bluuebunny/crossref_metadata_2025_split huggingface dataset:
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 StudyMaca (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.MethodsRNA‐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.ResultsTrinity 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.DiscussionThe 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.
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

AbstractWe 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

AbstractThe 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

AbstractTo 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

AbstractAqueous 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

AbstractThis 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

AbstractInvited 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

AbstractDirectional 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

AbstractThis 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

AbstractThe 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.
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

AbstractArsenene, 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

AbstractPrescribed 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

AbstractForest 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.
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

AbstractExtracellular 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

AbstractUnprecedented 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

AbstractAlthough 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.
Vitamin E: Mechanism of transport and regulation in the CNS
Authors: Lee Paris , Ulatowski Lynn M. 
Published: December 2018

AbstractAlthough 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