bluuebunny/crossref_metadata_2025_split huggingface dataset:
[2+2+2]‐Cyclotrimerization of 1‐Cyclopropyl‐1,6‐diynes with Alkynes: Formation of Cyclopropylarenes.
Authors: Matoušová Eliška , Gyepes Robert , Císařová Ivana , Kotora Martin 
Published: January 2016

AbstractCyclotrimerization of 1‐cyclopropyl‐1,6‐diynes with various terminal alkynes was tested under catalytic conditions using rhodium and ruthenium catalysts. We observed that the regioselectivity of the reaction, that is, formation of 1,2‐ or 1,3‐regioisomers, was opposite for the two metals. For the ruthenium complex [Cp*Ru(cod)Cl]‐catalyzed reactions the yields were in many cases high with a strong preference for the formation of 1,3‐substituted regioisomers. In the case of catalysis by the rhodium complex [RhCl(PPh3)3], 1,2‐substituted products were generally preferred, albeit the selectivity was often modest. However, by changing the ligand environment around the central rhodium atom the regioselectivity as well as yields of the products were significantly improved. For example, by using a combination of the rhodium complex [Rh(cod)2BF4] and 1,4‐bis(diphenylphosphino)butane the regioselectivity was changed from 1:1 to 1:12 in favor of the 1,2‐regioisomer. This catalytic system was also applied for synthesis of a substituted 4‐cyclopropyl‐3‐hydroisobenzofuran‐1‐one that could serve as a potential intermediate for preparation of antihypertensive agents.magnified image
Glochidial infestation by the endangered mollusc Unio crassus in rivers of north‐eastern France: Phoxinus phoxinus and Cottus gobio as primary fish hosts
Authors: Lamand Florent , Roche Kevin , Beisel Jean‐Nicolas 
Published: January 2016

Abstract

The thick‐shelled river mussel Unio crassus is an endangered freshwater bivalve species with a life cycle that includes an obligate glochidial larval stage that attaches to the gills of freshwater fish for several days to months.
Fish hosts were identified in nine north‐eastern French rivers in order to improve unionid conservation management.
Eurasian minnow Phoxinus phoxinus was the most important host at all study sites, with prevalence ranging from 15–100% (122 of 238 individuals infested), and bullhead Cottus gobio usually the second most important (prevalence 0–73%; 37 of 121). Other host species had a relatively low rate of infestation: chub Squalius cephalus (5 of 41), roach Rutilus rutilus (1 of 23), gudgeon Gobio gobio (2 of 50), stone loach Barbatula barbatula (2 of 58) and dace Leuciscus leuciscus (1 of 19). No glochidia were found on spirlin Alburnoides bipunctatus (0 of 24).
Parasitic load usually ranged between one and three per fish (60% of cases), and rarely exceeded 10. First results suggest that U. crassus glochidia influence the weight:length ratio of P. phoxinus but not C. gobio, with infested fish being heavier.
To date, the ecological function of P. phoxinus (and C. gobio) in small streams has been largely underestimated or ignored as the species is small, common and of no interest to anglers. There is increasing evidence, however, that P. phoxinus deserves conservation management owing to the essential role it plays in the reproduction, development and distribution of U. crassus.
Copyright © 2016 John Wiley & Sons, Ltd.
Robust Finite‐Time Control for Linear Time‐Varying Delay Systems With Bounded Control
Authors: Niamsup P. , Phat V. N. 
Published: January 2016

AbstractThis paper develops a novel finite‐time control design for linear systems subject to time‐varying delay and bounded control. Based on the Lyapunov‐like functional method and using a result on bounding estimation of integral inequality, we provide some sufficient conditions for designing state feedback controllers that guarantee the robust finite‐time stabilization with guaranteed cost control. The conditions are obtained in terms of linear matrix inequalities (LMIs), which can be determined by utilizing the MATLAB LMI Control Toolbox. A numerical example is given to show the effectiveness of the proposed method.
An undergraduate laboratory activity on molecular dynamics simulations
Authors: Spitznagel Benjamin , Pritchett Paige R. , Messina Troy C. , Goadrich Mark , Rodriguez Juan 
Published: January 2016

AbstractVision and Change [AAAS, 2011] outlines a blueprint for modernizing biology education by addressing conceptual understanding of key concepts, such as the relationship between structure and function. The document also highlights skills necessary for student success in 21st century Biology, such as the use of modeling and simulation. Here we describe a laboratory activity that allows students to investigate the dynamic nature of protein structure and function through the use of a modeling technique known as molecular dynamics (MD). The activity takes place over two lab periods that are 3 hr each. The first lab period unpacks the basic approach behind MD simulations, beginning with the kinematic equations that all bioscience students learn in an introductory physics course. During this period students are taught rudimentary programming skills in Python while guided through simple modeling exercises that lead up to the simulation of the motion of a single atom. In the second lab period students extend concepts learned in the first period to develop skills in the use of expert MD software. Here students simulate and analyze changes in protein conformation resulting from temperature change, solvation, and phosphorylation. The article will describe how these activities can be carried out using free software packages, including Abalone and VMD/NAMD. © 2016 by The International Union of Biochemistry and Molecular Biology, 44:130–139, 2016.
Online Pyrophosphate Assay for Analyzing Adenylation Domains of Nonribosomal Peptide Synthetases
Authors: Kittilä Tiia , Schoppet Melanie , Cryle Max J. 
Published: January 2016

AbstractNonribosomal peptide synthetases (NRPSs) produce many important and structurally complex natural products. Because of their architectures, reprogramming NRPSs has long been attempted to access new bioactive compounds. However, detailed characterization of NRPS catalysis and substrate selectivity by adenylation (A) domains is needed to support such efforts. We present a simple coupled NADH/pyrophosphate (PPi ) detection assay for analyzing A domain catalysis in vitro. PPi formation is coupled to the consumption of NADH by four enzymatic steps and is detected spectroscopically (λ=340 nm) for simple analysis. We demonstrate the effectiveness of this assay with several adenylation domains, including a stand‐alone A domain (DltA, cell wall biosynthesis) and an embedded A domain (Tcp10, teicoplanin biosynthesis). Substrate acceptance of the Tcp10 A domain was explored for the first time, thus demonstrating the applicability of the assay for complex, multi‐domain NRPSs.
Metal‐Free Dehydrogenation of Amine‐Boranes by Tunable N‐Heterocyclic Iminoboranes
Authors: Lui Melanie W. , Paisley Nathan R. , McDonald Robert , Ferguson Michael J. , Rivard Eric 
Published: January 2016

AbstractWe report the synthesis of structurally tunable boron complexes supported by N‐heterocyclic imine ligands IPr=N−BR2 (IPr=[(HCNDipp)2C], Dipp=2,6‐iPr2C6H3, R=Cl and/or Ph) that have the ability to abstract dihydrogen from amine‐boranes, and instigate their dehydrocoupling. In one instance, mild heating of the hydrogen addition product IPr=NH−B(Ph)HCl releases H2 to regenerate the starting N‐heterocyclic iminoborane; accordingly IPr=N−B(Ph)Cl can be used as a metal‐free catalyst to promote the dehydrocoupling of MeNH2⋅BH3 to yield N‐methylaminoborane oligomers [MeNH‐BH2]x.
A Puckered Singlet Cyclopentane‐1,3‐diyl: Detection of the Third Isomer in Homolysis
Authors: Ye Jianhuai , Hatano Sayaka , Abe Manabu , Kishi Ryohei , Murata Yusuke , Nakano Masayoshi , Adam Waldemar 
Published: January 2016

AbstractIn the photochemical denitrogenation of 1,4‐diaryl‐2,3‐diazabicyclo[2.2.1]heptane (AZ6) bearing sterically hindered substituents, a curious new absorption band at about 450 nm was observed under low‐temperature matrix conditions, together with the previously well‐characterized planar singlet diradical pl‐1DR6 with λmax=≈580 nm. The 450 nm species was electron paramagnetic resonance (EPR)‐silent. Instead of generating the planar diradical pl‐1DR6 and the precursor azoalkane AZ6 upon warming, the ring‐closed bicyclo[2.1.0]pentane derivative SB6, that is, the AZ6 denitrogenation product was identified. Based on product analysis, low‐temperature spectroscopic observations, high‐level quantum‐mechanical computations, viscosity effect, and laser‐flash photolysis, the puckered singlet diradicaloid puc‐1DR6 was assigned to the new 450 nm absorption. The latter was detected experimentally at the same time as the planar singlet diradical pl‐1DR6. Sterically demanding substituents as well as viscosity impediments were essential for the detection of the experimentally hitherto unknown puckered singlet cyclopentane‐1,3‐diyl diradicaloid puc‐1DR6, that is, the third isomer in homolysis. The present findings should stimulate future work on the mechanistically fascinating stereoselectivity documented in the formation of bicyclo[2.1.0]pentanes during the 2,3‐diazabicyclo[2.2.1]heptane denitrogenation.
Three‐Dimensional Macroassembly of Sandwich‐Like, Hierarchical, Porous Carbon/Graphene Nanosheets towards Ultralight, Superhigh Surface Area, Multifunctional Aerogels
Authors: Zhu Jiayi , Yang Xi , Fu Zhibing , He Junhui , Wang Chaoyang , Wu Weidong , Zhang Lin 
Published: January 2016

AbstractA new, ultralight, superhigh surface area, multifunctional aerogel, which is macroassembled from sandwich‐like, hierarchical, porous carbon/graphene nanosheets, is described. The multifunctional aerogel was characterized by means of XRD, SEM, TEM, Raman spectroscopy, and UV/Vis absorption spectroscopy. The multifunctional aerogel had an ultralow density of 8 mg cm−3 and a superhigh surface area of 2650 m2 g−1. The multifunctional aerogel was thermal stability and compressible. Meanwhile, the multifunctional aerogel exhibited high capacity for the adsorption of oils and organic solvents, unexpectedly high hydrogen adsorption and good electrochemical performance.
Novel Insights into Structure–Activity Relationships of N‐Terminally Modified PACE4 Inhibitors
Authors: Kwiatkowska Anna , Couture Frédéric , Levesque Christine , Ly Kévin , Beauchemin Sophie , Desjardins Roxane , Neugebauer Witold , Dory Yves L. , Day Robert 
Published: January 2016

AbstractPACE4 plays important roles in prostate cancer cell proliferation. The inhibition of this enzyme has been shown to slow prostate cancer progression and is emerging as a promising therapeutic strategy. In previous work, we developed a highly potent and selective PACE4 inhibitor, the multi‐Leu (ML) peptide, an octapeptide with the sequence Ac‐LLLLRVKR‐NH2. Here, with the objective of developing a useful compound for in vivo administration, we investigate the effect of N‐terminal modifications. The inhibitory activity, toxicity, stability, and cell penetration properties of the resulting analogues were studied and compared to the unmodified inhibitor. Our results show that the incorporation of a polyethylene glycol (PEG) moiety leads to a loss of antiproliferative activity, whereas the attachment of a lipid chain preserves or improves it. However, the lipidated peptides are significantly more toxic when compared with their unmodified counterparts. Therefore, the best results were achieved not by the N‐terminal extension but by the protection of both ends with the d‐Leu residue and 4‐amidinobenzylamide, which yielded the most stable inhibitor, with an excellent activity and toxicity profile.
Smart Approach for In Situ One‐Step Encapsulation and Controlled Delivery of a Chemotherapeutic Drug using Metal–Organic Framework–Drug Composites in Aqueous Media
Authors: Adhikari Chandan , Chakraborty Anjan 
Published: January 2016

AbstractControlled release of an anticancer drug, doxorubicin (dox), from metal–organic framework (MOF)–drug composites is demonstrated under different external stimuli. 1,3,5‐Benzenetricarboxylic acid (H3BTC) is used as an organic ligand, and iron acetate and zinc nitrate are used as metal sources to synthesize Fe–BTC and Zn–BTC MOFs, which are known to be biocompatible. The in situ formation of MOF–drug composites demonstrates high drug loading capacity compared to conventional methods. The present methodology is devoid of any extra steps for loading the drug after synthesis. Moreover, the drug loading is also independent of pore size of the MOF as the drug molecules are embedded inside the MOF during their in situ formation. The drug release was monitored under external stimuli including change to acidic pH and the presence of biocompatible liposomes for a period of more than 72 h. Steady‐state fluorescence spectroscopy is used to monitor the drug release as a function of time and confocal laser scanning microscopy is used to unravel the post‐release fate of doxorubicin in the presence of liposomes. It is found that drug release rate is higher for the Zn–BTC–dox composite than for the Fe–BTC–dox composite. This is attributed to the stronger binding between dox and Fe‐BTC than that between dox and Zn–BTC. This study highlights a novel approach for the preparation of MOF–drug composites in an aqueous medium for future biomedical applications.
VO2/V2O5:Ag Nanostructures on a DVD as Photoelectrochemical Sensors
Authors: Zheng Jian , Calvillo Laura , Rizzi Gian Andrea , Granozzi Gaetano 
Published: January 2016

AbstractThe electrochemical deposition of a mixed oxide on the Ag nanostructured surface of a commercial digital versatile disc (DVD) is described. The VO2/V2O5 mixture shows interesting photoelectrocatalytic performances under visible‐light illumination after diffusion of the Ag+ ions from the Ag‐DVD substrate through the layer and formation of surface vanadates, which also allows it to be applied as an inexpensive sensing device. The samples were characterized with X‐ray photoemission spectroscopy (XPS), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), and Raman measurements. The sensing properties towards oxidizable organic substances, such as glucose, were tested.
Grazing exclusion reduced soil respiration but increased its temperature sensitivity in a Meadow Grassland on the Tibetan Plateau
Authors: Chen Ji , Zhou Xuhui , Wang Junfeng , Hruska Tracy , Shi Weiyu , Cao Junji , Zhang Baocheng , Xu Gexi , Chen Yizhao , Luo Yiqi 
Published: January 2016

AbstractUnderstanding anthropogenic influences on soil respiration (Rs) is critical for accurate predictions of soil carbon fluxes, but it is not known how Rs responds to grazing exclusion (GE). Here, we conducted a manipulative experiment in a meadow grassland on the Tibetan Plateau to investigate the effects of GE on Rs. The exclusion of livestock significantly increased soil moisture and above‐ground biomass, but it decreased soil temperature, microbial biomass carbon (MBC), and Rs. Regression analysis indicated that the effects of GE on Rs were mainly due to changes in soil temperature, soil moisture, and MBC. Compared with the grazed blocks, GE significantly decreased soil carbon release by 23.6% over the growing season and 21.4% annually, but it increased the temperature sensitivity (Q10) of Rs by 6.5% and 14.2% for the growing season and annually respectively. Therefore, GE may reduce the release of soil carbon from the Tibetan Plateau, but under future climate warming scenarios, the increases in Q10 induced by GE could lead to increased carbon emissions.
Incidence of cancer in patients with chronic heart failure: a long‐term follow‐up study
Authors: Banke Ann , Schou Morten , Videbæk Lars , Møller Jacob E. , Torp‐Pedersen Christian , Gustafsson Finn , Dahl Jordi S. , Køber Lars , Hildebrandt Per R. , Gislason Gunnar H. 
Published: January 2016

AimsWith improvement in survival of chronic heart failure (HF), the clinical importance of co‐morbidity is increasing. The aim of this study was to assess the incidence and risk of cancer and all‐cause mortality in a large Danish HF cohort.Methods and resultsA total of 9307 outpatients with verified HF without a prior diagnosis of cancer (27% female, mean age 68 years, 89% with LVEF <45%) were included in the study. A diagnosis of any cancer and all‐cause mortality was obtained from Danish national registries. Outcome was compared with the general Danish population. Overall and type‐specific risk of cancer was analysed in an adjusted Poisson and Cox regression analysis. The 975 diagnoses of cancer in the HF cohort and 330 843 in the background population corresponded to incidence rates per 10 000 patient‐years of 188.9 [95% confidence interval (CI) 177.2–200.6] and 63.0 (95% CI 63.0–63.4), respectively. When stratified by age, incidence rates were increased in all age groups in the HF cohort. Risk of any type of cancer was increased, with an incidence rate ratio of 1.24 (95% CI 1.15–1.33, c < 0.0001). Type‐specific analysis demonstrated an increased hazard ratio for all major types of cancer except for prostate cancer. All‐cause mortality was higher in HF patients with cancer compared with cancer patients from the background population.ConclusionsPatients with HF have an increased risk of cancer, which persists after the first year after the diagnosis of HF, and their prognosis is worse compared with that of cancer patients without HF.
Transfer of benzo[a]pyrene from microplastics to Artemia nauplii and further to zebrafish via a trophic food web experiment: CYP1A induction and visual tracking of persistent organic pollutants
Authors: Batel Annika , Linti Frederic , Scherer Martina , Erdinger Lothar , Braunbeck Thomas 
Published: January 2016

Abstract

The uptake of microplastic particles and the transfer of potential harmful substances along with microplastics has been studied in a variety of organisms, especially invertebrates. However, the potential accumulation of very small microplastic particles along food webs ending with vertebrate models has not been investigated so far. Therefore, a simple artificial food chain with Artemia sp. nauplii and zebrafish (Danio rerio) was established to analyze the transfer of microplastic particles and associated persistent organic pollutants (POPs) between different trophic levels. Very small (1–20 μm) microplastic particles accumulated in Artemia nauplii and were subsequently transferred to fish. Virgin particles not loaded with POPs did not cause any observable physical harm in the intestinal tracts of zebrafish, although parts of the particles were retained within the mucus of intestinal villi and might even have been taken up by epithelial cells. The transfer of associated POPs was tested with the polycyclic aromatic hydrocarbon benzo[a]pyrene and an ethoxyresorufin-O-deethylase (EROD) assay for CYP1A induction in zebrafish liver as well as via fluorescence analyses. Whereas a significant induction in the EROD assay could not be shown, because of high individual variation and low sensitivity regarding substance concentration, the fluorescence tracking of benzo[a]pyrene indicates that food-borne microplastic-associated POPs may actually desorb in the intestine of fish and are thus transferred to the intestinal epithelium and liver. Environ Toxicol Chem 2016;35:1656–1666. © 2016 SETAC
Generation of mt:egfp transgenic zebrafish biosensor for the detection of aquatic zinc and cadmium
Authors: Liu Lili , Yan Yanchun , Wang Jian , Wu Wei , Xu Lei 
Published: January 2016

Abstract

Zebrafish embryo toxicity testing has become a popular method for detecting environmental pollutions. However, the present research showed that zebrafish embryos exhibited no visible paramorphia, malformation, or mortality when exposed to heavy metals in a range above environmental standard limits, indicating that zebrafish embryos are an imprecise model for monitoring environmental heavy metals concentrations above regulatory limits. Aiming to obtain a biosensor for aquatic heavy metals, a metal-sensitive vector including zebrafish metallothionein (MT) promoter and enhanced green fluorescent protein (EGFP) was reconstructed and microinjected into 1-cell stage zebrafish embryos. The authors obtained an mt:egfp transgenic zebrafish line sensitive to aquatic zinc and cadmium. A quantitative experiment showed that zinc and cadmium treatment significantly induced the expression of EGFP in a dose- and time-dependent manner. In particular, EGFP messenger RNA levels increased remarkably when exposed to heavy metals above the standard limits. The results suggest that the transgenic zebrafish is a highly sensitive biosensor for detecting environmental levels of zinc and cadmium. Environ Toxicol Chem 2016;35:2066–2073. © 2016 SETAC
Integrated simulations of CO2 spreading and pressure response in the multilayer saline aquifer of South Scania Site, Sweden
Authors: Tian Liang , Yang Zhibing , Jung Byeongju , Joodaki Saba , Erlström Mikael , Zhou Quanlin , Niemi Auli 
Published: January 2016

AbstractAn integrated modeling approach/workflow, in which a series of mathematical models of different levels of complexity are applied to evaluate the geological storage capacity of the Scania Site, southwest Sweden, is presented. The storage formation at the site is a layered formation limited by bounding fault zones, and injection is assumed to take place from one existing deep borehole into all layers. A semi‐analytical model for two‐phase flow is first used to evaluate the pressure response and related parameter sensitivity, as well as the first estimates of acceptable injection rates. These results are then used to guide the more detailed numerical simulations that address both pressure response and plume migration. The vertical equilibrium (VE) model is used to obtain a preliminary understanding of the plume migration with a larger number of simulations. Finally the full TOUGH2/ECO2N simulations are performed for the most detailed analyses of pressure responses and plume migration. Throughout, the results of the different modeling approaches are compared to each other. It is concluded that the key limiting factor for the storage capacity at the site in the injection scenario considered is the fast CO2 migration within the high permeability layer. Future studies can address alternative injection scenarios, including using horizontal injection wells and injection to other layers than the high permeability layer.
Macrophage Recruitment Contributes to Regeneration of Mechanosensory Hair Cells in the Zebrafish Lateral Line
Authors: Carrillo Simón A. , Anguita‐Salinas Consuelo , Peña Oscar A. , Morales Rodrigo A. , Muñoz‐Sánchez Salomé , Muñoz‐Montecinos Carlos , Paredes‐Zúñiga Susana , Tapia Karina , Allende Miguel L. 
Published: January 2016

ABSTRACTIn vertebrates, damage to mechanosensory hair cells elicits an inflammatory response, including rapid recruitment of macrophages and neutrophils. While hair cells in amniotes usually become permanently lost, they readily regenerate in lower vertebrates such as fish. Damage to hair cells of the fish lateral line is followed by inflammation and rapid regeneration; however the role of immune cells in this process remains unknown. Here, we show that recruited macrophages are required for normal regeneration of lateral line hair cells after copper damage. We found that genetic ablation or local ablation using clodronate liposomes of macrophages recruited to the site of injury, significantly delays hair cell regeneration. Neutrophils, on the other hand, are not needed for this process. We anticipate our results to be a starting point for a more detailed description of extrinsic signals important for regeneration of mechanosensory cells in vertebrates. J. Cell. Biochem. 117: 1880–1889, 2016. © 2016 Wiley Periodicals, Inc.