bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrocatalytic Synthesis of Ammonia at Room Temperature and Atmospheric Pressure from Water and Nitrogen on a Carbon‐Nanotube‐Based Electrocatalyst
Authors: Chen Shiming , Perathoner Siglinda , Ampelli Claudio , Mebrahtu Chalachew , Su Dangsheng , Centi Gabriele 
Published: January 2017

AbstractAmmonia is synthesized directly from water and N2 at room temperature and atmospheric pressure in a flow electrochemical cell operating in gas phase (half‐cell for the NH3 synthesis). Iron supported on carbon nanotubes (CNTs) was used as the electrocatalyst in this half‐cell. A rate of ammonia formation of 2.2×10−3 g
m−2 h−1 was obtained at room temperature and atmospheric pressure in a flow of N2, with stable behavior for at least 60 h of reaction, under an applied potential of −2.0 V. This value is higher than the rate of ammonia formation obtained using noble metals (Ru/C) under comparable reaction conditions. Furthermore, hydrogen gas with a total Faraday efficiency as high as 95.1 % was obtained. Data also indicate that the active sites in NH3 electrocatalytic synthesis may be associated to specific carbon sites formed at the interface between iron particles and CNT and able to activate N2, making it more reactive towards hydrogenation.
Enolonium Species—Umpoled Enolates
Authors: Arava Shlomy , Kumar Jayprakash N. , Maksymenko Shimon , Iron Mark A. , Parida Keshaba N. , Fristrup Peter , Szpilman Alex M. 
Published: January 2017

AbstractEnolonium species/iodo(III)enolates of carbonyl compounds have been suggested to be intermediates in a wide variety of hypervalent iodine induced chemical transformations of ketones, including α‐C−O, α‐C−N, α‐C−C, and α‐carbon–halide bond formation, but they have never been characterized. We report that these elusive umpoled enolates may be made as discrete species that are stable for several minutes at −78 °C, and report the first spectroscopic identification of such species. It is shown that enolonium species are direct intermediates in C−O, C−N, C−Cl, and C−C bond forming reactions. Our results open up chemical space for designing a variety of new transformations. We showcase the ability of enolonium species to react with prenyl, crotyl, cinnamyl, and allyl silanes with absolute regioselectivity in up to 92 % yield.
Retention of the Zn−Zn bond in [Ge9Zn−ZnGe9]6− and Formation of [(Ge9Zn)−(Ge9)−(ZnGe9)]8− and Polymeric [−(Ge9Zn)2−−]
Authors: Mayer Kerstin , Jantke Laura‐Alice , Schulz Stephan , Fässler Thomas F. 
Published: January 2017

AbstractReactions of ZnI2L2 (where L=[HC(PPh2NPh)]−) with solutions of the Zintl phase K4Ge9 in liquid ammonia lead to retention of the Zn−Zn bond and formation of the anion [(η4‐Ge9)Zn−Zn(η4‐Ge9)]6−, representing the first complex with a Zn−Zn unit carrying two cluster entities. The trimeric anion [(η4‐Ge9)Zn{μ2(η1:η1Ge9)}Zn(η4‐Ge9)]8− forms as a side product, indicating that oxidation reactions also take place. The reaction of Zn2Cp*2 (Cp*=1,2,3,4,5‐pentamethylcyclopentadienyl) with K4Ge9 in ethylenediamine yielded the linear polymeric unit
{[Zn[μ2(η4:η1Ge9)]}2− with the first head‐to‐tail arrangement of ten‐atom closo‐clusters. All anions were obtained and structurally characterized as [A(2.2.2‐crypt)]+ salts (A=K, Rb). Copious computational analyses at a DFT‐PBE0/def2‐TZVPP/PCM level of theory confirm the experimental structures and support the stability of the two hypothetical ten vertex cluster fragments closo‐[Ge9Zn]2− and (paramagnetic) [Ge9Zn]3−.
Turn‐On Fluorescence in Tetra‐NHC Ligands by Rigidification through Metal Complexation: An Alternative to Aggregation‐Induced Emission
Authors: Sinha Narayan , Stegemann Linda , Tan Tristan T. Y. , Doltsinis Nikos L. , Strassert Cristian A. , Hahn F. Ekkehardt 
Published: January 2017

AbstractTwo tetraphenylethylene (TPE) bridged tetraimidazolium salts, [H4L‐Et](PF6)4 and [H4L‐Bu](PF6)4, were used as precursors for the synthesis of the dinuclear AgI and AuI tetracarbene complexes [Ag2(L‐Et)](PF6)2, [Ag2(L‐Bu)](PF6)2, [Au2(L‐Et)](PF6)2, and [Au2(L‐Bu)](PF6)2. The tetraimidazolium salts show almost no fluorescence (ΦF<1 %) in dilute solution while their NHC complexes display fluorescence “turn‐on” (ΦF up to 47 %). This can be ascribed to rigidification mediated by the restriction of intramolecular rotation within the TPE moiety upon complexation. DFT calculations confirm that the metals are not involved in the lowest excited singlet and triplet states, thus explaining the lack of phosphorescence and fast intersystem crossing as a result of heavy atom effects. The rigidification upon complexation for fluorescence turn‐on constitutes an alternative to the known aggregation‐induced emission (AIE).
An NHC–Silyl–NHC Pincer Ligand for the Oxidative Addition of C−H, N−H, and O−H Bonds to Cobalt(I) Complexes
Authors: Sun Jian , Luo Lun , Luo Yi , Deng Liang 
Published: January 2017

AbstractN‐Heterocyclic carbene based pincer ligands bearing a central silyl donor, [CSiC]−, have been envisioned as a class of strongly σ‐donating ligands that can be used for synthesizing electron‐rich transition‐metal complexes for the activation of inert bonds. However, this type of pincer ligand and complexes thereof have remained elusive owing to their challenging synthesis. We herein describe the first synthesis of a CSiC pincer ligand scaffold through the coupling of a silyl–NHC chelate with a benzyl–NHC chelate induced by one‐electron oxidation in the coordination sphere of a cobalt complex. The monoanionic CSiC ligand stabilizes the CoI dinitrogen complex [(CSiC)Co(N2)] with an unusual coordination geometry and enables the challenging oxidative addition of E−H bonds (E=C, N, O) to CoI to form CoIII complexes. The structure and reactivity of the cobalt(I) complex are ascribed to the unique electronic properties of the CSiC pincer ligand, which provides a strong trans effect and pronounced σ‐donation.
Anisotropically Swelling Gels Attained through Axis‐Dependent Crosslinking of MOF Crystals
Authors: Ishiwata Takumi , Kokado Kenta , Sada Kazuki 
Published: January 2017

AbstractAnisotropically deforming objects have attracted considerable interest for use in molecular machines and artificial muscles. Herein, we focus on a new approach based on the crystal crosslinking of organic ligands in a pillared‐layer metal–organic framework (PLMOF). The approach involves the transformation from crosslinked PLMOF to polymer gels through hydrolysis of the coordination bonds between the organic ligands and metal ions, giving a network polymer that exhibits anisotropic swelling. The anisotropic monomer arrangement in the PLMOF underwent axis‐dependent crosslinking to yield anisotropically swelling gels. Therefore, the crystal crosslinking of MOFs should be a useful method for creating actuators with designable deformation properties.
Highly para‐Selective C−H Alkylation of Benzene Derivatives with 2,2,2‐Trifluoroethyl α‐Aryl‐α‐Diazoesters
Authors: Ma Ben , Chu Zhaowei , Huang Ben , Liu Zhenli , Liu Lu , Zhang Junliang 
Published: January 2017

AbstractCompared to the most popular directing‐group‐assisted strategy, the “undirected” strategy for C−H bond functionalization represents a more flexible but more challenging approach. Reported herein is a gold‐catalyzed highly site‐selective C(sp2)−H alkylation of unactivated arenes with 2,2,2‐trifluoroethyl α‐aryl‐α‐diazoesters. This protocol demonstrates that high site‐selective C−H bond functionalization can be achieved without the assistance of a directing group. In this transformation, both the gold catalyst and trifluoroethyl group on the ester of the diazo compound play vital roles for achieving the chemo‐ and regioselectivity.
Four‐Shell Polyoxometalates Featuring High‐Nuclearity Ln26 Clusters: Structural Transformations of Nanoclusters into Frameworks Triggered by Transition‐Metal Ions
Authors: Li Zhong , Li Xin‐Xiong , Yang Tao , Cai Zhen‐Wen , Zheng Shou‐Tian 
Published: January 2017

AbstractA series of polyoxometalates (POMs) that incorporate the highest‐nuclearity Ln clusters that have been observed in such structures to date (Ln26 , Ln=La and Ce) are described, which exhibit giant multishell configurations (Ln⊂W6⊂Ln26⊂W100). Their structures are remarkably different from known giant POMs that feature multiple Ln ions. In particular, the incorporated Ln–O clusters with a nuclearity of 26 are significantly larger than known high‐nuclearity (≤10) Ln–O clusters in POM chemistry. Furthermore, they also contain the largest number of La and Ce centers for any POM reported to date and represent a new kind of rare giant POMs with more than 100 W atoms. Interestingly, the La26‐containing POM can undergo a single‐crystal to single‐crystal structural transformation in the presence of various transition‐metal ions, such as Cu2+, Co2+, and Ni2+, from an inorganic molecular nanocluster into an inorganic–organic hybrid extended framework that is built from POM building blocks with even higher‐nuclearity La28 clusters bridged by transition‐metal complexes.
Physicochemical and antimicrobial properties of natural rubber latex films in the presence of vegetable oil microemulsions
Authors: Lee Siang Yin , Ng Angie , Jaswan Singh Manroshan Singh , Liew Yun Khoon , Gan Seng Neon , Koh Rhun Yian 
Published: January 2017

ABSTRACTA series of vegetable oil microemulsions are formulated and incorporated into NR latex to study the potent antimicrobial activity of vegetable oil‐plasticized NR latex film against the adherent bacteria on the treated film. The particle size of latex incorporated with 2.50 phr of oil has attained up to 424 nm after incubated at 35 ± 2 °C for 24 h. The tensile stress of all NR latex films are relatively low, ranged 0.289 to 0.511 MPa. All emulsions are found compatible with NR and the low contact angles (<90°) corresponded to no oil blooming onto the surfaces of NR latex films. The crosslink densities are in good correlation with tensile strengths. The potent antimicrobial properties of the NR latex films are investigated from the viability assessment of the adherent tested Escherichia coli ATCC 25922 (E. coli ATCC 25922) and Staphylococcus aureus ATCC 25923 (S. aureus ATCC 25923). Results shows that NR latex film incorporated with palm kernel oil/soybean oil blend, NR‐E(P/S = 7/3), has significantly killed the adherent S. aureus with 92.5% reduction but showed no significant log reduction in E. coli. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44788.
Automated home monitoring and management of patient‐reported symptoms during chemotherapy: results of the symptom care at home RCT
Authors: Mooney Kathi H. , Beck Susan L. , Wong Bob , Dunson William , Wujcik Debra , Whisenant Meagan , Donaldson Gary 
Published: January 2017

AbstractTechnology‐aided remote interventions for poorly controlled symptoms may improve cancer symptom outcomes. In a randomized controlled trial, the efficacy of an automated symptom management system was tested to determine if it reduced chemotherapy‐related symptoms. Prospectively, 358 patients beginning chemotherapy were randomized to the Symptom Care at Home (SCH) intervention (n = 180) or enhanced usual care (UC) (n = 178). Participants called the automated monitoring system daily reporting severity of 11 symptoms. SCH participants received automated self‐management coaching and nurse practitioner (NP) telephone follow‐up for poorly controlled symptoms. NPs used a guideline‐based decision support system. Primary endpoints were symptom severity across all symptoms, and the number of severe, moderate, mild, and no symptom days. A secondary endpoint was individual symptom severity. Mixed effects linear modeling and negative binominal regressions were used to compare SCH with UC. SCH participants had significantly less symptom severity across all symptoms (P < 0.001). On average, the relative symptom burden reduction for SCH participants was 3.59 severity points (P < 0.001), roughly 43% of UC. With a very rapid treatment benefit, SCH participants had significant reductions in severe (67% less) and moderate (39% less) symptom days compared with UC (both P < 0.001). All individual symptoms, except diarrhea, were significantly lower for SCH participants (P < 0.05). Symptom Care at Home dramatically improved symptom outcomes. These results demonstrate that symptoms can be improved through automated home monitoring and follow‐up to intensify care for poorly controlled symptoms.
Alcohol Dehydrogenases Catalyze the Reduction of Thioesters
Authors: Younes Sabry H. H. , Ni Yan , Schmidt Sandy , Kroutil Wolfgang , Hollmann Frank 
Published: January 2017

AbstractAlcohol dehydrogenases are well‐established catalysts for various reduction reactions. However, the reduction of carboxylic acid derivatives has not yet been reported with these enzymes. In this contribution, we demonstrated that carboxylic acid thioesters could be readily reduced by a range of alcohol dehydrogenases, albeit at significantly reduced rates relative to those observed for corresponding ketones. A molecular explanation, especially for the lower turnover rates for thioesters relative to those obtained for ketones, is presented, as is a preliminary substrate scope.
Luminescent Metal–Organic‐Framework‐Based Label‐Free Assay of Polyphenol Oxidase with Fluorescent Scan
Authors: Li Yue , Guo An , Chang Lan , Li Wen‐Juan , Ruan Wen‐Juan 
Published: January 2017

AbstractMetal–organic frameworks (MOFs) are emerging in recent years as a kind of versatile fluorescent sensing materials, but their application to enzyme assays has rarely been studied. Here, the first example of a MOF‐based label‐free enzyme assay system is reported. A luminescent MOF was synthesized and applied to the activity analysis of polyphenol oxidase (PPO). With its distinct responses to the phenolic substrate and o‐quinone product, this MOF could transduce the extent of PPO‐catalyzed oxidation to fluorescence signal and enable the real‐time monitoring of this reaction. Wide substrate adaptability and high sensitivity (detection limit=0.00012 U mL−1) were exhibited by this method, which meets the requirement of common bioanalysis. Interestingly, by the comparison with molecular capturing reagents, the heterogeneous nature of this MOF‐based assay effectively preventing the interaction with the enzyme was proven, thus ensuring the authenticity of results.
Functionalization of Hydrogenated Chemical Vapour Deposition‐Grown Graphene by On‐Surface Chemical Reactions
Authors: Drogowska Karolina , Kovaříček Petr , Kalbáč Martin 
Published: January 2017

AbstractInvited for the cover of this issue is the group of Martin Kalbáč at the Academy of Sciences of the Czech Republic. The image depicts in comic‐book style the exciting prospect of functionalizing partly hydrogenated graphene. Read the full text of the article at 10.1002/chem.201605385.
Sodium Titanate/Carbon (Na2Ti3O7/C) Nanofibers via Electrospinning Technique as the Anode of Sodium‐ion Batteries
Authors: Zou Wei , Fan Cong , Li Jingze 
Published: January 2017

AbstractTo overcome the sluggish kinetics in sodium‐ion batteries, sodium titanate/carbon (Na2Ti3O7/C) composite nanofibers as anode materials have successfully been synthesized via a simple electrospinning method. After calcination at 800 °C for 3 h, the obtained Na2Ti3O7 nanoparticles are randomly dispersed in the matrix of in situ pyrolized carbon nanofiber. The Na2Ti3O7/C hybrid nanofiber obtained with 2.5 wt% of poly (vinylpyrrolidone) additive in the precursor solution has the smallest diameter of ~120 nm and the finest particle size of ~40 nm, exhibiting the best rate performance of 101 mAh•g−1 at 4 C and excellent capacity retention of 82% at 1 C after 100 cycles. Furthermore, this composite nanofiber also demonstrates good cycling performance under low current density of 0.1 C, which is attributed to the formation of stable solid electrolyte interface (SEI) film induced by small volume expansion/contraction of the fine Na2Ti3O7 nanoparticles during the charge/discharge process.
Unconventional Nonlinear Input–Output Response in a Luminescent Molecular Switch by Inner Filtering Effects
Authors: Baroncini Massimo , Semeraro Monica , Credi Alberto 
Published: January 2017

AbstractNonlinear input–output relations are at the basis of the regulation of biochemical processes in living organisms and are important for the development of digital logic circuits based on molecules. In this article we show that a linear change of a chemical input can be translated into an exponential change of a luminescence output in a simple fluorescent acid‐base switch based on 8‐methoxyquinoline. Such unconventional behavior arises from the fact that part of the light emitted by the switch in its basic form is reabsorbed by the acid form, and is made possible by the particular spectroscopic properties of the two forms. Systems of this kind could act as noise filters in analog‐to‐digital conversion, and as control elements to increase the functional complexity of artificial molecular devices.
Towards full Quantum‐Mechanics‐based Protein–Ligand Binding Affinities
Authors: Ehrlich Stephan , Göller Andreas H. , Grimme Stefan 
Published: January 2017

AbstractComputational methods play a key role in modern drug design in the pharmaceutical industry but are mostly based on force fields, which are limited in accuracy when describing non‐classical binding effects, proton transfer, or metal coordination. Here, we propose a general fully quantum mechanical (QM) scheme for the computation of protein–ligand affinities. It works on a single protein cutout (of about 1000 atoms) and evaluates all contributions (interaction energy, solvation, thermostatistical) to absolute binding free energy on the highest feasible QM level. The methodology is tested on two different protein targets: activated serine protease factor X (FXa) and tyrosine‐protein kinase 2 (TYK2). We demonstrate that the geometry of the model systems can be efficiently energy‐minimized by using general purpose graphics processing units, resulting in structures that are close to the co‐crystallized protein–ligand structures. Our best calculations at a hybrid DFT level (PBEh‐3c composite method) for the FXa ligand set result in an overall mean absolute deviation as low as 2.1 kcal mol−1. Though very encouraging, an analysis of outliers indicates that the structure optimization level, conformational sampling, and solvation treatment require further improvement.
Characterization of hallucinogenic phenethylamines using high‐resolution mass spectrometry for non‐targeted screening purposes
Authors: Pasin Daniel , Cawley Adam , Bidny Sergei , Fu Shanlin 
Published: January 2017

Hallucinogenic phenethylamines such as 2,5‐dimethoxyphenethylamines (2C–X) and their N‐(2‐methoxybenzyl) derivatives (25X–NBOMe) have seen an increase in novel analogues in recent years. These rapidly changing analogues make it difficult for laboratories to rely on traditional targeted screening methods to detect unknown new psychoactive substances (NPS). In this study, twelve 2C–X, six 2,5‐dimethoxyamphetamines (DOX), and fourteen 25X–NBOMe derivatives, including two deuterated derivatives (2C–B‐d6 and 25I–NBOMe‐d9), were analyzed using ultra‐performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry (UPLC‐QTOF‐MS). Collision‐induced dissociation (CID) experiments were performed using collision energies set at 10, 20, and 40 eV. For 2C–X and DOX derivatives, common losses were observed including neutral and radical losses such as NH3 (17.0265 Da), •CH6N (32.0500 Da), C2H7N (45.0578 Da) and C2H9N (47.0735 Da). 2C–X derivatives displayed common product ions at m/z 164.0837 ([C10H12O2]+•), 149.0603 ([C9H9O2]+), and 134.0732 ([C9H10O]+•) while DOX derivatives had common product ions at m/z 178.0994 ([C11H14O2]+•), 163.0754 ([C10H11O2]+), 147.0804 ([C10H11O]+), and 135.0810 ([C9H11O]+). 25X–NBOMe had characteristic product ions at m/z 121.0654 ([C8H9O]+) and 91.0548 ([C7H7]+) with minor common losses corresponding to 2‐methylanisole (C8H10O, 122.0732 Da), 2‐methoxybenzylamine (C8H11NO, 137.0847 Da), and •C9H14NO (152.1074 Da). Novel analogues of the selected classes can be detected by applying neutral loss filters (NLFs) and extracting the common product ions. Copyright © 2017 John Wiley & Sons, Ltd.
Mediterranean diet and risk of heart failure: results from the PREDIMED randomized controlled trial
Authors: Papadaki Angeliki , Martínez‐González Miguel Ángel , Alonso‐Gómez Angel , Rekondo Javier , Salas‐Salvadó Jordi , Corella Dolores , Ros Emilio , Fitó Montse , Estruch Ramon , Lapetra José , García‐Rodriguez Antonio , Fiol Miquel , Serra‐Majem Lluís , Pintó Xavier , Ruiz‐Canela Miguel , Bulló Monica , Serra‐Mir Mercè , Sorlí Jose V. , Arós Fernando 
Published: January 2017

AbstractAimsThe aim of this study was to evaluate the effect of the Mediterranean diet (MedDiet) on the incidence of heart failure (HF), a pre‐specified secondary outcome in the PREDIMED (PREvención con DIeta MEDiterránea) primary nutrition‐intervention prevention trial.Methods and resultsParticipants at high risk of cardiovascular disease were randomly assigned to one of three diets: MedDiet supplemented with extra‐virgin olive oil (EVOO), MedDiet supplemented with nuts, or a low‐fat control diet. Incident HF was ascertained by a Committee for Adjudication of events blinded to group allocation. Among 7403 participants without prevalent HF followed for a median of 4.8 years, we observed 29 new HF cases in the MedDiet with EVOO group, 33 in the MedDiet with nuts group, and 32 in the control group. No significant association with HF incidence was found for the MedDiet with EVOO and MedDiet with nuts, compared with the control group [hazard ratio (HR) 0.68; 95% confidence interval (CI) 0.41–1.13, and HR 0.92; 95% CI 0.56–1.49, respectively].ConclusionIn this sample of adults at high cardiovascular risk, the MedDiet did not result in lower HF incidence. However, this pre‐specified secondary analysis may have been underpowered to provide valid conclusions. Further randomized controlled trials with HF as a primary outcome are needed to better assess the effect of the MedDiet on HF risk.Trial registration:ISRCTN35739639.
Impedimetric Enzyme‐Free Detection of Glucose via a Computation‐Designed Molecularly Imprinted Electrochemical Sensor Fabricated on Porous Ni Foam
Authors: Li X. , Niu X.H. , Wu H.Y. , Meng S.C. , Zhang W.C. , Pan J.M. , Qiu F.X. 
Published: January 2017

AbstractHere we report a new molecularly imprinted electrochemical sensor (MIECS) for the impedimetric enzyme‐free analysis of glucose. A computational modeling strategy was first utilized to screen promising functional monomers for imprinting assembly, and simulation data suggested that methacrylic acid (MAA) exhibited a preferable capability to recognize the target molecule compared to other common monomers. Then the MIECS was prepared via introducing MAA‐based recognition sites onto a porous Ni foam with large surface. The fabricated sensor was subtly characterized by Raman spectroscopy, scanning electron microscopy, and cyclic voltammetry, and an impedimetric method was selected to detect the glucose target in a basic medium. Experimental results demonstrated that the proposed MIECS could selectively recognize glucose against coexisting species, with good linear responses of the charge transfer resistance upon the target concentration in the scope of 10∼55 mM. These results indicate its potential applications in the recognization and detection of glucose in complex matrices.