bluuebunny/crossref_metadata_2025 huggingface dataset:
A Concise Total Synthesis of (±)‐Vibralactone
Authors: Nistanaki Sepand K. , Boralsky Luke A. , Pan Roy D. , Nelson Hosea M.
Published: December 2018

Disclosed is a five‐step synthesis of (±)‐vibralactone, a biologically active terpenoid natural product. A key photochemical valence isomerization of 3‐prenyl‐pyran‐2‐one produces both the all‐carbon quaternary stereocenter and the β‐lactone at an early stage. Cyclopropanation of the resulting bicyclic β‐lactone produces a strained housane structure that is converted to the natural product through a sequential ring expansion and reduction strategy. This concise and modular route to the natural product provides the shortest total synthesis of (±)‐vibralactone reported to date.
Highly Regioselective Remote Lithiation of Functionalized 1,3‐bis‐Silylated Arenes
Authors: Bellan Andreas B. , Knochel Paul
Published: December 2018

Substituted arenes flanked by two bulky triethylsilyl groups were regiospecifically lithiated at the 5‐position with nBuLi⋅PMDTA at 25 °C. The resulting aryllithiums reacted with a broad range of electrophiles such as ketones, isocyanates, Weinreb amides, allyl bromides, and CO2 at 25 °C. These bis‐silylated arenes were then converted in simple reaction sequences into silyl‐free tetrasubstituted arenes. This remote lithiation was extended to 2,6‐bis(triethylsilyl)pyridine as well as 3,3′‐bis(triethylsilyl)biphenyl.
Novel method for fabrication of PP/HDPE/PP trilayer microporous membrane with a highly orientated structure
Authors: Chen W. , Wu G. , Chu J. , Zhang Y. , Yang M.
Published: December 2018

In this work, a highly orientated polopropelene/high‐density polyethylene/polopropelene (PP/HDPE/PP) trilayer cast film was obtained from viscous encapsulation of HDPE and PP which involved of controlling the molecular factors and processing conditions. Consequently, a stable stratified flow was obtained as a result of phase‐segregation through a single screw extruder under a high draw ratio (DR). Microporous HDPE, PP monolayer films as well as PP/HDPE/PP trilayer film have been successfully fabricated after a proper cold and hot stretching. The influence of DR and annealing process on crystalline structure and orientation of monolayer and trilayer membrane was investigated by differential scanning calorimetry, two‐dimensional wide‐angle X‐ray diffraction and Fourier transform infrared. Both crystallinity and crystalline orientation increased with DR and annealing process. Additionally, the crystallinity in PP/HDPE/PP was lower than it in monolayer films but the orientation of PP/HDPE/PP was higher compared to monolayer films. The lamellae structure of HDPE, PP, and PP/HDPE/PP cast films prepared at different DR values and the influence of annealing process was also studied. The lamellae parameters, the long period (Lp), the thickness of crystalline region (Lc) and the thickness of amorphous region (La) were obtained via 2D‐small angle X‐ray scattering. The long period (Lp) of PP was 35% smaller than HDPE implying tight stacking in PP. The scanning electron microscopy micrographs of the membrane surface morphology and cross‐section obtained from the cold and hot stretching of 30% and 150%, respectively. The results showed that the pore size of HDPE was greater than PP. Besides, the pore number and regularity of PP/HDPE/PP at DR = 90, which had a porosity of 0.48, was the best among all samples. The cross‐section of PP/HDPE/PP trilayer membrane was found to be a multilayer structure. However, the majority of HDPE phase was in the middle of film while PP phase was absolutely at the edge of the film. The current work may open an entirely novel and simple way to fabricate PP/HDPE/PP trilayer microporous films. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47249.
Synthesis of polyamides from sugar derived d‐glucaric acid and xylylenediamines
Authors: Wu Yuxin , Enomoto Yukiko , Masaki Hisaharu , Iwata Tadahisa
Published: December 2018

d‐Glucaric acid (GA) is the one of aldaric acids and is an important bio‐based building block for polymers. In this study, poly(m‐xylylene‐acetyl glucaramide) and poly(p‐xylylene‐acetyl glucaramide) were synthesized from GA acetate and two kind of aromatic diamines by solution polymerization. The chemical structures of the polyamides were analyzed by nuclear magnetic resonance spectroscopy. The weight‐average molecular weights ranged from 3.3 × 103 to 1.15 × 104 with a polydispersity of 1.6–1.9, depending on monomer ratio or monomer concentration in solution. The 10% decomposition temperature of the polymers was about 210 °C. Differential scanning calorimetry revealed that the polyamides exhibited no peaks attributed to crystallization or melting point, which indicated that the polyamides were amorphous. No crystalline pattern was observed in the X‐ray diffractograms, supporting this result. Polarized optical microscopy observation revealed that the polyamides exhibited melting‐like behavior at above 150 °C, which was attributed to glass‐transition behavior. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47255.
Transcriptome analysis of maca (Lepidium meyenii) root at different developmental stages
Authors: Shang Rui‐Guang , Yang Pu , Wang Bing‐Yi , Zhao Zun‐Ling
Published: December 2018

Premise of the Study

Maca (Lepidium meyenii; Brassicaceae) has been cultivated by Andeans for thousands of years as a food source and has been used for medicinal purposes. However, little is known about the mechanism underlying material accumulation during plant growth.

Methods

RNA‐Seq technology was used to compare the transcriptome of black maca root at three developmental stages. Gene Ontology term enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were applied for the identification of pathways in which differentially expressed genes were significantly enriched.

Results

Trinity was used to de novo assemble the reads, and 120,664 unigenes were assembled. Of these, 71.53% of the unigenes were annotated based on BLAST. A total of 18,321 differentially expressed genes were observed. Gene Ontology term enrichment analysis found that the most highly represented pathway among the differentially expressed genes was for genes involved in starch and sucrose metabolism. We also found that genes involved in secondary metabolite biosynthesis, such as glucosinolate biosynthesis, were significantly enriched.

Discussion

The genes that were differentially expressed between developmental time points likely reflect both developmental pathways and responses to changes in the environment. As such, the transcriptome data in this study serve as a reference for subsequent mining of genes that are involved in the synthesis of important bioactive components in maca.
Use of Powdered Cockle Shell as a Bio‐Sorbent Material for Phosphate Removal from Water
Authors: Kim Youngjung , Kim Daeik , Kang Shin Wook , Ham Yoon Ho , Choi Jong‐Ha , Hong Yong Pyo , Ryoo Keon Sang
Published: December 2018

In this study, powdered cockle shell was used as a bio‐sorbent material for the removal of phosphates in water. The SEM–EDX, XRD, and FT‐IR analyses showed that calcium carbonate (CaCO3) exists in aragonite state in powdered cockle shell. The influences of pH, initial phosphate concentrations and contact time were conducted in a series of batch sorption experiments. Among the various factors studied, the pH was turned out to be a key variable for phosphate removal. Based on the experimental results for pH, it was found that the phosphate is chemically sorbed onto aragonite surface. At lower phosphate concentration, roughly 88% of sorption efficiency was accomplished by powdered cockle shell. The Pseudo‐second‐order kinetic and the Langmuir isotherm model were fitted well to the sorption experimental data of phosphate because of their higher correlation coefficients (R2).
Highly Efficient Route for the Synthesis of a Novel Generation of Tetraorganofunctional Double‐decker Type of Silsesquioxanes
Authors: Duszczak Julia , Mituła Katarzyna , Januszewski Rafał , Żak Patrycja , Dudziec Beata , Marciniec Bogdan
Published: December 2018

We present an efficient methodology for the synthesis of tetrafunctionalized double‐decker silsesquioxanes via hydrosilylation reaction. An investigation of the catalytic system, olefin structure, chemical and steric surrounding of Si−H moiety in the respective reagent was carried out on the progress, selectivity and rate of hydrosilylation process. Two alternative synthetic pathways for obtaining a variety of functionalized double‐decker silsesquioxanes with high yields based on the Pt catalysts were developed. These parallel routes concern reverse Si−H and −CH=CH2 reactive groups placement in the double‐decker silsesquioxane core. As a result, a series of new tetrasubstituted double‐decker silsesquioxanes derivatives were obtained with high yield and selectivity and comprehensively characterized in detail by spectroscopic analyses.
Recent Progress in Transition Metal‐Catalyzed Regioselective Functionalization of Unactivated Alkenes/Alkynes Assisted by Bidentate Directing Groups
Authors: Lin Cong , Shen Liang
Published: December 2018

The catalytic functionalization of alkenes is among the most important and powerful methods for construction of two new bonds through cleavage of the π bonds, which is widely used for construction of numerous complex organic molecules. Recently, the strategy that involves directing groups‐assisted regioselective functionalization of alkenes has found great synthetic application value, and great achievements have been made in the functionalization of unactivated alkenes and alkynes. This Minireview summarizes the recent progress in transition metal‐catalyzed functionalization of unactivated alkenes and alkynes assisted by bidentate directing groups with high chemo‐, regio‐, and stereo‐selectivity.
Reductive CO2 Homocoupling: Synthesis of a Borylated C3 Carbohydrate
Authors: Béthegnies Aurélien , Escudié Yannick , Nuñez‐Dallos Nelson , Vendier Laure , Hurtado John , del Rosal Iker , Maron Laurent , Bontemps Sébastien
Published: December 2018

To use carbon dioxide as a source of carbon, recent progress has been made toward the synthesis of higher value chemicals and in particular toward Cn compounds. In this context, we report here the synthesis of a borylated C3‐carbohydrate from CO2 as the only source of carbon. This result corresponds to the unprecedented formation of a polyol chain and of asymmetric carbon atoms from CO2. The adopted strategy involves the Fe‐catalysed selective 4e− reduction of CO2 into bis(boryl)acetal followed in one‐pot by a carbene‐mediated C−C coupling reaction. Boron is shown to play a key role in the coupling step enabling to observe the first diastereoselective formose‐type reaction. This result is in addition obtained under mild reaction conditions (T<80 °C, 1 atm of CO2) and short reaction time (t<2 h).
Ionic Liquids as Modifying Agents for Protein Separation in Centrifugal Partition Chromatography
Authors: Bezold Franziska , Roehrer Simon , Minceva Mirjana
Published: December 2018

Aqueous two‐phase systems (ATPSs) can be applied in centrifugal partition chromatography (CPC) to separate biomolecules. Two ionic liquids (ILs) served as modifying agents to tune partition coefficients in the separation of two model proteins, myoglobin and lysozyme. Myoglobin was not affected by the ILs, while the partition coefficient of lysozyme was lowered with addition of IL. High stationary phase retention was achieved with ATPSs in a CPC column with cell size and geometry specially designed for unstable biphasic systems. When ILs were used as modifying agents, no notable decrease in stationary phase retention was observed. The injection volume was increased to 20 % of the total column volume and process simulations indicate that a further increase in the injection volume is possible.
Electrodeposition and Characterization of a Tin Sulfide‐Electrochemically Reduced Graphene Oxide Heterojunction
Authors: Carrizo Rolando , Ramírez Daniel , Hernández Loreto , Lobos Gabriela , Häberle Patricio , Dalchiele Enrique A. , Riveros Gonzalo
Published: December 2018

This work shows the formation of a heterojunction between tin (II) sulfide (SnS) and electrochemically reduced graphene oxide (ERGO), carried out through two electrochemical steps. In the first step, graphene oxide (GO) was electrochemically reduced on a fluorine‐doped tin oxide (FTO) electrode. In the second step, the ERGO/FTO substrate was used as an electrode for the electrodeposition of SnS. In this study, each electrodeposited material (ERGO, SnS and SnS/ERGO heterojunction) was analyzed and characterized using different techniques, which confirmed the SnS/ERGO heterojunction formation. By employing electrochemical impedance spectroscopy (EIS) and linear sweep photovoltammetry measurements, it was confirmed that SnS deposited in both, bare FTO and ERGO, is a p‐type semiconductor. Furthermore, an improvement of the photocatalytic properties of the SnS/ERGO photocathode in comparison with the SnS film was observed. This effect is related to the ERGO interlayer between the SnS film and the FTO electrode, and the structural and morphology modification of the SnS film onto ERGO.
Designed Echinops‐Like Ni@NiNC as Efficient Bifunctional Oxygen Electrocatalyst for Zinc–Air Batteries
Authors: Zhao Jing , Li Congling , Liu Rui
Published: December 2018

Invited for this month's cover picture is the group of Prof. Rui Liu from Tongji University (China). The cover picture shows that the echinops‐like electrocatalyst has been prepared from the self‐assembly between folic acid and nickel ions. It exhibits high performance as a bifunctional oxygen electrocatalyst for a zinc–air battery, making it a promising catalyst to serve for energy‐storage devices and new‐concept vehicles. Read the full text of the Article at 10.1002/celc.201801197.
Self‐Assembly and Ordering of Peptide‐Based Cavitands in Water and DMSO: The Power of Hydrophobic Effects Combined with Neutral Hydrogen Bonds
Authors: Eichstaedt Katarzyna , Szpotkowski Kamil , Grajda Marcin , Gilski Mirosław , Wosicki Stanisław , Jaskólski Mariusz , Szumna Agnieszka
Published: December 2018

Directional self‐assembly of uncharged molecules in water is a major challenge in supramolecular chemistry. Herein, it is demonstrated that peptide‐based cavitands wrap around a hydrophobic core (fullerene C60) by a combination of the hydrophobic effect and hydrogen‐bonding interactions to form highly ordered three‐component complexes in water that resemble the molten‐globule stage of protein folding. The complexes were characterized by DOSY NMR spectroscopy, small‐angle X‐ray scattering, and circular dichroism, and their structures were confirmed by X‐ray crystallography. Enhancement of the CD signals by nearly one order of magnitude and increased hydrolytic stability of hydrazone bonds of the complexes relative to the nonassembled species were observed. In contrast, DMSO and DMSO/water mixtures were found to be highly disintegrative for these complexes. Interestingly, some cavitands can only be synthesized in the presence of the hydrophobic template followed by disassembly of the complexes.
Gram‐Scale Total Synthesis of Sarpagine Alkaloids and Non‐Natural Derivatives
Authors: Rebmann Heiko , Gerlinger Christa K. G. , Gaich Tanja
Published: December 2018

This work describes the total synthesis of three members of the sarpagine alkaloid family and ten non‐natural congeners through an improved synthetic sequence, which was designed for gram‐scale production of materials suited for structure–activity relationship (SAR) studies. Furthermore, the manuscript details how the synthetic route was used to access the biogenetically completely unrelated Stemona alkaloid parvineostemonine (34), providing a showcase for efficient synthetic design.
Chemoselective Intramolecular Formal Insertion Reaction of Rh–Nitrenes into an Amide Bond Over C−H Insertion
Authors: Kono Masato , Harada Shingo , Nemoto Tetsuhiro
Published: December 2018

The past few decades have witnessed extensive efforts to disclose the unique reactivity of metal–nitrenes, because they could be a powerful synthetic tool for introducing the amine functionality into unactivated chemical bonds. The reactivity of metal–nitrenes, however, is currently mainly confined to aziridination (an insertion into a C=C bond) and C−H amination (an insertion into a C−H bond). Nitrene insertion into an amide C−N bond, however, has not been reported so far. In this work we have developed a rhodium‐catalyzed one‐nitrogen insertion into amide C−N and sulfonamide S−N bonds. Experimental and theoretical analyses based on density functional theory indicate that the formal amide insertion proceeds via a rhodium‐coordinated ammonium ylide formed between the nitrene and the amide nitrogen, followed by acyl group transfer concomitant with C−N bond cleavage. Mechanistic studies have allowed rationalization of the origin of the chemoselectivity observed between the C−H and amide insertion reactions. The methodology presented herein is the first example of an insertion of nitrene into amide bonds and provides facile access to unique diazacyclic systems with an N−N bond linkage.
Hybrid Intelligent Modelling of the Viscoelastic Moduli of Coal Fly Ash Based Polymer Gel System for Water Shutoff Treatment in Oil and Gas Wells
Authors: Adewunmi Ahmad A. , Ismail Suzylawati , Owolabi Taoreed O. , Sultan Abdullah S. , Olatunji Sunday O. , Ahmad Zulkifli
Published: December 2018

Qualitative polymer gels exhibiting considerable viscoelastic properties are of immense significance in the petroleum industry as they curtail excessive water production during the tertiary stage of crude oil production. The incorporation of suitable organic or inorganic solid substances into the polymer gel system strengthens its viscoelastic properties. This research work presents hybrid gravitational search algorithm (GSA) and support vector regression (SVR) as novel modelling tools for viscoelastic properties estimation of polymer gel synthesized from polyacrylamide (PAM)/polyethyleneimine (PEI). The coal fly ash (CFA) was incorporated in PAM/PEI gel in order to enhance its viscoelastic characteristics. The hybrid GSA‐SVR models were developed using real‐life experimental data. The results of the models validated using unseen data show a high degree of correlation coefficients (87.3 % for elastic modulus and 97.2 % for viscous modulus), with experimental data generating a small root mean square error (coefficients 669.5Pa for elastic modulus and 38.5Pa for viscous modulus). The developed hybrid models were further used to scrutinize the effect of the addition of various amounts of CFA on the PAM/PEI viscoelastic properties and observed behaviours were presented and discussed. The predictive capability of the developed hybrid model coupled with its strength in modelling the impact of CFA in the PAM/PEI gel are highly meritorious and the outcomes from this investigation would be relevant during the design and formulation of polymer gels employed for water shutoff treatment during hydrocarbon recovery.
A First‐Principles Study on the Adsorption of Small Molecules on Arsenene: Comparison of Oxidation Kinetics in Arsenene, Antimonene, Phosphorene, and InSe
Authors: Kistanov Andrey A. , Khadiullin Salavat Kh. , Dmitriev Sergey V. , Korznikova Elena A.
Published: December 2018

Arsenene, a new group‐V two‐dimensional (2D) semiconducting material beyond phosphorene and antimonene, has recently gained an increasing attention owning to its various interesting properties which can be altered or intentionally functionalized by chemical reactions with various molecules. This work provides a systematic study on the interactions of arsenene with the small molecules, including H2, NH3, O2, H2O, NO, and NO2. It is predicted that O2, H2O, NO, and NO2are strong acceptors, while NH3serves as a donor. Importantly, it is shown a negligible charge transfer between H2and arsenene which is ten times lower than that between H2and phosphorene and about thousand times lower than that between H2and InSe and antimonene. The calculated energy barrier for O2splitting on arsenene is found to be as low as 0.67 eV. Thus, pristine arsenene may easily oxidize in ambient conditions as other group V 2D materials. On the other hand, the acceptor role of H2O on arsenene, similarly to the cases of antimonene and InSe, may help to prevent the proton transfer between H2O and O− species by forming acids, which suppresses further structural degradation of arsenene. The structural decomposition of the 2D layers upon interaction with the environment may be avoided due to the acceptor role of H2O molecules as the study predicts from the comparison of common group V 2D materials. However, the protection for arsenene is still required due to its strong interaction with other small environmental molecules. The present work renders the possible ways to protect arsenene from structure degradation and to modulate its electronic properties, which is useful for the material synthesis, storage and applications.
Prescribed fire regimes subtly alter ponderosa pine forest plant community structure
Authors: Kerns Becky K. , Day Michelle A.
Published: December 2018

Prescribed fire is an active management tool used to address wildfire hazard and ecological concerns associated with fire exclusion and suppression over the past century. Despite widespread application in the United States, there is considerable inconsistency and lack of information regarding the extent to which specific outcomes are achieved and under what prescribed fire regimes, particularly in regard to ecological goals related to plant community structure. We quantify differences and patterns in plant functional group abundance, species richness and diversity, and other key forest components through time from a unique long‐term (15‐yr) experiment within the Malheur National Forest of Oregon. Treatments included five fire regimes: fall and spring 5‐yr burning, fall and spring single burn, and no burning. Original burns were conducted in the fall of 1997 and spring of 1998, and plant data were collected every five years starting in 2002. Many perennial plant group responses were neutral, subtle, and ephemeral. Total cover increased marginally in response to the first burn, but this response disappeared within a decade. Three 5‐yr reburns did not increase or decrease total plant cover, richness, or diversity. Some plant groups with fire resistant and resilient traits, such as annual forbs, exotic forbs, open bunchgrasses, and rhizomatous and resprouting perennials, showed some short‐term positive responses to initial burning and 1–2 reburns, but not 3. The moderately more severe fall burns generally impacted plant responses more than spring burning, but many patterns were legacies from the original higher severity burns. Burn frequency was more important for less severe spring burning. Overall, we document that most native perennial plant functional groups were able to resist or recover from burning and reburning, but did not necessarily strongly respond. This may be due to the importance of other overriding forcing factors and ecosystem inertia not easily overcome by very low‐severity prescribed burns. Results from our study are important for practitioners using prescribed fire to achieve biodiversity, conservation, and habitat goals that hinge on a vigorous native perennial plant response, as such outcomes are not certain even with frequent burn regimes.
Forest canopy restoration has indirect effects on litter decomposition and no effect on denitrification
Authors: Wallace K. J. , Laughlin Daniel C. , Clarkson Bruce D. , Schipper Louis A.
Published: December 2018

Forest restoration has potential to recover degraded ecosystem functions in disturbed environments. Decomposition and denitrification are two critical functions involved in forest nutrient cycling that are often compromised in degraded ecosystems. As forest canopy structure develops following initial plantings, it may indirectly impact ecosystem functions by altering abiotic conditions. It is likely, however, that there are other abiotic factors that affect decomposition and denitrification that are unrelated to forest canopy structure. Here, we aimed to determine whether forest canopy openness, topography, and soil sand content would affect litter decomposition and denitrification by regulating the microclimate, the herbaceous plant layer, soil chemistry, and soil moisture. Research occurred in restored native temperate rainforest patches in two New Zealand cities. Urban forests are an excellent context for measuring impact of canopy restoration on ecosystem properties such as microclimate due to the extreme swings in city conditions (e.g., urban heat island). Decomposition rates were determined using leaf litter bags and denitrification rates through denitrification enzyme activity assays. We used structural equation modeling to quantify the direct and indirect drivers of these ecosystem functions. Results indicated that decomposition rates were positively related to soil moisture, relative humidity, and herbaceous plant cover. Interestingly, forest canopy openness indirectly affected decomposition through counteracting forces, meaning greater canopy openness in young forests permitted dense herbaceous plant growth which enhanced decomposition, while less canopy openness in older forests enhanced humidity levels which increased decomposition. Denitrification was negatively related to soil pH and positively related to soil moisture, but these abiotic factors were unrelated to the forest canopy. Discovering drivers of ecosystem functions can improve approaches to the restoration of degraded ecosystems, especially in disturbed urban areas. Identifying counteracting effects on ecosystem functions could improve management by focusing restoration actions on specific drivers to elicit desired changes. Some ecosystem processes, like denitrification, are not affected by forest canopy restoration or management, but are instead driven by edaphic and landscape factors.
Copper(I) Complexes with Anionic Acylthio‐ or Acylselenourea Ligands and N‐Heterocyclic Carbenes or Phosphanes
Authors: Kuchar Julia , Rust Jörg , Lehmann Christian W. , Mohr Fabian
Published: December 2018

Copper(I) complexes containing acylthio‐ and selenoureato ligands can be accessed either by transmetallation from the corresponding silver compounds or by direct reaction of the acylthio/selenourea with a copper(I) precursor in the presence of base. Several examples of tricoordinate organocopper(I) complexes containing N‐heterocyclic carbenes as well as tetrahedral bis(phosphane) copper(I) compounds are reported with their spectroscopic and structural characterization.
Mechanistic Insights into Light‐Activated Catalysis for Water Oxidation
Authors: Natali Mirco , Nastasi Francesco , Puntoriero Fausto , Sartorel Andrea
Published: December 2018

The development of catalysts for water oxidation to oxygen has been the subject of intense investigation in the last decade. In parallel to the search for high catalytic performance, many works have focused on the mechanistic analysis of the process. In this perspective, the oxidation of water through light‐assisted cycles composed of an electron acceptor (EA), a photosensitizer (PS), and a water oxidation catalyst (WOC) can provide insightful and complementary information with respect to the use of chemical oxidants or to electrochemical techniques. In this minireview, we discuss the mechanistic aspects of the EA/PS/WOC photoactivated cycles, and in particular: (i) the general elementary steps; (ii) the required features and the nature of the PS employed; (iii) the electron transfer processes and kinetics from the WOC to PS+ (hole scavenging); (iv) the detrimental quenching of the PS by the WOC and the alternative mechanistic routes; (v) the identification of WOC intermediates and, finally, (vi) the transposition of the above processes into a dye‐sensitized photoanode embedding a WOC.
A New Entry of Highly Selective and Nucleophilic BrH2C‐ and ClH2C‐Titanium Complexes for Carbonyl Coupling
Authors: Yan Tu Hsin , Ananthan Bakthavachalam , Chang Su Haur
Published: December 2018

The direct coupling of various aldehydes and ketones with CH2Br2 or CH2Cl2 promoted by TiCl4‐Mg bimetallic complex provides an extremely simple, practical, and efficient approach for the construction of bromomethyl or chloromethyl carbinols. The high chemoselectivity of this chemistry is illustrated by the TiCl4‐Mg‐promoted selective coupling of CH2Br2 or CH2Cl2 with an aldehyde in the presence of ketone and selective transfer of CH2Br or CH2Cl to saturated carbonyl moiety. This protocol is also suitable for sterically hindered and enolizable carbonyl compounds.
Exosome isolation and purification via hydrophobic interaction chromatography using a polyester, capillary‐channeled polymer fiber phase
Authors: Bruce Terri F. , Slonecki Tyler J. , Wang Lei , Huang Sisi , Powell Rhonda R. , Marcus R. Kenneth
Published: December 2018

Extracellular vesicles, including microvesicles and exosomes, are lipidic membrane‐derived vesicles that are secreted by most cell types. Exosomes, one class of these vesicles that are 30–100 nm in diameter, hold a great deal of promise in disease diagnostics, as they display the same protein biomarkers as their originating cell. For exosomes to become useful in disease diagnostics, and as burgeoning drug delivery platforms, they must be isolated efficiently and effectively without compromising their structure. Most current exosome isolation methods have practical problems including being too time‐consuming and labor intensive, destructive to the exosomes, or too costly for use in clinical settings. To this end, this study examines the use of poly(ethylene terephthalate) (PET) capillary‐channeled polymer (C‐CP) fibers in a hydrophobic interaction chromatography (HIC) protocol to isolate exosomes from diverse matrices of practical concern. Initial results demonstrate the ability to isolate extracellular vesicles enriched in exosomes with comparable yields and size distributions on a much faster time scale when compared to traditional isolation methods. As a demonstration of the potential analytical utility of the approach, extracellular vesicle recoveries from cell culture milieu and a mock urine matrix are presented. The potential for scalable separations covering submilliliter spin‐down columns to the preparative scale is anticipated.
Synthesis and olfactory evaluation of allylic α‐quaternary ether ketones
Authors: Lempenauer Luisa , Soupart Aline , Lemière Gilles , Duñach Elisabet
Published: December 2018

Unprecedented α‐oxygenated β,γ‐unsaturated ketones bearing a quaternary carbon at the α‐position were synthesized in two steps from readily available α,β‐unsaturated ketones. The compounds were prepared on a gram scale under mild conditions via a key rearrangement step catalysed by 1 mol% of p‐toluenesulfonic acid as a low‐priced and sustainable catalyst. The olfactory properties of this novel family of odorants as well as of some derivatives have been assessed, revealing a quite broad odour spectrum and a pronounced susceptibility of the olfactory properties towards structural changes.
Prediction of treatment response in rheumatoid arthritis patients using genome‐wide SNP data
Authors: Cherlin Svetlana , Plant Darren , Taylor John C. , Colombo Marco , Spiliopoulou Athina , Tzanis Evan , Morgan Ann W. , Barnes Michael R. , McKeigue Paul , Barrett Jennifer H. , Pitzalis Costantino , Barton Anne , Consortium MATURA , Cordell Heather J.
Published: December 2018

Although a number of treatments are available for rheumatoid arthritis (RA), each of them shows a significant nonresponse rate in patients. Therefore, predicting a priori the likelihood of treatment response would be of great patient benefit. Here, we conducted a comparison of a variety of statistical methods for predicting three measures of treatment response, between baseline and 3 or 6 months, using genome‐wide SNP data from RA patients available from the MAximising Therapeutic Utility in Rheumatoid Arthritis (MATURA) consortium. Two different treatments and 11 different statistical methods were evaluated. We used 10‐fold cross validation to assess predictive performance, with nested 10‐fold cross validation used to tune the model hyperparameters when required. Overall, we found that SNPs added very little prediction information to that obtained using clinical characteristics only, such as baseline trait value. This observation can be explained by the lack of strong genetic effects and the relatively small sample sizes available; in analysis of simulated and real data, with larger effects and/or larger sample sizes, prediction performance was much improved. Overall, methods that were consistent with the genetic architecture of the trait were able to achieve better predictive ability than methods that were not. For treatment response in RA, methods that assumed a complex underlying genetic architecture achieved slightly better prediction performance than methods that assumed a simplified genetic architecture.
Intestine‐Specific Overexpression of Carboxylesterase 2c Protects Mice From Diet‐Induced Liver Steatosis and Obesity
Authors: Maresch Lisa Katharina , Benedikt Pia , Feiler Ursula , Eder Sandra , Zierler Kathrin A. , Taschler Ulrike , Kolleritsch Stephanie , Eichmann Thomas O. , Schoiswohl Gabriele , Leopold Christina , Wieser Beatrix I. , Lackner Caroline , Rülicke Thomas , van Klinken Jan , Kratky Dagmar , Moustafa Tarek , Hoefler Gerald , Haemmerle Guenter
Published: December 2018

Murine hepatic carboxylesterase 2c (Ces2c) and the presumed human ortholog carboxylesterase 2 (CES2) have been implicated in the development of nonalcoholic fatty liver disease (NAFLD) in mice and obese humans. These studies demonstrated that Ces2c hydrolyzes triglycerides (TGs) in hepatocytes. Interestingly, Ces2c/CES2 is most abundantly expressed in the intestine, indicating a role of Ces2c/CES2 in intestinal TG metabolism. Here we show that Ces2c is an important enzyme in intestinal lipid metabolism in mice. Intestine‐specific Ces2c overexpression (Ces2cint) provoked increased fatty acid oxidation (FAO) in the small intestine accompanied by enhanced chylomicron clearance from the circulation. As a consequence, high‐fat diet–fed Ces2cint mice were resistant to excessive diet‐induced weight gain and adipose tissue expansion. Notably, intestinal Ces2c overexpression increased hepatic insulin sensitivity and protected mice from NAFLD development. Although lipid absorption was not affected in Ces2cint mice, fecal energy content was significantly increased. Mechanistically, we demonstrate that Ces2c is a potent neutral lipase, which efficiently hydrolyzes TGs and diglycerides (DGs) in the small intestine, thereby generating fatty acids (FAs) for FAO and monoglycerides (MGs) and DGs for potential re‐esterification. Consequently, the increased availability of MGs and DGs for re‐esterification and primordial apolipoprotein B48 particle lipidation may increase chylomicron size, ultimately mediating more efficient chylomicron clearance from the circulation. Conclusion: This study suggests a critical role for Ces2c in intestinal lipid metabolism and highlights the importance of intestinal lipolysis to protect mice from the development of hepatic insulin resistance, NAFLD, and excessive diet‐induced weight gain during metabolic stress.
Vitamin E: Mechanism of transport and regulation in the CNS
Authors: Lee Paris , Ulatowski Lynn M.
Published: December 2018

Although vitamin E has been recognized as a critical micronutrient to neuronal health for more than half a century, vitamin E transport and regulation in the brain remain a mystery. Currently, the majority of what is known about vitamin E transport has been delineated in the liver. However, clues from the pathogenesis of neurological‐related vitamin E deficient diseases point to compromised neuronal integrity and function, underlining the critical need to understand vitamin E regulation in the CNS. Additionally, most of the same molecular players involved in vitamin E transport in the liver are also found in CNS, including sterol SRB1, TTP, and ABCA/ABCG, suggesting similar intracellular pathways between these organ systems. Finally, based on chemical similarities, intracellular CNS shuttling of vitamin E likely resembles cholesterol's use of ApoE particles. Utilizing this information, this review will address what is currently known about trafficking vitamin E across the blood brain barrier in order to ensure an adequate supply of the essential nutrient to the brain. Although debatable, the health of the brain in relation to vitamin E levels has been demonstrated, most notably in oxidative stress‐related conditions such as ataxias, Alzheimer's disease, and Parkinson's disease. Future vitamin E research is vital in understanding how the regulation of the vitamin can aid in the prevention, treatment, and curing of neurological diseases. © 2018 IUBMB Life, 71(4):424–429, 2019
The role of inflammasome complex in ischemia‐reperfusion injury
Authors: Mohamadi Yousef , Mousavi Mahboubeh , Khanbabaei Hashem , Salarinia Reza , Javankiani Sepide , Hassanzadeh Gholamreza , Momeni Fatemeh
Published: December 2018

Ischemia‐reperfusion injury refers to a temporary interruption of blood flow in a tissue. Restoration of blood flow initiates the inflammation in tissue causing ischemic damage through the activation of a multiprotein complex termed inflammasome. The complex contains a receptor, mainly a member of nucleotide oligomerization domain–like receptors, that receives danger signals. The receptor is oligomerized as a response to danger signals and then the apoptosis‐associated speck‐like protein containing a caspase recruitment domain and procaspase protein are added to the oligomerized receptors to form the inflammasome complex. In the next step, the isolated procaspase is converted into an active caspase molecule that initiates the inflammation through the release of interleukin‐1β and interleukin‐18. The inflammasome has an important role in the pathogenesis of ischemia‐reperfusion injury in different tissues. Here, we summarized the role of inflammasome in the pathogenesis of ischemia‐reperfusion of brain, liver, kidney, and heart. Moreover, we highlighted the expression of inflammasome components, the mechanisms involved in activation of the complex, and its inhibition as an optimistic therapeutic technique in ischemia‐reperfusion injuries.
The effect of early growth response 1 on levels of Amyloid‐β 40 peptide in U87MG cells
Authors: Zhao Xinyu , Wang Xiaojie , Su Gang , Sun Qi , Fu Jitong , Zhang Huili , Teng Junfang
Published: December 2018

A recent study has shown that early growth response 1 (EGR1) plays a critical role in the β‐amyloid cascade and tau hypotheses. In addition, evidence has suggested that EGR1 can regulate levels of amyloid‐beta peptides, key molecules in the pathogenesis of Alzheimer's disease (AD). However, whether EGR1 is a deleterious or protective factor in the AD is still controversial. In this present study, we constructed an overexpression plasmid, CMV‐EGFP‐EGR1‐Kanamycin, and transfected it into U87MG cells to investigate the effects of EGR1 expression on amyloid‐β (1‐40) peptide (Aβ40) levels. U87MG cells transfected by CMV‐EGFP‐EGR1‐Kanamycin and CMV‐EGFP‐Kanamycin were assigned, respectively, to experimental and control groups. Fluorescence microscopy was used to observe transfection efficiencies of the plasmids after 6 hours. EGR1 messenger RNA levels were measured by quantitative reverse transcription polymerase chain reaction. Aβ40 secretion was analyzed by enzyme‐linked immunosorbent assay. Expression of the amyloid precursor protein, beta‐secretase enzyme, and presenilin 1 proteins were analyzed by Western blot analysis. The results showed that EGR1 overexpression increased Aβ40 secretion in vitro, possibly through increasing BACE1 expression. Based on these results, EGR1 might be a promising therapeutic target for the AD.
Long noncoding RNA CCAT2 functions as a competitive endogenous RNA to regulate FOXC1 expression by sponging miR‐23b‐5p in lung adenocarcinoma
Authors: Hu Guo‐dong , Wang Cheng‐xiang , Wang Hong‐ying , Wang Ya‐qin , Hu Shuo , Cao Zheng‐wu , Min Bo , Li Lei , Tian Xiao‐feng , Hu Hai‐bo
Published: December 2018

Long noncoding RNA (lncRNA) may regulate the process of tumor formation. Although lncRNA CCAT2 has been identified as a key point in many diseases, its pathophysiological mechanism in lung adenocarcinoma remains unknown. We measured the expression level of CCAT2 in lung adenocarcinoma cells and normal lung epithelial cell line BEAS‐2B by quantitative real‐time polymerase chain reaction (qRT‐PCR). As well, cell migration and proliferation were detected by transwell detection and CCK8 assay. At the same time, the new target point of CCAT2 was confirmed with bioinformatics analysis and dual‐luciferase reporter assay. In addition, potential mechanisms were studied by Western blot analysis and RNA immunoprecipitation (RIP) analysis. The expression of CCAT2 was upregulated obviously in lung adenocarcinoma cells. Cell function analysis showed that upregulation of CCAT2 significantly promoted cell proliferation and migration, and reduction of CCAT2 inhibited cell migration and proliferation. In addition, CCAT2 positively regulated the expression of FOXC1 by competitive binding with miR‐23b‐5p. These findings indicated that CCAT2 may act as a competitive endogenous RNA (ceRNA) to regulate FOXC1 expression by competitively binding miR‐23b‐5p in lung adenocarcinoma.
RETRACTED: MicroRNA‐205 affects mouse granulosa cell apoptosis and estradiol synthesis by targeting CREB1
Authors: Zhang Pengju , Wang Jun , Lang Hongyan , Wang Weixia , Liu Xiaohui , Liu Haiyan , Tan Chengcheng , Li Xintao , Zhao Yumin , Wu Xinghong
Published: December 2018

MicroRNA‐205 (miR‐205) is involved in various physiological and pathological processes, but its biological function in follicular atresia remains unclear. In this study, we investigated miR‐205 expression in mouse granulosa cells (mGCs) and analyzed its functions in primary mGCs by performing a series of in vitro experiments. Quantitative real‐time polymerase chain reaction showed that miR‐205 expression was significantly higher in early atretic follicles and progressively atretic follicles than in healthy follicles. miR‐205 overexpression in mGCs significantly promoted apoptosis and caspase‐3/9 activities, as well as inhibited estrogen (E2) release and cytochrome P450 family 19 subfamily A polypeptide 1 (CYP19A1, a key gene in E2 production) expression. Bioinformatics and luciferase reporter assays revealed that the gene encoding cyclic AMP response element (CRE)‐binding protein 1 (CREB1) was a direct target of miR‐205 in mGCs. CREB1 upregulation partially rescued the effects of miR‐205 on apoptosis, caspase‐3/9 activities, E2 production, and CYP19A1 expression on mGCs. These results indicate that miR‐205 might play an important role in ovarian follicular development and provide new insights into follicular atresia
Peroxisome proliferator‐activated receptor‐α agonist and all‐trans retinoic acid induce epithelial differentiation of subcutaneous adipose‐derived stem cells from debrided burn skin
Authors: Natesan Shanmugasundaram , Wrice Nicole L. , Christy Robert J.
Published: December 2018

This study demonstrates that adipose‐derived stem cells from debrided skin (dsASCs) of burn patients can be isolated in sufficient quantities and differentiated into cytokeratin‐expressing cells by treating them with all‐trans retinoic acid (ATRA) and the peroxisome proliferator‐activated receptor‐α (PPARα) specific activator fenofibrate. Differentiation of dsASCs with ATRA and a combination of growth factors induced expression of simple epithelial markers (KRT7, KRT8, KRT18, and KRT19), along with low levels of stratified epithelial markers (KRT5, KRT10, KRT13, and KRT14). We have optimized a condition to induce dsASCs differentiation to epithelial cells by treatment with ATRA and fenofibrate alone. Real‐time polymerase chain reaction analysis showed a significant increase in transcript levels (>75‐fold) for basal (KRT5 and KRT14), suprabasal (KRT10), and cornified envelope markers (involucrin [IVL] and Loricrin [LOR]) with this treatment. Expression of the proteins encoded by these transcripts was confirmed by immunocytochemical analysis. Further, we show that dsASCs differentiated to a skin epithelial cell phenotype through activation of nuclear hormone receptors PPARα and RXRγ. Collectively this study shows that dsASCs can be differentiated to skin epithelial cells, without the requirement for exogenous growth factors. This differentiation protocol using dsASCs in combination with an appropriate biocompatible scaffold can be adapted to develop epithelial skin substitute for burn wound treatment.
Paeoniflorin attenuates oxidized low‐density lipoprotein‐induced apoptosis and adhesion molecule expression by autophagy enhancement in human umbilical vein endothelial cells
Authors: Wang Yi , Che Jianbo , Zhao Hui , Tang Jianyu , Shi Gongning
Published: December 2018

Oxidized low‐density lipoprotein (ox‐LDL)‐induced endothelial dysfunction is recognized as a driving force in the development of atherosclerosis (AS). Paeoniflorin (Pae), a typical traditional herbal medicine, possesses anti‐inflammatory, antioxidative, antihyperglycaemic, and antiapoptotic properties. Our study aimed to investigate the effects of Pae on ox‐LDL‐induced injury of the human umbilical vein endothelial cells (HUVECs) and to explore its molecular mechanism. We found that ox‐LDL stimulation inhibited cell viability, activated autophagy, and induced apoptosis and adhesion molecule expression in HUVECs. Pae rescued ox‐LDL‐induced viability reduction and enhanced the ox‐LDL‐induced autophagy activation in HUVECs. Pae inhibited ox‐LDL‐induced apoptosis and adhesion molecule expression by autophagy enhancement in HUVECs. In addition, inhibition of SIRT1 by EX‐527 abolished the promoting effect of Pae on autophagy and restored the inhibitory effect of Pae on apoptosis and adhesion molecule expression in the presence of ox‐LDL. In conclusion, Pae attenuated ox‐LDL‐induced apoptosis and adhesion molecule expression by autophagy enhancement via upregulation of SIRT1 in HUVECs, shedding light on the mechanism underlying the protective effect of Pae on ox‐LDL‐induced injury of HUVECs.
Augmentation of miR‐202 in varicose veins modulates phenotypic transition of vascular smooth muscle cells by targeting proliferator–activated receptor‐γ coactivator‐1α
Authors: Huang Xianchen , Liu Zhao , Shen Liming , Jin Yiqi , Xu Guoxiong , Zhang Zhixuan , Fang Changwen , Guan Wenxian , Liu Changjian
Published: December 2018

In varicose veins, vascular smooth muscle cells (VSMCs) often show abnormal proliferative and migratory rates and phenotypic transition. This study aimed to investigate whether microRNA (miR)‐202 and its potential target, peroxisome proliferator–activated receptor‐γ coactivator‐1α (PGC‐1α), were involved in VSMC phenotypic transition. miR‐202 expression was analyzed in varicose veins and in VSMCs conditioned with platelet‐derived growth factor. The effect of miR‐202 on cell proliferation and migration was assessed. Furthermore, contractile marker SM‐22α, synthetic markers vimentin and collagen I, and PGC‐1α were analyzed by Western blot analysis. The modulation of PGC‐1α expression by miR‐202 was also evaluated. In varicose veins and proliferative VSMCs, miR‐202 expression was upregulated, with decreased SM‐22α expression and increased vimentin and collagen I expression. Transfection with a miR‐202 mimic induced VSMC proliferation and migration, whereas a miR‐202 inhibitor reduced cell proliferation and migration. miR‐202 mimic constrained luciferase activity in HEK293 cells that were cotransfected with the PGC‐1α 3′‐untranslated region (3′‐UTR) but not those with mutated 3′‐UTR. miR‐202 suppressed PGC‐1α protein expression, with no influence on its messenger RNA expression. PGC‐1α mediated VSMC phenotypic transition and was correlated with reactive oxygen species production. In conclusion, miR‐202 affects VSMC phenotypic transition by targeting PGC‐1α expression, providing a novel target for varicose vein therapy.