bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of temporal variation in community‐level fruit abundance on seed dispersal by birds across woody species
Authors: Naoe Shoji , Masaki Takashi , Sakai Shoko 
Published: October 2018

Premise of the StudyIn animal‐dispersed plants, seed dispersal patterns of the same species in the same habitat can greatly differ among individuals and temporally. Many studies have revealed the pervasive effects of spatial variation in fruit abundance on seed dispersal of individual plants. By contrast, very few studies have investigated the temporal variation in seed dispersal.MethodsWe investigated the effects of conspecific and community‐level fruit abundance on fruit removal rate and seed dispersal distance of six bird‐dispersed woody species in a Japanese temperate forest for 3 yr. The six species share similar fruit characteristics but have different fruiting seasons. In addition, we also considered the effects of bird seasonality in diet and species composition on seed dispersal.Key ResultsInter‐annual and inter‐seasonal variation in community‐level fruit abundance determined both fruit removal and the seed dispersal distance across species, but the effect differed with seasonal changes in bird behavior. Abundant fruit satiated fruit removal by birds only during fruit‐feeding periods, not during insect‐feeding periods. A scarcity of fruit increased the dispersal distance, but only during the migratory period. This difference was probably due to the different foraging behaviors of passing migrants and territorial birds.ConclusionsOur results illustrated that temporal variation in community‐level fruit abundance could be a determining factor for seed dispersal in temperate forests. The effects of temporal variations in fruit abundance on seed dispersal patterns should be investigated in other ecosystems in order to understand their importance and associations with frugivore phenology.
Molecular Sieving of Ethane from Ethylene through the Molecular Cross‐Section Size Differentiation in Gallate‐based Metal–Organic Frameworks
Authors: Bao Zongbi , Wang Jiawei , Zhang Zhiguo , Xing Huabin , Yang Qiwei , Yang Yiwen , Wu Hui , Krishna Rajamani , Zhou Wei , Chen Banglin , Ren Qilong 
Published: October 2018

AbstractPurification of C2H4 from an C2H4/C2H6 mixture, one of the most important while challenging industrial separation processes, is mainly through energy‐intensive cryogenic distillation. Now a family of gallate‐based metal–organic framework (MOF) materials is presented, M‐gallate (M=Ni, Mg, Co), featuring 3D interconnected zigzag channels, the aperture sizes of which (3.47–3.69 Å) are ideally suitable for molecular sieving of ethylene (3.28×4.18×4.84 Å3) and ethane (3.81×4.08×4.82 Å3) through molecular cross‐section size differentiation. Co‐gallate shows an unprecedented IAST selectivity of 52 for C2H4 over C2H6 with a C2H4 uptake of 3.37 mmol g−1 at 298 K and 1 bar, outperforming the state‐of‐the‐art MOF material NOTT‐300. Direct breakthrough experiments with equimolar C2H4/C2H6 mixtures confirmed that M‐gallate is highly selective for ethylene. The adsorption structure and mechanism of ethylene in the M‐gallate was further studied through neutron diffraction experiments.
A Stable Bifunctional Catalyst for Rechargeable Zinc–Air Batteries: Iron–Cobalt Nanoparticles Embedded in a Nitrogen‐Doped 3D Carbon Matrix
Authors: Liu Xu , Wang Lei , Yu Peng , Tian Chungui , Sun Fanfei , Ma Jingyuan , Li Wei , Fu Honggang 
Published: October 2018

AbstractLow‐cost, efficient bifunctional electrocatalysts are needed to mediate the oxygen reduction and oxygen evolution reactions (ORR/OER) in Zn–air batteries. Such catalysts should offer binary active sites and an ability to transfer oxygen‐based species and electrons. A 3D catalyst, composed of nanoparticles of CoFe alloy embedded in N‐doped carbon nanotubes tangled with reduced graphene oxide, was developed, which presents appreciable ORR/OER activity when applied in a Zn–air battery. A high open‐circuit voltage of 1.43 V, a stable discharge voltage of 1.22 V, a high energy efficiency of 60.1 %, and excellent stability after 1 600 cycles at 10 mA cm−2 are demonstrated. An all‐solid‐state battery had an outstanding lifetime and high cell efficiency even upon bending. In situ X‐ray absorption spectroscopy revealed that OOH* and O* intermediates induce variations in the Fe−Fe and Co−Co bond lengths, respectively, suggesting that Fe and Co species are crucial to the ORR/OER processes.
Radical‐Mediated Thiol‐Ene Strategy: Photoactivation of Thiol‐Containing Drugs in Cancer Cells
Authors: Sun Shuang , Oliveira Bruno L. , Jiménez‐Osés Gonzalo , Bernardes Gonçalo J. L. 
Published: October 2018

AbstractPhotoactivated drugs provide an opportunity to improve efficacy alongside reducing side‐effects in the treatment of severe diseases such as cancer. Described herein is a photoactivation decaging method of isobutylene‐caged thiols through a UV‐initiated thiol‐ene reaction. The method was demonstrated with an isobutylene‐caged cysteine, cyclic disulfide‐peptide, and thiol‐containing drug, all of which were rapidly and efficiently released under mild UV irradiation in the presence of thiol sources and a photoinitiator. Importantly, it is shown that the activity of histone deacetylase inhibitor largazole can be switched off when stapled, but selectively switched on within cancer cells when irradiated with non‐phototoxic light.
Spectroscopic Evidence for an Attractive Cation–Cation Interaction in Hydroxy‐Functionalized Ionic Liquids: A Hydrogen‐Bonded Chain‐like Trimer
Authors: Niemann Thomas , Strate Anne , Ludwig Ralf , Zeng Helen J. , Menges Fabian S. , Johnson Mark A. 
Published: October 2018

AbstractWe address the formation of hydrogen bonded domains among the cationic constituents of the ionic liquid (IL) 1‐(3‐hydroxypropyl)pyridinium tetrafluoroborate [HPPy][BF4] by means of cryogenic ion vibrational predissociation spectroscopy of cold (ca. 35 K) gas‐phase cluster ions and quantum chemistry. Specifically, analysis of the OH stretching bands reveals a chain‐like OH⋅⋅⋅OH⋅⋅⋅OH⋅⋅⋅BF4− binding motif involving the three cations in the cationic quinary cluster ion (HPPy+)3(BF4−)2. Calculations show that this cooperative H‐bond attraction compensates for the repulsive Coulomb forces and results in stable complexes that successfully compete with those in which the OH groups are predominantly attached to the counter anions. Our combined experimental and theoretical approach provides insight into the cooperative effects that lead to the formation of hydrogen bonded domains involving the cationic constituents of ILs.
Multifunctional Catalysts for H2O2‐Resistant Hydrogen Fuel Cells
Authors: Mori Yuki , Ando Tatsuya , Matsumoto Takahiro , Yatabe Takeshi , Kikkawa Mitsuhiro , Yoon Ki‐Seok , Ogo Seiji 
Published: October 2018

AbstractThe development of hydrogen fuel cells is greatly hindered by the unwanted generation of H2O2 at the cathode. A non‐Pt cathode catalyst is now shown to be capable of simultaneously reducing both O2 and H2O2, thus rendering H2O2 a useful part of the feed stream. The applicability of this unique catalyst is demonstrated by employing it in a fuel cell running on H2/CO and O2/H2O2.
One‐pot stepwise reductive amination reaction by N‐coordinate sulfonamido‐functionalized Ru(II) complexes in water
Authors: Kayacı Nilgün , Dayan Serkan , Özdemir Namık , Dayan Osman , Kalaycıoğlu Özpozan Nilgün 
Published: October 2018

New complexes of formula [RuCl(p‐cymene)(L)] (7–12) were prepared with [RuCl2(p‐cymene)]2 and pre‐synthesized N‐arenesulfonly‐o‐phenylenediamines (1–6) and characterized using 1H NMR, 13C NMR, Fourier transform infrared and UV–visible spectroscopic techniques, and single‐crystal X‐ray diffraction analysis was performed for one complex (8). Complexes 7–12 were investigated in the reduced imine synthesis reaction (in the presence of HCOONa/HCOOH). The best turnover frequency values were found to be 100 h−1 for 1 and 99 h−1 for 6 in the transfer hydrogenative reductive amination reaction of 4‐methoxyaniline and 3,4,5‐trimethoxybenzaldehyde. The most important feature of this reaction is that it is an environmental friendly procedure because of being conducted in an aqueous environment. That no organic solvent is used allows one to say that this reaction represents green chemistry.
Synthesis and Characterization of VO2+, Co2+, Ni2+, Cu2+ and Zn2+ Complexes of a Schiff base ligand derived from ethyl 2‐amino‐6‐ethyl‐4,5,6,7‐tetrahydrothieno[2,3‐c]pyridine‐3‐carboxylate and their Investigation as fungicide Agents
Authors: Shakdofa Mohamad M.E. , Labib Ammar A. , Abdel‐Hafez Naglaa A. , Mousa Hanan A. 
Published: October 2018

Complexes of VO2+, Co2+, Ni2+, Cu2+, and Zn2+ ethyl‐6‐ethyl‐2‐((2‐hydroxybenzylidene)amino)‐4,5,6,7‐tetrahydrothieno[2,3‐c]pyridine‐3‐carboxylate were synthesized and characterized via different spectroscopic techniques. The whole results declared that the complexes assembled in 1:1 mole ratio furthermore, the spectroscopic data analysis proved the present ligand adhered to the different metal ions in neutral or monobasic tridentate ligand via azomethine nitrogen, carbonyl oxygen atoms and protonated/deprotonated phenolic hydroxyl group. The UV–Vis. and ESR spectroscopic data analysis proposed a distorted octahedral or octahedral structure for all complexes. The ESR spectra for Cu2+ complexes (5–6) revealed an axial symmetry with g‖ > g┴ > ge, denoting to distorted octahedral Cu2+ complex and the free electrons in the M shell exist in a d(x2‐y2) orbital with a remarkable covalent bond aspect. The synthesized complexes showed moderate to superb fungicide activity. All complexes are more active than both standard drug and ligand against C. albicans where complexes (5–7) are more active against A. flavus and compounds (1), (4–5), (7) against S. cerevisiae whereas only complex (6) is more active against A niger.
Mitochondrial Deformation During the Cardiac Mechanical Cycle
Authors: Rog‐Zielinska E. A. , O'Toole E. T. , Hoenger A. , Kohl P. 
Published: October 2018

ABSTRACTCardiomyocytes both cause and experience continual cyclic deformation. The exact effects of this deformation on the properties of intracellular organelles are not well characterized, although they are likely to be relevant for cardiomyocyte responses to active and passive changes in their mechanical environment. In the present study we provide three‐dimensional ultrastructural evidence for mechanically induced mitochondrial deformation in rabbit ventricular cardiomyocytes over a range of sarcomere lengths representing myocardial tissue stretch, an unloaded “slack” state, and contracture. We also show structural indications for interaction of mitochondria with one another, as well as with other intracellular elements such as microtubules, sarcoplasmic reticulum and T‐tubules. The data presented here help to contextualize recent reports on the mechanosensitivity and cell‐wide connectivity of the mitochondrial network and provide a structural framework that may aide interpretation of mechanically‐regulated molecular signaling in cardiac cells. Anat Rec, 302:146–152, 2019. © 2018 The Authors. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.
Adjusting the structure and luminescence properties of Sr2−xBaxMgAl22O36:Eu2+ phosphors by Sr:Ba ratio
Authors: Wang Qiang , Mu Zhongfei , Zhang Shaoan , Feng Xing , Zhang Qingtian , Zhu Daoyun , Du Qingping , Wu Fugen 
Published: October 2018

AbstractEuropium ion (Eu2+)‐doped phosphors exhibit adjustable photoluminescence due to the sensitivity of their luminescence to the local environment. It is of great significance to adjust the luminescence of Eu2+ by changing their local environment in the host. In this work, we investigated the effect of strontium/barium (Sr:Ba) ratio on the structure and luminescence properties of Sr2−xBaxMgAl22O36:Eu2+ phosphors. Our investigation indicates that with the decrease of Sr:Ba ratio, the matrix lattice gradually expands and the peak wavelength for the luminescence of Eu2+ presents an obvious blue shift. The occupancy of Eu2+ was analyzed and the reason for the blue shift was explained. Thermal stability for the luminescence of Eu2+ can also be adjusted by changing the Sr:Ba ratio. This work has a positive effect on the regulation of the emission of phosphors and the improvement of thermal stability, which will promote the application of Sr2−xBaxMgAl22O36:Eu2+ phosphors in the field of white light emitting diodes.
Spatiotemporal‐Controlled Reporter for Cell‐Surface Proteolytic Enzyme Activity Visualization
Authors: Cheong Haolun , Kim Jisu , Mu Jing , Zhang Wenmin , Li Juan , Yang HuangHao , Xing Bengang 
Published: October 2018

AbstractLive‐cell imaging of cell‐surface‐associated proteolytic enzymes is crucial to understand their biological roles and functions in both physiological and pathological processes. However, the complexity of the cell membrane environment increases difficulties in specifically investigating targeted proteolytic activities within the microenvironment. Towards this end, a unique, photoremovable, furin‐responsive peptide probe that can undergo spatiotemporal control through UV‐light illumination has been designed and synthesized to aid in visualizing the activity of a cell‐surface‐associated protease enzyme, furin, in live cells. Prior to light irradiation, the photolabile moiety, 4,5‐dimethoxy‐2‐nitrobenzyl, in the peptide sequence of the reporter will block furin‐like enzymatic hydrolysis, and thus, no fluorescence will be observed. Upon simple light illumination, photolysis will occur, thereby revealing the uncaged peptide probe, which can undergo enzyme hydrolysis and lead to an increase in fluorescence signal; this allows the real‐time imaging of endogenous cell‐surface‐associated furin‐like enzyme function in living cells through precise spatial and temporal resolution.
Discovery and Elucidation of the Biosynthesis of Aspernidgulenes: Novel Polyenes from Aspergillus Nidulans by Using Serial Promoter Replacement
Authors: Lin Tzu‐Shyang , Chen Bethany , Chiang Yi‐Ming , Wang Clay C. C. 
Published: October 2018

AbstractThrough serial promoter exchanges, we isolated several novel polyenes, the aspernidgulenes, from Aspergillus nidulans and uncovered their succinct biosynthetic pathway involving only four enzymes. An enoyl reductase (ER)‐less highly reducing polyketide synthase (HR‐PKS) putatively produces a 5,6‐dihydro‐α‐pyrone polyene, which undergoes bisepoxidation, epoxide ring opening, cyclization, and hydrolytic cleavage by three tailoring enzymes to generate aspernidgulene A1 and A2. Our findings demonstrate the prowess of fungal‐tailoring enzymes to transform a polyketide scaffold concisely and efficiently into complex structures. Moreover, comparison with citreoviridin and aurovertin biosynthesis suggests that methylation of the α‐pyrone hydroxy group by methyltransferase (CtvB or AurB) is the branching point at which the biosynthesis of these two classes of compounds diverge. Therefore, scanning for the presence or absence of the gatekeeping α‐pyrone methyltransferase gene in homologous clusters might be a potential way to classify the product bioinformatically as belonging to methylated α‐pyrone polyenes or polyenes containing rings derived from the cyclization of the unmethylated 5,6‐dihydro‐α‐pyrone, such as 2,3‐dimethyl‐γ‐lactone and oxabicyclo[2.2.1]heptane.
Facet Sensitivity of Capping Ligand‐Free Ag Crystals in CO2 Electrochemical Reduction to CO
Authors: Yang Min , Zhang Jiazhou , Cao Yongyong , Wu Minfang , Qian Kun , Zhang Zhenhua , Liu Hongyang , Wang Jianguo , Chen Wei , Huang Weixin 
Published: October 2018

AbstractSilver‐based electrocatalysts are active in catalyzing electrochemical reduction of CO2 to CO. We herein report synthesis of capping ligand‐free Ag cubes and octahedra by morphology‐preserved CO reduction from corresponding Ag2O counterparts and their performance in electrochemical reduction of CO2. Ag cubes are much more active than Ag octahedra and exhibit a stable CO formation rate as high as 142.4 mmolCO gcat−1 h−1 at −0.95 V (vs. RHE). Ag films transiently formed on Ag2O crystals during CO2 electroreduction were observed more active than Ag crystals, revealing a promoting effect of Ag2O substrate on electrocatalytic activity of Ag film. These results clearly identify a facet sensitivity of silver electrocatalysts and highlight the importance of surface cleanness of Ag colloids as efficient electrocatalysts.
Low‐Dimensional Copper Selenide Nanostructures: Controllable Morphology and its Dependence on Electrocatalytic Performance
Authors: Chen Xinqi , Dai Wei , Qin Feng , Xu Kaibing , Xu Hui , Wu Tian , Li Jie , Luo Wei , Yang Jianping 
Published: October 2018

AbstractLow‐dimensional copper selenide (Cu2‐xSe) nanostructures with controllable morphologies are fabricated via the chemical synthesis. The ratio of reactants and the concentration of ligands affect the kinetics of the transformation reaction and control the morphology of Cu2‐xSe nanostructures. The resultant Cu2‐xSe nanostructures are valuated as potential electrocatalysts for oxygen reduction reaction (ORR) in alkaline media at room temperature. The electrocatalytic activity of the Cu2‐xSe nanorods is better than that of other nanostructures. The type and amount of carbon materials mixed with Cu2‐xSe nanorods influence the catalytic performance of the modified electrodes. This study illustrates that the low‐dimensional Cu2‐xSe nanostructures can perform as electrocatalysts for ORR in alkaline media.
A method for improvement of mass resolution and isotope accuracy for laser ablation time‐of‐flight mass spectrometers
Authors: Wiesendanger Reto , Tulej Marek , Grimaudo Valentine , Cedeño‐López Alena , Lukmanov Rustam , Riedo Andreas , Wurz Peter 
Published: October 2018

AbstractAccumulation of spectra is a common approach for improvement of the signal‐to‐noise ratio (SNR) in mass spectrometry. However, severe degradation of the overall spectrum can occur if some individual mass spectra, affected by peak broadening, are included in the accumulation process. In this contribution, we discuss potential sources and effects of spectral distortions by using examples from mass spectra acquired by our miniature laser ablation/ionisation time‐of‐flight mass spectrometer. We show how recent developments in acquisition systems enable to identify individual spectra subjected to peak broadening and present a filtering method capable of systematic and reproducible exclusion of such spectra from the accumulation process. We show that the method can be used on a wide range of materials and present a detailed case study performed on a trevorite mineral sample. Using this method, improvements of the isotope accuracy of Si, Ni, and Cr by factors between 1.6 and 7.7 were achieved. Finally, we discuss the limitations of the method and provide complementary analysis of other materials in the supplementary documents provided with this contribution.
B–B Coupling and B–B Catenation: Computational Study of the Structure and Reactions of Metal–Bis(borylene) Complexes
Authors: Ghorai Sagar , Jemmis Eluvathingal D. 
Published: October 2018

AbstractA detailed molecular orbital analysis of the metal–bis(borylene) complex [Fe(CO)3{B(Dur)B(N(SiMe3)2)}] (Dur=2,3,5,6‐tetramethylphenyl) (1 a) serves as a focal point of recent developments in this area of chemistry, such as B–B coupling and B–B catenation reactions. There is strong a π delocalization between the Fe(CO)3 and (B‐Dur)(B‐N(SiMe3)2) units; the short B–B distance in 1 a is due to this π delocalization. The π‐donor ligand N(SiMe3)2 on the boron provides a decisive stability to the complex 1 a. The LUMO of 1 a has B–B σ‐bonding character. Hence B–B coupling is facilitated by filling the LUMO. Strong σ‐donating ligands, such as PMe3 or PCy3, induce B–B coupling. Expulsion of one CO from 1 a followed by dimerization leads to [Fe(CO)2{B(Dur)B(N(SiMe3)2)}]2 (3 a) with a short Fe−Fe distance of 2.355 Å. A detailed mechanism for the reaction of 3 a with CO to give the B–B catenation product 2 f is presented. The bonding of all intermediates is compared to their isolobal main‐group analogues.
5‐Oxyacetic Acid Modification Destabilizes Double Helical Stem Structures and Favors Anionic Watson–Crick like cmo5U‐G Base Pairs
Authors: Strebitzer Elisabeth , Rangadurai Atul , Plangger Raphael , Kremser Johannes , Juen Michael Andreas , Tollinger Martin , Al‐Hashimi Hashim M. , Kreutz Christoph 
Published: October 2018

AbstractWatson–Crick like G‐U mismatches with tautomeric Genol or Uenol bases can evade fidelity checkpoints and thereby contribute to translational errors. The 5‐oxyacetic acid uridine (cmo5U) modification is a base modification at the wobble position on tRNAs and is presumed to expand the decoding capability of tRNA at this position by forming Watson–Crick like cmo5Uenol‐G mismatches. A detailed investigation on the influence of the cmo5U modification on structural and dynamic features of RNA was carried out by using solution NMR spectroscopy and UV melting curve analysis. The introduction of a stable isotope labeled variant of the cmo5U modifier allowed the application of relaxation dispersion NMR to probe the potentially formed Watson–Crick like cmo5Uenol‐G base pair. Surprisingly, we find that at neutral pH, the modification promotes transient formation of anionic Watson–Crick like cmo5U−‐G, and not enolic base pairs. Our results suggest that recoding is mediated by an anionic Watson–Crick like species, as well as bring an interesting aspect of naturally occurring RNA modifications into focus—the fine tuning of nucleobase properties leading to modulation of the RNA structural landscape by adoption of alternative base pairing patterns.