All‐DNA energy conversion: ZnIIPPIX/G‐quadruplex aptamer/electron acceptor nanostructures provide effective scaffolds for mimicking photosynthesis. Abstract All‐DNA scaffolds act as templates for the organization of photosystem I model systems. A series of DNA templates composed of ZnII‐protoporphyrin IX (ZnIIPPIX)‐functionalized G‐quadruplex conjugated to the 3′‐ or 5′‐end of the tyrosinamide (TA) aptamer and ZnIIPPIX/G‐quadruplex linked to the 3′‐ and 5′‐ends of the TA aptamer through a four‐thymidine...
Thu Mar 26, 2020 18:56
Diradicaloids derived from cyclic carbenes are singlet‐fission molecules with exceptionally large diradicaloid character, which self‐assemble at cryogenic temperatures in solution. Abstract Herein, we present a new class of singlet fission (SF) materials based on diradicaloids of carbene scaffolds, namely cyclic (alkyl)(amino)carbenes (CAACs). Our modular approach allows the tuning of two key SF criteria: the steric factor and the diradical character. In turn, we modified the energy landscapes...
Thu Mar 26, 2020 18:55
Difluorocarbene is reversibly trapped by intramolecular frustrated Lewis pairs. The reaction proceeds stepwise via interaction of the carbene with the phosphorus atom followed by formation of the carbon‐boron bond. Abstract Frustrated Lewis pairs consisting of diphenylphosphino and boryl groups located at the ortho‐position can trap difluorocarbene affording stable zwitterionic adducts. The reaction can be reversed to release difluorocarbene at elevated temperatures.
Thu Mar 26, 2020 18:54
Thu Mar 26, 2020 18:54
Organic solid‐state semiconductor lasers are attracting ever increasing interests for their potential application in future photonic circuits. Despite the great progresses made in recent years, organic laser from 3D chiral structures has not been achieved. In this paper, we report the first example of organic nano‐laser from micro‐helix structure of an achiral molecule. Highly regular micro‐helixes with left/right‐handed helicity from a distyrylbenzene derivative (HM‐DSB) were fabricated and characterized...
Thu Mar 26, 2020 18:14
A general efficient protocol was developed for the synthesis of carboxylic acids, esters, and amides via oxidation of alkynyl boronates, generated directly from terminal alkynes. This protocol represents the first example of C(sp)–B bond oxidation. This approach displays a broad substrate scope, including aryl and alkyl alkynes, and exhibits excellent functional group tolerance. Water, primary and secondary alcohols, and amines are suitable nucleophiles for this transformations. Notably, amino acids...
Thu Mar 26, 2020 17:43
Silicon‐containing compounds are widely used as synthetic building blocks, functional materials, or bioactive reagents, and silyl radicals are important intermediates for syntheses and transformations of organosilicons. Here we describe the first protocol for the generation of silyl radicals by photo‐induced decarboxylation of silacarboxylic acids, which can be easily prepared in high yield on a gram scale and are very stable to air and moisture. Irradiation of silacarboxylic acids with blue LEDs...
Thu Mar 26, 2020 16:50
Conformationally restricted azabicycles are becoming increasingly important in medicinal research. Asymmetric Heck bicyclization of enynes proceeds to give medicinally useful aza[3.1.0] and aza[4.1.0] bicycles in excellent enantioselectivity. The key organopalladium species after bicyclization can be trapped by silanes and terminal alkynes.
Thu Mar 26, 2020 16:50
A method for catalytic regio‐ and enantioselective synthesis of trifluoromethyl‐substituted and aryl‐, heteroaryl‐, alkenyl‐, and alkynyl‐substituted homoallylic a‐tertiary NH2‐amines is introduced. Easy‐to‐synthesize and robust N‐silyl ketimines are converted to NH‐ketimines in situ, which then react with a Z‐allyl boronate. Transformations are promoted by a readily accessible L‐threonine‐derived aminophenol‐based boryl catalyst, affording the desired products in up to 91% yield, >98:2 a:g selectivity,...
Thu Mar 26, 2020 16:49
Excitonic processes of semiconductors open up the possibility for pursuing photocatalytic organic syntheses. However, the insufficient spin relaxation and robust nonradiative decays in semiconductors place restrictions on both quantum yield and selectivity of these reactions. Herein, by taking polymeric carbon nitride (PCN)/acetone as a prototypical system, we propose that extrinsic aliphatic ketones can serve as molecular co‐catalysts for synergistically promoting spin‐flip transition and suppressing...
Thu Mar 26, 2020 16:49
We report the preparation of lithium salt free KDA (potassium diisopropylamide; 0.6 m in hexane) complexed with TMEDA (N,N,N',N'‐tetramethylethylenediamine) and its use for the flow‐metalation of (hetero)arenes between ‐78 °C and 25 °C with reaction times between 0.2 s and 24 s and a combined flow rate of 10 mL/min using a commercial flow set‐up. The resulting potassium organometallics react instantaneously with various electrophiles, such as ketones, aldehydes, alkyl and allylic halides, disulfides,...
Thu Mar 26, 2020 16:14
Please don′t you rock my boat: A highly curved boat‐shaped molecule was synthesized by the cyclization of fjords of a bisacridone derivative. Analysis of the structure and properties reveals a stepwise inversion process, red shifts in the absorption and emission spectra, an enhanced emission intensity and a convergence of frontier molecular orbital energy levels in comparison to those of the related concave N‐heterotriangulene. Abstract The surface extension of all‐carbon based bowl‐shaped...
Thu Mar 26, 2020 10:03
With the help of selective 15 N labeling experiments, it has been confirmed that nucleophilic attack of azide at iminium‐activated organic azides leads to short‐lived hexazene intermediates. Such species do not only tend to a cleavage reaction with formation of N‐azido compounds, but also undergo ring closure to generate unprecedented amidino‐functionalized pentazoles. Thus, treatment of the parent Vilsmeier reagent with two equivalents of sodium azide creates an aminopentazole derivative as the...
Wed Mar 25, 2020 21:00
Particle‐based amphiphiles: Ultra‐small Janus particles (JPs) have been prepared using magnetite/organosilica particles in a click reaction with spatial control. The JPs show a pronounced and reversible magnetic response when applying a weak magnetic field to a dispersion which results in a difference in the interfacial energy. Abstract Amphiphiles alter the energy of surfaces, but the extent of this feature is typically constant. Smart systems with amphiphilicity as a function of an external,...
Wed Mar 25, 2020 20:17
The attachment of peptides onto the surface of gold nanoparticles emerged as a promising strategy towards the creation of artificial enzymes. This Minireview summarizes the contributions to and progress made in the field of catalytically active peptide–gold nanoparticle conjugates over the past 15 years. The origin of distinct properties, as well as potential applications, are discussed. Abstract The self‐assembly of peptides onto the surface of gold nanoparticles has emerged as a promising...
Wed Mar 25, 2020 20:15
<p class="Abstract" style="margin: 0in 0in 0.25in; text‐align: justify; line‐height: 11.25pt; font‐size: 8pt; font‐family: Arial; caret‐color: rgb(0, 0, 0); color: rgb(0, 0, 0);">Enantioselective conjunctive cross‐coupling of enyne‐derived boronate complexes occurs with 1,4 addition of the electrophile and migrating group across the <span style="font‐family: Symbol;">π </span>system. This reaction pathway furnishes <span style="font‐family: Symbol;">α</span>‐boryl allenes...
Wed Mar 25, 2020 18:14
The inside walls of a nanopipette tip are decorated by a Pt deposit that is used as an open bipolar electrochemiluminescence (ECL) device to achieve intracellular wireless electroanalysis . The synergetic actions of nanopipette and of bipolar ECL lead to the spatial confinement of the voltage drop at the level of the Pt deposit, which generates ECL emission from luminol. The porous structure of Pt deposit permits the electrochemical transport of intracellular molecules into the nanopipette that...
Wed Mar 25, 2020 18:13
Catalytic electrodes with the capability to directly convert atmospheric CO 2 into value‐added products are of potential environmental and economic benefit, but entail an effective CO 2 selection strategy to impede the competing O 2 reduction reaction. In this work, we have developed a new generation of hybrid electrodes with improved O 2 tolerance and unprecedented capability of CO 2 conversion to liquid products in the presence of O 2 . We introduce aniline molecules into the pore structure...
Wed Mar 25, 2020 16:44
The borocarbonylative coupling of unactivated alkenes with alkyl halides remains a challenge. In this communication, a Cu‐catalyzed borocarbonylative coupling of unactivated alkenes with alkyl halides for the synthesis of ß‐boryl ketones has been developed. A broad range of β‐boryl ketone derivatives was prepared in moderate to excellent yields with complete regioselectivity.
Wed Mar 25, 2020 16:44
Phosphorescence energy transfer from long‐lived organic phosphors (donors) is introduced as a novel design strategy for realizing afterglow fluorescence from commercially available organic dyes (acceptors) under ambient conditions. This triplet‐to‐singlet Förster‐resonance energy transfer leads to ambient red afterglow in water‐processable and flexible films via a delayed sensitization process of the acceptor singlet state. Abstract Ambient afterglow luminescence from metal‐free organic chromophores...
Wed Mar 25, 2020 16:39
An overhang‐eave carbon cage decorated with single‐atom iron catalysts for oxygen reduction (ORR) is prepared. This structure could furnish more stretched edges as three‐phase boundaries to support the mass transport of ORR‐relevant species and to expose the atomically dispersed/catalytically active iron sites to the utmost, thus increasing the utilization of each active site. Abstract Single‐atom catalysts have drawn great attention, especially in electrocatalysis. However, most of previous...
Wed Mar 25, 2020 16:38
A short enzymatic synthesis is established to generate terpene natural products and key intermediates directly from inexpensive prenols. This approach allows the incorporation of additional alkyl‐ or hydroxyl‐groups at positions of interest and is applied in the synthesis of high‐value semiochemicals and medicinal chemistry intermediates. Abstract Non‐natural terpenoids offer potential as pharmaceuticals and agrochemicals. However, their chemical syntheses are often long, complex, and not easily...
Wed Mar 25, 2020 16:38
Piece of cake: A straightforward multicomponent decarboxylative cross coupling of redox‐active esters, sodium dithionite and electrophiles was established to construct sterically bulky sulfones. The inorganic salt sodium dithionite not only served as the sulfur dioxide source, but also acted as an efficient radical initiator for the decarboxylation. Abstract A straightforward multicomponent decarboxylative cross coupling of redox‐active esters (N‐hydroxyphthalimide ester), sodium dithionite,...
Wed Mar 25, 2020 16:37
A designed dipeptide with azide and alkyne groups at its termini adopts β‐sheet packing in its crystal and undergoes single‐crystal‐to‐single‐crystal polymerization via topochemical azide‐alkyne cycloaddition to evolve into a pseudoprotein with interesting helical‐sheet packing in its crystals. This helical‐sheet orientation in the pseudoprotein crystal resembles the novel cross‐α‐amyloids, wherein α‐helical protein assembles laterally. Abstract Protein‐mimics are of great interest for their...
Wed Mar 25, 2020 16:36
G4 on the floor: The unprecedented K+ G‐quartet has been detected as a transient intermediate along the course of G‐quadruplex self‐assembly following an approach that is reminiscent of classical covalent mechanistic studies. Abstract In analogy to covalent reactions, the understanding of noncovalent association pathways is fundamental to influence and control any supramolecular process. Following an approach that is reminiscent of covalent methodologies, we study here, for the first time,...
Wed Mar 25, 2020 16:36
What is the limit? High pressure is predicted to allow for the synthesis of several new transition‐metal fluorides. Record‐high formal oxidation states of +8 can be reached in octafluorides of osmium and iridium below 300 GPa. The stabilization of OsF8 and IrF8 by pressure is explained by valence expansions, where 6p orbitals are lowered in energy and allow for ligand‐to‐metal F 2p→M 6p charge transfer. Abstract Fluorination is a proven method for challenging the limits of chemistry, both structurally...
Wed Mar 25, 2020 16:36
Hierarchical supramolecular self‐assembly of a cyclic peptide functional amphiphilic diblock copolymer into photo‐responsive tubisomes in water was investigated. These tubisomes are employed as photo‐controlled drug delivery vehicles for anticancer drug Doxorubicin to achieve enhanced intracellular DOX release and improved anticancer activity. Abstract Typically, the morphologies of the self‐assembled nanostructures from block copolymers are limited to spherical micelles, wormlike micelles...
Wed Mar 25, 2020 16:36
Abstract Objective This study aimed to assess psychological functioning, quality of life, and regret about screening after a positive FIT and subsequent colonoscopy, and to evaluate changes over time. Methods This is a prospective cohort study. Individuals aged 55‐75 with a positive Fecal Immunochemical Test (FIT) that were referred for colonoscopy between July 2017 and November 2018, were invited to complete questionnaires related to psychological distress and health‐related quality...
Tue Mar 31, 2020 17:20
Abstract Purpose : To evaluate the linear and volumetric dimensional changes that occur throughout the fabrication process of monolithic 4.5‐6% yttria‐stabilized zirconia copings under the influence of different preparation designs and two sintering protocols. Materials and Methods : A titanium master die was fabricated using Atlantis core file implant‐abutment. Six copings were designed virtually according to different finish line offsets and coping thicknesses, with four equidistant...
Tue Mar 31, 2020 15:23
Abstract Purpose To evaluate and compare the surface properties (roughness and hardness) of poly(methylmethacrylate) (PMMA) denture base material modified with zirconium dioxide (ZNPs), silicon dioxide (SNPs), and diamond (DNPs) nanoparticles. Materials and methods Two hundred sixty heat‐polymerized acrylic resin discs (15 × 2mm) were prepared. ZNPs, SNPs, and DNPs were added in concentrations of 0%, 0.5%, 1.0%, 2.5%, and 5.0% by weight of acrylic powder. This yielded a total of...
Tue Mar 31, 2020 18:55
Authors: Lijun Jia, Shaowei Zhao, Suzhu Xie, Hang Li, Hao Wang and Shuang Zhang.Parasite Vol. 27 , page 19Published online: 30/03/2020 Keywords: Theileria orientalis ; Theileria sinensis ; Yanbian ; Epidemiology.
Mon Mar 30, 2020 03:00
Authors: František Moravec and Jean-Lou Justine.Parasite Vol. 27 , page 20Published online: 30/03/2020 Keywords: Nematode parasite ; Ascaridoidea ; Aulopiformes ; Elopiformes ; Perciformes ; South Pacific.
Mon Mar 30, 2020 03:00
Advances in next-generation sequencing technologies have reduced the cost of whole transcriptome analyses, allowing characterization of non-model species at unprecedented levels. The rapid pace of transcriptom...
Mon Mar 30, 2020 03:00
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Effect of Diquafosol Ophthalmic Solution on Airflow-Induced Ocular Surface Disorder in Diabetic Rats
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Purpose: Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease with dismal survival rates. Tumor microenvironment (TME), comprising of immune cells and cancer-associated fibroblasts, plays a key role in driving poor prognosis and resistance to chemotherapy. Herein, we aimed to identify a TME-associated, risk-stratification gene biomarker signature in PDAC. Experimental Design: The initial biomarker discovery was performed in The Cancer Genome Atlas (TCGA, n=163) transcriptomic data. This was...
Tue Mar 31, 2020 16:00
Purpose: Adults with T-cell lymphoblastic lymphoma (T-LBL) generally benefit from treatment with acute lymphoblastic leukemia (ALL)-like regimens, but approximately 40% will relapse after such treatment. We evaluated the value of CpG methylation in predicting relapse for adults with T-LBL treated with ALL-like regimens. Experimental Design: A total of 549 adults with T-LBL from 27 medical centers were included in the analysis. Using the Illumina Methylation 850K Beadchip, 44 relapse-related CpGs...
Tue Mar 31, 2020 16:00
Purpose: Over 60% of melanoma patients respond to immune checkpoint inhibitor (ICI) therapy, but many subsequently progress on these therapies. Second-line targeted therapy is based on BRAF mutation status, but no available agents are available for NRAS, CDKN2A, PTEN, and TP53 mutations. Over 70% of melanoma tumors have activation of the MAPK pathway due to BRAF or NRAS mutations, while loss or mutation of cdkn2a occurs in ~40% of melanomas, resulting in unregulated MDM2-mediated ubiquitination...
Tue Mar 31, 2020 16:00
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