bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of aeration on growth, ethanol and polyol accumulation by Spathaspora passalidarum NRRL Y‐27907 and Scheffersomyces stipitis NRRL Y‐7124
Authors: Su Yi‐Kai , Willis Laura B. , Jeffries Thomas W. 
Published: August 2014

ABSTRACTSpathaspora passalidarum NN245 (NRRL‐Y27907) is an ascomycetous yeast that displays a higher specific fermentation rate with xylose than with glucose. Previous studies have shown that its capacity for xylose fermentation increases while cell yield decreases with decreasing aeration. Aeration optimization plays a crucial role in maximizing bioethanol production from lignocellulosic hydrolysates. Here, we compared the kinetics of S. passalidarum NN245 and Scheffersomyces (Pichia) stipitis NRRL Y‐7124 fermenting 15% glucose, 15% xylose, or 12% xylose plus 3% glucose under four different aeration conditions. The maximum specific fermentation rate for S. passalidarum was 0.153 g ethanol/g CDW · h with a yield of 0.448 g/g from 150 g/L xylose at an oxygen transfer rate of 2.47 mmol O2/L h. Increasing the OTR to 4.27 mmol O2/L h. decreased the ethanol yield from 0.46 to 0.42 g/g xylose while increasing volumetric ethanol productivity from 0.52 to 0.8 g/L h. Both yeasts had lower cells yields and higher ethanol yields when growing on xylose than when growing on glucose. Acetic acid accretions of both strains correlated positively with increasing aeration. S. passalidarum secreted lower amounts of polyols compared to S. stipitis under most circumstances. In addition, the composition of polyols differed: S. passalidarum accumulated mostly xylitol and R,R‐2,3‐butanediol (BD) whereas S. stipitis accumulated mostly xylitol and ribitol when cultivated in xylose or a mixture of 12% xylose and 3% glucose. R,R‐2,3‐BD accumulation by S. passalidarum during xylose fermentation can be as much as four times of that by S. stipitis, and R,R‐2,3‐BD is also the most abundant byproduct after xylitol. The ratios of polyols accumulated by the two species under different aeration conditions and the implications of these observations for strain and process engineering are discussed. Biotechnol. Bioeng. 2015;112: 457–469. © 2014 Wiley Periodicals, Inc.
Quantitative determination of metformin, glyburide and its metabolites in plasma and urine of pregnant patients by LC‐MS/MS
Authors: Zhang Xing , Wang Xiaoming , Vernikovskaya Daria I. , Fokina Valentina M. , Nanovskaya Tatiana N. , Hankins Gary D. V. , Ahmed Mahmoud S. 
Published: August 2014

AbstractThis report describes the development and validation of an LC‐MS/MS method for the quantitative determination of glyburide (GLB), its five metabolites (M1, M2a, M2b, M3 and M4) and metformin (MET) in plasma and urine of pregnant patients under treatment with a combination of the two medications. The extraction recovery of the analytes from plasma samples was 87–99%, and that from urine samples was 85–95%. The differences in retention times among the analytes and the wide range of the concentrations of the medications and their metabolites in plasma and urine patient samples required the development of three LC methods. The lower limit of quantitation (LLOQ) of the analytes in plasma samples was as follows: GLB, 1.02 ng/mL; its five metabolites, 0.100–0.113 ng/mL; and MET, 4.95 ng/mL. The LLOQ in urine samples was 0.0594 ng/mL for GLB, 0.984–1.02 ng/mL for its five metabolites and 30.0 µg/mL for MET. The relative deviation of this method was <14% for intra‐day and inter‐day assays in plasma and urine samples, and the accuracy was 86–114% in plasma, and 94–105% in urine. The method described in this report was successfully utilized for determining the concentrations of the two medications in patient plasma and urine. Copyright © 2014 John Wiley & Sons, Ltd.
Determination of proline in human serum by a robust LC‐MS/MS method: application to identification of human metabolites as candidate biomarkers for esophageal cancer early detection and risk stratification
Authors: Liang Su , Sanchez‐Espiridion Beatriz , Xie Huan , Ma Jing , Wu Xifeng , Liang Dong 
Published: August 2014

AbstractAltered serum proline levels are related to cancer metabolism. This study developed and validated a LC‐MS/MS method to analyze proline in human serum. Surrogate blank serum, coupled with stable isotope l‐proline‐13C5,15 N as internal standard, was used for generating standard curves ranging from 2.5 to 100 μg/mL. Proline was extracted from serum samples using methanol. A Phenomenex Lux 5u Cellulose‐1 column (250 × 4.6 mm) was used for chromatographic separation with 40% methanol in 0.05% formic acid aqueous solution as a mobile phase. Mass detection was performed under positive ionization electrospray. Intra‐ and inter‐day accuracy and precision were <10%. The extraction recovery and matrix factor were 99.17 and 1.47%, respectively. Our study showed that the chiral column had high specificity and selectivity for separating proline from serum components. The assay was successfully applied for the quantification of human serum proline levels from 30 esophageal cancer patients and 30 healthy volunteers. Statistical analyses showed significantly lower levels of serum proline in the patients as compared with the healthy volunteers (p‐value = 0.011). We report here a simple, specific and reproducible LC‐MS/MS method for the quantification of proline in human serum as a potential screening biomarker for esophageal cancer. Copyright © 2014 John Wiley & Sons, Ltd.
Survival of melanoma patients with brain metastases treated with ipilimumab and stereotactic radiosurgery
Authors: Tazi Karim , Hathaway Amanda , Chiuzan Cody , Shirai Keisuke 
Published: August 2014

AbstractHistorically, melanoma with brain metastases has a poor prognosis. In this retrospective medical record review, we report the outcome of patients with stage IV melanoma with brain metastases treated with ipilimumab and brain stereotactic radiosurgery (SRS). All patients with metastatic melanoma treated with ipilimumab from June 2010 to September 2012 were identified and stratified by presence (A) or absence (B) of brain metastases at the time of ipilimumab administration. All patients with brain metastases received SRS. Overall survival (OS) was defined as time from the date of stage IV diagnosis and the time of ipilimumab administration to death or last follow‐up. Survival curves were estimated using the Kaplan–Meier method, and Cox proportional hazards model was employed to compute the hazard ratios (HR). Results: Five out of 10 patients in Cohort A and 10 out of 21 patients in Cohort B died as of last follow‐up. In Cohort A, median number of lesions treated with SRS was 3. Median survivals from date of stage IV for Cohorts A and B were 29.3 and 33.1 months, respectively (HR = 0.93, P = 0.896). Median survival from cycle 1 ipilimumab was 16.5 and 24.5 months for Cohort A and B, respectively (HR = 1.05, P = 0.931). The 3‐year survival rates from the date of cycle one of ipilimumab administration for Cohort A and B were 50% (95% CI: 27–93%) and 39% (95% CI: 19–81%), respectively. Eight of 10 patients in Cohort A maintained a good PS. Survival of patients with melanoma brain metastases treated with ipilimumab combined with SRS may be comparable to patients without brain metastases.
Selective Dissociation of Dihydrogen over Dioxygen on a Hindered Platinum Surface for the Direct Synthesis of Hydrogen Peroxide
Authors: Yook Sunwoo , Shin Hyeyoung , Kim Hyungjun , Choi Minkee 
Published: August 2014

AbstractTo achieve high catalytic selectivity towards H2O2 from a H2/O2 mixture, HH bonds should be dissociated and OO bonds should be kept intact in the course of the reaction. A major dilemma in catalyst design, however, is that the metal catalysts that dissociate HH bonds have a thermodynamic preference for the dissociation of OO bonds. In this work, the selective dissociation of H2 over O2 was realized by the deposition of H2‐selective carbon diffusion layers on a Pt catalyst. Because O2 cannot access the carbon‐coated Pt surface, O2 hydrogenation occurs at the carbon surface from spilt‐over hydrogen rather than at the Pt surface on which OO dissociation is likely. This leads to the great suppression of OO dissociation, which allows the highly selective synthesis of H2O2. Notably, N‐doping of the carbon diffusion layer could increase the selectivity towards H2O2 significantly because of the stabilization of the hydroperoxy radical on the carbon surface.
NH4PF6 as a Structural Modifier for Building a Robust Carbon‐Coated Natural Graphite Anode for Lithium‐Ion Batteries
Authors: Lee Jaewoo , Park Min‐Sik , Park Yoon‐Soo , Jung Kyu‐Nam , Lee Jong‐Won , Kim So Yeun , Jo Yong Nam , Yim Taeeun , Lee Sung‐Man , Kim Young‐Jun 
Published: August 2014

AbstractTo improve the electrochemical performance of natural graphite anodes, we have designed a facile, scalable carbon‐coating process using coal‐tar pitch and ammonium hexafluorophosphate (NH4PF6) as a structural modifier. NH4PF6 effectively modifies the microstructure of amorphous carbon, coated on the surface of the natural graphite, leading to better, reversible Li+‐storage characteristics within a wide operating‐temperature range (from −20 to 60 °C). The COP linkage introduced as a result of the thermal decomposition of NH4PF6 assists the formation of open nanopores in the amorphous carbon layer. The integrated nanopores act as additional reversible Li+‐storage sites, which minimize the reversible capacity loss and improve the cycle performance of natural graphite. Moreover, the thermal stability of natural graphite can also be improved while maintaining the improved electrochemical performance. Thus, this approach is a step toward the practical use of natural graphite anodes for lithium‐ion batteries for electric‐vehicle applications.
Experimental and Theoretical Studies of Quadrupolar Oligothiophene‐Cored Chromophores Containing Dimesitylboryl Moieties as π‐Accepting End‐Groups: Syntheses, Structures, Fluorescence, and One‐ and Two‐Photon Absorption
Authors: Ji Lei , Edkins Robert M. , Sewell Laura J. , Beeby Andrew , Batsanov Andrei S. , Fucke Katharina , Drafz Martin , Howard Judith A. K. , Moutounet Odile , Ibersiene Fatima , Boucekkine Abdou , Furet Eric , Liu Zhiqiang , Halet Jean‐François , Katan Claudine , Marder Todd B. 
Published: August 2014

AbstractQuadrupolar oligothiophene chromophores composed of four to five thiophene rings with two terminal (E)‐dimesitylborylvinyl groups (4 V–5 V), and five thiophene rings with two terminal aryldimesitylboryl groups (5 B), as well as an analogue of 5 V with a central EDOT ring (5 VE), have been synthesized via Pd‐catalyzed cross‐coupling reactions in high yields (66–89 %). Crystal structures of 4 V, 5 B, bithiophene 2 V, and five thiophene‐derived intermediates are reported. Chromophores 4 V, 5 V, 5 B and 5 VE have photoluminescence quantum yields of 0.26–0.29, which are higher than those of the shorter analogues 1 V–3 V (0.01–0.20), and short fluorescence lifetimes (0.50–1.05 ns). Two‐photon absorption (TPA) spectra have been measured for 2 V–5 V, 5 B and 5 VE in the range 750–920 nm. The measured TPA cross‐sections for the series 2 V–5 V increase steadily with length up to a maximum of 1930 GM. We compare the TPA properties of 2 V–5 V with the related compounds 5 B and 5 VE, giving insight into the structure–property relationship for this class of chromophore. DFT and TD‐DFT results, including calculated TPA spectra, complement the experimental findings and contribute to their interpretation. A comparison to other related thiophene and dimesitylboryl compounds indicates that our design strategy is promising for the synthesis of efficient dyes for two‐photon‐excited fluorescence applications.
Light Harvesting and Directional Energy Transfer in Long‐Lived Homo‐ and Heterotrimetallic Complexes of FeII, RuII, and OsII
Authors: Maity Dinesh , Bhaumik Chanchal , Mardanya Sourav , Karmakar Srikanta , Baitalik Sujoy 
Published: August 2014

AbstractA new family of trimetallic complexes of the form [(bpy)2M(phen‐Hbzim‐tpy)M′(tpy‐Hbzim‐phen)M(bpy)2]6+ (M=RuII, Os; M′=FeII, RuII, Os; bpy=2,2′‐bipyridine) derived from heteroditopic phenanthroline–terpyridine bridge 2‐{4‐[2,6‐di(pyridin‐2‐yl) pyridine‐4‐yl]phenyl}‐1H‐imidazole[4,5‐f][1,10]phenanthroline (phen‐Hbzim‐tpy) were prepared and fully characterized. Zn2+ was used to prepare mixed‐metal trimetallic complexes in situ by coordinating with the free tpy site of the monometallic precursors. The complexes show intense absorptions throughout the UV/Vis region and also exhibit luminescence at room temperature. The redox behavior of the compounds is characterized by several metal‐centered reversible oxidation and ligand‐centered reduction processes. Steady‐state and time‐resolved luminescence data show that the potentially luminescent RuII‐ and OsII‐based triplet metal‐to‐ligand charge‐transfer (3MLCT) excited states in the triads are quantitatively quenched, most likely by intercomponent energy transfer to the lower lying 3MLCT (for Ru and Os) or triplet metal‐centered (3MC) excited states of the FeII subunit (nonluminescent). Interestingly, iron did not adversely affect the photophysics of the respective systems. This suggests that the multicomponent molecular‐wire‐like complexes investigated here can behave as efficient light‐harvesting antennas, because all the light absorbed by the various subunits is efficiently channeled to the subunit(s) in which the lowest‐energy excited states are located.
Hetero‐tri‐spin [2p‐3d‐4f] Chain Compounds Based on Nitronyl Nitroxide Lanthanide Metallo‐Ligands: Synthesis, Structure, and Magnetic Properties
Authors: Zhu Mei , Hu Peng , Li Yungai , Wang Xiufeng , Li Licun , Liao Daizheng , Durga Prasad Goli V. M. L. , Ramasesha S. , Sutter Jean‐Pascal 
Published: August 2014

AbstractEmploying nitronyl nitroxide lanthanide(III) complexes as metallo‐ligands allowed the efficient and highly selective preparation of three series of unprecedented hetero‐tri‐spin (CuLn‐radical) one‐dimensional compounds. These 2p–3d–4f spin systems, namely [Ln3Cu(hfac)11(NitPhOAll)4] (LnIII=Gd 1Gd, Tb 1Tb, Dy 1Dy; NitPhOAll=2‐(4′‐allyloxyphenyl)‐4,4,5,5‐tetramethylimidazoline‐1‐oxyl‐3‐oxide), [Ln3Cu(hfac)11(NitPhOPr)4] (LnIII=Gd 2Gd, Tb 2Tb, Dy 2Dy, Ho 2Ho, Yb 2Yb; NitPhOPr=2‐(4′‐propoxyphenyl)‐4,4,5,5‐tetramethyl‐imidazoline‐1‐oxyl‐3‐oxide) and [Ln3Cu(hfac)11(NitPhOBz)4] (LnIII=Gd 3Gd, Tb 3Tb, Dy 3Dy; NitPhOBz=2‐(4′‐benzyloxyphenyl)‐4,4,5,5‐tetramethyl‐imidazoline‐1‐oxyl‐3‐oxide) involve O‐bound nitronyl nitroxide radicals as bridging ligands in chain structures with a [Cu‐Nit‐Ln‐Nit‐Ln‐Nit‐Ln‐Nit] repeating unit. The dc magnetic studies show that ferromagnetic metal–radical interactions take place in these hetero‐tri‐spin chain complexes, these and the next‐neighbor interactions have been quantified for the Gd derivatives. Complexes 1Tb and 2Tb exhibit frequency dependence of ac magnetic susceptibilities, indicating single‐chain magnet behavior.
One‐Pot Tandem Diastereoselective and Enantioselective Synthesis of Functionalized Oxindole‐Fused Spiropyrazolidine Frameworks
Authors: Mei Liang‐Yong , Tang Xiang‐Ying , Shi Min 
Published: August 2014

AbstractA highly efficient palladium(0)‐catalyzed asymmetric [3+2] cycloaddition using 3‐diazooxindoles serving as dipolarophiles affords functionalized pyrazolidine derivatives in an atom‐economical way. In addition, by trapping the pyrazolidine derivatives with maleimides, the corresponding spiropyrazolidine oxindoles containing multiple stereogenic centers have been obtained in high yields along with moderate to good levels of diastereoselectivity and enantioselectivity under mild conditions. Thus, a novel three‐component one‐pot tandem reaction has been developed.
C‐2 Selective Arylation of Indoles with Heterogeneous Nanopalladium and Diaryliodonium Salts
Authors: Malmgren Joel , Nagendiran Anuja , Tai Cheuk‐Wai , Bäckvall Jan‐E. , Olofsson Berit 
Published: August 2014

AbstractA simple and efficient method to prepare synthetically useful 2‐arylindoles is presented, using a heterogeneous Pd catalyst and diaryliodonium salts in water under mild conditions. A remarkably low leaching of metal catalyst was observed under the applied conditions. The developed protocol is highly C‐2 selective and tolerates structural variations both in the indole and in the diaryliodonium salt. Arylations of both NH indoles and N‐protected indoles with ortho‐substituted, electron‐rich, electron‐deficient, or halogenated diaryliodonium salts were achieved to give the desired products in high to excellent isolated yields within 6 to 15 h at room temperature or 40 °C.
A Cationic Ruthenium Complex for the Dynamic Kinetic Resolution of Secondary Alcohols
Authors: Fernández‐Salas José A. , Manzini Simone , Nolan Steven P. 
Published: August 2014

AbstractA synthetic protocol making use of a well‐defined cationic ruthenium complex 2 enabling the racemization of enantiomerically pure secondary alcohols in the presence of a weak base (K2CO3) is described. The compatibility of 2 with Candida Antarctica lipase B (Novozym 435) allows the development of an efficient dynamic kinetic resolution of sec‐alcohols in the absence of an additional strong base. This procedure involves the first example of a dynamic kinetic resolution of alcohols in the presence of a cationic ruthenium catalyst. In addition, we describe the conversion of ketones to the enantioenriched acetates in a one‐pot reaction, probing the versatility of complex 2.
Cross‐Metathesis of Terminal Alkynes
Authors: Lhermet Rudy , Fürstner Alois 
Published: August 2014

AbstractTerminal acetylenes are amongst the most problematic substrates for alkyne metathesis because they tend to undergo rapid polymerization on contact with a metal alkylidyne. The molybdenum complex 3 endowed with triphenylsilanolate ligands, however, is capable of inducing surprisingly effective cross‐metathesis reactions of terminal alkyl acetylenes with propynyl(trimethyl)silane to give products of type R1CCSiMe . This unconventional way of introducing a silyl substituent onto an alkyne terminus complements the conventional tactics of deprotonation/silylation and excels as an orthogonal way of alkyne protecting group chemistry for substrates bearing base‐sensitive functionalities. Moreover, it is shown that even terminal aryl acetylenes can be cross‐metathesized with internal alkyne partners. These unprecedented transformations are compatible with various functional groups. The need to suppress acetylene formation, which seems to be a particularly effective catalyst poison, is also discussed.
Total Synthesis of Five Lipoteichoic acids of Clostridium difficile
Authors: Hogendorf Wouter F. J. , Gisch Nicolas , Schwudke Dominik , Heine Holger , Bols Mikael , Pedersen Christian Marcus 
Published: August 2014

AbstractThe emergence of hypervirulent resistant strains have made Clostridium difficile a notorious nosocomial pathogen and has resulted in a renewed interest in preventive strategies, such as vaccines based on (synthetic) cell wall antigens. Recently, the structure of the lipoteichoic acid (LTA) of this species has been elucidated. Additionally, this LTA was found to induce the formation of protective antibodies against C. difficile in rabbits and mice. The LTA from C. difficile is isolated as a microheterogenous mixture, differing in size and composition, impeding any structure–activity relationship studies. To ensure reliable biological results, pure and well‐defined synthetic samples are required. In this work the total synthesis of LTAs from C. difficile with defined chain length is described and the initial biological results are presented.
Palladium‐Catalyzed Cross‐Coupling of Unactivated Aryl Sulfides with Arylzinc Reagents under Mild Conditions
Authors: Otsuka Shinya , Fujino Daishi , Murakami Kei , Yorimitsu Hideki , Osuka Atsuhiro 
Published: August 2014

AbstractCross‐coupling of general aryl alkyl sulfides with arylzinc reagents proceeds smoothly, even at room temperature or below, with a palladium–N‐heterocyclic carbene (NHC) catalyst. When combined with reactions that are unique to organosulfurs, that is, the SNAr sulfanylation or Pummerer reaction, the cross‐coupling offers interesting transformations that are otherwise difficult to achieve. An alkylsulfanyl group is preferentially converted whilst leaving the tosyloxy and chloro intact, which expands the variety of orthogonal cross‐coupling.
Complexation‐Induced Supramolecular Assembly Drives Metal‐Ion Extraction
Authors: Ellis Ross J. , Meridiano Yannick , Muller Julie , Berthon Laurence , Guilbaud Philippe , Zorz Nicole , Antonio Mark R. , Demars Thomas , Zemb Thomas 
Published: August 2014

AbstractInvited for the cover of this issue is the Franco–American collaboration between Commissariat à l′énergie atomique et aux énergies alternatives ‐Marcoule and Argonne National Laboratory. The image (artwork from Sana Sandler, Argonne National Laboratory) depicts a malonamide amphiphile that extracts metal ions from water into oil through complexation interactions, which cause nanoscale ordering. This aggregation is induced by complexation as well as long‐range interactions and drives metal‐ion separation processes for nuclear fuel reprocessing and refining technologies. Read the full text of the article at 10.1002/chem.201403859.
Cucurbituril: Chiral Applications
Authors: Mandadapu Vijaybabu , Day Anthony I. , Ghanem Ashraf 
Published: August 2014

ABSTRACTThis review brings together the past and current methods for synthesizing the classical cucurbit[n]uril (Q[n]), structural variants, and derivatives. Here we refer to the first family of Q[n] as " classical," where the cavity is spheroidal and carry no substituents at any of the equatorial methine carbons or the methylene bridging carbons. The synthetic background and general physical and chemical properties of the Q[n] as molecular hosts is discussed. Particular attention is drawn to the synthesis of structural variants that have significance for chiral recognition properties such as (±)‐bis‐nor‐seco‐Q[6] and (±)‐bis‐nor‐seco‐Q[10]. Furthermore, examples of chiral recognition, enantio‐ and stereoselectivity using the achiral Q[n] as supramolecular structures with a chiral function directly or indirectly via another chiral agent are also discussed. Chirality 26:712–723, 2014. © 2014 Wiley Periodicals, Inc.
Inkjet Printing of 2D Layered Materials
Authors: Li Jiantong , Lemme Max C. , Östling Mikael 
Published: August 2014

AbstractInkjet printing of 2D layered materials, such as graphene and MoS2, has attracted great interests for emerging electronics. However, incompatible rheology, low concentration, severe aggregation and toxicity of solvents constitute critical challenges which hamper the manufacturing efficiency and product quality. Here, we introduce a simple and general technology concept (distillation‐assisted solvent exchange) to efficiently overcome these challenges. By implementing the concept, we have demonstrated excellent jetting performance, ideal printing patterns and a variety of promising applications for inkjet printing of 2D layered materials.