Soft Robotics, Ahead of Print.
Mon Sep 23, 2019 10:00
Publication date: Available online 23 September 2019Source: Academic RadiologyAuthor(s): Rania Refaat, Mohammad Abd Alkhalik BashaRationale and ObjectivesSphenoid sinus (SS) pneumatization is greatly variable. Precise determination of the pattern of SS pneumatization and its relationship to the vital neurovascular structures will provide a more comprehensive understanding of the regional SS anatomy to avoid the risk of potentially serious neural and vascular injury. We aimed to study the relationships...
Tue Sep 24, 2019 18:35
The memory of the immune system is able to distinguish a foreign protein with which the organism has already come into contact from another and to react with a corresponding antibody. Researchers have now discovered in flour beetles that the immune system's ability to specifically fend off pathogens can adapt in the course of evolution.
Tue Sep 24, 2019 17:40
It is highly needed but still challenging to develop Ti‐based catalysts simultaneously achieving a large NH 3 yield with a high Faradic efficiency (FE) for electrocatalytic N 2 reduction to NH 3 . Here, we report that Fe, one of the cheapest and most abundant metals on the earth, acts as an effective dopant to greatly improve the NRR performances of TiO 2 nanoparticle for ambient N 2 ‐to‐NH 3 conversion. In 0.5 M LiClO 4 , such Fe‐doped TiO 2 catalyst attains a high FE of 25.6 % and...
Mon Sep 23, 2019 17:04
Upon incubation with Au nanocages, pyrrole (Py) molecules can enter the cavities by diffusing through the porous walls and then be polymerized to generate a polypyrrole (PPy) coating on the inner surface. The thicknesses of the PPy coating can serve as a direct indicator for the amount of Py molecules that diffuse into the cavity. We found that Py are able to diffuse into the cavities throughout the polymerization process, while a prolonged incubation time increases the amount of Py accumulated on...
Mon Sep 23, 2019 17:05
Monodispersed hairy nanocomposites system with typical 2‐nm (isophthalic acid) 24 Cu 24 metal‐organic polyhedron (MOP) as core protected by 24 polymer chains with controlled narrow molecular weight distribution has been experimentally probed by imaging and scattering studies for the heterogeneity of polymers in the nanocomposites and the confinement effect the MOPs imposing to anchored polymers. Typical confined‐extending surrounded by one entanglement area is proposed to picture the physical...
Mon Sep 23, 2019 17:06
Catalytic CO2 reduction to fuels and chemicals is one of the major pursuits in reducing greenhouse gas emissions. One such popular approach utilizes the reverse water‐gas shift reaction, followed by Fischer‐Tropsch synthesis, and iron is a well‐known candidate for this process. Some attempts have been made to modify and improve its reactivity, but resuted in limited success. In this work, using ruthenium‐iron oxide colloidal heterodimers we demonstrate that close contact between the two phases promotes...
Mon Sep 23, 2019 17:35
Disclosed here is a new catalytic approach for a most efficient access to cyclic β‐amino acids widely found in bioactive small molecules and peptidic foldamers. Our method involves addition of the remote γ‐carbon atoms of α,β‐unsaturated imines to enals via iminium organic catalysis. This highly chemo‐ and stereo‐selective reaction affords cyclic β‐amino aldehydes that can be converted to amino acids bearing quaternary stereocenters with exceptional optical purities. Our study demonstrates the unique...
Mon Sep 23, 2019 18:36
A pair of radial [5]catenanes with an isomeric cyclic –AABB– or –ABAB– type sequence of the interlocked β‐cyclodextrin (β‐CD) and cucurbit[6]uril (CB[6]) have been efficiently synthesized via CB[6]‐mediated azide‐alkyne cycloaddition of strategically designed building blocks. Due to a marked difference in the binding strength and interlocking sequence of the peripheral macrocycles, interesting sequence‐dependent properties characteristic to mechanically bonded macrocycles were realized. Variable...
Mon Sep 23, 2019 19:48
Metal halide perovskites have emerged as a new generation of X‐ray detect materials of great promise. However, large‐sized MAPbI3 single crystals (SCs) still exhibit lower performance compared to MAPbBr3 SCs in X‐ray detection. DFT (density functional theory) simulations suggest the problem could be overcome by alloying large‐sized cations at A site. The alloyed process could notably decrease the electron‐phonon coupling strength and increase the materials defect formation energy. Accordingly, centimeter‐sized...
Mon Sep 23, 2019 19:52
Hierarchical helical structures are the most interesting supramolecular structures in nature. Here, we report unprecedented fluorescent superhelices composed of primary, opposite helical supramolecular polymers. A new class of functional dendrimers was synthesized from a C 3 ‐symmetrical trismaleimide by highly efficient, clean “click‐chemistry” reactions under mild conditions. These dendrimers demonstrate an alternating fluorescence OFF/ON growth fashion with generations. The supramolecular polymerization...
Mon Sep 23, 2019 20:04
Achieving energetic materials with a balanced ratio of oxidant to fuel is a challenge that has been difficult to meet through molecular synthesis. The alternative approach, composite formulation, fails to achieve intimate association of the components to the detriment of performance. Herein, the energetic oxidizer ammonium dinitramide (ADN) is combined with fuel‐rich pyrazine‐1,4‐dioxide via cocrystallization. The result is a material with a balanced oxidant/fuel ratio in which the components maintain...
Mon Sep 23, 2019 21:34
Two‐dimensional molecular crystals with a defined number of molecular layers were produced by a layer‐defining strategy of crystal growth on a liquid substrate. In their Communication (DOI: https://doi.org/10.1002/anie.20190955210.1002/anie.201909552), R. Li, W. Hu, and co‐workers describe their technique. By controlling the spreading of the solution on the liquid surface, large‐area quasi‐freestanding two‐dimensional molecular crystals can be obtained ranging from bulk size down to the monolayer...
Tue Sep 24, 2019 11:41
The selective one‐electron reduction of nontrigonal R3E compounds (E=P, As, Sb) afforded the first stable tricoordinate pnictogen‐centered radical anion salts; the pnictogen atoms retain a planar T‐shaped structure. EPR spectroscopy and calculations reveal that the spin density mainly resides at the p orbital of the pnictogen atom, which is perpendicular to the N3E plane. Abstract The search for main‐group element‐based radicals is one of the main research topics in contemporary chemistry because...
Tue Sep 24, 2019 11:44
Predicted more than 40 years ago, the first direct evidence of N5‐hydrogen blocking is provided by the investigation of a peroxy‐flavinium intermediate. In their Research Article (DOI: https://doi.org/10.1002/anie.20190629310.1002/anie.201906293), J. Roithová and co‐workers show that mass spectrometry and ion spectroscopy can be used to trap and characterise intermediates with a life span below 1 s and thus fill in missing pieces in photochemical catalytic cycles.
Tue Sep 24, 2019 11:44
Pressure drop: A simple and effective strategy for regulating chemical equilibrium improves the efficiency of electrochemical ammonia synthesis by using an only lightly pressurized reaction system. The strategy not only can improve the efficiency of the nitrogen reduction reaction, but also can greatly reduce the cell voltage of the ammonia synthesis reaction under mild conditions. Abstract We demonstrate a simple and effective chemical equilibrium regulation strategy to improve the efficiency...
Tue Sep 24, 2019 11:46
An N‐doping plus PO4 3− intercalation strategy is used to induce high conversion (ca. 41 %) of 2H‐MoS2 into 1T‐MoS2, which is much higher than single N‐doping or PO43− intercalation (ca. 28 % and ca. 10 %, respectively). A scattering mechanism is proposed to illustrate the synergistic phase transformation from 2H phase to 1T phase, confirmed by synchrotron radiation and spherical aberration TEM. Abstract A synergistic N doping plus PO43− intercalation strategy is used to induce high conversion...
Tue Sep 24, 2019 11:47
At the border: The relative surface propensity of hydrated proton and hydroxide at the D2O–air interface in the presence of excess D3O+/OD− was determined by probing the stretching vibration of interfacial water with sum‐frequency generation spectroscopy. The hydrated proton is found to be orders of magnitude more surface active than the hydroxide ion. Abstract The behavior of hydroxide and hydrated protons, the auto‐ionization products of water, at surfaces is important for a wide range of...
Tue Sep 24, 2019 11:47
Despite an excellent safety profile due to their low thermal potential, α‐carbonyl sulfoxonium ylides remains underexploited for the functionalization of (hetero)aryls without recourse to directing groups. Described is a cyclization of these valuable reagents on aryls and heteroaryls that is chemospecific, depending on the reaction conditions. Abstract The functionalization of aryl and heteroaryls using α‐carbonyl sulfoxonium ylides without the help of a directing group has remained so far...
Tue Sep 24, 2019 11:48
A perfect fit: The protein‐like pocket‐substrate shape complementarity (see picture) in an ultrastable MOF solves the problem of balancing high uptake capacity/selectivity and low energy penalty for CO2 capture from fuel gas. Abstract In the evolution of metal–organic frameworks (MOFs) for carbon capture, a lasting challenge is to strike a balance between high uptake capacity/selectivity and low energy cost for regeneration. Meanwhile, these man‐made materials have to survive from practical...
Tue Sep 24, 2019 11:49
Guest in/out mechanisms: Planar N‐oxides are encapsulated in mono‐metallic PdII/PtII‐cages. The entrance/exchange of the planar guests involves a “French doors” mechanism. The PdII‐cage features a switching from the “French doors” to a partial ligand‐metal dissociation mechanism to accommodate a sterically demanding N‐oxide. Nevertheless, the bulky guest is imprisoned in the PtII‐cage. Abstract Planar pyridyl N‐oxides are encapsulated in mono‐metallic PdII/PtII‐cages based on a tetra‐pyridyl...
Tue Sep 24, 2019 11:51
Reductive Functionalization: The transition‐metal‐free synthesis of tetrahydroisoquinolines that bear a quaternary center through a reductive hydroxymethylation process is reported. It is a simple and robust method using cheap and accessible reagents to prepare complex heterocyclic motifs. Abstract A transition‐metal‐free reductive hydroxymethylation reaction has been developed, enabling the preparation of tetrahydroisoquinolines bearing C4‐quaternary centers from the corresponding isoquinolines....
Tue Sep 24, 2019 11:52
Wing it: Highly enantioselective rhodium‐catalyzed addition of arylboroxines to N‐unprotected ketimines is realized for the first time by employing chiral BIBOP‐type ligands with a Rh loading as low as 1 mol %. A range of chiral α‐trifluoromethyl‐α,α‐diaryl α‐tertiary amines or 3‐amino‐3‐aryloxindoles were formed in excellent yields by employing either WingPhos or PFBO‐BIBOP as the ligand. The method enabled an efficient enantioselective synthesis of cipargamin. Abstract Highly enantioselective...
Tue Sep 24, 2019 11:53
As the most promising biofuel, biobutanol is considered a competitive substitute of fossil fuels. Efficient separation of biobutanol from fermentation broth requires the application of membrane technologies. The commonly used polydimethylsiloxane (PDMS) membrane cannot meet the required demand due to its discontinuous and highly polluting thermal fabrication process. Herein, we proposed an ultraviolet (UV)‐induced polymerization strategy and realize the ultrafast and continuous fabrication of the...
Tue Sep 24, 2019 12:16
C‐H bond activation is mostly limited to ortho selectivity. Activation of both ortho and meta C‐H bonds constitutes a particularly impotatant strategy for annulation, but this has been rarely studied in enantioselective systems. Reported herein is Rh(III)‐catalyzed [3+2] transannulation of arenes with 7‐azabenzonorbornadienes for enantioselective synthesis of cis ‐dihydrocarbazoles. Two distinct classes of arenes have been identified as viable substrates, and the coupling proceeded under...
Tue Sep 24, 2019 14:10
Chiral tetrahydrothiophenes and tetrahydroselenophenes are highly useful structural units. Here we describe a new catalytic asymmetric approach for their synthesis. With a suitable chiral Brønsted acid catalyst, an oxetane desymmetrization by a well‐positioned internal sulfur or selenium nucleophile proceeded efficiently to generate all‐carbon quaternary stereocenters with excellent enantioselectivity. Taming the sulfur and selenium nucleophile in the form of thioester and selenoester is crucial...
Tue Sep 24, 2019 15:05
Aluminium oxides constitute an important class of inorganic compound that are widely exploited in the chemical industry as catalysts and catalyst supports. Due to the tendency for such systems to aggregate via Al‐O‐Al bridges, the synthesis of well‐defined, soluble, molecular models for these materials is challenging. Here we show that reactions of the potassium aluminyl complex K 2 [( NON )Al] 2 ( NON = 4,5‐bis(2,6‐diiso‐propylanilido)‐2,7‐di‐tert‐butyl‐9,9‐dimethylxanthene) with CO 2 ...
Tue Sep 24, 2019 16:06
Neutron diffraction reveals how the position of a hydrogen atom in a catalytic triad of a protein leads to a 30‐fold kinetic discrimination of similar antibiotics. In the case of the ligand with the worst catalytic efficiency a canonical hydrogen bond is found, whereas a low‐barrier hydrogen bond is found in the best turned over substrates. Abstract The position, bonding and dynamics of hydrogen atoms in the catalytic centers of proteins are essential for catalysis. The role of short hydrogen...
Tue Sep 24, 2019 18:50
The crystalline sponge method (CSM) primary application has been the unambiguous structural determination via Single Crystal X‐ray Diffraction (SCXRD) of a single analyte encapsulated inside a porous MOF. As the host‐guest systems often show severe disorder, their reliable crystallographic determination is very demanding thus the dynamics of the guest entering and the formation of nanoconfined molecular aggregates has not been in the spotlight yet. We extended the concept of the CSM stepwisely monitoring...
Tue Sep 24, 2019 18:50
Infections result from invasions of an organism into body tissues leading to diseases and complications that might eventually lead to death. Inappropriate use of antimicrobials has led to development of antimi...
Tue Sep 24, 2019 03:00
Identification of all possible HIV reservoirs is an important aspect in HIV eradication efforts. The urinary tract has however not been well studied as a potential HIV reservoir. In this pilot study we molecul...
Tue Sep 24, 2019 03:00
Publication date: Available online 23 September 2019Source: Allergology InternationalAuthor(s): Hirokazu Arakawa, Naoki Shimojo, Norito Katoh, Kazumi Hiraba, Yasusuke Kawada, Keiichi Yamanaka, Ken Igawa, Hiroyuki Murota, Ikuo Okafuji, Tatsuki Fukuie, Takeshi Nakahara, Taro Noguchi, Akira Kanakubo, Ichiro KatayamaAbstractBackgroundPediatric atopic dermatitis (PAD) is a pluricausal disease and is frequently seen in dermatological and pediatric practice. Therefore, it is important to find common views...
Tue Sep 24, 2019 19:40
Tue Sep 24, 2019 03:00
Tue Sep 24, 2019 03:00
Nature Communications, Published online: 24 September 2019; doi:10.1038/s41467-019-12184-8The identification of synthetic essential genes of PTEN is of therapeutic potential for PTEN-deficient prostate cancers. Here, the authors show that ARID4B is a synthetic essential gene in these cancers in which deficiency of PTEN prompts the AKT-ARID4B feedback loop required for activation of the PI3K-AKT signaling pathway.
Tue Sep 24, 2019 03:00
Nature Communications, Published online: 24 September 2019; doi:10.1038/s41467-019-12313-3Antibiotic resistance is a major global health challenge. Here, the authors report on a thermoresponsive delivery system for combined photothermal and antibiotic delivery with fluorescent tracking abilities and demonstrate application against antibiotic resistant bacteria in vitro and in vivo.
Tue Sep 24, 2019 03:00
Nature Communications, Published online: 24 September 2019; doi:10.1038/s41467-019-12275-6Lipid nanoparticles (LNPs) are potential platforms for RNA-based therapeutics, but the fate of LNP-RNAs upon internalization into the cell is unclear. Here, the authors show that LNP-mRNAs and ionizable lipids escape the endosomes and are re-released via extracellular vesicles which could deliver the functional mRNA to other cells.
Tue Sep 24, 2019 03:00
Nature Communications, Published online: 24 September 2019; doi:10.1038/s41467-019-11954-8Cardiovascular diseases (CVD) are associated with plasma lipid levels. Here, Tabassum et al. perform genome-wide association studies for lipidomic profiles with 141 (non-standard) lipid species which highlights shared genetic loci with CVD and that traditional lipids have low genetic correlation with other lipids.
Tue Sep 24, 2019 03:00
Nature Communications, Published online: 24 September 2019; doi:10.1038/s41467-019-12026-7The majority of published GWAS was performed in European ancestry populations. Here, Kuchenbaecker et al., test to which extent lipid loci are shared and find that the major lipid loci are mostly transferrable between Europeans and Asians while there are notable exceptions for African populations.
Tue Sep 24, 2019 03:00
Nature Communications, Published online: 24 September 2019; doi:10.1038/s41467-019-12395-zDesigning free-style display technology with rapid manufacturing process at low production cost and high flexibility for the substrate´s choice remains a challenge. Here, the authors propose a pen drawing display technology that facilitates display production using liquid light-emitting materials.
Tue Sep 24, 2019 03:00
Tue Sep 24, 2019 03:00
Tue Sep 24, 2019 03:00
Nature Communications, Published online: 24 September 2019; doi:10.1038/s41467-019-12278-3The Chang’E-4 mission in January 2019 had the major challenge to land on the lunar far side without traditional radiometric techniques due to the missing line-of-sight. The authors here describe landing trajectory reconstruction and positioning techniques based upon the Moon’s digital terrain model that allowed reproducing the entire process of a successful landing.
Tue Sep 24, 2019 03:00
Nature Communications, Published online: 24 September 2019; doi:10.1038/s41467-019-12069-wThere is a lack of human models to study vocal fold epithelia making it difficult to provide therapies for vocal fold disease. Here, the authors generate a human-based model of vocal fold mucosa that mimics in utero development and shows inflammation on exposure to cigarette smoke abstract.
Tue Sep 24, 2019 03:00
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