bluuebunny/crossref_metadata_2025_split huggingface dataset:
UV‐associated decline in systemic folate: implications for human nutrigenetics, health, and evolutionary processes
Authors: Lucock Mark , Beckett Emma , Martin Charlotte , Jones Patrice , Furst John , Yates Zoe , Jablonski Nina G. , Chaplin George , Veysey Martin 
Published: October 2016

AbstractObjectivesThe purpose of this study was to examine whether UV exposure alters folate status according to C677T‐MTHFR genotype, and to consider the relevance of this to human health and the evolutionary model of skin pigmentation.MethodsTotal Ozone Mapping Spectrometer (TOMS) satellite data were used to examine surface UV‐irradiance, as a marker of UV exposure, in a large (n = 649) Australian cross‐sectional study population. PCR/RFLP analysis was used to genotype C677T‐MTHFR.ResultsOverall, cumulative UV‐irradiance (42 and 120 days pre‐clinic) was significantly negatively related to red cell folate (RCF) levels. When the cohort was stratified by MTHFR‐C677T genotype, the relationship between UV‐irradiance (42 days pre‐clinic) and RCF remained significant only in the cohorts containing carriers of the T allele. Statistically significant z‐score statistics and interaction terms from genotype and UV‐irradiance (p‐interaction) demonstrated that genotype did modify the effect of UV‐irradiance on RCF, with the largest effect of UV being demonstrated in the 677TT‐MTHFR subjects.ConclusionsData provide strong evidence that surface UV‐irradiance reduces long‐term systemic folate levels, and that this is influenced by the C677T‐MTHFR gene variant. We speculate this effect may be due to 677TT‐MTHFR individuals containing more 5,10CH2‐H4PteGlu, and that this folate form may be particularly UV labile. Since UV‐irradiance lowers RCF in an MTHFR genotype‐specific way, there are likely implications for human health and the evolution of skin pigmentation.
Total Syntheses of (+)‐T988 B and (+)‐T988 C through the AgNTf2‐Mediated Coupling of Bromopyrroloindoline with Indole
Authors: Sato Soichiro , Hirayama Azusa , Ueda Hirofumi , Tokuyama Hidetoshi 
Published: October 2016

AbstractThe total syntheses of (+)‐T988 B and (+)‐T988 C were accomplished in 19 and 18 steps, respectively, in 20.2 % overall yield. The indole segment was regioselectively introduced at the sterically hindered C10b position through a diastereoselective bromocyclization reaction and a subsequent AgNTf2‐mediated Friedel–Crafts reaction. The dithiodioxopiperazine moiety was efficiently constructed through a one‐pot radical‐mediated C−H bromination/dehydrobromination procedure on the dioxopiperazine ring.
Naturstoffbasierte Aminoepoxybenzochinone inhibieren das Wachstum verschiedener Serovare des Gram‐negativen Krankheitserregers Salmonella durch Abschwächen der bakteriellen Stressabwehr
Authors: Mandl Franziska A. , Kirsch Volker C. , Ugur Ilke , Kunold Elena , Vomacka Jan , Fetzer Christian , Schneider Sabine , Richter Klaus , Fuchs Thilo M. , Antes Iris , Sieber Stephan A. 
Published: October 2016

AbstractAufgrund ihrer undurchlässigeren Zellmembran und der damit verbundenen eingeschränkten Aufnahme von niedermolekularen Verbindungen stellen Gram‐negative Bakterien eine große Herausforderung für die Entwicklung neuer Antibiotika dar. Hier wurden naturstoffbasierte Epoxycyclohexenone synthetisiert und deren antibiotische Aktivität gegen mehrere pathogene Bakterien untersucht. Eine dieser Verbindungen inhibierte das Wachstum von Salmonella Typhimurium, weswegen deren Zielenzyme mittels quantitativer chemischer Proteomik bestimmt wurden. Zwei dieser Enzyme konnten der bakteriellen Stressabwehr zugeordnet werden, und entsprechende Assays bestätigten eine erhöhte Anfälligkeit der mit der Sonde inkubierten Bakterien gegen reaktive Sauerstoffspezies. Die antibakterielle Aktivität der Sonde kann somit durch die parallele Inhibition dieser beiden Enzyme begründet werden, wodurch deutlich wird, dass Epoxycyclohexenone geeignete Naturstoffe zur Bekämpfung Gram‐negativer Bakterien darstellen.
Unprecedented Charge‐Transfer Complex of Fused Diporphyrin as Near‐Infrared Absorption‐Induced High‐Aspect‐Ratio Nanorods
Authors: Achary B. Shivaprasad , Gokulnath Sabapathi , Ghosh Samrat , Mrinalini Madoori , Prasanthkumar Seelam , Giribabu Lingamallu 
Published: October 2016

AbstractCharge‐transfer (CT) complexes of near‐infrared absorbing systems have been unknown until now. Consequently, structural similarities between donor and acceptor are rather important to achieve this phenomenon. Herein, we report electron donors such as non‐fused diporphyrin‐anthracene (DP), zinc diporphyrin‐anthracene (ZnDP) and fused zinc diporphyrin‐anthracene (FZnDP) in which FZnDP absorbs in NIR region and permits a CT complex with the electron acceptor, perylene diimide (PDI) in CHCl3 exclusively. UV/Vis‐NIR absorption, 1H NMR, NOESY and powder X‐ray diffraction analysis demonstrated that the CT complex formation occurs by π–π stacking between perylene units in FZnDP and PDI upon mixing together in a 1:1 molar concentration in CHCl3, unlike non‐fused ZnDP and DP. TEM and AFM images revealed that the CT complex initially forms nanospheres leading to nanorods by diffusion of CH3OH vapors into the CHCl3 solution of FZnDP/PDI (1:1 molar ratio). Therefore, these CT nanorods could lead to significant advances in optical, biological and ferroelectric applications.
Comparison of outcomes between rectal squamous cell carcinoma and adenocarcinoma
Authors: Chiu Max S. , Verma Vivek , Bennion Nathan R. , Bhirud Abhijeet R. , Li Jinluan , Charlton Mary E. , Are Chandrakanth , Lin Chi 
Published: October 2016

AbstractLarge, population‐based analyses of rectal squamous cell carcinoma (SCC) have not been previously conducted. We assessed patterns of care, prognostic factors, and outcomes of rectal SCC and adenocarcinoma (AC) in population‐based cohorts. Surveillance, Epidemiology, and End Results (SEER) registry searches were performed (1998–2011), producing 42,308 nonmetastatic rectal cancer patients (999 SCC and 41,309 AC). Patient, tumor, and treatment characteristics were compared. Based on risk factors, SCC/AC groups were subdivided into low‐, intermediate‐, and high‐risk groups. Overall survival (OS) was compared between histological and risk groups using Kaplan–Meier method and log‐rank test. Multivariate logistic regression models evaluated prognostic factors for 5‐year survival. Cox regression modeling was performed on propensity‐matched data. Rectal SCC, more common in females and associated with larger tumors of higher grade, was more often treated with radiotherapy (RT) than surgery. Surgery was associated with higher OS in AC but not SCC, and RT had proportionally greater benefits in SCC. These effects of RT and surgery were retained when stratified into risk groups (particularly high/intermediate‐risk). Favorable prognostic factors for survival included younger age, non‐black race, SCC histology, size ≤3.9 cm, localized stage, lower grade, surgery, and RT. For SCC, race, tumor grade, and surgery were not prognostic factors for survival. Cox regression modeling of propensity‐matched data showed that AC histology increased risk of death versus SCC. In the largest analysis of rectal SCC to date, and in the notable absence (and unlikelihood) of prospective data, nonsurgical and RT‐based treatment is recommended.
Expression profile of E‐cadherin, estrogen receptors, and P53 in early‐onset gastric cancers
Authors: Zhou Fan , Xu Yuanyuan , Shi Jiong , Lan Xing , Zou Xiaoping , Wang Lei , Huang Qin 
Published: October 2016

AbstractEarly‐onset gastric cancer (EOGC) is predominant in females, diffuse histology, and hereditary pattern. Germline mutation of CDH1 and p53 has been reported previously and female dominance was speculated to be associated with estrogen and its receptors. Expression of E‐cadherin, estrogen receptor α (ERα), estrogen receptor β (ERβ), and p53 in EOGC remains unclear, which was the focus of this study, to assess clinical significance of their expression in EOGC. The expression of E‐cadherin, ERα, ERβ, and p53 in tumors and normal tissues from surgically resected EOGCs was assessed by immunohistochemistry (n = 139) and Western blot (n = 7) methods, respectively. The expression in tumor tissues was significantly higher for ERα, ERβ, and p53, but lower for E‐cadherin, compared to uninvolved mucosa. Positive staining of ERβ and p53 was more frequently observed in younger patients with advanced TNM stages. For E‐cadherin, significant correlation was observed between the immunopositivity and TNM stages IA+IB. P53‐negative patients had significantly better outcomes than p53‐positive patients. Significant association between expression of E‐cadherin and histologic types was found in familial, but not in sporadic, EOGC. In conclusion, our results demonstrated E‐cadherin may have a role in initiation of EOGC and positive ERβ and p53 expression may partially explained early‐onset and tumor progression of EOGC.
Methanol Partial Oxidation on Ag(1 1 1) from First Principles
Authors: Aljama Hassan , Yoo Jong Suk , Nørskov Jens K. , Abild‐Pedersen Frank , Studt Felix 
Published: October 2016

AbstractIn this work, we examine the thermochemistry and kinetics of the partial oxidation of methanol to formaldehyde on silver surfaces. Periodic density functional theory calculations employing the BEEF‐vdW functional are used to identify the most stable phases of the silver surface under relevant reaction conditions and the reaction energetics are obtained on these surfaces. The calculated binding energies and transition state energies are used as input in a mean‐field microkinetic model providing the reaction kinetics on silver surfaces under different reaction conditions. Our results show that, under conditions pertaining to methanol partial oxidation, oxygen is present at low concentrations and it plays a critical role in the catalytic reaction. Surface oxygen promotes the reaction by activating the OH bond in methanol, thus forming a methoxy intermediate, which can react further to form formaldehyde. The dissociation of molecular oxygen is identified as the most critical step.
Ir‐Catalyzed C−H Amidation of Aldehydes with Stoichiometric/Catalytic Directing Group
Authors: Zhang Yun‐Fei , Wu Bin , Shi Zhang‐Jie 
Published: October 2016

AbstractIr‐catalyzed sp2 C−H amidation of aldehydes with various anilines as stoichiometric or catalytic directing groups was accomplished. A wide range of substrates were selectively amidated in good to excellent yields with broad functional group tolerance. The iridacycle complexes were isolated, characterized, and proved as key intermediates. Kinetic studies and Hammett plots provided detailed understandings of this amidation. According to the mechanism, the electron‐rich ArSO2N3 was proved effective for intermolecular sp3 C−H amidation.
[NMe4][I4Br5]: A new Iodobromide from an Ionic Liquid with Halogen–Halogen Interactions
Authors: Mann Lisa , Voßnacker Patrick , Müller Carsten , Riedel Sebastian 
Published: October 2016

AbstractTetramethylammonium tetraiodopentabromide [NMe4][I4Br5] was the first iodobromide to be synthesized and crystallized in an ionic liquid as well as in dichloromethane. The new iodobromides show different structure motives yet are unknown from other nonahalides and can be better described as [(I2Br3)−⋅2 IBr]. The additional IBr units are connected by halogen–halogen interactions on the central V‐shaped [I2Br3]−. The characterization was performed by Raman spectroscopy and single crystal X‐ray structure determination. Conductivity measurements, thermogravimetric analysis and quantum‐chemical calculations completed the structural discussion.
Structure and Bonding in Nickel–Thiolate–Iodine Charge‐Transfer Complexes
Authors: Beyer Norman , Steinfeld Gunther , Lozan Vasile , Naumov Sergej , Flyunt Roman , Abel Bernd , Kersting Berthold 
Published: October 2016

AbstractThe dinuclear nickel complexes [Ni2L(μ‐O2CR)](ClO4) [R=Me (4), R=OMe (6)], where L2− is a 24‐membered macrocyclic N6S2 ligand, react readily with excess I2 in MeCN solution at 4 °C to form stable mono‐(I2) and bis‐(I2) charge‐transfer (CT) adducts of the type [Ni2L(μ‐O2CR)(I2)n]+ (n=1 or 2) containing linear RS‐I‐I linkages. Three new CT compounds, namely, [Ni2L(OAc)(I2)](I2)(I3) (5), [Ni2L(O2COMe)(I2)](I5)⋅MeCN (7⋅MeCN), and [Ni2L(O2COMe)(I2)2](I5)⋅MeCN (8⋅MeCN) as well as the triiodide salt [Ni2L(OAc)](I3) (9) were synthesized and fully characterized. A common feature of the CT adducts is a polyiodide matrix, which surrounds the individual complex molecules, stabilized by secondary I⋅⋅⋅I interactions with the CT linkages. The scatter in both the RS−I (2.6 to 3.0 Å) and the I−I bond lengths (2.7 to 3.0 Å) is indicative of both a variable strength of the RS−→I2 bond and a varying degree of charge transfer. An analysis of the structural parameters was undertaken accompanied by DFT calculations to quantify the donating ability of the bridging thiolate functions and to shed more light on the bonding in this rare sort of charge‐transfer complexes. The stability of the CT complexes and the results of preliminary transport measurements are also reported.
Mechanically Induced Opening–Closing Action of Binaphthyl Molecular Pliers: Digital Phase Transition versus Continuous Conformational Change
Authors: Mori Taizo , Ishikawa Daisuke , Yonamine Yusuke , Fujii Yoshihisa , Hill Jonathan P. , Ichinose Izumi , Ariga Katsuhiko , Nakanishi Waka 
Published: October 2016

AbstractReversible dynamic control of structure is a significant challenge in molecular nanotechnology. Previously, we have reported a mechanically induced continuous (analog) conformational variation in an amphiphilic binaphthyl, where closing of molecular pliers was achieved by compression of a molecular monolayer composed of these molecules at the air–water interface. In this work we report that a phase transition induced by an applied mechanical stress enables discontinuous digital (1/0) opening of simple binaphthyl molecular pliers. A lipid matrix at the air–water interface promotes the formation of quasi‐stable nanocrystals, in which binaphthyl molecules have an open transoid configuration. The crystallization/dissolution of quasi‐stable binaphthyl crystals with accompanying conformational change is reversible and repeatable.
Secrecy outage analysis in a hybrid cognitive relay network with energy harvesting
Authors: Maji Pranabesh , Dhar Roy Sanjay , Kundu Sumit 
Published: October 2016

SummaryIn this paper, we investigate the physical layer security of a hybrid cognitive relay network using an energy harvesting relay in presence of an eavesdropper. In the hybrid scheme, a secondary user (SU) as well as a cognitive relay works either in underlay or in overlay mode. In underlay, the transmit power of the SU as well as the relay is limited by the maximum acceptable interference at primary user (PU) receiver as required by an outage constraint of PU, a quality of service for PU. The secondary network consists of a decode and forward relay that harvests energy from radio frequency signal of secondary transmitter as well as PU transmitter to assist the SU in forwarding the information signal to the destination. A time switching relaying protocol is used at the relay. We evaluate the secrecy outage probability of secondary relay network assuming that channel state information of the interfering links from both the SU and relay transmitter to PU receiver is imperfect. Our results reveal the impact of imperfect channel state information, energy harvesting time, tolerable interference threshold, and PU outage constraint on the secrecy outage probability of SU.
Spatial pattern of distribution of marine invertebrates within a subtidal community: do communities vary more among patches or plots?
Authors: Chang Chun‐Yi , Marshall Dustin J. 
Published: October 2016

AbstractMaking links between ecological processes and the scales at which they operate is an enduring challenge of community ecology. Our understanding of ecological communities cannot advance if we do not distinguish larger scale processes from smaller ones. Variability at small spatial scales can be important because it carries information about biological interactions, which cannot be explained by environmental heterogeneity alone. Marine fouling communities are shaped by both the supply of larvae and competition for resources among colonizers—these two processes operate on distinctly different scales. Here, we demonstrate how fouling community structure varies with spatial scale in a temperate Australian environment, and we identify the spatial scale that captures the most variability. Community structure was quantified with both univariate (species richness and diversity) and multivariate (similarity in species composition) indices. Variation in community structure was unevenly distributed between the spatial scales that we examined. While variation in community structure within patch was usually greater than among patch, variation among patch was always significant. Opportunistic taxa that rely heavily on rapid colonization of free space spread more evenly among patches during early succession. In contrast, taxa that are strong adult competitors but slow colonizers spread more evenly among patches only during late succession. Our findings show significant patchiness can develop in a habitat showing no systematic environmental spatial variation, and this patchiness can be mediated through different biological factors at different spatial scales.
Spatial subsidies in spider diets vary with shoreline structure: Complementary evidence from molecular diet analysis and stable isotopes
Authors: Hambäck Peter A. , Weingartner Elisabeth , Dalén Love , Wirta Helena , Roslin Tomas 
Published: October 2016

AbstractInflow of matter and organisms may strongly affect the local density and diversity of organisms. This effect is particularly evident on shores where organisms with aquatic larval stages enter the terrestrial food web. The identities of such trophic links are not easily estimated as spiders, a dominant group of shoreline predator, have external digestion. We compared trophic links and the prey diversity of spiders on different shore types along the Baltic Sea: on open shores and on shores with a reed belt bordering the water. A priori, we hypothesized that the physical structure of the shoreline reduces the flow between ecosystem and the subsidies across the sea–land interface. To circumvent the lack of morphologically detectable remains of spider prey, we used a combination of stable isotope and molecular gut content analyses. The two tools used for diet analysis revealed complementary information on spider diets. The stable isotope analysis indicated that spiders on open shores had a marine signal of carbon isotopes, while spiders on reedy shores had a terrestrial signal. The molecular analysis revealed a diverse array of dipteran and lepidopteran prey, where spiders on open and reedy shores shared a similar diet with a comparable proportion of chironomids, the larvae of which live in the marine system. Comparing the methods suggests that differences in isotope composition of the two spider groups occurred because of differences in the chironomid diets: as larvae, chironomids of reedy shores likely fed on terrestrial detritus and acquired a terrestrial isotope signature, while chironomids of open shores utilized an algal diet and acquired a marine isotope signature. Our results illustrate how different methods of diet reconstruction may shed light on complementary aspects of nutrient transfer. Overall, they reveal that reed belts can reduce connectivity between habitats, but also function as a source of food for predators.
Bienzymatic Biosensor for Malic Acid Based on Malate Dehydrogenase and Transaminase Immobilized onto a Glassy Carbon Powder/Carbon Nanotubes/Nad+ Composite Electrode
Authors: Mundaca‐Uribe Rodolfo , Valencia‐Muñoz Daniela , Castillo Felices Rosario , Hinojosa José Neira , Bustos Mario Aranda , Peña‐Farfal Carlos 
Published: October 2016

AbstractA biosensor for malic acid detection in fruit juices, based on malate dehydrogenase (MDH) glutamate oxaloacetate transaminase (GOT) in a powder vitreous carbon, carbon nanotubes and mineral oil, composite matrix has been developed. By employing amperometry at a constant potential of 0.4 V (vs. Ag/AgCl), an enzymatic reaction promoted by these species in a support solution Mc Ilvaine buffer (phosphate/citrate pH 10.0) with glutamic acid was generated, causing the oxidation of electro active species, that was stoichiometrically equal to the amount of malic acid present in the sample. The response was linear over the range 2–50 mM, with an analytical sensitivity of 2.24×10−4 to 2,55×10−4 AM−1 and r2=0.9980 to 0.9983, a LOD of 4.02 μM and LOQ of 13.4 μM. Malic acid concentration detected was 0.23–1.07 g/L in fruit juice samples. Results were validated using an enzymatic spectrophotometric method as a reference. To the best of our knowledge, this is the first bienzymatic biosensor using both malate dehydrogenase and glutamate oxaloacetate transaminase enzymes.
Maternal transfer of perfluoroalkyl substances in hooded seals
Authors: Grønnestad Randi , Villanger Gro D. , Polder Anuschka , Kovacs Kit M. , Lydersen Christian , Jenssen Bjørn M. , Borgå Katrine 
Published: October 2016

Abstract

The role of milk in the transfer of perfluoroalkyl substances (PFASs) to offspring is not well known in wildlife. Eight PFASs were quantified in plasma and milk in mother–pup pairs of hooded seals (Cystophora cristata) during the nursing period, and the role of milk in the transfer process was analyzed. Hooded seal was chosen because of its short lactation period (3–4 d), during which the pup feeds only on milk. Placental or lactation transfer would thus be the only source of PFAS in the pup. Of the 8 PFASs analyzed (Σ8PFAS), 7 were found in all samples; therefore, milk is a source to PFASs in pups. Perfluorooctane sulfonate was the dominant PFAS in all samples. Mean Σ8PFAS concentrations were 6.0 ng/g protein (36 ng/g wet wt) in maternal plasma, 0.77 ng/g protein (3.2 ng/g wet wt) in milk, and 12 ng/g protein (66 ng/g wet wt) in pup plasma. Measured concentrations in plasma were within ranges previously reported from other seal species, below known toxicity thresholds for experimental rodents. Individual PFASs differed in transfer efficiency from mother to pup, depending on carbon chain lengths, with the lowest relative transfer for the intermediate-chained PFASs (C9–C10). The results show maternal transfer of PFASs via both milk and the placenta, of which placental transfer is the dominant pathway. Environ Toxicol Chem 2017;36:763–770. © 2016 SETAC