bluuebunny/crossref_metadata_2025 huggingface dataset:
Explaining European fungal fruiting phenology with climate variability
Authors: Andrew Carrie , Heegaard Einar , Høiland Klaus , Senn‐Irlet Beatrice , Kuyper Thomas W. , Krisai‐Greilhuber Irmgard , Kirk Paul M. , Heilmann‐Clausen Jacob , Gange Alan C. , Egli Simon , Bässler Claus , Büntgen Ulf , Boddy Lynne , Kauserud Håvard
Published: April 2018

Here we assess the impact of geographically dependent (latitude, longitude, and altitude) changes in bioclimatic (temperature, precipitation, and primary productivity) variability on fungal fruiting phenology across Europe. Two main nutritional guilds of fungi, saprotrophic and ectomycorrhizal, were further separated into spring and autumn fruiters. We used a path analysis to investigate how biogeographic patterns in fungal fruiting phenology coincided with seasonal changes in climate and primary production. Across central to northern Europe, mean fruiting varied by approximately 25 d, primarily with latitude. Altitude affected fruiting by up to 30 d, with spring delays and autumnal accelerations. Fruiting was as much explained by the effects of bioclimatic variability as by their large‐scale spatial patterns. Temperature drove fruiting of autumnal ectomycorrhizal and saprotrophic groups as well as spring saprotrophic groups, while primary production and precipitation were major drivers for spring‐fruiting ectomycorrhizal fungi. Species‐specific phenology predictors were not stable, instead deviating from the overall mean. There is significant likelihood that further climatic change, especially in temperature, will impact fungal phenology patterns at large spatial scales. The ecological implications are diverse, potentially affecting food webs (asynchrony), nutrient cycling and the timing of nutrient availability in ecosystems.
Emergent niche structuring leads to increased differences from neutrality in species abundance distributions
Authors: Rael Rosalyn C. , D'Andrea Rafael , Barabás György , Ostling Annette
Published: April 2018

Species abundance distributions must reflect the dynamic processes involved in community assembly, but whether and when specific processes lead to distinguishable signals is not well understood. Biodiversity and species abundances may be shaped by a variety of influences, but particular attention has been paid to competition, which can involve neutral dynamics, where competitor abundances are governed only by demographic stochasticity and immigration, and dynamics driven by trait differences that enable stable coexistence through the formation of niches. Key recent studies of the species abundance patterns of communities with niches employ simple models with pre‐imposed niche structure. These studies suggest that species abundance distributions are insensitive to the relative contributions of niche and neutral processes, especially when diversity is much higher than the number of niches. Here we analyze results from a stochastic population model with competition driven by trait differences. With this model, niche structure emerges as clumps of species that persist along the trait axis, and leads to more substantial differences from neutral species abundance distributions than have been previously shown. We show that heterogeneity in “between‐niche” interaction strength (i.e., in the strength of competition between species in different niches) plays the dominant role in shaping the species abundances along the trait axis, acting as a biotic filter favoring species at the centers of niches. Furthermore, we show that heterogeneity in “within‐niche” interactions (i.e., in the competition between species in the same niche) counteracts the influence of heterogeneity in “between‐niche” interactions on theSADto some degree. Our results suggest that competitive interactions that produce niches can also influence the shapes ofSADs.
Screening and Application of a New Aptamer for the Rapid Detection of Sudan Dye III
Authors: Wang Ying , Li Jie , Qiao Pu , Jing Le , Song Yuzhu , Zhang Jinyang , Chen Qiang , Han Qinqin
Published: April 2018

Sudan dye is generally used as a coloring agent in textile and cosmetic industries. However, Sudan dye exhibits potentials to cause cancer, toxicity, and allergy because of its metabolites including amines and naphthol related substances. Despite banning Sudan dye, the Sudan dye is used by many unscrupulous food manufacturers for enhancing food appearance. This paper introduces a new aptamer based on Sudan III detection methods. An in vitro selection and amplification method named SELEX (Systematic Evolution of Ligands by Exponential Enrichment) is employed to screen out Sudan III specific aptamer. The desired aptamer is obtained after 12 rounds of screening and cloning. To establish aptamer affinity and specificity for Sudan III, ELONA (enzyme‐linked oligonucleotide assay) and dot blot analyses are performed. ELONA assay indicates that 100 nM is the optimum concentration of the aptamer for Sudan III detection, while the minimum detection limit of Sudan III is 4 ng/well. The aptamer exhibits stable secondary structure with the stem‐loop and G‐quadruplex in the main structure. The selected single ssDNA aptamer C07 demonstrates binding affinity and the highest specificity to Sudan III (C07: KD = 22.37 ± 3.943 nmol L−1). Based on the results, a good correlation is observed between aptamer C07 and Sudan III and it is concluded that the new Sudan III specific aptamer has potential to be applied for rapid and accurate detection of the Sudan III in food products.

Practical Applications: Examination of the chili sauce sample in a simulation experiment indicates that the aptamer C07 can be applied to rapid detection in foods. The nucleic acid aptamers‐based food detection method has the advantages of high sensitivity, specificity, easy operation, short detection time, and low cost. It can realize the rapid detection of illegal additives in foods, which has a great significance in the field of food safety research.

The SELEX method is used to select a new Sudan III specific aptamer. ELONA and Dot blot assays further suggest that aptamer C07 can be used for selective detection of Sudan III. Therefore, the detection in chili sauce samples offers feasibility for more complex samples.
Comparison of Various Phosphine Additives in Zeolite Based Catalytic Isomerization of Oleic Acid
Authors: Sarker Majher I. , Moreau Robert A. , Ngo Helen
Published: April 2018

Isostearic acids (ISA) are important bio‐based ingredients for many commercial products such as lubricants, detergents, and cosmetics. This study is targeted to compare the efficacy of various phosphine derivatives in neutralizing the external acidic surface of zeolite which is responsible for the unwanted oligomerization during zeolite based skeletal isomerization reaction producing dimer as byproducts. Sixteen phosphine derivatives were individually evaluated with heat activated ammonium (NH4+) cationic ferrierite zeolite to produce iso‐oleic acid from oleic acid which was converted to ISA through the hydrogenation process. In comparison, eight newly tested phosphine additives were found more effective than the previously reported phosphines (TPP, TPTP) to increase the product yield of iso‐oleic acid, ultimately ISA, either by suppressing the byproducts or accelerating the reaction rate as a whole. The performance depends on the electron donating capacity of central phosphorus atom of phosphine derivative attracting proton from the external surface of zeolite. This phenomenon is resulted from the combination of electronic effects and structural hindrances posed by the different substituents attached to the phosphine derivatives.

The effectiveness of sixteen Lewis base phosphine additives were tested in neutralizing the external acidic surface of zeolite. The neutral outer surface of zeolite is ideal for suppressing dimer formation and thus producing the iso‐oleic acid (precursor of isostearic acid) in high yield through Lewis base‐zeolite combination skeletal isomerization reaction.
Gene transfer of a naked plasmid (pUDK‐HGF) encoding human hepatocyte growth factor attenuates skin/muscle incision and retraction‐induced chronic post‐surgical pain in rats
Authors: Hu C. , Lu Y. , Chen X. , Wu Z. , Zhang Q.
Published: April 2018

Background

Chronic post‐surgical pain (CPSP) remains a major clinical problem and is often refractory to current treatments. New analgesic medications and strategies for pain relief are needed. Hepatocyte growth factor (HGF) is known to be a multi‐functional growth factor and regulates various biological activities.

Methods

We investigated the analgesic effect and underlying mechanism of plasmid pUDK‐HGF encoding human HGF gene on CPSP induced by skin/muscle incision and retraction (SMIR) in rats. The possible changes of inflammatory factors, glial cell activation and pain sensitivity after pUDK‐HGF administration were investigated by ELISA, western blot and Von Frey tests, respectively.

Results

In behavioural assays, we found that a single intramuscular or intrathecal injection of pUDK‐HGF significantly attenuated mechanical hypersensitivity to von Frey stimulation of plantar ipsilateral hind paw after SMIR. Intramuscular injection of pUDK‐HGF promoted blood flow and proliferation of satellite cells and inhibited inflammatory cells recruitment, collagen accumulation and expression of pronociceptive factors. Intrathecal injection of pUDK‐HGF inhibited activation of spinal glial cells and production of inflammatory mediators induced by SMIR.

Conclusions

pUDK‐HGF has a strong analgesic potency and efficacy in CPSP induced by SMIR in rats. This study highlights a new strategy for the treatment of CPSP.

Significance

The CPSP occurs following various surgical procedures and remains a major clinical problem due to the lack of study on the mechanisms of CPSP. Our findings provide the first evidence that pUDK‐HGF attenuates SMIR‐induced pain behaviuors through peripheral or central mechanisms. The peripheral analgesic effect of pUDK‐HGF is associated with promoting tissue repair and inhibiting inflammatory response; furthermore, pUDK‐HGF inhibits activation of spinal glial cells and overexpression of inflammatory mediators in spinal cord. Therefore, naked pUDK‐HGF may be a potential therapeutic strategy for treatment of CPSP in clinic.
Electrochemistry in and of the Fly Brain
Authors: Majdi Soodabeh , Larsson Anna , Hoang Philipsen Mai , Ewing Andrew G.
Published: April 2018

Studying brain function and neuronal communication has been always crucial due to the complexity of these systems. A great deal of technology and model systems have been developed to study this subject. Yet, very small invertebrate systems such as the fruit fly, Drosophila are excellent models and often have better defined and more easily manipulated genetics. This review focuses on in vivo, ex vivo, and in vitro measurements of biogenic amines by electrochemical techniques on the fly nervous system. The methods include capillary electrophoresis, fast scan cyclic voltammetry, and chronoamperometry have been used to study both larval and adult central nervous systems. Better understanding of brain function in model systems should aid in finding solutions to biological and bioanalytical challenges related to human brain function and also neurodegenerative disease.
Gold Nanoparticle‐labeled Electrochemical Immunoassay Using Open Circuit Potential for Human Chorionic Gonadotropin Detection
Authors: Charoenkitamorn Kanokwan , Trong Tue Phan , Chikae Miyuki , Chailapakul Orawon , Takamura Yuzuru
Published: April 2018

This study presents a new approach for an electrochemical immunoassay using gold nanoparticle (AuNP)‐labeled antibodies and pre‐oxidation and reduction processes, followed by open circuit potential (OCP) measurement. Detection of the pregnancy marker, human chorionic gonadotropin hormone (hCG), was used as a model. After preparation of a sandwich‐type immunosystem, the pre‐oxidation and reduction processes were applied, followed by OCP detection. The applied potential and time period were studied for the optimization of pre‐oxidation and reduction processes. We observed that the pre‐oxidation potential of 1.2 V for 60 s and reduction potential of −0.2 V for 30 s provided the highest OCP signal. The detection limit was 79 pg/mL using the optimal conditions. This system could be applied to a simplified and miniaturized diagnostic system for integration in compact analytical devices.
MnO2‐TiO2 Nanocomposite and 2‐(3,4‐Dihydroxyphenethyl) Isoindoline‐1,3‐Dione as an Electrochemical Platform for the Concurrent Determination of Cysteine, Tryptophan and Uric Acid
Authors: Bananezhad Asma , Karimi‐Maleh Hassan , Ganjali Mohammad R. , Norouzi Parviz
Published: April 2018

A novel modified carbon paste electrode (CPE) based on an MnO2‐TiO2 nanocomposite and 2‐(3,4 dihydroxyphenethyl) isoindoline‐1,3‐dione (DPID) as the modifier for the simultaneous analysis of cysteine (Cys), tryptophan (Trp) and uric acid (UA), as three key biochemicals present in human body. The MnO2/TiO2 nanocomposite was synthesized through a chemical co‐precipitation approach and the resulting electrode (MnO2‐TiO2/DPID/CPE) was used for studying the electrochemical oxidation of cysteine (Cys), tryptophan (Trp) and uric acid. As opposed to conventional CPEs, the oxidation peak potential of cysteine on MnO2‐TiO2/DPID/CPE had a 600.0 mV decrease in overpotential and could be observed at 30.0 mV, and the signals were linear from 0.025 to 200.0 μM, and a lower detection limit of 0.013 μM was reached. The MnO2‐TiO2/DPID/CPE was satisfactorily used for the concurrent analysis of Cys, Trp and UA in pharmaceutical and biological samples.
Gold Nanoparticles Decorated Graphene as a High Performance Sensor for Determination of Trace Hydrazine Levels in Water
Authors: Amin Hatem M. A. , El‐Kady Maher F. , Atta Nada F. , Galal Ahmed
Published: April 2018

Electrochemical sensors provide a selective, sensitive and an easy approach to detect hazardous substances such as hydrazine. Herein, we investigate a facile route for the fabrication of a nanostructured composite based on Au nanoparticles (AuNPs) decorated graphene and present its sensing performance towards hydrazine. Our strategy involves electrophoretic deposition (EPD) of graphene oxide (GO) on Au substrate to obtain a uniform layer EPD‐GO, followed by electrochemical reduction of GO to yield high quality graphene ERGO and electrodeposition of monodispersed AuNPs on ERGO (AuNPs/ERGO/Au). The modified AuNPs/ERGO/Au electrode was characterized using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT‐IR) techniques. The sensor exhibited an improved catalytic activity with a peak potential of +87 mV (vs. Ag/AgCl) for hydrazine oxidation. The high performance of this hybrid electrode is due to the presence of a synergistic effect between AuNPs and ERGO at their interface. Insights into the mechanism and kinetics of hydrazine oxidation are withdrawn from varying the voltage scan rate as the reaction is fully irreversible and diffusion‐controlled. The proposed hydrazine sensor showed suitability for nanomolar detection (detection limit of 74 nM), high selectivity in the presence of common ions and efficiency for application in water samples.
Predicting crypto‐currencies using sparse non‐Gaussian state space models
Authors: Hotz‐Behofsits Christian , Huber Florian , Zörner Thomas Otto
Published: April 2018

In this paper we forecast daily returns of crypto‐currencies using a wide variety of different econometric models. To capture salient features commonly observed in financial time series like rapid changes in the conditional variance, non‐normality of the measurement errors and sharply increasing trends, we develop a time‐varying parameter VAR witht‐distributed measurement errors and stochastic volatility. To control for overparametrization, we rely on the Bayesian literature on shrinkage priors, which enables us to shrink coefficients associated with irrelevant predictors and/or perform model specification in a flexible manner. Using around one year of daily data, we perform a real‐time forecasting exercise and investigate whether any of the proposed models is able to outperform the naive random walk benchmark. To assess the economic relevance of the forecasting gains produced by the proposed models we, moreover, run a simple trading exercise.
Tribological analysis of the TBM tool wear in soil from the view of material science
Authors: Küpferle Jakob , Röttger Arne , Theisen Werner , Alber Michael
Published: April 2018

Excessive wear to excavation tools leads to unplanned downtime, which results in additional costs. To predict tool wear during the planning phase of a project, an analysis of the acting tribological system is essential. The different influential factors and interactions have to be considered. The abrasive surface degradation of tools is investigated on a microstructural scale with nano‐scratch experiments. Material‐dependent variables like hard phase content and size are discussed in terms of the resulting wear‐resistance. Using the RUB Tunnelling Device, abrasive surface degradation can be investigated on a more global scale and correlated with the acting tribological system, and the different tribological system components and influential factors can be considered.
Lagerungsdichte von nichtbindigen Böden aus Ramm‐ und Drucksondierungen
Authors: Vrettos Christos , Papamichael Salomi
Published: April 2018

Der Einsatz von Rammsonden zur Abschätzung der Lagerungsdichte von nichtbindigen Böden ist in Deutschland sehr verbreitet. Die zugehörigen empirischen Korrelationen aus der inzwischen zurückgezogenen DIN 4094‐3 wurden teils in die DIN EN 1997‐2 und teils in die DIN 4094‐2 übernommen. Die Abhängigkeit der Schlagzahl von der Tiefe und somit vom Spannungsniveau wird dabei nicht explizit berücksichtigt und es wird lediglich zwischen Situationen über und im Grundwasser unterschieden. Der Einfluss des Überlagerungsdrucks wird auch bei den Drucksondierungen nicht berücksichtigt. Bedingt durch die verfeinerte Instrumentierung und die damit verbundene Möglichkeit einer differenzierteren Charakterisierung des Baugrunds gewinnen Drucksondierungen zunehmend an Bedeutung, so dass für diesen Sondierungstyp der Fundus von Korrelationen in der internationalen Fachliteratur groß ist. Im Rahmen einer Vergleichsuntersuchung werden die Anwendungsgrenzen und die Zuverlässigkeit der in den Regelwerken vorgeschlagenen empirischen Beziehungen kritisch bewertet und durch neue Ansätze erweitert. Besonderes Augenmerk wird dabei auf Korrelationen zwischen den Ergebnissen der beiden Sondierungstypen gelegt.
Fluid inclusion and isotope characteristics of the Xishanwanyangchang silver polymetallic deposit, Inner Mongolia, China
Authors: Kang Ming , Yuan Ye , Yue Changcheng , Gao Chao
Published: April 2018

The Xishanwanyangchang silver polymetallic deposit is located in Inner Mongolia. The upper part is a silver orebody, and the lower part is a lead–zinc orebody. The Xishanwanyangchang deposit is related to Mesozoic volcanic hydrothermal activity, and the hydrothermal ore‐forming process of the deposit includes 3 stages, that is, the early, middle, and late stages. The early lead–zinc mineralization stage is marked by quartz–pyrite–galena–sphalerite, with salinities of 0.88 to 13.94 wt% NaCl equivalent and homogenization temperatures of greater than 330°C. Fluid inclusions are mainly composed of gas–liquid two‐phase aqueous solutions, characterized by high‐temperature and low‐salinity fluid. The middle mineralization stage is marked by quartz‐polymetallic sulphide minerals, with salinities of 0.35 to 31.90 wt% NaCl equivalent and homogenization temperatures of 250°C to 330°C. Inclusions are characterized by coexistence of low‐salinity aqueous inclusions and high‐salinity multiphase inclusions containing daughter minerals. The late mineralization stage is marked by quartz–carbonate, with salinities of 0.71 to 32.66 wt% NaCl equivalent and homogenization temperatures of 169°C to 250°C. Inclusions are characterized by coexistence of low‐salinity aqueous solution inclusions and high‐salinity inclusions, containing halite daughter minerals. The δ34S values of sulphides range from 4.0‰ to 6.1‰, and the 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204 ratios range from 16.641 to 16.798, 15.366 to 15.590, and 36.972 to 37.696, respectively, showing that ore‐forming materials were mainly from deep‐source magmas, and fluid mixing may be the main ore‐forming mechanism. The deposit formed through mixing of metal‐bearing high‐salinity fluid and cold groundwater at the ore precipitation site, followed by precipitation and enrichment of metals.
Spatial interrelationship of landslides, litho‐tectonics, and climate regime, Satluj valley, Northwest Himalaya
Authors: Kumar Vipin , Gupta Vikram , Sundriyal Y.P.
Published: April 2018

Landslides have been considered widely as principal mass wasting agents in the valleys experiencing varied influence of tectonics and climate. However, pattern of landslides is rarely addressed in the literature that may act as a surface manifestation of interrelationship of tectonics, climate, and lithology. Here, we have attempted to understand such interrelationship in the context of landslide distribution pattern in the Satluj valley, Northwest Himalaya. Geomorphic indices such as steepness index, valley floor width to valley height ratio, and topographic swath profile were used for tectonic inference. Daily rainfall data of the year 2000–2016, using 5 rain‐gauge stations and swath profile of Normalized Difference Vegetation Index, were used to deduce spatial variability of climate. Influence of lithological variability and regional faults; Sangla Detachment, Main Central Thrust, and Munsiari Thrust on the landslide distribution are also inferred. A total of 55 landslides (20 rock avalanche, 19 debris slides, and 16 rockfalls) are found to exist in 6 clusters along 130 km stretch of the Satluj valley. These landslides, covering a total area (A) and volume (V) of 1.05 × 107 m2 and 4.4 × 107 m3, respectively, are also noted to follow a power law (R2 = 0.8) and result in a scaling relationship of V = (0.180)A1.208.
Detrital zircon U–Pb–Hf isotopes study of the Lower Carboniferous Anjihai Formation from the northern margin of the Yili Block, NW China
Authors: Wang Meng , Zhang Jinjiang , Pei Xianzhi , Zhang Bo , Chen Youxin , Xiao Zhibin , Zheng Yanrong
Published: April 2018

The North Tianshan Accretionary Complex represents a Late Palaeozoic suture between the Junggar Terrane and the Yili Block. We report detrital zircon U–Pb dating and Hf isotope results for a sandstone from the Lower Carboniferous Anjihai Formation in the northern margin of the Yili Block, to reveal the geochronological framework of the northern Yili Block, and discuss the subduction process of the North Tianshan Ocean (NTO). The detrital zircon ages were divided into 2 clusters, namely, the Precambrian and Palaeozoic ones. The Palaeozoic age group can be further divided into 3 subgroups, that is, 472–461 Ma, 448–423 Ma, and 406–335 Ma, with peaks at 465, 436, and 346 Ma, respectively. All the Palaeozoic zircons have oscillatory zoning textures and high Th/U ratios, showing an igneous provenance. The zircon Ti‐temperatures are between 584 and 809 °C, suggesting that their source rocks were I‐ or S‐type granitic rocks. In addition, most of the Palaeozoic zircons have positive εHf(t) values, indicating that the source rocks of the Palaeozoic zircons are derived from not only Mesoproterozoic continental crust but also involved depleted mantle components, which matched well with the Hf isotopic signatures of magmatic rocks from the northern Yili Block. Based on the regional geology, these zircons were thought to be sourced from magmatic rocks that were related to the subduction of the NTO. Taking into consideration the Middle–Late Ordovician arc‐type granitoids in the Wenquan area, we conclude that the northern margin of the Yili Block was a unified active continental margin in the Palaeozoic, and the subduction of the NTO started at least from the Middle Ordovician.
Neuroplasticity and network connectivity of the motor cortex following stroke: A transcranial direct current stimulation study
Authors: Hordacre Brenton , Moezzi Bahar , Ridding Michael C.
Published: April 2018

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that has potential for clinical utility in neurorehabilitation. However, recent evidence indicates that the responses to tDCS are highly variable. This study investigated whether electroencephalographic (EEG) measures of functional connectivity of the target network were associated with the response to ipsilesional anodal tDCS in stroke survivors. Ten chronic stroke patients attended two experimental sessions in a randomized cross‐over trial and received anodal or sham tDCS. Single‐pulse transcranial magnetic stimulation was used to quantify change in corticospinal excitability following tDCS. At the beginning of each session, functional connectivity was estimated using the debiased‐weighted phase lag index from EEG recordings at rest. Magnetic resonance imaging identified lesion location and lesion volume. Partial least squares regression identified models of connectivity which maximally accounted for variance in anodal tDCS responses. Stronger connectivity of a network with a seed approximating the stimulated ipsilesional motor cortex, and clusters of electrodes approximating the ipsilesional parietal cortex and contralesional frontotemporal cortex in the alpha band (8–13 Hz) was strongly associated with a greater increase of corticospinal excitability following anodal tDCS. This association was not observed following sham stimulation. Addition of a structural measure(s) of injury (lesion volume) provided an improved model fit for connectivity between the seed electrode and ipsilesional parietal cortex, but not the contralesional frontotemporal cortex. TDCS has potential to greatly assist stroke rehabilitation and functional connectivity appears a robust and specific biomarker of response which may assist clinical translation of this therapy.
Mechanosensitive Oligodithienothiophenes: Transmembrane Anion Transport Along Chalcogen‐Bonding Cascades
Authors: Macchione Mariano , Tsemperouli Maria , Goujon Antoine , Mallia Ajith R. , Sakai Naomi , Sugihara Kaori , Matile Stefan
Published: April 2018

The design, synthesis, and evaluation of multifunctional dithieno[3,2‐b;2′,3′‐d]thiophene (DTT) trimers is described. Twisted push‐push‐pull or donor‐donor‐acceptor (DDA) trimers composed of one DTT acceptor and two DTT donors show strong mechanochromism in lipid bilayer membranes. Red shifts in excitation rather than emission and fluorescence recovery with increasing membrane order are consistent with planarization of the twisted, extra‐long mechanophores in the ground state. The complementary pull‐pull‐pull or AAA trimers with deep σ holes all along the scaffold are not mechanochromic in membranes but excel with submicromolar anion transport activity. Anion transport along membrane‐spanning strings of chalcogen‐bond donors is unprecedented and completes previous results on transmembrane cascades that operate with equally unorthodox interactions such as halogen bonds and anion‐π interactions.
Gold‐Catalyzed Migration of Propargyl Acetate as an Entry into the Total Synthesis of Natural Products
Authors: Mouriès‐Mansuy Virginie , Fensterbank Louis
Published: April 2018

Gold catalysis has emerged over the last two decades as a protocole of choice for the efficient and selective activation of a variety of organic functional groups. This has served to the total synthesis of natural products at several occasions. In this context, the gold‐catalyzed migration (1,2‐ or 1,3‐) of propargyl acetates has been particularly used. This review highlights these different synthetic developments which are presented according to the involved mechanisms.
Joint tagging assisted fluctuation nanoscopy enables fast high‐density super‐resolution imaging
Authors: Zeng Zhiping , Ma Jing , Xi Peng , Xu Canhua
Published: April 2018

In fluctuation‐based optical nanoscopy, investigating high‐density labeled subcellular structures with high fidelity has been a significant challenge. In this study, based on super‐resolution radial fluctuation (SRRF) microscopy, the joint tagging (JT) strategy is employed to enable fast high‐density nanoscopic imaging and tracking. In fixed cell experiment, multiple types of quantum dots with distinguishable fluorescence spectra are jointly tagged to subcellular microtubules. In each spectral channel, the decrease in labeling density guarantees the high‐fidelity super‐resolution reconstruction using SRRF microscopy. Subsequently, the combination of all spectral channels achieves high‐density super‐resolution imaging of subcellular microtubules with a resolution of ~62 nm using JT assisted SRRF technique. In the live‐cell experiment, 3‐channel JT is utilized to track the dynamic motions of high‐density toxin‐induced lipid clusters for 1 minute, achieving the simultaneous tracking of many individual toxin‐induced lipid clusters spatially distributed significantly below the optical diffraction limit in living cells.
The sensing mechanism of fluoride anion for a novel molecule D2: Desilylation and intramolecular charge transfer
Authors: Jia Min , Yang Guang , Guo Yuanyuan , Song Xiaoyan , Zhang Qiaoli , Yang Dapeng
Published: April 2018

In this work, the sensing mechanism of a new fluoride chemosensor 12‐([tert‐butyldiphenylsilyl]oxy)‐8a,13a‐dihydro‐7H‐benzo[de]benzo[4,5]imidazo[2,1‐a]‐isoquinolin‐7‐one (abbreviated as D2) is investigated using density functional theory (DFT) and time‐dependent DFT (TDDFT) methods. The theoretical electronic spectra (vertical excitation energies and fluorescence peak) reproduced previous experimental results (D. Li et al., Spectrochim. Acta A Mol. Biomol. Spectrosc. 2017, 185, 173), which confirms the rationality of the theoretical level used in this work. The constructed potential energy curve of the desilylation process suggests that the low barrier could be responsible for the rapid response to fluoride anions. Analyses of the binding energies show that only fluoride anion can be detected by D2 chemosensor in dimethylsulfoxide (DMSO). In view of the excitation process, the strong intramolecular charge transfer (ICT) process of the S0 → S1 transition explains the red shift of the absorption peak of the D2 sensor with the addition of fluoride anions. This work not only presents a straightforward sensing mechanism of sensing of the fluoride anion by the D2 chemosensor but should also play an important role in the synthesis and design of fluorescent sensors in future.
A randomized trial of adjunct testosterone for cancer‐related muscle loss in men and women
Authors: Wright Traver J. , Dillon E. Lichar , Durham William J. , Chamberlain Albert , Randolph Kathleen M. , Danesi Christopher , Horstman Astrid M. , Gilkison Charles R. , Willis Maurice , Richardson Gwyn , Hatch Sandra S. , Jupiter Daniel C. , McCammon Susan , Urban Randall J. , Sheffield‐Moore Melinda
Published: April 2018

Background

Cancer cachexia negatively impacts cancer‐related treatment options, quality of life, morbidity, and mortality, yet no established therapies exist. We investigated the anabolic properties of testosterone to limit the loss of body mass in late stage cancer patients undergoing standard of care cancer treatment.

Methods

A randomized, double‐blind, placebo‐controlled phase II clinical trial was undertaken to assess the potential therapeutic role of adjunct testosterone to limit loss of body mass in patients with squamous cell carcinoma of the cervix or head and neck undergoing standard of care treatment including chemotherapy and chemoradiation. Patients were randomly assigned in blocks to receive weekly injections of either 100 mg testosterone enanthate or placebo for 7 weeks. The primary outcome was per cent change in lean body mass, and secondary outcomes included assessment of quality of life, tests of physical performance, muscle strength, daily activity levels, resting energy expenditure, nutritional intake, and overall survival.

Results

A total of 28 patients were enrolled, 22 patients were studied to completion, and 21 patients were included in the final analysis (12 placebo, nine testosterone). Adjunct testosterone increased lean body mass by 3.2% (95% confidence interval [CI], 0–7%) whereas those receiving placebo lost 3.3% (95% CI, −7% to 1%, P = 0.015). Although testosterone patients maintained more favourable body condition, sustained daily activity levels, and showed meaningful improvements in quality of life and physical performance, overall survival was similar in both treatment groups.

Conclusions

In patients with advanced cancer undergoing the early phase of standard of care therapy, adjunct testosterone improved lean body mass and was also associated with increased quality of life, and physical activity compared with placebo.
Healthy community‐living older men differ from women in associations between myostatin levels and skeletal muscle mass
Authors: Peng Li‐Ning , Lee Wei‐Ju , Liu Li‐Kuo , Lin Ming‐Hsien , Chen Liang‐Kung
Published: April 2018

Background

Myostatin is a negative regulator of muscle growth but the relationship between serum myostatin levels and muscle mass is unclear. This study investigated the association between serum myostatin levels and skeletal muscle mass among healthy older community residents in Taiwan, to evaluate the potential of serum myostatin as a biomarker for diagnosing sarcopenia and/or evaluating the effect of its treatment.

Methods

Study data were excerpted from a random subsample of the I‐Lan Longitudinal Aging Study population. Serum myostatin levels were determined and categorized into tertiles (low, medium, high). Relative appendicular skeletal muscle mass (RASM) was calculated as appendicular lean body mass by dual‐energy X‐ray absorptiometry divided by height squared (kg/m2). Low muscle mass was defined as recommended by the Asian Working Group for Sarcopenia.

Results

The analytic study sample comprised 463 adults (mean age: 69.1 years; 49.5% men). Compared with subjects with normal RASM, those with lower RASM were older and frailer, with significantly higher prevalence of malnutrition, lower serum dehydroepiandrosterone (DHEA) levels, and were more likely to have low serum myostatin status. Multivariable logistic regression analysis showed that male sex (OR 3.60, 95% CI 1.30–9.92), malnutrition (OR 4.39, 95% CI 1.56–12.36), DHEA (OR 0.99, 95% CI 0.99–1.00), and low myostatin (OR 3.23, 95% CI 1.49–7.01) were all independent risk factors for low RASM (all P < 0.05). In men, DHEA (OR 0.99, 95% CI 0.98–1.00) and low myostatin (OR 4.89, 95% CI 1.79–13.37) were significantly associated with low RASM (both P < 0.05); however, only malnutrition was associated with low RASM in women (OR 13.59, 95% CI 2.22–83.25, P < 0.05).

Conclusions

Among healthy community‐living older adults, low serum myostatin levels were associated with low skeletal muscle mass in men, but not in women. Our results do not support using serum myostatin levels to diagnose sarcopenia, or to monitor how it responds to treatments. Further research is needed to understand why men apparently differ from women in the interrelationship between their myostatin levels and muscle mass.
Preparation of 5‐(Aminomethyl)‐2‐furanmethanol by direct reductive amination of 5‐Hydroxymethylfurfural with aqueous ammonia over the Ni/SBA‐15 catalyst
Authors: Chen Wei , Sun Yong , Du Juan , Si Zhihao , Tang Xing , Zeng Xianhai , Lin Lu , Liu Shijie , Lei Tingzhou
Published: April 2018

BACKGROUND

5‐(Aminomethyl)‐2‐furanmethanol (AMF), used widely in medicinal chemistry, is usually synthesized by the reductive amination of furfural or 5‐hydroxymethylfurfural (HMF) with ammonia. However, a challenging task when synthesizing this furyl primary amine is to enhance the selectivity of the product due to its high nucleophilicity. Conventional measures have used excessive liquid ammonia and precious metal catalysts. Usually, the molar ratio of ammonia to substrate is up to 30:1. This study employed aqueous ammonia to synthesize AMF by the direct reductive amination of HMF using the non‐noble metal Ni/SBA‐15 catalyst.

RESULTS

The Ni/SBA‐15 catalyst displayed higher catalytic selectivity in the reductive amination of HMF to AMF compared to other precious metal catalysts, such as Ru/C, Pd/C and Pt/C. The AMF yield of 89.8% was obtained at the relatively mild reaction temperature of 100 °C for 4 h. After the fifth cycle, an acceptable decrease in catalytic activity with 74.2% yield of AMF was observed.

CONCLUSION

An improved process was developed for preparing AMF by the reductive amination of HMF with aqueous ammonia using the non‐noble Ni/SBA‐15 catalyst. The high selectivity of nickel catalyst is attributed mainly to the moderate catalytic activity. Moreover, a small amount of water enhanced the yield of AMF by promoting the formation of ammonium ions to prevent the further side reaction of AMF with HMF. Results of recycling experiments and analyses showed that agglomeration, loss and oxidization of nickel species together with carbon deposition were responsible for the slight deactivation of the catalyst. © 2018 Society of Chemical Industry
Enhanced bioconversion of L‐phenylalanine into 2‐phenylethanol via an oxygen control strategy and in situ product recovery
Authors: Shu Chin‐Hang , Chen Yi‐Jun , Nirwana Wa Ode Cakra , Cahyani Chandrawati
Published: April 2018

BACKGROUND

2‐Phenylethanol (PEA) production through bioconversion of L‐phenylalanine (L‐Phe) has been gaining increasing global interest in recent years. Studies have been conducted on the bioconversion of L‐Phe into PEA using Saccharomyces cerevisiae. However, the influence of oxygen supply on the bioconversion has not been investigated thus far. In this research, we have attempted not only to explore the effects of oxygen on bioconversion of L‐Phe, but also to develop strategies to enhance PEA production.

RESULTS

Experimental results indicated that two‐stage batch fermentation with oxygen supply control showed optimal operation for culture. The employment of a semi‐continuous culture enhanced total PEA by 35.53% more in comparison to batch culture. In situ product recovery (ISPR) using polydimethylsiloxane (PDMS) sponge reduced the ethanol and PEA in the broth by approximately 4.2 and 0.50 g L−1 for each operation, respectively. However, semi‐continuous culture with ISPR failed to enhance total PEA because high glucose concentration and low oxygen supply triggered ethanol production. Based on these results, a novel three‐stage ISPR fermentation by oxygen supply control was designed to maximize PEA production and minimize both the product feedback inhibition and ethanol formation. As a result, the total PEA concentration at 5.14 g L−1 was achieved.

CONCLUSION

We propose that a multi‐stage fermentation strategy with both oxygen control and ISPR can be employed to enhance PEA formation by S. cerevisiae. © 2018 Society of Chemical Industry
Role of non‐ion surfactants in three‐dimensional ordered porous biomass carbon foam derived from the liquefied eucalyptus sawdust for metronidazole adsorption
Authors: Hua Zulin , Wan Shungang , Sun Lei , Yu Zebin , Bai Xue
Published: April 2018

BACKGROUND

Three‐dimensional ordered honeycomb‐like structured biomass carbon foams (BCFs) were prepared from eucalyptus sawdust using polyethylene glycol 2000 (PEG), Pluronic® P‐123 and Pluronic® F‐127 as structure‐directing agents. The effect of different surfactants on the morphology and pore structure of BCFs, and the adsorption performance and mechanisms of metronidazole onto BCFs was clarified.

RESULTS

The physicochemical characteristics of BCFs depend on the surfactant molecular structure. The adsorption process of metronidazole was spontaneous and endothermic in nature and followed a pseudo‐second‐order kinetic model. Metronidazole adsorption onto BCF‐PEG and BCF‐F127 followed the Langmuir isotherm, whereas that onto BCF‐P123 followed the Freundlich isotherm. The maximum adsorption capacities for BCF‐PEG, BCF‐P123 and BCF‐F127 were 56.40, 67.52 and 42.92 mg g−1, respectively. The adsorption mechanisms of metronidazole onto BCF‐PEG and BCF‐P123 were mainly hydrogen bonding, π‐π interactions and pore filling. Hydrogen bonding and π–π interactions were mainly responsible for adsorption of metronidazole onto BCF‐F127.

CONCLUSION

All results demonstrated that types of surfactant significantly affected the BCFs' physicochemical properties, and played an important role in controlling the adsorption characteristics of metronidazole onto BCFs. In addition, shaped BCF can be utilized as an effective, easily recovered and promising adsorbent for the removal of pollutants in wastewater. © 2018 Society of Chemical Industry
An evaluation of a visual–visual successive matching‐to‐sample procedure to establish equivalence classes in adults
Authors: Lantaya Charisse A. , Miguel Caio F. , Howland Timothy G. , LaFrance Danielle L. , Page Scott V.
Published: April 2018

Traditionally, behavior analysts have studied stimulus equivalence using a matching‐to‐sample (MTS) preparation. Although researchers have shown the utility of MTS to yield equivalence classes, the procedure requires several prerequisite skills for a learner to accurately respond. Previous research with humans and nonhumans has shown that relational responding can be produced via compound stimulus discrimination and successive matching‐to‐sample (S‐MTS). We conducted four experiments with college students to further evaluate the effectiveness of S‐MTS in the establishment of stimulus relations. S‐MTS trials consisted of the presentation of a single sample stimulus followed by one comparison in a fixed location on a computer screen. Depending upon the sample–comparison relation, participants touched (i.e., go) or did not touch (i.e., no‐go) the comparison stimulus. Following training of the baseline relations (AB/BC), we assessed the emergence of symmetry, transitivity, and equivalence performances (i.e., BA/CB and AC/CA). Results support the utility of the S‐MTS procedure as a possible alternative to traditional MTS. This study has direct implications for participants for whom traditional three‐array MTS procedures may be challenging.
Screening for intellectual disability in Dutch police suspects
Authors: Geijsen Koen , Kop Nicolien , de Ruiter Corine
Published: April 2018

The screener for mild intellectual disability (SCIL) was developed to screen for mild intellectual disability (IQ below 85). The aims of this study were (a) to examine the predictive validity of the SCIL in screening for intellectual disability among police suspects and (b) to explore the prevalence of cognitive intellectual disability among suspects in police custody in the Netherlands. An unselected sample of police suspects (N = 178) charged with a variety of offences was assessed with the SCIL, a Wechsler Adult Intelligence Scale (WAIS)‐III‐NL short form, and a malingering measure. The SCIL screened 50.0% of the sample as having mild intellectual disabilities, whereas the short WAIS classified 84.3% of the sample with an IQ below 85. A principal component analysis of the SCIL showed ambiguous results. Furthermore, the short WAIS classified 55.6% of our sample with a borderline IQ (IQ = 70–84), 84.3% with an IQ below 85 and 28.7% with an IQ below 70. The prevalence of intellectual disability in this sample of Dutch (police) suspects appears to be higher than prevalence rates found in previous international studies. More exhaustive research is needed to examine the prevalence of intellectual disabilities in police suspects, and the utility of the SCIL to screen for these disabilities.
Reducing tunnel vision with a pen‐and‐paper tool for the weighting of criminal evidence
Authors: Rassin Eric
Published: April 2018

In order to prevent tunnel vision, and ultimately miscarriages of justice, police, prosecutors, and judges must remain open to alternative scenarios in which the suspect is in fact innocent. However, it is not evident from the literature that people are sufficiently aware of how alternative scenarios should be employed in the decision‐making process. In the present research, participants read a case vignette and formed an impression of the suspect's guilt. Some participants were made familiar with an alternative scenario. Others were not only presented with an alternative scenario but were also instructed to score (with pen and paper) the extent to which every piece of evidence fitted in the primary and the alternative scenario. Findings suggest that this pen‐and‐paper task helped to reduce tunnel vision.
miR-181c-BRK1 axis plays a key role in actin cytoskeleton-dependent T cell function
Authors: Lim Shok Ping , Ioannou Nikolaos , Ramsay Alan G , Darling David , Gäken Joop , Mufti Ghulam J
Published: April 2018

MicroRNAs are short endogenous noncoding RNAs that play pivotal roles in a diverse range of cellular processes. The miR-181 family is important in T cell development, proliferation, and activation. In this study, we have identified BRK1 as a potential target of miR-181c using a dual selection functional assay and have showed that miR-181c regulates BRK1 by translational inhibition. Given the importance of miR-181 in T cell function and the potential role of BRK1 in the involvement of WAVE2 complex and actin polymerization in T cells, we therefore investigated the influence of miR-181c-BRK1 axis in T cell function. Stimulation of PBMC derived CD3+ T cells resulted in reduced miR-181c expression and up-regulation of BRK1 protein expression, suggesting that miR-181c-BRK1 axis is important in T cell activation. We further showed that overexpression of miR-181c or suppression of BRK1 resulted in inhibition of T cell activation and actin polymerization coupled with defective lamellipodia generation and immunological synapse formation. Additionally, we found that BRK1 silencing led to reduced expressions of other proteins in the WAVE2 complex, suggesting that the impairment of T cell actin dynamics was a result of the instability of the WAVE2 complex following BRK1 depletion. Collectively, we demonstrated that miR-181c reduces BRK1 protein expression level and highlighted the important role of miR-181c-BRK1 axis in T cell activation and actin polymerization-mediated T cell functions.
The binding interaction between cadmium‐based, aqueous‐phase quantum dots with Candida rugosa lipase
Authors: Zhao Lining , Hu Shimeng , Meng Qiwei , Xu Mengchen , Zhang Hao , Liu Rutao
Published: April 2018

As a promising biolabeling biomaterials, quantum dots (QDs) present a great potential. However, the toxicity of QDs to organisms has attracted wide attention. In our research, we introduced an in vitro method to study the molecular mechanisms for the structure and activity alterations of Candida rugosa lipase (CRL) with the binding of 3‐mercaptopropionic acid‐capped CdTe QDs. Multiple spectroscopic methods, isothermal titration calorimetry, and enzyme activity measurements were used in this paper. QDs statically quenched the intrinsic fluorescence of CRL with the quenching constant decreases from 2.46 × 1013 to 1.64 × 1013 L mol−1 second−1 (298 to 310 K). It binds to CRL through hydrophobic force with 1 binding site, unfolding and loosening the skeleton and changed its secondary structure. Rather than aggregating on the surface, it enters the pocket of the CRL to interact with Ser‐209 (2.43 Å) and the residues surrounding Ser‐209, making the catalytic triad more exposed. Furthermore, the activity of CRL was inhibited by approximately 15%. This work demonstrates that 3‐mercaptopropionic acid‐capped CdTe QDs may cause negative effects to CRL and obtains a molecular mechanism on QD‐induced toxicity to proteins in vitro.