bluuebunny/crossref_metadata_2025_split huggingface dataset:
2H‐Tetrakis(3,5‐di‐tert‐butyl)phenylporphyrin on a Cu(110) Surface: Room‐Temperature Self‐Metalation and Surface‐Reconstruction‐Facilitated Self‐Assembly
Authors: Zhang Liang , Lepper Michael , Stark Michael , Schuster Ralf , Lungerich Dominik , Jux Norbert , Steinrück Hans‐Peter , Marbach Hubertus 
Published: February 2016

AbstractThe adsorption behavior of 2H‐tetrakis(3,5‐di‐tert‐butyl)phenylporphyrin (2HTTBPP) on Cu(110) and Cu(110)–(2×1)O surfaces have been investigated by using variable‐temperature scanning tunneling microscopy (STM) under ultrahigh vacuum conditions. On the bare Cu(110) surface, individual 2HTTBPP molecules are observed. These molecules are immobilized on the surface with a particular orientation with respect to the crystallographic directions of the Cu(110) surface and do not form supramolecular aggregates up to full monolayer coverage. In contrast, a chiral supramolecular structure is formed on the Cu(110)–(2×1)O surface, which is stabilized by van der Waals interactions between the tert‐butyl groups of neighboring molecules. These findings are explained by weakened molecule–substrate interactions on the Cu(110)–(2×1)O surface relative to the bare Cu(110) surface. By comparison with the corresponding results of Cu–tetrakis(3,5‐di‐tert‐butyl)phenylporphyrin (CuTTBPP) on Cu(110) and Cu(110)–(2×1)O surfaces, we find that the 2HTTBPP molecules can self‐metalate on both surfaces with copper atoms from the substrate at room temperature (RT). The possible origins of the self‐metalation reaction at RT are discussed. Finally, peculiar irreversible temperature‐dependent switching of the intramolecular conformations of the investigated molecules on the Cu(110) surface was observed and interpreted.
Nickel(II)meso‐Hydroxyporphyrin Complexes Revisited: Palladium‐Catalysed Synthesis, Electronic Structures of Derived Oxy Radicals, and Oxidative Coupling to a Dioxoporphodimethene Dyad
Authors: Esdaile Louisa J. , Rintoul Llew , Goh Mean See , Merahi Khalissa , Parizel Nathalie , Wellard R. Mark , Choua Sylvie , Arnold Dennis P. 
Published: February 2016

AbstractWe report the synthesis and characterisation of new examples ofmeso‐hydroxynickel(II) porphyrins with 5,15‐diphenyl and 10‐phenyl‐5,15‐diphenyl/diaryl substitution. The OH group was introduced by using carbonate or hydroxide as nucleophile by using palladium/phosphine catalysis. The NiPor−OHs exist in solution in equilibrium with the corresponding oxy radicals NiPor−O.. The 15‐phenyl group stabilises the radicals, so that the1H NMR spectra of {NiPor−OH} are extremely broad due to chemical exchange with the paramagnetic species. The radical concentration for the diphenylporphyrin analogue is only 1 %, and its NMR line‐broadening was able to be studied by variable‐temperature NMR spectroscopy. The EPR signals of NiPor−O.are consistent with somewhat delocalised porphyrinyloxy radicals, and the spin distributions calculated by using density functional theory match the EPR and NMR spectroscopic observations. Nickel(II)meso‐hydroxy‐10,20‐diphenylporphyrin was oxidatively coupled to a dioxo‐terminated porphodimethene dyad, the strongly red‐shifted electronic spectrum of which was successfully modelled by using time‐dependent DFT calculations.
A Highly Reactive Geminal P/B Frustrated Lewis Pair: Expanding the Scope to C−X (X=Cl, Br) Bond Activation
Authors: Samigullin Kamil , Georg Isabelle , Bolte Michael , Lerner Hans‐Wolfram , Wagner Matthias 
Published: February 2016

AbstractThe geminal frustrated Lewis pair tBu2PCH2B(Fxyl)2 (1; Fxyl=3,5‐(CF3)2C6H3) is accessible in 65 % yield from tBu2PCH2Li and (Fxyl)2BF. According to NMR spectroscopy and X‐ray crystallography, 1 is monomeric both in solution and in the solid state. The intramolecular P⋅⋅⋅B distance of 2.900(5) Å and the full planarity of the borane site exclude any significant P/B interaction. Compound 1 readily activates a broad variety of substrates including H2, EtMe2SiH, CO2/CS2, Ph2CO, and H3CCN. Terminal alkynes react with heterolysis of the C−H bond. Haloboranes give cyclic adducts with strong P−BX3 and weak R3B−X bonds. Unprecedented transformations leading to zwitterionic XP/BCX3 adducts occur on treatment of 1 with CCl4 or CBr4 in Et2O. In less polar solvents (C6H6, n‐pentane), XP/BCX3 adduct formation is accompanied by the generation of significant amounts of XP/BX adducts. FLP 1 catalyzes the hydrogenation of PhCH=NtBu and the hydrosilylation of Ph2CO with EtMe2SiH.
Generation of Aryl Radicals through Reduction of Hypervalent Iodine(III) Compounds with TEMPONa: Radical Alkene Oxyarylation
Authors: Hartmann Marcel , Li Yi , Mück‐Lichtenfeld Christian , Studer Armido 
Published: February 2016

AbstractA novel method for selective generation of aryl radicals from diaryliodonium salts and iodanylidene malonates with sodium 2,2,6,6‐tetramethylpiperidine‐1‐oxyl (TEMPONa) as a single‐electron transfer (SET) reducing reagent is described. In the presence of various alkenes, aryl radicals formed after SET‐reduction of hypervalent iodine compounds undergo alkene addition and the adduct radicals that are thus generated are efficiently trapped by the concomitantly generated TEMPO radical to eventually afford oxyarylated products in moderate to very good yields. The efficiency of aryl radical generation of various iodine(III) reagents is studied and the generation of an iodanylidene malonate aryl radical is also investigated by computational methods.
Micro‐Macroporous Composite Materials: SiC Ceramic Foams Functionalized With the Metal Organic Framework HKUST‐1
Authors: Betke Ulf , Proemmel Steven , Eggebrecht Jakob G. , Rannabauer Stefan , Lieb Alexandra , Scheffler Michael , Scheffler Franziska 
Published: February 2016

AbstractThe metal organic framework material Cu3(btc)2·3H2O (HKUST‐1) was grown on differently activated oxide‐bonded SiC ceramic foams with varying pore sizes. Activation was performed by an alkaline etching procedure under dissolution of the SiO2 binder phase in the ob‐SiC microstructure leading to an increase in strut surface roughness. The influence of foam pore size, etching conditions (duration, temperature) and the effect of a subsequent alumina coating to increase the coverage with –OH moieties was studied. The activated foams and MOF@ob‐SiC composites were characterized by microstructural analysis, H2O adsorption and thermal conductivity measurements.
Cancer Immunotherapy: Selected Targets and Small‐Molecule Modulators
Authors: Weinmann Hilmar 
Published: February 2016

AbstractThere is a significant amount of excitement in the scientific community around cancer immunotherapy, as this approach has renewed hope for many cancer patients owing to some recent successes in the clinic. Currently available immuno‐oncology therapeutics under clinical development and on the market are mostly biologics (antibodies, proteins, engineered cells, and oncolytic viruses). However, modulation of the immune system with small molecules offers several advantages that may be complementary and potentially synergistic to the use of large biologicals. Therefore, the discovery and development of novel small‐molecule modulators is a rapidly growing research area for medicinal chemists working in cancer immunotherapy. This review provides a brief introduction into recent trends related to selected targets and pathways for cancer immunotherapy and their small‐molecule pharmacological modulators.
Enantiomeric Excess Sensitivity to Below One Percent by Using Femtosecond Photoelectron Circular Dichroism
Authors: Kastner Alexander , Lux Christian , Ring Tom , Züllighoven Stefanie , Sarpe Cristian , Senftleben Arne , Baumert Thomas 
Published: February 2016

AbstractPhotoelectron circular dichroism (PECD) is experimentally investigated with chiral specimens with varying amounts of enantiomeric excess (ee). As a prototype, we measure and analyze the photoelectron angular distribution from randomly oriented fenchone molecules in the gas phase that result from ionization with circularly polarized femtosecond laser pulses. The quantification of these measurements shows a linear dependence with respect to the ee values. In addition, differences in the ee values (denoted as detection limit) of below one percent can be distinguished for nearly enantiopure samples, as well as for almost racemates. In combination with the use of a reference, the assignment of absolute ee values is possible. The present measurement time is a few minutes, but this could be reduced. This table‐top laser‐based approach should facilitate widespread implementation in chiral analysis.
Photometric Detection of Nitric Oxide Using a Dissolved Iron(III) Corrole as a Sensitizer
Authors: Fischer Stefan , Vestfrid Jenya , Mahammed Atif , Herrmann‐Westendorf Felix , Schulz Martin , Müller Jürgen , Kiesewetter Olaf , Dietzek Benjamin , Gross Zeev , Presselt Martin 
Published: February 2016

AbstractThe potential of an iron(III) corrole complex for use in the detection of nitric oxide (NO) was investigated. The reversible conversion of an dissolved iron(III) corrole to its corresponding nitrosyl complex using gaseous nitric oxide was monitored by UV/Vis spectroscopy. The spectral differences between both coordination compounds were used to determine photometrically small amounts of nitric oxide in the sub‐parts‐per‐million range. The spectral changes due to NO binding were assigned to charge‐transfer transitions arising upon NO coordination and were analyzed in detail with support from quantum chemical calculations. Finally, films of the iron(III) corrole were deposited on quartz glass. Thus, the great potential of iron(III) corroles for the development of advanced, highly sensitive and low‐energy‐consuming photonic sensing devices was demonstrated.
The depth distribution of organic carbon in the soils of eastern Australia
Authors: Hobley Eleanor U. , Wilson Brian 
Published: February 2016

AbstractSubsurface soil organic carbon (SOC) is a large but still poorly understood component of the global carbon cycle. We investigated the depth distribution of SOC in eastern Australia, testing the hypotheses that SOC content near the surface is linked with water availability, whereas the distribution of SOC with depth is linked with land use, site factors and temperature. To do this, we measured SOC concentration to 1 m at 100 sites across eastern Australia, and fitted three parameter exponential depletion models to the results. Three machine learning algorithms were used to identify predictors important to the model parameters. Multiple regression models were then created based upon the machine learning results using bootstrapped stepwise regressions and the relative importance of the selected variables was assessed using proportional marginal variance decomposition. Surface SOC concentration was influenced predominantly by climate variables, of which seasonal rainfall was by far the most important. At depth, SOC storage was most influenced by site factors (mainly bulk density and soil type), and both land use and climate contributed similar amounts to model explained variance. The depth distribution of SOC was most influenced by land use, which accounted for ~60% of model explained variance, with site and climate factors being approximately equally important. These results support our hypotheses regarding the drivers of SOC depth distribution in eastern Australia and can be used to identify regions with the potential for additional subsurface soil carbon storage.
Timing of translocation influences birth rate and population dynamics in a forest carnivore
Authors: Facka Aaron N. , Lewis Jeffrey C. , Happe Patricia , Jenkins Kurt , Callas Richard , Powell Roger A. 
Published: February 2016

AbstractTiming can be critical for many life history events of organisms. Consequently, the timing of management activities may affect individuals and populations in numerous and unforeseen ways. Translocations of organisms are used to restore or expand populations but the timing of translocations is largely unexplored as a factor influencing population success. We hypothesized that the process of translocation negatively influences reproductive rates of individuals that are moved just before their birthing season and, therefore, the timing of releases could influence translocation success. Prior to reintroducing fishers (Pekania pennanti) into northern California and onto the Olympic Peninsula of Washington, we predicted that female fishers released in November and December (early) would have a higher probability of giving birth to kits the following March or April than females released in January, February, and March (late), just prior to or during the period of blastocyst implantation and gestation. Over four winters (2008–2011), we translocated 56 adult female fishers that could have given birth in the spring immediately after release. Denning rates, an index of birth rate, for females released early were 92% in California and 38% in Washington. In contrast, denning rates for females released late were 40% and 11%, in California and Washington, a net reduction in denning rate of 66% across both sites. To understand how releasing females nearer to parturition could influence population establishment and persistence, we used stochastic population simulations using three‐stage Lefkovitch matrices. These simulations showed that translocating female fishers early had long‐term positive influences on the mean population size and on quasi‐extinction thresholds compared to populations where females were released late. The results from both empirical data and simulations show that the timing of translocation, with respect to life history events, should be considered during planning of translocations and implemented before the capture, movement, and release of organisms for translocation.
Carbon stocks and accumulation rates in Pacific Northwest forests: role of stand age, plant community, and productivity
Authors: Gray Andrew N. , Whittier Thomas R. , Harmon Mark E. 
Published: February 2016

AbstractForest ecosystems are removing significant amounts of carbon from the atmosphere. Both abiotic resource availability and biotic interactions during forest succession affect C accumulation rates and maximum C stocks. However, the timing and controls on the peak and decline in C accumulation rates as stands age, trees increase in size, and canopy gaps become prevalent are not well‐understood. Our study examines measured change in live and dead woody C pools from 8767 inventory plots on 9.1 million ha of Pacific Northwest National Forest lands to determine how the balance of tree growth, mortality, and dead wood decomposition varied by stand age, plant community type, and site productivity; and to compare the contribution of different tree sizes to C accumulation. Maximum non‐mineral soil C for old‐growth stands varied significantly by productivity class within plant community types, but on average stands accumulated 75% of maximum stocks by age 127 ± 35 yr. We did not see a decline in net primary production of wood (NPPw) with age in moderate and low‐productivity classes, but found a 33% reduction in high‐productivity classes. Mortality increased with stand age such that net change in live tree biomass, and change in total woody C, was not significantly different from zero in old‐growth stands over age 400 (0.15 ± 0.64 Mg C·ha−1·yr−1for woody C). However, significant though modest C accumulation was found in forests 200–400 yr old (0.34–0.70 Mg C·ha−1·yr−1, depending on age class). Mortality of trees >100 cm diameter exceeded or equaled NPPw, but trees were growing into the larger sizes at a high‐enough rate that a net increase in large tree C was seen across the region. Although large trees accumulated C at a faster rate than small trees on an individual basis, their contribution to C accumulation rates was smaller on an area basis, and their importance relative to small trees declined in older stands compared to younger stands. In contrast to recent syntheses, our results suggest that old‐growth and large trees are important C stocks, but they play a minor role in additional C accumulation.
Aspirin does not reduce the clinical benefits of the mineralocorticoid receptor antagonist eplerenone in patients with systolic heart failure and mild symptoms: an analysis of the EMPHASIS‐HF study
Authors: Chin Ken Lee , Collier Timothy J. , Pitt Bertram , McMurray John J.V. , Swedberg Karl , van Veldhuisen Dirk J. , Pocock Stuart J. , Vincent John , Turgonyi Eva , Zannad Faiez , Krum Henry ,   for the EMPHASIS‐HF Study Investigators
Published: February 2016

AbstractAimsIt is not known whether concomitant use of aspirin might attenuate the beneficial effects of mineralocorticoid receptor antagonists (MRAs). The purpose of this subgroup analysis was to explore the interaction between baseline aspirin treatment and the effect of eplerenone on the primary efficacy outcomes (composite of hospitalization for heart failure or cardiovascular mortality), its components, and safety markers [estimated glomerular filtration rate (eGFR), systolic blood pressure (SBP), and serum potassium >5.5 mmol/L] in the Eplerenone in Mild Patients Hospitalization and SurvIval Study in Heart Failure trial (EMPHASIS‐HF).Methods and resultsPatients with chronic heart failure, reduced ejection fraction (HFREF), and mild symptoms were enrolled in EMPHASIS‐HF. We evaluated baseline characteristics according to aspirin use. We explored the interaction between aspirin and eplerenone, using Cox proportional hazards models providing adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) and P‐values for interaction. Of the 2737 patients randomized, 1605 patients (58.6%) were taking aspirin. The beneficial effects of eplerenone on the primary endpoint were similar in patients not treated (adjusted HR 0.59, 95% CI 0.46–0.75) or treated (adjusted HR 0.71, 95% CI 0.59–0.87) with aspirin at baseline (interaction P‐value = 0.19). We did not observe any significant modification of the safety markers by aspirin that was clinically meaningful.ConclusionAspirin use in patients with chronic systolic heart failure and mild symptoms did not substantially reduce the overall beneficial effects of the MRA eplerenone contrary to what has been described in some studies with ACE inhibitors.
Mitochondria‐Targeting Iron(III) Catecholates for Photoactivated Anticancer Activity under Red Light
Authors: Basu Uttara , Pant Ila , Kondaiah Paturu , Chakravarty Akhil R. 
Published: February 2016

AbstractIron(III) catecholates [Fe(R′‐bpa)(R‐dopa)Cl] (1, 2) with a triphenylphosphonium (TPP) moiety, where R′‐bpa is 2‐(TPP‐N,N‐bis((pyridin‐2‐yl)methyl)ethanamine) chloride (TPPbpa) and R‐dopa is 4‐{2‐[(anthracen‐9‐yl)methylamino]ethyl}benzene‐1,2‐diol (andopa, 1) or 4‐{2‐[(pyren‐1‐yl)‐methylamino]ethyl}benzene‐1,2‐diol (pydopa, 2), were synthesized and their photocytotoxicity studied. Complexes 3 and 4 with [phenyl‐N,N‐bis(pyridin‐2‐yl)methyl]methanamine (phbpa) were used as controls. The catecholate complexes showed an absorption band near 720 nm. The 5e– paramagnetic complexes showed a FeIII/FeII irreversible response near –0.45 V and a quasi‐reversible catechol/semiquinone couple near 0.5 V versus saturated calomel electrode (SCE) in DMF/0.1 M tetrabutylammonium perchlorate. They showed photocytotoxicity in red/visible light in HeLa, HaCaT, MCF‐7, and A549 cells. Complexes 1 and 2 displayed mitochondrial localization, reactive oxygen species (ROS) generation under red light, and apoptotic cell death. Control complexes 3 and 4 exhibited uniform distribution throughout the cell. The complexes showed DNA photocleavage under red light (785 nm), forming hydroxyl radicals as the ROS.
The influence of methyl jasmonate, cholesterol and l‐arginine on solasodine production in hairy root culture of Solanum mammosum
Authors: Ooi Chai Theam , Syahida Ahmad , Stanslas Johnson , Maziah Mahmood 
Published: February 2016

The increasing demand of diosgenin for high‐revenue synthesis of steroid hormones by the pharmaceutical industries has driven researchers to look for other alternatives. Solasodine which was reported to be present in Solanum mammosum is known to be a potential source. The present study highlighted that added methyl jasmonate, cholesterol and l‐arginine into the modified liquid full‐strength Murashige and Skoog (MS) medium (with ammonium to nitrate ratio 10.3 mM: 39.4 mM, and 4% (w/v) sucrose) could influence the solasodine production in the hairy roots of S. mammosum. The findings showed that both hairy root line‐ATCC31798 and line‐A4 (which were separately induced by Agrobacterium rhizogenes strain ATCC31798 and A4) acquired solasodine productivity of 4.5 mg/g dry weight roots with average dry biomass of 190 mg after 32 days culture, when using 50 mg fresh weight roots as initial inoculum size, with 100 mM cholesterol, 1000 μM l‐arginine and 300 μM methyl jasmonate added simultaneously into the culture medium on day 20 of culture. The amount of solasodine obtained was five times higher than those without both the elicitor and precursor treatment. The improved solasodine production with a high‐biomass growth could reduce the production cost of steroid synthesis in the long run.
Planform dynamics of the Iquitos anabranching structure in the Peruvian Upper Amazon River
Authors: Mendoza Alejandro , Abad Jorge D. , Frias Christian E. , Ortals Collin , Paredes Jorge , Montoro Hugo , Vizcarra Jorge , Simon Cesar , Soto‐Cortés Gabriel 
Published: February 2016

AbstractThe upper reach of the Amazon River has a very dynamic morphology, with the highest rates of migration observed in the entire Amazon River. It has an anabranching channel pattern which alternates between a condition of single channel and anabranching structures; in particular, the anabranching structure near Iquitos City shows an interesting channel behavior. Its channels migrate at different rates, where there are processes of narrowing and widening, and also collision and development of new channels. The temporal evolution of the Iquitos anabranching structure is described during the period from 1985 to 2014. The study is carried out by using satellite images to track the migration patterns, which are contrasted to the underlying geological units in the valley. Bathymetry of the structure and several velocity transects were obtained during a field campaign prior to the 2012 historic flood event. This information allowed for numerical modeling in order to compute the hydrodynamic flow field that complements the temporal analysis, aiming to understand the planform migration patterns after the 2012 flood event. It is observed that the geological units play an important role in modulating the migration rates and planform development of the channels. The channels in the structure are in contention to be the main channel, which become the secondary channel after migration. This causes the channels to experience a rise in bed elevation and narrowing of the channel itself; if this trend continues for several more years, these channels will detach from the Iquitos anabranching structure, thus forming paleo‐channels. This geomorphic process is important for horizontal and vertical soil heterogeneity along the floodplain. In general, the analysis shows a complex interaction between the underlying geological units, flow structure, morphology of the bed and planform migration. Copyright © 2016 John Wiley & Sons, Ltd.