bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vertically π‐Expanded Imidazo[1,2‐a]pyridine: The Missing Link of the Puzzle
Authors: Firmansyah Dikhi , Banasiewicz Marzena , Deperasińska Irena , Makarewicz Artur , Kozankiewicz Boleslaw , Gryko Daniel T. 
Published: May 2014

AbstractThe dehydrogenative coupling of imidazo[1,2‐a]pyridine derivative has been achieved for the first time. In cases in which the most‐electron‐rich position of the electron‐excessive heterocycle was blocked by a naphthalen‐1‐yl substituent, neither oxidative aromatic coupling nor reaction under Scholl conditions enabled the fusion of the rings. The only method that converted the substrate into the corresponding imidazo[5,1,2‐de]naphtho[1,8‐ab]quinolizine was coupling in the presence of potassium in anhydrous toluene. Moreover, we discovered new, excellent conditions for this anion‐radical coupling reaction, which employed dry O2 from the start in the reaction mixture. This method afforded vertically fused imidazo[1,2‐a]pyridine in 63 % yield. Interestingly, whereas the fluorescence quantum yield (Φfl) of compound 3, despite the freedom of rotation, was close to 50 %, the Φfl value of flat naphthalene‐imidazo[1,2‐a]pyridine was only 5 %. Detailed analysis of this compound by using DFT calculations and a low‐temperature Shpol′skii matrix revealed phosphorescence emission, thus indicating that efficient intersystem‐crossing from the lowest‐excited S1 level to the triplet manifold was the competing process with fluorescence.
Laser light scan analysis of the “anticonvulsant face”
Authors: Orup H. Ivan , Deutsch Curtis K. , Holmes Lewis B. 
Published: May 2014

BackgroundThe “anticonvulsant face,” with a short nose, broad nasal bridge, epicanthal folds, and wide mouth, was described in the 1970s in children who had been exposed during pregnancy to the anticonvulsant drugs phenytoin and phenobarbital. The laser light scan makes it possible to establish three‐dimensional positions of physical features and to determine more objectively the changes in the size and shape of the affected soft tissues of the faces of children exposed to these anticonvulsant drugs during pregnancy.MethodsThirteen individuals, exposed throughout pregnancy to phenytoin as either monotherapy or polytherapy, were identified in a previous analysis as having significant changes in their craniofacial features based on measurements of cephalometric radiographs. Those changes were associated with midface hypoplasia and a short nose, features of the “anticonvulsant face.” The soft tissues of their faces have been evaluated with laser light scans.ResultsThe notable changes in soft tissues identified by laser light scans were a wide philtrum (cph‐cph), narrow mouth (ch‐ch), short nasal bridge (n‐prn), shortened nose height (n‐sn), and flattened orbits (orbital protrusion index).ConclusionThis analysis of the facial features of phenytoin‐exposed individuals, selected because of changes in their craniofacial bony structures, showed that there were several significant changes, two of which, widening of the philtrum and a small mouth, have not been described previously as part of this phenotype. Birth Defects Research (Part A), 2014. © 2014 Wiley Periodicals, Inc. Birth Defects Research (Part A) 100:905–911, 2014. © 2014 Wiley Periodicals, Inc.
Cost-effectiveness of the National Health Service abdominal aortic aneurysm screening programme in England
Authors: Glover M J , Kim L G , Sweeting M J , Thompson S G , Buxton M J 
Published: May 2014

AbstractBackgroundImplementation of the National Health Service abdominal aortic aneurysm (AAA) screening programme (NAAASP) for men aged 65 years began in England in 2009. An important element of the evidence base supporting its introduction was the economic modelling of the long-term cost-effectiveness of screening, which was based mainly on 4-year follow-up data from the Multicentre Aneurysm Screening Study (MASS) randomized trial. Concern has been expressed about whether this conclusion of cost-effectiveness still holds, given the early performance parameters, particularly the lower prevalence of AAA observed in NAAASP.MethodsThe existing published model was adjusted and updated to reflect the current best evidence. It was recalibrated to mirror the 10-year follow-up data from MASS; the main cost parameters were re-estimated to reflect current practice; and more robust estimates of AAA growth and rupture rates from recent meta-analyses were incorporated, as were key parameters as observed in NAAASP (attendance rates, AAA prevalence and size distributions).ResultsThe revised and updated model produced estimates of the long-term incremental cost-effectiveness of £5758 (95 per cent confidence interval £4285 to £7410) per life-year gained, or £7370 (£5467 to £9443) per quality-adjusted life-year (QALY) gained.ConclusionAlthough the updated parameters, particularly the increased costs and lower AAA prevalence, have increased the cost per QALY, the latest modelling provides evidence that AAA screening as now being implemented in England is still highly cost-effective.
Hydrodeoxygenation of Phenol as a Model Compound for Bio‐oil on Non‐noble Bimetallic Nickel‐based Catalysts
Authors: Huynh Thuan Minh , Armbruster Udo , Pohl Marga‐Martina , Schneider Matthias , Radnik Joerg , Hoang Dang‐Lanh , Phan Binh Minh Quoc , Nguyen Duc Anh , Martin Andreas 
Published: May 2014

AbstractNi/HZSM‐5 catalysts for the hydrodeoxygenation of bio‐oil were modified with Cu and Co. A first test series with phenol as a model revealed that the presence of Ni is essential for high activity. However, modification with Cu deteriorated the catalytic performance significantly whereas an admixture of Co increased the activity and selectivity toward the target hydrocarbons benzene and cyclohexane. Characterization studies performed by using TEM, X‐ray photoelectron spectroscopy, and XRD techniques elucidated detrimental effects of the second metals: both Cu and Co form alloys with Ni; however, Cu caused a loss of active sites as well as tended to segregate at the surface whereas Co made the particles smaller and strongly stabilized the active Ni sites, that is, Ni dispersion increased. A NiCo/HZSM‐5 catalyst (10 wt % of each metal content) showed 99 % hydrocarbon selectivity at complete phenol conversion. Additional studies using intermediate products such as benzene, cyclohexene, and C6 oxygenates as feeds highlight the effect of the catalyst composition on key reaction steps.
Elucidating the Effect of the Nucleophilicity of the Silyl Group in the Reduction of CO2 to CO Mediated by Silyl‐Copper(I) Complexes
Authors: Tan Gengwen , Blom Burgert , Gallego Daniel , Irran Elisabeth , Driess Matthias 
Published: May 2014

AbstractThe reduction of CO2 to CO with silyl‐copper(I) complexes bearing various silyl groups has been investigated. The silyl‐copper(I) complexes [LSi(X)Cu(IPr)] 2–5 (X=OtBu (2), OH (3), H (4), OC6F5 (5); L=CH{CCH2}(CMe)(NAr)2, IPr=(CHNAr)2C:, Ar=2,6‐iPr2C6H3) bearing OtBu, OH, H, and OC6F5 as functional groups are readily accessible by the activation of the CuO and CuH bonds in (IPr)CuX with silylene LSi: (1). These complexes are not readily accessible by the commonly used transmetallation reaction, rendering this methodology rather unique and facile in synthesizing silicon‐functionalized silyl‐metal complexes. The functional groups at the silicon atoms in compounds 2–5 enable the silyl groups to feature different nucleophilicity, which affords different activities toward CO2 reduction to CO. The silyl moieties of complexes 2 and 3, containing electron‐donating groups (i.e., OtBu and OH) at the silicon centers, are more nucleophilic than that of compound 4 and 5, bearing a hydride and the electron‐withdrawing group OC6F5 at the silicon centers, respectively. Consistent with this observation, compounds 2 and 3 show higher activity in CO2 reduction to CO compared to compounds 4 and 5, and the latter cases are zero‐order reactions with respect to 4 and 5 (4: k=7.8×10−6 mol L−1 s−1; 5: 2.7×10−8 mol L−1 s−1). This suggests that the more nucleophilic the silyl moiety in a silyl‐copper(I) complex is, the higher is the efficiency in CO2 reduction to CO. In addition, the siloxyl‐copper(I) complexes [LSi(X)OCu(IPr)] 6–9 [X=OtBu (6), OH (7), H (8), OC6F5 (9)] were isolated as the products from the corresponding reduction reactions. Complexes 2–4 and 6–8 were characterized by spectroscopic and structural means.
Oligosaccharide Shells as a Decisive Factor for Moderate and Strong Ionic Interactions of Dendritic Poly(ethylene imine) Scaffolds under Shear Forces
Authors: Tripp Sandra , Appelhans Dietmar , Striegler Christin , Voit Brigitte 
Published: May 2014

AbstractFor better understanding and improving the non‐covalent interactions of dendritic core–shell, we evaluated the interactions of hyperbranched poly(ethylene imine) (PEI) decorated with various oligosaccharide shells with water‐soluble B vitamins, an estradiol derivative and pantoprazole. Depending on the different properties of the analyte molecules, dendritic core–shell glyco architectures showed (very) weak, moderate and strong interactions with the analyte molecules. Thus, ionic interactions are the strongest driving force for the formation of host–guest complexes. The core–shell glyco architecture is a necessary prerequisite for stable analyte/PEI complexes; the pure hyperbranched PEI did not show any sufficiently strong interactions with neutral, cationic or anionic analytes under the shear forces applied during ultrafiltration of pure aqueous solution without an adjusted pH. Thus, only robust non‐covalent interactions between analytes and the dendritic polyamine scaffold of the glycopolymer structure survive this separation step and allow isolation of stable host–guest complexes in aqueous solution.
One‐Pot Synthesis and Electrocatalytic Properties of Pd@Pt Core‐Shell Nanocrystals with Tailored Morphologies
Authors: Kim Yena , Lee Young Wook , Kim Minjune , Han Sang Woo 
Published: May 2014

AbstractPd@Pt core‐shell nanocrystals consisting of well‐defined Pd nanocube cores and dendritic Pt shells were prepared by a new facile aqueous one‐pot synthetic method. The prepared Pd@Pt nanocrystals exhibited efficient catalytic activity and stability toward methanol electrooxidation, and their catalytic function was highly dependent on their Pt shell thickness due to the different synergism between Pt and Pd.
Covalent Embedding of Ni2+/Fe3+ Cyanometallate Structures in Silica by Sol–Gel Processing
Authors: Felbermair Elisabeth , Sidorenko Andrey , Paschen Silke , Akbarzadeh Johanna , Peterlik Herwig , Schubert Ulrich 
Published: May 2014

AbstractCompound [Ni(AEAPTS)2]3[Fe(CN)6]2 (AEAPTS=N‐(2‐aminoethyl)‐3‐aminopropyltrimethoxysilane), in which Ni2+ and Fe3+ ions are ferromagnetically coupled through cyano bridges, was prepared. Sol–gel processing of the AEAPTS derivative resulted in incorporation of the cyanometallate in silica. The obtained material is magnetically ordered below 22 K with an effective magnetic moment μeff of 4.46 μB at room temperature, a maximum of 8.60 μB at approximately 15 K and a narrow hysteresis at 2 K, with a saturation remanence of about 300 emu mol−1 and a coercitivity of 0.03 T.
Highly Selective Water Adsorption in a Lanthanum Metal–Organic Framework
Authors: Plessius Raoul , Kromhout Rosa , Ramos André Luis Dantas , Ferbinteanu Marilena , Mittelmeijer‐Hazeleger Marjo C. , Krishna Rajamani , Rothenberg Gadi , Tanase Stefania 
Published: May 2014

AbstractWe present a new metal–organic framework (MOF) built from lanthanum and pyrazine‐2,5‐dicarboxylate (pyzdc) ions. This MOF, [La(pyzdc)1.5(H2O)2]⋅2 H2O, is microporous, with 1D channels that easily accommodate water molecules. Its framework is highly robust to dehydration/hydration cycles. Unusually for a MOF, it also features a high hydrothermal stability. This makes it an ideal candidate for air drying as well as for separating water/alcohol mixtures. The ability of the activated MOF to adsorb water selectively was evaluated by means of thermogravimetric analysis, powder and single‐crystal X‐ray diffraction and adsorption studies, indicating a maximum uptake of 1.2 mmol g−1 MOF. These results are in agreement with the microporous structure, which permits only water molecules to enter the channels (alcohols, including methanol, are simply too large). Transient breakthrough simulations using water/methanol mixtures confirm that such mixtures can be separated cleanly using this new MOF.
Shape‐ and Size‐Controlled Synthesis of Mn3O4 Nanocrystals at Room Temperature
Authors: Chen Chao , Jian Hong , Mai Kaiguang , Ren Zhimin , Wang Jia , Fu Xinxin , Fan Chenyao , Sun Chunxiao , Qian Guodong , Wang Zhiyu 
Published: May 2014

AbstractA versatile synthetic method has been developed for the fabrication of Mn3O4 nanocrystals with different sizes and shapes, such as square nanoplates, mesocrystal nanodisks, and nanopolyhedra. Manganese(II) acetate tetrahydrate and hydrazine monohydrate were the only two reactants used in aqueous solution, and no surfactant was employed. The key advantages of our approach are (1) the room‐temperature synthesis, (2) the facile operation, (3) the flexibility in shape‐ and size‐control, and (4) the ease of scale‐up. The exposed surfaces of the as‐prepared nanoparticles were carefully characterized and indexed. The catalytic properties of the nanoplates for the degradation of methylene blue were evaluated in detail. The catalytic properties are closely related to the shape and size of the Mn3O4 nanocrystals, and nanoplates with a size of 50 nm exhibited the best catalytic performance. The magnetic properties were investigated with a superconducting quantum interference device magnetometer.
Giant Photoconductivity in NMQ[Ni(dmit)2]
Authors: Naito Toshio , Karasudani Tomoaki , Nagayama Naoki , Ohara Keishi , Konishi Kensuke , Mori Shigeki , Takano Takahiro , Takahashi Yukihiro , Inabe Tamotsu , Kinose Shota , Nishihara Sadafumi , Inoue Katsuya 
Published: May 2014

AbstractThe simple molecular salt NMQ[Ni(dmit)2] (NMQ = N‐methylquinolinium, dmit = 1,3‐dithiol‐2‐thione‐4,5‐dithiolate) functions as a diamagnetic insulator with an activation energy Ea(dark) of 0.20 eV. However, at 300 K, it exhibits ca. 40 times higher conductivity (σUV) under UV irradiation [(375 ± 5) nm, 15.7 mW cm–2] than it does under dark conditions (σdark). The ratio σUV/σdark rapidly increases with decreasing temperature and reaches ca. 880 at 200 K. From the temperature dependence of σUV, the activation energy under irradiation Ea(UV) is 0.12 eV. These observations cannot be explained as the result of sample heating during UV irradiation. Rather, the X‐ray photoelectron spectra of the sulfur and nickel atoms, the calculated band structure, and the UV/Vis spectra of the salt can all be explained consistently as follows: charge transfer between the Ni(dmit)2 moieties upon exposure to 375 nm UV light induces melting of the charge‐ordered state and produces the unusually large photoconductivity of NMQ[Ni(dmit)2].
Lanthanide Complexes Assembled from 3‐Fluorophthalate and 1,10‐Phenanthroline: Syntheses, Crystal Structure, Photoluminescence, and White‐Light Emission
Authors: Cha Yu‐E , Li Xia , Ma Dou , Huo Rui 
Published: May 2014

AbstractTwo different crystal forms, [Ln4(Fpht)6(phen)6(H2O)4]·nH2O (Ln = Eu 1, n = 14; Tb 2, n = 12) and [Ln(Fpht)(HFpht)(phen)(H2O)] (Ln = La 3, Eu 4, Tb 5) were obtained from the one‐pot reaction of LnIII ions with 3‐fluorophthalic acid (H2Fpht) and 1,10‐phenanthroline (phen). Complexes 1 and 2 are centrosymmetric tetranuclear molecules with two crystallographically different LnIII ion environments, [Ln(1)O6N2] and [Ln(2)O4N4]. The complexes have a tridentate bridging Fpht ligand and a bidentate terminal Fpht ligand. Complexes 3–5 show 2D networks with [LnO7N2] polyhedra. There are two kinds of ligands, Fpht and HFpht, which adopt chelating‐bridging/monodentate and bidentate‐bridging coordination modes, respectively. The LaIII complex shows ligand‐centered fluorescence. EuIII and TbIII complexes display red 5D0 → 7F0–4 and green 5D4 → 7F6–2 characteristic luminescence, respectively. Intriguingly, white‐light emission was produced when EuIII and TbIII were codoped into the 2D LaIII complex.
Photolabile Protecting Groups for Nitroxide Spin Labels
Authors: Seven Ibrahim , Weinrich Timo , Gränz Markus , Grünewald Christian , Brüß Silke , Krstić Ivan , Prisner Thomas F. , Heckel Alexander , Göbel Michael W. 
Published: May 2014

AbstractNitroxide spin labels can be protected against critical conditions of DNA/RNA or peptide synthesis by reduction and alkylation with light‐sensitive groups such as nitrobenzyl‐ or aminocoumarins. High chemical stability qualifies tetraethylisoindoline 5 and, with some restrictions, (2,2,6,6‐tetramethylpiperidin‐1‐yl)oxy (TEMPO) precursor 4 as building blocks for spin‐labeled biopolymers. The yield of recovered nitroxides (80–95 %) is sufficient for PELDOR experiments. A protected TEMPO phosphoramidite was successfully used to synthesize a short spin‐labeled DNA with high yield and purity.
Scaling and Learning Effects of Biofuels Conversion Technologies
Authors: Festel Gunter , Würmseher Martin , Rammer Christian 
Published: May 2014

AbstractThe convergence in production costs between biofuels and fossil fuels may be driven by an increase of the market price for crude oil on the one hand and by a decrease of the production costs for alternative fuels on the other. Whereas the price for fossil fuels mainly depends on the price of crude oil, the conversion costs often have a decisive impact on fuels produced from biomass. This study shows that the total conversion costs can be primarily reduced by scaling effects. Therefore, for all discussed types of biofuels, the total conversion costs can be reduced by a factor of ten, solely through scale economies associated with upscaling of the production plant size from 10 kt to 500 kt. In contrast, between 2005 and 2020, the expected reduction of the conversion costs attributable to learning effects is approximately one half, resulting from the learning curve factors during this time period. Although 2nd generation biofuels have been closely linked to higher conversion costs in comparison to 1st generation biofuels, this gap is expected to almost vanish over the next decade.
Synthesis, Reactivities, and Coordination Chemistry of Tris(2‐isopropoxyphenyl)phosphine
Authors: Takeda Nobuhiro , Tagawa Tomonori , Unno Masafumi 
Published: May 2014

ABSTRACTA phosphine bearing three 2‐isopropoxyphenyl groups, P{C6H4[2‐O(i‐Pr)]}3 (1), was synthesized. Phosphine 1 readily reacted with CH2Cl2 and ClCH2CH2Cl at 25°C to give the corresponding phosphonium salts [RCH2P{C6H4[2‐O(i‐Pr)]}3]X (2: R=X=Cl, 3: R=CH2Cl, X=BF4). Platinum, palladium, and rhodium complexes with ligand 1, [PtCl2(1)2] (4), [PdCl2(1)2] (5), [{PdCl(1)}2(μ‐Cl)2] (6), and [RhCl(cod)(1)] (7) were synthesized and their structures were determined by X‐ray crystallography, which revealed that ligand 1 works as a monodentate ligand in these complexes.
Synthesis, Structure, and Thermolysis of Tetracoordinated 1λ4,2‐Selenazetidines Bearing Two Chiral Centers at the 3‐ and 4‐Positions
Authors: Daicho Yuya , Kano Naokazu , Yukimoto Mariko , Minoura Mao , Kawashima Takayuki 
Published: May 2014

ABSTRACTThe title trans and cis isomers (trans‐3 and cis‐3) were successfully synthesized as stable compounds by taking advantage of the Martin ligand. The X‐ray crystallographic analysis of trans‐3 showed that it has a distorted pseudotrigonal bipyramidal structure, and that the two phenyl groups at the 3‐ and 4‐positions are cis to each other. The thermolysis of trans‐3 in the presence of excess dimethyl acetylenedicarboxylate (DMAD) gave a mixture of the corresponding aziridines (trans‐7 and cis‐7) and cycloadducts (11a and 11b) of the azomethine ylides formed by ring opening of the aziridines with DMAD. Heating of cis‐7 and excess DMAD under the same conditions gave diastereomeric mixtures of both the aziridines and the cycloadducts, which means that the stereochemistry of the aziridine formation from the 1,2‐selenazetidine cannot be determined in this system.
What Currently Limits Charge Carrier Mobility in Crystals of Molecular Semiconductors?
Authors: Schweicher Guillaume , Olivier Yoann , Lemaur Vincent , Geerts Yves Henri 
Published: May 2014

AbstractCharge carrier mobility is a central property that characterizes the performances of organic semiconductors and is mostly measured in field‐effect transistors. High mobility values are sought by many research teams. This article, that provides an overview of best performing molecular semiconductors is constructed on the question: What currently limits charge carrier mobility in crystals of molecular semiconductors? With this in mind, we confront, in a critical way, the current theoretical understanding to the most salient experimental results with the hope to reach a deeper understanding based on first principles and order of magnitudes of the main physical parameters.
Investigation of Gallic Acid Induced Anticancer Effect in Human Breast Carcinoma MCF‐7 Cells
Authors: Wang Ke , Zhu Xue , Zhang Kai , Zhu Ling , Zhou Fanfan 
Published: May 2014

ABSTRACTGallic acid (GA), a polyhydroxylphenolic compound abundantly distributed in plants, fruits, and foods, has been reported to have various biological activities including an anticancer effect. In this study, we extensively investigated the anticancer effect of GA in human breast carcinoma MCF‐7 cells. Our study indicated that treatment with GA resulted in inhibition of proliferation and induction of apoptosis in MCF‐7 cells. Then, the molecular mechanism of GA's apoptotic action in MCF‐7 cells was further investigated. The results revealed that GA induced apoptosis by triggering the extrinsic or Fas/FasL pathway as well as the intrinsic or mitochondrial pathway. Furthermore, the apoptotic signaling induced by GA was amplified by cross‐link between the two pathways. Taken together, our findings may be useful for understanding the mechanism of action of GA on breast cancer cells and provide new insights into the possible application of such compound and its derivatives in breast cancer therapy.
Comparison of PAT based approaches for making real‐time pooling decisions for process chromatography – use of feed forward control
Authors: Mendhe Rakesh , Thukkaram Muralikrishnan , Patil Nitin , Rathore Anurag S. 
Published: May 2014

ABSTRACTBACKGROUNDProcess analytical technology (PAT) is gradually being implemented in the biopharmaceutical industry due to the potential for continuous real‐time quality assurance resulting in improved operational control and compliance. Process chromatography remains the primary unit operation for purification of biotech therapeutics for separation of the various host cell related, process related, and product related impurities and variants. The latter often have very similar physicochemical properties to that of the product and hence in the absence of baseline separation, a robust pooling strategy is required to ensure consistent product quality.RESULTSThis paper presents an evaluation of a variety of PAT based and pseudo‐PAT based approaches for pooling a real commercial process chromatography column. The pseudo‐PAT approaches that have been evaluated include ultraviolet (UV) absorbance, % peak height, retention time, and relative retention time. These approaches do not involve direct measurement of product quality attributes, but are operationally simpler to implement. Two other PAT based approaches have also been considered. The first involves use of a feed forward control based model that uses as an input the retention time of a characteristic peak that elutes prior to the main peak. The second PAT based approach involves use of a rapid HPLC method that can facilitate near‐real‐time decision making on pooling.CONCLUSIONSThe paper provides a comparison of the advantages and drawbacks of the various approaches that have been examined and establishes the feasibility of multiple approaches that can facilitate implementation of PAT for pooling of process chromatography columns. © 2014 Society of Chemical Industry