Abstract Focal adhesion kinase (FAK) is involved in progression of various cancers, and FAK overexpression has been associated with cancer invasion and metastasis. However, the involvement of FAK expression in the clinicopathological malignancy of oral squamous cell carcinoma (OSCC) remains unknown. In addition, there is no consensus regarding the role of p16 expression in OSCC. In this study, the immunohistochemically measured expression of FAK, phosphorylated FAK (FAKpY397) and...
Sat Sep 14, 2019 03:00
The position, bonding and dynamics of hydrogen atoms in the catalytic centers of proteins are essential for catalysis. The role of short hydrogen bonds in catalysis has remained highly debated and led to establishment of several distinctive geometrical arrangements of hydrogen atoms vis‐à‐vis the heavier donor and acceptor counterparts, i.e. low‐barrier, single‐well or short canonical hydrogen bonds. Here we demonstrate how the position of a hydrogen atom in the catalytic triad of an aminoglycoside...
Fri Sep 13, 2019 11:15
Glutamine‐binding protein (GlnBP) from Escherichia coli is a prototypical periplasmic binding protein that has been crystallized in an apo, “open” conformation, with its two domains far apart, and a holo, “closed” form, with proximal domains that engulf the cognate L‐Gln ligand. A fundamental question about such large‐scale conformational transitions—whether the closed state exists in the absence of ligand—is a matter of controversy in the case of GlnBP. Previously, NMR observations have indicated...
Fri Sep 13, 2019 11:19
A biomimetic route to farnesyl pyrophosphate and dimethyl orsellinic acid (DMOA)‐derived meroterpenoid scaffolds has yet to be reported despite great interest from the chemistry and biomedical research communities. A concise synthetic route with the potential to access DMOA‐derived meroterpenoids is highly desirable to create a library of related compounds. Herein, we report novel dearomatization methodology followed by polyene cyclization to access DMOA‐derived meroterpenoid frameworks in six...
Fri Sep 13, 2019 11:24
For electrocatalysts for hydrogen evolution reaction (HER), encapsulating transition metal phosphides (TMPs) into nitrogen‐doped carbon materials has been known as an effective strategy to elevate the activity and stability. Yet still, it remains unclear how the TMPs work synergistically with the N‐doped support, and which N configuration (among pyridinic N, pyrrolic N and graphitic N) contributes predominantly to the synergy. Here we present a HER electrocatalyst (denoted as MoP@NCHSs) comprising...
Fri Sep 13, 2019 11:38
Surface organic ligands play a critical role in stabilizing atomically precise metal nanoclusters in solutions. However, it is still challenging to prepare highly robust ligated metal nanoclusters that are surface‐active for liquid‐phase catalysis without any pre‐treatment. Herein, we report a novel N‐heterocyclic carbene‐stabilized Au25 nanocluster with high thermal and air stabilities as a homogenous catalyst for cycloisomerization of alkynyl amines to indoles. The nanocluster, characterized as...
Fri Sep 13, 2019 12:13
The Al‐Ca team: The oxidative addition of a low‐valent AlI species to benzene at room temperature is catalyzed by a Ca hydride complex. The aromatic substrate is activated by π‐bonding to Ca, while hydride interaction with the empty Al p‐orbital boosts the nucleophilicity of the sp2 lone‐pair. Abstract The low‐valent ß‐diketiminate complex (DIPPBDI)Al is stable in benzene but addition of catalytic quantities of [(DIPPBDI)CaH]2 at 20 °C led to (DIPPBDI)Al(Ph)H (DIPPBDI=CH[C(CH3)N‐DIPP]2, DIPP=2,6‐diisopropylphenyl)....
Fri Sep 13, 2019 12:53
Not just one, but two: An organocatalytic asymmetric functionalization of unactivated benzylic C(sp3)−H bonds of alkyl indoles with trifluoropyruvates was developed with high enantioselectivity. Mechanistic studies and DFT calculations show an unusual mechanism, including the first installation of a trifluoropyruvate electrophile at C3 of indoles, towards the formation of the key enamine nucleophile, followed by the addition of the second trifluoropyruvate. Abstract Described here is a direct...
Fri Sep 13, 2019 12:53
All aglow: Organic–metal halide perovskite materials present a high blue photoluminesence quantum yield of up to 63.55 %, an ultralong TADF lifetime of 103.12 ms, and optical waveguide properties. These endow the 2D perovskite micro/nanosheets with both space and time dual‐resolved visible luminescence. Abstract Molecular solid‐state materials with long‐lived luminescence (such as thermally activated delayed fluorescence (TADF) and room temperature phosphorescence (RTP) systems) are promising...
Fri Sep 13, 2019 12:54
Triafulvene (C4H4), the simplest member of the fulvene family, is formed as the nascent product upon reaction of methylidyne radicals (CH) with allene (CH2CCH2) and methylacetylene (CH3CCH). As shown by A. M. Mebel, R. I. Kaiser, and co‐workers in their Research Article (DOI: https://doi.org/10.1002/anie.20190803910.1002/anie.201908039), the formation of triafulvene is favored due to the cycloaddition of the CH radical to unsaturated C3H4 bonds followed immediately by the elimination of atomic hydrogen....
Fri Sep 13, 2019 12:54
Hydrophobic DD3R zeolite is a benchmark membrane material for Xe recovery. The CO2 permeance is one order magnitude higher than conventional membranes and is less susceptible to humidity. The high performance and long‐term stability endow DD3R zeolite membranes great potential for on‐stream CO2 removal from the exhaled Xe‐based anaesthetic gas. Abstract Xe is only produced by cryogenic distillation of air, and its availability is limited by the extremely low abundance. Therefore, Xe recovery...
Fri Sep 13, 2019 12:55
A tetraurea macrocycle and other synthetic anion transporters facilitate transmembrane H+/Cl− symport and show attenuated transport rates in the presence of a membrane potential, as described by P. A. Gale and co‐workers in their Research Article (DOI: https://doi.org/10.1002/anie.20190746610.1002/anie.201907466). This voltage‐dependent property, reminiscent of voltage‐gated ion channels, is related to the binding of anion transporters to lipid phosphate headgroups that inhibits the transmembrane...
Fri Sep 13, 2019 12:55
The ring of fire: A strong chirality transfer is observed in a resonance Raman optical activity (ROA) experiment of a nickel complex in various solvents. A simplified model rationalizes the observations and shows that the through‐space interaction is strongest at a certain distance from the resonating complex. The phenomenon might find applications in molecular studies, for example, in the sensitive detection of biomolecules. Abstract We report extremely strong chirality transfer from a chiral...
Fri Sep 13, 2019 13:00
Host‐enhanced intermolecular charge transfer enabled the fabrication of a supramolecular radical dimer with strong absorption in the NIR‐II biowindow and high stability. The dimer exhibited high‐efficiency photothermal conversion and strong inhibition on cancer cells through NIR‐II photothermal therapy. Abstract Photothermal therapy at the NIR‐II biowindow (1000–1350 nm) is drawing increasing interest because of its large penetration depth and maximum permissible exposure. Now, the supramolecular...
Fri Sep 13, 2019 13:02
A MOF thin film (down to 200 nm in thickness) is synthesized to enable selective Mg2+ transport with negligible crossover of the solvents and the counterions. When synthesized directly onto a porous anodized aluminum oxide (AAO) support, it permits stable, low overpotential Mg striping and plating. This work demonstrates that MOF thin film is a promising choice for future Mg battery applications. Abstract The incompatibility between the anode and the cathode chemistry limits the used of Mg...
Fri Sep 13, 2019 13:02
Fri Sep 13, 2019 13:03
CO2 splitting by a single iron centre is achieved through the joint action of the metal atom and the 2‐(2′‐pyridyl)‐4,6‐diphenylphosphinine ligand (L) in the ferrate anion [Cp*FeL]− (Cp*=C5Me5). The outcome of the reaction depends on the coordination mode of L. Electrophilic addition of CO2 to the phosphinine group is observed when L is π‐coordinated, while the σ‐coordinated ligand induces C=O bond cleavage. Abstract New iron complexes [Cp*FeL]− (1‐σ and 1‐π, Cp*=C5Me5) containing the chelating...
Fri Sep 13, 2019 13:05
Protection at the nano‐level: Molecular layer deposition is employed to fabricate a nanoscale “zircone” coating that is highly effective at stabilizing the Li metal anode interface. In‐situ XAS is used for the first time to study the lithiation process of the artificial coating and the protected Li metal anode shows significantly enhanced cycling stability and lifetime in Li‐O2 batteries. Abstract Herein, molecular layer deposition is used to form a nanoscale “zircone” protective layer on Li...
Fri Sep 13, 2019 13:48
Carbon dioxide activation by amines leads to a range of C−N bond forming reactions. Most types of organocatalysts promote the reactions predominantly by acting as bases that stabilize formation of carbamate salts in the form [BaseH][RR′NCOO]. Alternative mechanistic roles of organocatalysts in CO2 based reactions with amines are extremely rare. Abstract Organocatalysts promote a range of C−N bond forming reactions of amines with CO2. Herein, we review these reactions and attempt to identify...
Fri Sep 13, 2019 13:49
Concerted or stepwise? A class of nucleophilic aromatic substitutions has been developed that proceed by concerted (cSNAr) rather than classical, two‐step, SNAr mechanisms. Whereas traditional SNAr reactions require substantial activation of the aromatic ring by electron‐withdrawing substituents, such activating groups are not mandatory in the concerted pathways. Abstract Recent developments in experimental and computational chemistry have identified a rapidly growing class of nucleophilic...
Fri Sep 13, 2019 13:50
Balancing spins: A new strategy of manipulating spin state for Ru25+ species results in the first example of mixed spin Ru25+‐ based complex [Ru2(μ‐ap)4‐CN‐Ru2(μ‐ap)4](BPh4). The complex possesses uncommon electronic configuration of (π*)3(S=1/2)–(π*δ*)3(S=3/2) and shows inter‐cluster metal‐to‐metal charge transfer. Abstract An unusual tetra‐nuclear linear cyanido‐bridged complex [Ru2(μ‐ap)4‐CN‐Ru2(μ‐ap)4](BPh4) (1) (ap=2‐anilinopyridinate) has been synthesized and well characterized. The crystallographic...
Fri Sep 13, 2019 13:50
A 2D aminated graphdiyne nanofilm with well‐ordered structure is prepared. Its intrinsic in‐plane selectivity is beneficial for suppressing methanol crossover. The performance and durability of the direct methanol fuel cell are thus greatly improved. Abstract A two‐dimensional (2D) carbon nanofilm with uniform artificial nanopores is an ideal material to ultimately suppress the fuel permeation in the proton exchange membrane fuel cells. Graphdiyne has great mechanical strength, high dimensional...
Fri Sep 13, 2019 13:51
Although great effort has been made in the past several decades, challenges still remain in the design and synthesis of uranium sorbent materials with high uptake efficiency, capacity and selectivity, as well as excellent hydrolytic stability and radiation resistance. Herein, a polyoxometalate (POM)‐organic framework material ( SCU‐19 ) with a rare inclined polycatenation structure was successfully designed, synthesized through solvothermal method, and tested for uranium separation for the first...
Fri Sep 13, 2019 16:08
Manipulation of low‐dimensional solids through soft chemical routes is an elegant way to realize newer materials. A new family of single crystalline transition metal layered organophosphates, with ~185000 metal phosphate layers in a single crystal, can be exfoliated to a single‐layer nanosheet via a facile and rapid solvent assisted methodology. This exfoliation aids the formation of high surface area pyrophosphates with enhanced super‐capacitance.
Fri Sep 13, 2019 16:56
The CDK family plays a crucial role in the control of the cell cycle. Dysregulation and mutation of the CDKs has been implicated in cancer and the CDKs have been investigated extensively as potential therapeutic targets. Selective inhibition of specific isoforms of the CDKs is crucial to achieve therapeutic effect while minimising toxicity. We present a group of photoaffinity probes designed to bind to the family of CDKs. The site of crosslinking of the optimised probe, as well as its ability to...
Fri Sep 13, 2019 17:02
Stereocontrolled chemical glycosylation remains a major challenge despite vast efforts reported in the literature over many decades and so far still mainly relies on trial and error. Herein, we describe that the relative reactivity value (RRV) of thioglycosides is an indicator for revealing stereoselectivities according to four types of acceptors. Mechanistic studies show that the reaction is dominated by two distinct intermediates: glycosyl triflates and glycosyl halides from N ‐halosuccinimide...
Fri Sep 13, 2019 18:19
DNA nanotechnology can be used to form amphiphilic DNA nanoplates that stabilize water droplets in oil by accumulating at the oil–water interface. These DNA nanoplates stabilize the oil–water interface and can function as channels to transport ions across this interface. These findings provide a general strategy for the design of microcapsules to engineer artificial cells and molecular robots. Abstract Bio‐inspired functional microcapsules have attracted increasing attention in many fields...
Fri Sep 13, 2019 19:53
Linker desymmetrization has been witnessed as a powerful design strategy for the discovery of highly connected metal‐organic frameworks (MOFs) with unprecedented topologies. Herein, we introduce molecular pivot‐hinge installation as a linker desymmetrization strategy to evolve topology of highly connected rare‐earth (RE) MOFs, where a pivot group is placed in the center of a linker similar to a hinge. By tuning the composition of pivot groups and steric hindrances of the substituents on various linker...
Fri Sep 13, 2019 19:24
Silicon‐bridged [1]ferrocenophanes are a versatile class of monomers to obtain well‐defined metallopolymers, however, their boron‐bridged analogs are far less utilized despite being significantly higher strained. We speculate that the reactivity of known bora[1]ferrocenophanes towards ring‐opening polymerization is hampered by pi‐donating R2N groups at the bridging boron atom and, therefore, prepared the first bora[1]ferrocenophanes lacking such electronic stabilization. The new isolated ferrocenophane...
Fri Sep 13, 2019 19:24
The development of efficient protocols for cancer diagnosis remains highly challenging. An emerging approach relies on the detection in exhaled breath of volatile organic compounds (VOC) produced by tumours. In this context, we propose a novel strategy in which a VOC‐based probe is converted selectively in malignant tissues by a tumour‐associated enzyme for releasing the corresponding VOC. The latter is then detected in the breath as a tumour marker for cancer diagnosis. This approach allows the...
Fri Sep 13, 2019 19:25
We report here a straightforward process in which cyclic (alkyl)(amino)carbene‐Rh‐catalyzed preferential addition of hydrogen to the substitution sites of difluoromethylated and trifluoromethylated arenes and heteroarenes occurs, leading to dearomative reduction. This strategy enables the diastereoselective synthesis of cis‐difluoromethylated and trifluoromethylated cycloalkanes and saturated heterocycles, and even allows forming all‐ cis multi‐trifluoromethylated cyclic products with defined equatorial...
Fri Sep 13, 2019 19:25
Chiroptical properties of two chiral atropisomers of propeller‐like trityl‐based radical derivatives have been analyzed. A new absolute configuration (AC) assignment has been made, according to the combination of experimental and theoretical data. In this sense, their ACs have been determined through the comparison of the Cotton effects recorded by electronic circular dichroism (ECD) with the theoretical ECD of the open shell structures obtained by TD‐DFT calculations. Finally, their circularly polarized...
Fri Sep 13, 2019 19:48
C‐Nucleosides are characterized by a C‐C rather than a C‐N linkage between the heterocyclic base and the ribofuranose ring. While the biosynthesis of pseudouridine‐C‐nucleosides has been studied, less is known about the pyrazole‐C‐nucleosides such as the formycins and pyrazofurin. Herein, genome screening of Streptomyces candidus NRRL 3601 led to the discovery of the pyrazofurin biosynthetic gene cluster pyf. In vitro characterization of gene product PyfQ demonstrated that it is able to catalyze...
Fri Sep 13, 2019 20:44
Publication date: Available online 12 September 2019Source: Journal of Surgical EducationAuthor(s): Austin M. Beason, Collin E. Hitt, Janet Ketchum, Heather Rogers, Hilary SanfeyObjectiveThe American College of Surgeons and the Association of Program Directors in Surgery developed a curriculum in 2001 that involved instructional modules for 11 basic surgical skills and a standardized Verification of Proficiency (VOP) evaluation instrument. Our institution continues to employ a modified version of...
Fri Sep 13, 2019 15:53
Publication date: Available online 14 September 2019Source: Journal of Surgical EducationAuthor(s): Alison O. Flentje, Ilaria Caturegli, Stephen M. KavicBackgroundThe American Board of Surgery In-Training Examination (ABSITE) is an important predictor of passing the Qualifying Examination and a determinant of fellowship competitiveness.ObjectionStudy the impact of providing program-wide access to a commercially available question bank for ABSITE preparation.Study designThe surgery residency program...
Sat Sep 14, 2019 18:24
Publication date: Available online 13 September 2019Source: Journal of the American College of SurgeonsAuthor(s): Shaojie Li, Hongbing Xiao, Li Yang, Lei Hua, Zhiying Qiu, Xingchen Hu, Ding Ping, Kan Zheng, Hongbing He, Jiangxiong TangAbstractObjectiveTo compare primary efficacy indicators of a low-cost, electrospun, nanoscale P(LLA-CL)/fibrinogen patch with a porcine small intestine submucosa patch for hernia repair.StudyDesign: A randomized, single-blind, controlled multicenter trial was performed...
Sat Sep 14, 2019 18:29
Abstract Purpose Whether autophagy plays a key role in thyroxine-induced cardiomyocyte hypertrophy, and whether the role of autophagy in thyroxine-induced cardiomyocyte hypertrophy is related to targeting of Beclin-1 by miR-762 remains unclear. This research focused on testing these two hypotheses. Importantly, the results of this study will help us better understand the molecular mechanisms of thyroxine-induced cardiomyocyte hypertrophy....
Sat Sep 14, 2019 03:00
Publication date: Available online 12 September 2019Source: Acta HistochemicaAuthor(s): Amina Cheboub, Nadia Regouat, Reda Djidjik, Assia Slimani, Fatima Hadj-BekkoucheAbstractPurposeThis study aimed to evaluate the effects of estrogen reduction on amyloid deposition, some lipid metabolism and oxidative stress markers, PSA-like production and p63 expression in the prostate of the adult rat.MethodsAromatase inhibitor: Formestane (4-OHA), was administrated to male rats, at a dose of 0.1 mg/kg b.w./day,...
Fri Sep 13, 2019 18:59
Publication date: October 2019Source: Acta Histochemica, Volume 121, Issue 7Author(s):
Sat Sep 14, 2019 19:36
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