Landbird vital rates, such as productivity and adult survivorship, can be estimated by modeling mist-netting capture data. The proportion in which an adult breeding bird is 1 year of age (a “yearling”), however, has been studied only minimally in a few landbird species. Here we relate yearling proportion to habitat-structure covariates, including reclamation age, in a boreal forest landbird community. Data were collected at 35 constant-effort mist-netting stations over a 6-year period, and consisted...
Fri Apr 24, 2020 03:00
Background Anthracycline-induced liver injury (AILI) is one of the serious complications of anthracycline-based adjuvant chemotherapy for postoperative breast cancer patients. Exosomal miRNAs, as signaling molecules in intercellular communication, play the essential roles in drug-induced liver injury (DILI). However, the expression profiles of them in patients with AILI remains unknown. Methods Seven post-chemotherapy...
Fri Apr 24, 2020 03:00
Ursolic acid improves the bacterial community mapping of the intestinal tract in liver fibrosis mice
Liver fibrosis often appears in chronic liver disease, with extracellular matrix (ECM) deposition as the main feature. Due to the presence of the liver-gut axis, the destruction of intestinal homeostasis is often accompanied by the development of liver fibrosis. The inconsistent ecological environment of different intestinal sites may lead to differences in the microbiota. The traditional Chinese medicine ursolic acid (UA) has been proven to protect the liver from fibrosis. We investigated the changes...
Fri Apr 24, 2020 03:00
As a first step in achieving an evidence-based classification system for the sport of Para Dressage, there is a clear need to define elite dressage performance. Previous studies have attempted to quantify performance with able-bodied riders using scientific methods; however, definitive measures have yet to be established for the horse and/or the rider. This may be, in part, due to the variety of movements and gaits that are found within a dressage test and also due to the complexity of the horse-rider...
Fri Apr 24, 2020 03:00
The Journal of Antibiotics, Published online: 24 April 2020; doi:10.1038/s41429-020-0307-4Chlorinated bis-indole alkaloids from deep-sea derived Streptomyces sp. SCSIO 11791 with antibacterial and cytotoxic activities
Fri Apr 24, 2020 03:00
Fri Apr 24, 2020 03:00
Publication date: Available online 23 April 2020Source: TalantaAuthor(s): Ecenaz Bilgen, Mehrdad Forough, Özgül Persil Çetinkol
Fri Apr 24, 2020 15:46
Publication date: Available online 23 April 2020Source: TalantaAuthor(s): Lili Liu, Peng Bao, Juan Qiao, Hongyi Zhang, Li Qi
Fri Apr 24, 2020 15:46
Publication date: Available online 23 April 2020Source: TalantaAuthor(s): Jing Xie, Ming-Qing Tang, Jia Chen, Ya-Han Zhu, Chao-Bo Lei, Hong-Wei He, Xiao-Hong Xu
Fri Apr 24, 2020 15:46
Publication date: Available online 23 April 2020Source: TalantaAuthor(s): Pavel Dvořák, Rui Miguel Ramos, Vlastimil Vyskočil, José António Rodrigues
Fri Apr 24, 2020 15:46
Abstract Objectives Hearing impairment (HI) is a leading impairment worldwide and identifying modifiable risk factors of HI may have major public health implications. The aim of this study was to investigate the association between obstructive sleep apnea (OSA) and HI. Design Observational longitudinal study (the Paris Prospective Study 3). Setting Population‐based. Participants Volunteers aged 50‐75 years and consulting at a preventive medical center were included between 2008...
Thu Apr 23, 2020 19:13
Abstract Purpose To investigate the effect of 254nm ultraviolet light on the viability of Candida albicans biofilm on poly(methylmethacrylate). Methods Poly(methylmethacrylate) specimens (1cm x 1cm x 1mm) were placed in 6‐well culture plates. Each well contained 8ml of 104 colony forming units/milliliter of C. albicans ATCC90028 and Sabouraud dextrose broth. Plates were incubated at 37°Celcius for 24hours. Specimens were then divided into 11 groups (n = 4): no treatment control groups,...
Fri Apr 24, 2020 21:09
Three paramagnetic Co(II) macrocyclic complexes containing 2‐hydroxypropyl pendant groups, 1,1',1'',1'''‐(1,4,8,11‐tetraazacyclotetradecane‐1,4,8,11‐tetrayl)tetrakis(propan‐2‐ol) ([Co(L1)] 2+ , 1,1'‐(4,11‐dibenzyl‐1,4,8,11‐tetraazacyclotetradecane‐1,8‐diyl)bis(propan‐2‐ol) ([Co(L2)] 2+ ( , and 1,1'‐(4,11‐dibenzyl‐1,4,8,11‐tetraazacyclotetradecane‐1,8‐diyl)bis(octadecan‐2‐ol) ([Co(L3)] 2+ ( were synthesized to prepare transition metal liposomal chemical exchange saturation transfer (lipoCEST)...
Fri Apr 24, 2020 22:53
The SARS‐CoV‐2 outbreak causing the respiratory disease COVID‐19 has left many chemists in academia without an obvious option to contribute to fighting the pandemic. Some of our recent experiences indicate that there are ways to overcome this dilemma. A three‐pronged approach is proposed.
Fri Apr 24, 2020 22:27
The π coordination of arene and anionic heteroarene ligands is a ubiquitous bonding motif in the organometallic chemistry of d‐block and f‐block elements. By contrast, related π interactions of neutral heteroarenes including neutral bora‐π‐aromatics are less prevalent particularly for the f‐block, due to less effective metal‐to‐ligand backbonding. In fact, π complexes with neutral heteroarene ligands are essentially unknown for the actinides. We have now overcome these limitations by exploiting the...
Fri Apr 24, 2020 22:26
Soft polymeric Janus nanoparticles (JNPs), made from polystyrene‐b‐poly(butadiene)‐b‐poly(methylmethacrylate), PS‐PBPMMA, triblock terpolymers, assemble into a monolayer at the water/oil interface to reduce interfacial tension. The extent to which the polymer chains can deform, influences the packing density of the JNPs at the interface. The longer the polymer chains are relative to the core, the softer are the JNPs, resulting in a JNPs assembly with a lower initial lateral packing density. The interfacial...
Fri Apr 24, 2020 22:25
In pursuit of inexpensive and earth abundant photocatalysts for solar hydrogen production from water, conjugated polymers have shown potential to be a viable alternative to widely used inorganic counterparts. The photocatalytic performance of polymeric photocatalysts, however, is very poor in comparison to that of inorganic photocatalysts. Most of the organic photocatalysts are active in hydrogen production only when a sacrificial electron donor (SED) is added into the solution, and their high performances...
Fri Apr 24, 2020 22:00
Fluorine is known to promote ortho‐ C−H metalation. 1 Based upon this reactivity, we employed an activated norbornene to trap the ortho‐palladation intermediate and relay to the meta‐position, leading to a meta‐selective C−H arylation of fluoroarenes. Deuterium experiment suggests that this meta‐arylation is initiated by ortho C−H activation and the catalytic cycle is terminated by the C‐2 protonation. The dual ligand system is crucial for the observed high reactivty and site‐selectivity. Applying...
Fri Apr 24, 2020 21:54
Strain‐engineering can be used to increase the activity and selectivity of an electrocatalyst. Tensile strain is known to improve the electrocatalytic activity of palladium electrodes for reduction of carbon dioxide or dioxygen, but determining how strain affects the hydrogen evolution reaction (HER) is complicated by the fact that palladium can absorb hydrogen concurrently with HER. We report here a custom electrochemical cell that applies tensile strain to a flexible working electrode that enabled...
Fri Apr 24, 2020 21:25
Cryogenic single‐particle photoluminescence (PL) spectroscopy has been used with great success to directly observe the heterogeneous photophysical states present in a population of luminescent particles. Cryogenic electron tomography provides complimentary nanometer scale structural information to PL spectroscopy, but the two techniques have not been correlated due to technical challenges. Here, we present a method for correlating single‐particle information from...
Fri Apr 24, 2020 20:00
A pair of giant calix[n]phyrin derivatives namely calix[8]‐ ( 4 ) and calix[16]phyrin ( 5 ), involving two and four BF 2 units, respectively, were prepared via the condensation of the bisnaphthobipyrrolylmethene‐BF 2 complex ( 3 ) with pentafluorobenzaldehyde. Both systems and precursor 3 were fully characterized, including via single crystal X‐ray diffraction analyses. Calix[n]phyrins 4 and 5 display extremely high extinction coefficients (3.67 and 4.82 105 M ‐1 cm ‐1 , respectively)...
Fri Apr 24, 2020 20:00
Porous materials, especially the metal‐organic frameworks, covalent organic frameworks and supramolecular organic frameworks are widely used in the fields of heterogeneous catalysis, adsorption, and ion exchange. Cucurbit[ n ]urils (Q[ n ]s) are expected to become basic building units because they possess neutral electrostatic potential cavities, negative electrostatic potential portal carbonyls and positive electrostatic potential outer surfaces, which may result in the formation of Q[ n ]‐based...
Fri Apr 24, 2020 19:57
Reductions play a key role in organic synthesis, producing chiral products with new functionalities. Enzymes can catalyse such reactions with exquisite stereo‐, regio‐ and chemoselectivity, leading the way to alternative shorter classical synthetic routes towards not only high added value compounds but also bulk chemicals. In this review we display the synthetic state‐of‐the‐art and potential of enzymes that catalyse reductions, ranging from carbonyl‐, enone‐ and aromatic reductions to reductive...
Fri Apr 24, 2020 19:55
The four contiguous all‐carbon quaternary centers of waihoensene, coupled with the absence of any traditional reactive functional groups other than a single alkene, renders it a particularly challenging synthetic target among angular triquinane natural products. Here, we show that its polycyclic frame can be assembled concisely by using a strategically selected quaternary center to guide the formation of the other three through judiciously selected C–C bond formation reactions. Those events, which...
Fri Apr 24, 2020 19:27
The development of methods to pattern nanocrystals with different sizes and shapes remains a challenge. In this study, we demonstrate a unique class of bottom‐up approaches to assemble nanocrystals into patterns. Our approach for patterning nanocrystals focuses on the utilization and control of the chemical reaction of solvents surrounding nanocrystals. The photopolymerization of solvent molecules through a photomask creates time‐dependent concentration gradients of the solvents. Dispersed nanocrystals...
Fri Apr 24, 2020 19:26
A freestanding 3D graphdiyne‐cobalt nitrides (GDY/Co 2 N) with highly active and selective interface is fabricated for electrochemical nitrogen reduction reaction (ECNRR). Density function theory (DFT) calculations reveal that the interface bonded GDY contributes an unique p‐electronic character to optimally modify the Co‐N compound surface bonding, which generates as‐observed superior electronic activity for NRR catalysis at the interface region. Experimentally, at the atmospheric pressure and...
Fri Apr 24, 2020 19:24
An unprecedented photo‐promoted skeletal rearrangement reaction of phosphine‐borane frustrated Lewis pairs, o ‐(borylaryl)phosphines, involving cleavage of an unstrained sp 2 C–sp 3 C σ‐bond is reported. The reaction realizes an efficient synthesis of cyclic phosphonium‐borate compounds. The reaction mechanism via a boranorcaradiene intermediate is proposed based on theoretical calculations. This work sheds light on the new photoreactivity of phosphine‐borane FLPs.
Fri Apr 24, 2020 18:29
The stability of luminescent materials is a key factor for the practical application in white light‐emitting diodes (LEDs). Poor chemical stability of narrow‐band green‐emitting RbLi(Li 3 SiO 4 ) 2 :Eu 2+ (RLSO:Eu 2+ ) phosphor hinders its further commercialization even if it possesses excellent stability against thermal quenching. Herein, we propose an efficient protection scheme by combining the surface coating of amorphous Al 2 O 3 and hydrophobic modification by octadecyltrimethoxysilane...
Fri Apr 24, 2020 18:27
A concise and asymmetric total synthesis of five kopsane alkaloids which share a unique heptacyclic caged ring system was accomplished. The key transformation in our sequence involved a remarkable PtCl 2 catalyzed intramolecular [3+2] cycloaddition, which allowed for the rapid assembly of pentacyclic carbon skeletons bearing 2,3‐quaternary functionalized indoline. Expeditious construction of diverse indoline scaffolds with excellent control of diastereoselectivity demonstrated the broad scope and...
Fri Apr 24, 2020 18:24
Superstructures have attracted extensive attention because of their potential applications in materials science and biology. Herein, we fabricate the first centimeter‐sized porous superstructure of carbon nanosheets (SCNS) by using metal‐organic framework (MOF) nanoparticles as a template and polyvinylpyrrolidone as an additional carbon source. The SCNS shows an obviously honeycomb‐like morphology with wall‐sharing carbon cages, in each cavity of which a porous carbon sphere is encapsulated. A single...
Fri Apr 24, 2020 18:23
Native plant cellulose has an intrinsic supramolecular structure. Consequently, it can be isolated as nanocellulose species, which can be utilized as building blocks for renewable nanomaterials. The structure of cellulose also permits its end‐wise modification, i.e., chemical reactions exclusively on one end of a cellulose chain or a nanocellulose particle. The premises for end‐wise modification have been known for decades. Nevertheless, different approaches for the reactions have emerged only recently,...
Fri Apr 24, 2020 18:02
An unprecedented cationic supramolecule [(Cp’’Fe(η5‐ P5))12{CuNCMe}8]8+ of 2.66 nm in diameter was selectively isolated as a salt of the weakly coordinating anion [Al{OC(CF3)3}4]‐ for the first time and characterized by X‐ray structure analysis, PXRD, NMR spectroscopy and mass spectrometry. Its metal‐deficient core contains the lowest possible number of Cu atoms to connect 12 pentaphosphaferrocene units providing a supramolecule with fullerene topology which, topologically,...
Fri Apr 24, 2020 18:01
Here we report a strategy for the synthesis of crystalline porous c ovalent organic frameworks via t opology‐templated polymerization. The template is based on imine‐linked frameworks and their (001) facet s seed the C=C bond formation reaction to constitute 2D sp 2 carbon‐conjugated frameworks. This strategy is applicable to templates with different topologies, enables designed synthesis of frameworks that cannot be prepared via direct polymerization, and creates a series of sp 2 carbon...
Fri Apr 24, 2020 16:59
Oxidative [3+3] cycloaddition offers an efficient route for 6‐membered ring formation. This approach has been realized based on electrochemical oxidative coupling of indoles/enamines with active methylene compounds followed by tandem 6π‐electrocyclization leading to the synthesis of dihydropyrano[4,3‐b]indoles and 2,3‐dihydrofurans. The radical‐radical cross‐coupling of the corresponding radical species by anodic oxidation combined with cathodic generation of the base from O 2 allows mild reaction...
Fri Apr 24, 2020 16:55
Flexible organic single crystals capable of plastic or elastic deformations have a variety of potential applications. Although the integration of plasticity and elasticity on a crystal is theoretically possible and it benefits the rich and complex deformations which are highly demanded for applications, the integration is hard to be realized practically. Here, we show that through utilizing different modes of external forces for influencing molecular packing of different crystallographic directions,...
Fri Apr 24, 2020 16:55
Developing strong visible‐light‐absorbing (SVLA) earth‐abundant photosensitizers (PSs) for significantly improving the utilization of solar energy is highly desirable, yet it remains a great challenge. Herein, we adopt a though‐bond energy transfer (TBET) strategy by bridging boron dipyrromethene (Bodipy) and a Cu(I) complex with an electronically conjugated bridge, resulting in the first SVLA Cu(I) PSs ( Cu‐2 and Cu‐3 ). Cu‐3 possesses an extremely high molar extinction coefficient of 162260...
Fri Apr 24, 2020 16:54
We report herein an unprecedented highly efficient Guerbet‐type reaction at room temperature (catalytic TON up to >6000). This β ‐alkylation of secondary methyl carbinols with primary alcohols has significant advantage of delivering higher‐order secondary alcohols in an economical, redox‐neutral fashion. In addition, the first enantioselective Guerbet reaction has also been achieved using a commercially available chiral ruthenium complex to deliver secondary alcohols with moderate yield and...
Fri Apr 24, 2020 16:53
Although the cell surfaceome is predominantly targeted and drugged with antibodies, its pocketome fraction is only accessible to small molecules and constitutes a rich subset of binding sites with immense potential diagnostic and therapeutic utility. Compared to antibodies, however, small molecules are disadvantaged by their less confined biodistribution, shorter circulatory half‐life, and inability to communicate with the immune system. Presented herein is a method that endows small molecules with...
Fri Apr 24, 2020 16:19
We have developed a general and site‐predictable manganese‐catalyzed hydroarylation of internal alkynes in the presence of water, under an air atmosphere without the involvement of ligand. The unique catalytic feature of this reaction is highlighted by comparison with other widely used transition metal catalysts including palladium, rhodium, nickel or copper. The simple operation, high efficiency and excellent functional group compatibility make this protocol to be practical for more than 90 structurally...
Fri Apr 24, 2020 15:26
Δεν υπάρχουν σχόλια:
Δημοσίευση σχολίου