based HTS assays in 96‐well microtiter plates. The combination of inductive nESI and micro‐electrophoresis makes it possible to p
- Evolved Aliphatic Halogenases Enable Regiocomplementary C‐H Functionalization of an Added‐Value ChemicalNon‐heme iron halogenases represent synthetically valuable biocatalysts that are capable of halogenating unactivated sp3‐hybridized carbon centers with exquisite stereo‐ and regioselectivity. The reported substrate scope of these enzymes, however, is limited primarily to the natural substrates and their analogues. Here we engineered the recently discovered halogenase WelO5* for chlorination of a pharmaceutically interesting martinelline‐derived f
- A Minimal Variation Strategy for the Construction of Diverse Poly‐NHC Derived Assemblies and Their Photoinduced TransformationA series of supramolecular assemblies of types [Ag 8 L 4 ](PF 6 ) 8 and [Ag 4 L 2 ](PF 6 ) 4 obtained from tetraphenylethylene (TPE) bridged tetrakis(1,2,4‐triazolium) salts H 4 ‐L(PF 6 ) 4 and Ag I ions is described. The type of assembly obtained is highly dependent on the N‐wingtip substituents of the tetrakis(1,2,4‐triazolium) starting materials (H 4 ‐L)(PF 6 ) 4 . Minute changes in the lengths of the N4‐wingtip s
- Blocking the hype‐hypocrisy‐falsification‐fakery pathway is needed to safeguard scienceIn chemistry and other sciences, hype has become commonplace, compounded by the hypocrisy of those who tolerate or encourage it while disapproving of the consequences. This reduces the credibility and trust upon which all science depends for support. Moreover, hype and hypocrisy are but first steps down a slippery slope towards falsification of results and dissemination of fake science. Systemic drivers in the contemporary structure of the scienc
- Detection and chiral recognition of α‐hydroxyl acid through proton and CEST NMR using Yb macrocyclic complexChiral α‐hydroxyl acids are of great importance in chemical synthesis. Current methods for recognizing their chirality by proton NMR are limited by very few chemical shift difference and their intrinsic solubility problem in organic solvent. Herein, we developed three YbDO3A(ala) 3 derivatives to recognize four different commercially available chiral α‐hydroxyl acids through proton NMR and chemical exchange saturation transfer (CEST) methodolog
- Self‐Assembly of MXene‐Surfactants at Liquid‐Liquid Interfaces: From Structured Liquids to 3D AerogelsTwo‐dimensional (2D) transition metal carbides and nitrides (MXenes), which are a class of emerging nanomaterials with intriguing properties, have attracted significant attention in recent years. However, due to the highly hydrophilic nature of MXene nanosheets, assembly strategies of MXene at liquid‐liquid interfaces have been very limited and challenging. Herein, via the cooperative assembly of MXene and amine‐functionalized polyhedral oligomer
- A Low‐cost and Environmental Friendly Mixed Polyanionic Cathode for Sodium‐Ion StorageSodium‐ion batteries (NIBs) are the most promising alternatives to lithium‐ion batteries in the development of renewable energy sources. The advancement of NIBs depends on the exploration of new electrode materials and fundamental understanding of working mechanisms. In this work, we develop a mixed polyanionic compound, Na2Fe(C2O4)SO4·H2O, as cathode for NIBs via experimental and simulation methods. Thanks to its rigid three dimensional framewor
- An Unprecedented Hetero‐Epitaxially Grown Zeolite MembraneThe secondary growth methodology to form zeolite membranes involves covering the surface of a porous support with zeolite seed particles and using a hydrothermal process to close gaps between the seeds. However, stringent requirements for homogeneous epitaxial inter‐growth of the seed layer limit the number of high‐quality zeolite membranes. Despite previous reports on hetero‐epitaxial growth, high performance zeolite membranes have yet to be rep
- Genetically Encoded Ratiometric RNA‐based Sensors for Quantitative Imaging of Small Molecules in Living CellsPrecisely determining the intracellular concentrations of metabolites and signaling molecules is critical in studying cell biology. Fluorogenic RNA‐based sensors have emerged to detect various targets in living cells. However, it is still challenging to apply these genetically encoded sensors to quantify the cellular concentrations and distributions of targets. Herein, using a pair of orthogonal fluorogenic RNA aptamers, DNB and Broccoli, we engi
- HydrostibinationA rigid naphthalenediamine framework has been used to prepare antimony hydrides that feature LUMO shapes and energies similar to those found in secondary boranes. Exploiting this feature, we introduce the first examples of uncatalyzed hydrostibination of robust C≡C, C=C, C=O, and N=N bonds as new elementary hydrometallation reactions analogous to hydroboration. These results endorse the notion of a diagonal relationship between the lightest p‐blo
- Discovery of a potent GLUT inhibitor using rapafucin 3D microarraysGlucose transporters play an essential role in cancer cell proliferation and survival and have been pursued as promising cancer drug targets. Using microarrays of a new macrocycle library known as rapafucins that was inspired by rapamycin, we screened for new inhibitors of GLUT1. We identified multiple hits from the rapafucin 3D microarray and confirmed one hit as a bona fide GLUT1 ligand, named Rapaglutin A (RgA). We demonstrated that RgA is a p
- Rational design of nanogels for overcoming the biological barriers in various administration routesNanogels have been identified as outstanding nanocarrier candidates for drug delivery due to the desirable physiochemical properties and versatile applicability for diverse therapeutic molecules and imaging probes. One of the main challenges that hinder the clinical translation of nanogels is the low efficiency of drug transmitting to the target sites because of the impedance of complex biological barriers during the in vivo journey. The purpos
- Not limited to Iron: A Cobalt Heme–NO Model Facilitates N–N Coupling with External NO in the Presence of a Lewis Acid to Generate N2OSome bacterial heme proteins catalyze the coupling of two NO molecules to generate N2O. We previously reported that a heme Fe–NO model engages in this N–N bond‐forming reaction with NO. We now demonstrate that (OEP)CoII(NO) similarly reacts with 1 equiv. of NO in the presence of the Lewis acids BX3 (X = F, C6F5) to generate N2O. DFT calculations support retention of the CoII oxidation state for the experimentally observed adduct (OEP)CoII(NO•BF3)
- Di‐tert‐butyldiphosphatetrahedrane: Catalytic Synthesis of the Elusive Phosphaalkyne DimerWhile tetrahedranes as a family are scarce, neutral heteroatomic species are all but unknown, with the only reported example being AsP 3 . Herein, we report the first isolation of a neutral heteroatomic X 2 Y 2 molecular tetrahedron (X, Y = p‐block elements), which is also the first example of the long‐sought‐after free phosphaalkyne dimer. Di‐ tert ‐butyldiphosphatetrahedrane, ( t BuCP) 2 , is formed from the monomer t BuCP in a ni
- X‐ray Crystallography and Vibrational Spectroscopy Reveal Key Determinants of Biocatalytic Dihydrogen Cycling by [NiFe] hydrogenases[NiFe] hydrogenases are complex model enzymes for the reversible cleavage of dihydrogen (H 2 ). However, structural determinants of efficient H 2 binding to their [NiFe] active site are not properly understood. Here, we present crystallographic and vibrational spectroscopic insights into the unexplored structure of the H 2 ‐binding [NiFe] intermediate. Using an F 420 ‐reducing [NiFe]‐hydrogenase from Methanosarcina barkeri as a model en
- 1‐Picolinyl‐5‐azido Thiosialosides: Versatile Donors for the Stereoselective Construction of Sialyl LinkagesSugar building blocks: With 1‐Picolinyl‐5‐azido thiosialoside as donor, a robust sialylation protocol, which enjoys broad substrate scope, good to excellent chemical yield, excellent α‐stereoselectivity, flexible synthesis of sialosides, applicable in complex sialoside synthesis, as well as high temperature tolerance and easy scalability, was established. Abstract With the picolinyl (Pic) group as a C‐1 located directing group and N3 as ver
- Unraveling Dual Aggregation‐Induced Emission Behavior in Steric‐Hindrance Photochromic System for Super Resolution ImagingDual AIE behavior: The steric‐hindrance photochromic system efficiently regulates the intramolecular rotational/vibrational magnitude and intermolecular stacking to tune aggregation‐induced emission (AIE) activity. The off‐to‐on fluorescent photoswitch is successfully established in super resolution imaging. Abstract Unprecedented dual aggregation‐induced emission (AIE) behavior based on a steric‐hindrance photochromic system is presented,
- A Sodiophilic Interphase‐Mediated, Dendrite‐Free Anode with Ultrahigh Specific Capacity for Sodium‐Metal BatteriesStaying on the ground: A stable sodium anode with ultra‐high specific capacity (1078 mAh g−1) is achieved by accommodating metallic sodium into a sodiophilic interphase based on oxygen‐functionalized carbon nanotube networks. The interphase renders the Na anode with a homogeneous nucleation process and a lateral plating behavior, which thermodynamically contrasts with regular vertical Na growth (dendrites). Abstract Despite efforts to stabi
- Dual Graphitic‐N Doping in a Six‐Membered C‐Ring of Graphene‐Analogous Particles Enables an Efficient Electrocatalyst for the Hydrogen Evolution ReactionThat material is dope! Graphene‐analogous particles with dual graphitic‐N doping in a six‐membered carbon ring are successfully prepared. Infrared spectroscopy, synchrotron‐based X‐ray absorption spectroscopy, and solid‐state NMR spectroscopy are applied to study its structure and mechanism in the hydrogen evolution reaction, where a current density of 10 mA cm−2 is achieved at an overpotential of 57 mV. Abstract Graphene‐based materials st
- Identification of the C‐Glycoside Synthases during Biosynthesis of the Pyrazole‐C‐Nucleosides Formycin and PyrazofurinEnzymatic C ‐glycoside bond formation: The C‐glycoside synthases encoded in the formycin and pyrazofurin biosynthetic gene clusters are identified and compared by genomic analysis of the producing strains. Both enzymes catalyze decarboxylative C‐glycoside bond formation between phosphoribosyl pyrophosphate and a pyrazole nucleobase in reactions likely to involve electrophilic aromatic substitution. Abstract C‐Nucleosides are chara
- The Application of Fluorine‐Containing Reagents in Structural ProteomicsChemical approaches, in combination with mass‐ spectrometry analysis, have emerged as powerful tools to enable a broad range of biological applications. This approach is called structural proteomics. The key to success is a biocompatible reagent that modifies a protein without affecting its high‐order structure. Fluorine, well‐known to exert profound effects on the physical and chemical properties of reagents, should have an impact on structural
- Switchable Solvatochromic Probes for Live‐Cell Super‐resolution Imaging of Plasma Membrane OrganizationTargeting, switching, and sensing were combined in one fluorescent probe to achieve the nanoscale cartography of cell plasma membranes. The proposed design is based on a new functionalization strategy of solvatochromic dye Nile Red, which is sensitive to lipid order, and a new membrane‐targeting moiety that controls binding/unbinding‐induced on/off switching for super‐resolution microscopy. Abstract Visualization of the nanoscale organizati
- Single Electron Transfer to Diazomethane‐Borane Adducts Prompts C‐H Bond ActivationsWhile (Ph 2 CN 2 )B(C 6 F 5 ) 3 is a unstable species, single electron transfer from Cp* 2 Co affords the isolation of stable products [Cp* 2 Co][Ph 2 CNNHB(C 6 F 5 ) 3 ] 1 and [Cp*Co(C 5 Me 4 CH 2 B(C 6 F 5 ) 3 )] 2 . The analogous combination of Ph 2 CN 2 and BPh 3 showed no evidence of adduct formation and yet single electron transfer from Cp* 2 Cr affords the species [Cp* 2 Cr][PhC(C 6 H 4 )
- Normalization Li growth from nucleation stage for dendrite‐free Li metal anodesInducing uniform deposition of lithium from the stage of metal crystallization nucleation is of vital importance to achieve dendrite‐free lithium anode. Herein, using experiments and simulation, homogenization of Li nucleation and normalization of Li growth can be achieved on PNIPAM polymer brushes with lithiophilic functional groups modified Cu substrates. The lithiophilic functional groups of amide O can homogenize ion mass transfer, and induce
- Rapid Activation of Platinum via Black Phosphorus for Efficient Hydrogen EvolutionModulation of the electronic structure of metal catalysts is an effective approach to optimize the electrocatalytic activity. In this study, we discover surprisingly strong activation effects of black phosphorus (BP) on platinum (Pt) catalysts. In this way, the surface electronic structure of Pt can be effectively and rapidly modulated to produce greatly enhanced catalytic activity in the hydrogen evolution reaction (HER). The unique and negative
- Inside Back Cover: Van der Waals Heterostructured MOF‐on‐MOF Thin Films: Cascading Functionality to Realize Advanced Chemiresistive Sensing (Angew. Chem. Int. Ed. 42/2019)Heterostructured MOF‐on‐MOF thin films combined with van der Waals forces offer functionality beyond that of a single MOF layer. In their Communication on https://doi.org/10.1002/anie.201907772page 14915 ff., G. Xu et al. present a device that combines molecular sieving and chemiresistive sensing MOF layers. The MOF‐on‐MOF thin film demonstrates the highest response to benzene among reported recoverable chemiresistive sensing materials active at
- Towards Reliable and Quantitative SERS: from Key Parameters to Good Analytical PracticeExperimental results obtained in different laboratories world‐wide by researchers using surface‐enhanced Raman scattering (SERS) can differ significantly. We, an international team of scientists with long‐standing expertise in SERS, address this issue from our perspective by presenting considerations on reliable and quantitative SERS. The central idea of this joint effort is to highlight key parameters and pitfalls that are often encountered in t
- Tuning the gate‐opening pressure in a switching pcu coordination network, X‐pcu‐5‐Zn, by pillar ligand substitution.Coordination networks that reversibly switch between closed and open phases are of topical interest since their stepped isotherms can offer higher working capacity for gas storage applications than related rigid porous coordination networks. In order to be of practical utility, the pressures at which switching occurs, the gate‐opening and gate‐closing pressures. Here we study the effect of linker substitution to fine‐tune gate‐opening and gate‐cl
- Hold up an “Umbrella” for Lithium Metal Anode towards a Safe Flexible Lithium‐Air Battery in Ambient AirFlexible Li‐air battery (FLAB) with ultrahigh energy density is a hopeful candidate for the forthcoming flexible energy storage devices. However, most current FLAB operated in the pure oxygen atmosphere which limited by the safety and corrosion issues from metallic lithium anode had greatly impeded the broad application of FLAB. Herein, inspired by the protection effect of the umbrella, a stable hydrophobic composite polymer electrolyte (SHCPE) f
- A Simple Organic Molecule Realizing Simultaneous TADF, RTP, AIE and Mechanoluminescence: Understanding the Mechanism Behind the Multifunctional EmitterRecently, aggregation‐induced emission (AIE), thermally activated delayed fluorescence (TADF), room‐temperature phosphorescence (RTP) and mechanoluminescence (ML) etc. pure organic emitters, have attracted widespread interests. However, a multifunctional organic emitter exhibiting simultaneous AIE, TADF, RTP and ML has not been reported. Moreover, the mechanism behind the multifunctional emitters is to be deeply explored. In this work, two mul
- Hydrogen bonding between ions of like charge in ionic liquids characterized by NMR deuteron quadrupole coupling constants – Comparison with salt bridges and molecular systemsWe present deuteron quadrupole coupling constants (DQCC) for hydroxyl‐functionalized ionic liquids (ILs) in the crystalline or glassy states characterizing two types of hydrogen bonding: The regular Coulomb‐enhanced hydrogen bonds between cation and anion (c‐a), and the unusual hydrogen bonds between cation and cation (c‐c), present despite the repulsive forces between ions of like charge. We measure these sensitive probes of hydrogen bonding by
- [ASAP] Hydrogen/Deuterium Exchange Aiding Compound Identification for LC-MS and MALDI Imaging LipidomicsAnalytical ChemistryDOI: 10.1021/acs.analchem.9b02461
- [ASAP] Neutrophils Activated by Nanoparticles and Formation of Neutrophil Extracellular Traps: Work Function Mapping and Element Specific ImagingAnalytical ChemistryDOI: 10.1021/acs.analchem.9b02579
- [ASAP] Dual Separation of Krypton and Argon from Environmental Samples for Radioisotope DatingAnalytical ChemistryDOI: 10.1021/acs.analchem.9b02716
- [ASAP] Deciphering Metabolic Heterogeneity by Single-Cell AnalysisAnalytical ChemistryDOI: 10.1021/acs.analchem.9b02410
- [ASAP] Flow Water Proton NMR: In-Line Process Analytical Technology for Continuous BiomanufacturingAnalytical ChemistryDOI: 10.1021/acs.analchem.9b02622
- [ASAP] Chaotropic Effects in Sub/Supercritical Fluid Chromatography via Ammonium Hydroxide in Water-Rich Modifiers: Enabling Separation of Peptides and Highly Polar Pharmaceuticals at the Preparative ScaleAnalytical ChemistryDOI: 10.1021/acs.analchem.9b03408
- [ASAP] Dramatic Improvement in Sensitivity with Pulsed Mode Charge Detection Mass SpectrometryAnalytical ChemistryDOI: 10.1021/acs.analchem.9b03586
- [ASAP] Visualizing ToF-SIMS Hyperspectral Imaging Data Using Color-Tagged Toroidal Self-Organizing MapsAnalytical ChemistryDOI: 10.1021/acs.analchem.9b03322
- [ASAP] Characterization of Flagellar Filaments and Flagellin through Optical Microscopy and Label-Free Nanopore ResponsivenessAnalytical ChemistryDOI: 10.1021/acs.analchem.9b02874
- [ASAP] Correction to Functional Titanium Carbide MXenes-Loaded Entropy-Driven RNA Explorer for Long Noncoding RNA PCA3 Imaging in Live CellsAnalytical ChemistryDOI: 10.1021/acs.analchem.9b04283
- [ASAP] An Activatable Chemiluminescent Probe for Sensitive Detection of ?-Glutamyl Transpeptidase Activity in VivoAnalytical ChemistryDOI: 10.1021/acs.analchem.9b02839
Medicine by Alexandros G. Sfakianakis,Anapafseos 5 Agios Nikolaos 72100 Crete Greece,00302841026182,00306932607174,alsfakia@gmail.com,
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Medicine by Alexandros G. Sfakianakis,Anapafseos 5 Agios Nikolaos 72100 Crete Greece,00302841026182,00306932607174,alsfakia@gmail.com,
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00302841026182,
00306932607174,
alsfakia@gmail.com,
Anapafseos 5 Agios Nikolaos 72100 Crete Greece,
Medicine by Alexandros G. Sfakianakis
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