bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conformational Analysis of trans‐2,11‐Dithia‐4e,5,6,7e,8,9‐hexahydro[3.3]paracyclophane Using VT‐NMR
Authors: Yang Ya‐Chen , Lin Chen‐Huei , Lin Lee‐Huei , Lin Shaw‐Tao 
Published: March 2012

AbstractThe conformation of trans‐2,11‐dithia‐4e,5,6,7e,8,9‐hexahydro[3.3]paracyclophanes (5, tDTHHPCP) was investigated by using 1H NMR analysis under variable‐temperature condition. Based on the dynamic 1H NMR behavior along with a structure obtained from simulation using the MM2 method, it has been deduced that 5 occurs preferentially in conformer 5a in CD2Cl2 solution, which the two sulfur atoms are situated as the chair form and cyclohexano unit as a distorted boat form. The energy barrier (ΔG‡) for the inversion of the bridge (‐CH2SCH2‐) has been estimated to be 11.6 kcal mol‐1 (600 MHz, Tc = ‐30 °C). The proton chemical shifts are assigned for the individual hydrogen according to the spectra obtained at ‐70 °C.
Synthesis of Chiral Pyrrolidine Isostere Inserted into Pyrrole Polyamide Skeleton
Authors: Lin Chun‐Yu , Yang Ya‐Ting , Ong Chi Wi 
Published: March 2012

AbstractAn efficient and general route towards the synthesis of a series of chiral pyrrolidine pyrrole polyamide distamycin analogues starting from (L)‐hydroxyproline is described. The binding abilities of these chiral pyrrolidine containing molecules to calf thymus DNA were evaluated by duplex DNA melting temperature analysis. The results revealed that both the chirality at the pyrrolidine ring and the site of incorporation plays an important role for binding at the duplex DNA.
Synthesis and Spectroscopic Characterization of Dual Absorption BODIPY Type Dyes and their Light Harvesting Application in Polymer‐Based Bulk Hetrojunction Organic Photovoltaics
Authors: Chi Chih‐Chin , Huang Yu‐Jui , Chen Chin‐Ti 
Published: March 2012

AbstractWe reported the synthesis and characterization of two new BODIPY type dyes with fluorine‐bridged two chromophores, boron‐dipyrromethene (BDP) and boron‐diindomethene (BDI). Each of BODIPY dyes 7a and 7b has two strong absorption bands around 500 and 600 nm bearing high extinction coefficients (76,000 M‐1cm‐1 for 7a and 71,000 M‐1cm‐1 for 7b at 501 nm; 115,000 M‐1cm‐1 for 7a and 110,000 M‐1cm‐1 for 7b at 603 nm). For light harvesting enhancement of solar cell, we have fabricated bulk heterojunction photovoltaics with various weight percentages of 7a as dopant dye in P3HT:PCBM blends in attempting to improve power conversion efficiency of solar energy.
A Gold(I) Complex Based on 1,8‐Naphthyridine Functionalized N‐Heterocyclic Carbene (NHC) and Its Catalytic Activity
Authors: Liu Zu‐Yin , Liu Shiuh‐Tzung 
Published: March 2012

AbstractA gold complex containing 2,7‐bis(mesitylimidazolylidenyl)naphthyridine (NHC‐NP) has been synthesized. Thus, reaction of [{Ag3(NHC‐NP)2}(PF6)3] with [Au(Me2S)Cl] provided an unusual digold complex bridged by two NHC‐NP, forming a 20‐membered dinuclear metallacycle [{Au2(NHC‐NP)2Cl2}(PF6)2] (2) in high yield. This complex was characterized by spectroscopic and elemental analysis. This gold complex is active for the hydrolysis of 2,2,5‐trimethyl‐1,3‐dioxane‐5‐methanol and can be recycled without losing the activity.
Synthesis of a Versatile Probe for Analysis of Cytoplasmic Peptide‐N‐Glycanase
Authors: Masuda Mizuho , Miyazawa Shinpei , Ito Yukishige , Matsuo Ichiro 
Published: March 2012

AbstractA clickable alkyne tagged chloroacetamidyl chitobiose derivative was synthesized as a potential inhibitor of cytoplasmic peptide‐N‐glycanase (PNGase). Construction of a chitobiose structure containing both alkyne and azide functional groups was performed using a thioglycoside donor having a triisopropylsilyl (TIPS) protected alkyne group and a glycosyl azide acceptor. The resultant chitobiosyl azide derivative was reduced to the corresponding glycosyl amine and a chloroacetyl group was introduced. Finally, removal of the TIPS group using tetrabutylammonium fluoride (TBAF) gave the target compound. We conjugated the dansyl derivative, using click conditions and obtained the fluorescent labeled disaccharide derivative, selectively. Our probe can easily lead to a variety of compounds and should help in the understanding of the biological functions of cytoplasmic PNGase.
FeCl3 Catalyzed Barbier Homocoupling Reaction for Synthesis of Symmetric Biaryls
Authors: Lee Adam Shih‐Yuan , Chen Pin‐Lung , Chang Yu‐Ting , Tsai Heng‐Tser 
Published: March 2012

AbstractA series of biaryls and biheteroaryls were synthesized by the Barbier reaction of aryl bromide with magnesium powder and 1,2‐dibromoethane in the presence of FeCl3 in THF under reflux reaction condition. The catalytic system differentiates itself from other homocoupling reactions catalyzed by iron salts in that it requires neither the preliminary preparation of Grignard reagent nor the addition of an oxidant.
Development of a Plate‐Based Assay Platform to Monitor Cellular SHP2 Phosphatase Activity During Erythroid Differentiation
Authors: Chu Chi‐Yuan , Kuo Chun‐Chen , Chen Mei‐Hsiao , Chen Kuan‐Ju , Lo Lee‐Chiang , Lin Jing‐Jer 
Published: March 2012

AbstractIn light of the growing interest in understanding the roles of protein tyrosine phosphatases (PTPs) in the complicated signaling pathways, convenient methods to profile and analyze PTP activities in various cellular processes are in high demand. We previously demonstrated a two‐step assay platform that combined the use of a universal activity‐based probe with a PTP‐specific antibody, by which the designated PTP activity in a cellular event could be successfully determined. Here, we describe an improved plate‐based assay platform by replacing the immunoprecipitation step with a simpler immunocapture step using an antibody on a plate. An assay protocol targeting SHP2 activity was thus established and a universal probe with a sulforhodamine B tag was used to afford a direct fluorescent readout. The protocol was employed for the monitoring of SHP2 activities during K562 erythroid differentiation. Comparative study using the previous protocol was also conducted. Both PTP assay protocols consistently showed that SHP2 was activated during K562 erythroid differentiation.
Environmental effects in kelvin force microscopy of modified diamond surfaces
Authors: Araujo W.W.R. , Salvadori M.C. , Teixeira F.S. , Cattani M. , Brown I.G. 
Published: March 2012

AbstractWe have explored the effects of atmospheric environment on Kelvin force microscopy (KFM) measurements of potential difference between different regions of test polycrystalline diamond surfaces. The diamond films were deposited by microwave plasma‐assisted chemical vapor deposition, which naturally produces hydrogen terminations on the surface of the films formed. Selected regions were patterned by electron‐beam lithography and chemical terminations of oxygen or fluorine were created by exposure to an oxygen or fluorine plasma source. For KFM imaging, the samples were mounted in a hood with a constant flow of helium gas. Successive images were taken over a 5‐h period showing the effect of the environment on KFM imaging. We conclude that the helium flow removes water molecules adsorbed on the surface of the samples, resulting in differences in surface potential between adjacent regions. The degree of water removal is different for surfaces with different terminations. The results highlight the importance of taking into account the atmospheric environment when carrying out KFM analysis. © 2012 Wiley Periodicals, Inc.
Pedotransfer functions for water retention and unsaturated hydraulic conductivity of forest soils
Authors: Puhlmann Heike , von Wilpert Klaus 
Published: March 2012

AbstractThe hydraulic properties of soils, i.e., their ability to store and conduct water, mainly govern the availability of soil water for plants. Information on the hydraulic properties is needed, e.g., for the quantification of drought risk at a given site. Furthermore, knowledge of the water transport is the precondition for the estimation of element fluxes in the soil, e.g., when predicting element leaching from the root zone to the groundwater. For forest soils, only few systematic investigations of their hydraulic properties exist. Within the 2nd forest‐soil survey of Germany, soil samples were taken along a regular 8 km × 8 km grid in the forests of the State of Baden‐Württemberg and the hydraulic properties were estimated in the laboratory by multistep outflow experiments. Besides the soil‐hydraulic measurements, numerous additional soil chemical and physical analyses were carried out and comprehensive profile descriptions were compiled and integrated in a hydraulic database. Based on this database, multiple‐linear‐regression techniques were used to develop pedotransfer functions for the water‐retention curve and the unsaturated‐hydraulic‐conductivity curve using the parametric models of Mualem/van‐Genuchten. Our work fills a gap since to our knowledge, no pedotransfer functions for the unsaturated hydraulic conductivity for forest soils exist so far. The predictive accuracy of the established pedotransfer functions, both for the water‐retention curve and the hydraulic‐conductivity curve, is in the range of (and in some cases better than) other published pedotransfer functions that were mostly derived for agricultural soils.
IMPLICATIONS OF COVER CROPS FOR SOIL QUALITY AND GEODIVERSITY IN A HUMID‐TEMPERATE REGION IN THE MIDWESTERN USA
Authors: Stavi I. , Lal R. , Jones S. , Reeder R. C. 
Published: March 2012

ABSTRACTWinter cover cropping plays an important role in conservation farming. In the Midwest region of the USA, strips planted with Austrian winter peas [AWP (Pisum sativum L.)], radishes [RAD (Raphanus sativus L.)], and a mixed cover of both cultivars (MIX) were compared during the spring season to determine their impact on the soil quality at 0–5 and 5–10 cm depths. The treatments RAD, AWP, and MIX had the highest, intermediate, and lowest soil bulk density impacts (1·67, 1·52, and 1·50 Mg m−3, respectively). An opposite trend was observed for the concentrations of soil organic carbon (15·9, 17·6, and 19·4 g kg−1, respectively) and total nitrogen (1·5, 1·7, and 2·8 g kg−1, respectively), the calcium exchange capacity (8·6, 9·5, and 11·4 cmol+c kg−1, respectively), and earthworm density (85, 221 and 226 per m2 x 0·15 m, respectively). The AWP, MIX, and RAD resulted in the highest, intermediate, and lowest water stable aggregates (91·6, 87·4, and 79·9 per cent, respectively), mean weight diameter of aggregates (3·4, 2·7, and 2·1 mm, respectively), saturated hydraulic conductivity (15·7, 13·0, and 6·3 cm h−1, respectively), and intrinsic permeability (1·69, 1·37, and 0·70 cm2 10−10, respectively). The AWP and RAD treatments resulted in a similar C:N ratio (10·5), which was larger than associated with MIX (7·2). Overall, AWP and MIX had a larger positive impact on soil quality than RAD did, and the impact was greater at the 0–5 than the 5–10 cm depth. This indicates the suitability of the various cover crops for improving the soil quality and restoring geodiversity. Copyright © 2012 John Wiley & Sons, Ltd.
Betulinic acid decreases ER‐negative breast cancer cell growth in vitro and in vivo: Role of Sp transcription factors and microRNA‐27a:ZBTB10
Authors: Mertens‐Talcott Susanne U. , Noratto Giuliana D. , Li Xiangrong , Angel‐Morales Gabriela , Bertoldi Michele C. , Safe Stephen 
Published: March 2012

AbstractBetulinic acid (BA), a pentacyclic triterpenoid isolated from tree bark is cytotoxic to cancer cells. There is evidence that specificity proteins (Sps), such as Sp1, Sp3, and Sp4, are overexpressed in tumors and contribute to the proliferative and angiogenic phenotype associated with cancer cells. The objective of this study was to determine the efficacy of BA in decreasing the Sps expression and underlying mechanisms. Results show that BA decreased proliferation and induced apoptosis of estrogen‐receptor‐negative breast cancer MDA‐MB‐231 cells. The BA‐induced Sp1, Sp3, and Sp4 downregulation was accompanied by increased zinc finger ZBTB10 expression, a putative Sp‐repressor and decreased microRNA‐27a levels, a microRNA involved in the regulation of ZBTB10. Similar results were observed in MDA‐MB‐231 cells transfected with ZBTB10 expression plasmid. BA induced cell cycle arrest in the G2/M phase and increased Myt‐1 mRNA (a microRNA‐27a target gene), which causes inhibition in G2/M by phosphorylation of cdc2. The effects of BA were reversed by transient transfection with a mimic of microRNA‐27a. In nude mice with xenografted MDA‐MB‐231 cells, tumor size and weight were significantly decreased by BA treatment. In tumor tissue, ZBTB10 mRNA was increased while mRNA and protein of Sp1, Sp3 and Sp4, as well as mRNA of vascular endothelial growth factor receptor (VEGFR), survivin and microRNA‐27a were decreased by BA. In lungs of xenografted mice, human β2‐microglobulin mRNA was decreased in BA‐treated animals. These results show that the anticancer effects of BA are at least in part based on interactions with the microRNA‐27a‐ZBTB10‐Sp‐axis causing increased cell death. © 2012 Wiley Periodicals, Inc.
Methionine synthase and thymidylate synthase gene polymorphisms and colorectal adenoma risk: The self defense forces study
Authors: Yoshimitsu Shinichiro , Morita Makiko , Hamachi Tadamichi , Tabata Shinji , Abe Hiroshi , Tajima Osamu , Uezono Kousaku , Ohnaka Keizo , Kono Suminori 
Published: March 2012

AbstractFolate‐mediated one‐carbon metabolism has been implicated in colorectal carcinogenesis. We investigated associations of functional genetic polymorphisms of methionine synthase (MTR), MTR reductase (MTRR), and thymidylate synthase (TS) with colorectal adenomas. The study subjects were 455 cases of colorectal adenomas and 1052 controls with no polyp at colonoscopy. Genotypes were determined for MTR A2756G, MTRR A66G and two polymorphisms in the TS gene, 28‐bp tandem repeat polymorphism in the promoter enhancer region (TSER) and 6‐bp deletion polymorphism at position 1494 in the 3′ untranslated region (TS 1494del6). We also examined the alcohol–genotype and gene–gene interactions on adenoma risk. The GG genotype of MTR A2756G was associated with an increased risk of colorectal adenomas; odds ratios for AG and GG versus AA genotype were 0.99 (95% confidence interval 0.78–1.26) and 1.72 (1.04–2.82), respectively. The increase in the risk associated with MTR 2756GG genotype was evident in men with high alcohol consumption (≥30 mL/d), but not in those with low alcohol consumption (interaction P = 0.03). Men who were homozygous for the TSER double‐repeat allele had a slightly decreased risk of colorectal adenomas as compared with those homozygous for the TSER triple‐repeat allele. Neither MTRR A66G nor TS 1494del6 was associated with colorectal adenomas. There was no measurable interaction either between MTR A2756G and MTRR A66G or between TSER and TS 1494del6. MTR A2756G appears to be associated with colorectal adenoma risk differently according to alcohol consumption. The MTR‐catalyzed reaction may play an important role in the development of colorectal adenomas. © 2012 Wiley Periodicals, Inc.
Matchmaking using Fuzzy Analytical Hierarchy Process, Compatibility Measure and Stable Matching for Online Matrimony in India
Authors: Joshi Kedar , Kumar Sushil 
Published: March 2012

ABSTRACTUse of online matrimony for matchmaking is rapidly growing in India. One of the major difficulties faced by the users of such websites is the long time taken to realize the matches. We propose an integrated approach to matchmaking in e‐matrimony environment using fuzzy analytical hierarchy process considering multiple criteria involved in the process. The objective of the study is to enable users to search their partners effectively and efficiently and narrow down to the desired matches so that the chances of matchmaking through online portal are maximized. A compatibility index, that is match metric, is developed that enhances the probability of matchmaking with reduction in lead time. Furthermore, Gale‐Shapley stable matching algorithm is used to help customers obtain the desired shortlist of profiles with a suggested stable match. An illustrated hypothetical example of matchmaking using an Indian matrimony portal is presented, and the use of the proposed methodology is demonstrated. Copyright © 2012 John Wiley & Sons, Ltd.
Global solutions of a class of discrete‐time backward nonlinear equations on ordered Banach spaces with applications to Riccati equations of stochastic control
Authors: Ungureanu V. M. , Dragan V. , Morozan T. 
Published: March 2012

SUMMARYIn this paper, we consider the problem of existence of certain global solutions for general discrete‐time backward nonlinear equations, defined on infinite dimensional ordered Banach spaces. This class of nonlinear equations includes as special cases many of the discrete‐time Riccati equations arising both in deterministic and stochastic optimal control problems. On the basis of a linear matrix inequalities approach, we give necessary and sufficient conditions for the existence of maximal, stabilizing, and minimal solutions of the considered discrete‐time backward nonlinear equations. As an application, we discuss the existence of stabilizing solutions for discrete‐time Riccati equations of stochastic control and filtering on Hilbert spaces. The tools provided by this paper show that a wide class of nonlinear equations can be treated in a uniform manner. Copyright © 2012 John Wiley & Sons, Ltd.
Effect of argon on the structure of hydrogenated nanocrystalline silicon deposited from tetrachlorosilane/hydrogen/argon plasma
Authors: Zhang Lin , Gao Junhua , Xiao Jinquan , Wen Lishi , Gong Jun , Sun Chao 
Published: March 2012

AbstractHydrogenated nanocrystalline silicon films (nc‐Si:H) have been deposited by the decomposition of tetrachlorosilane (SiCl4) diluted with hydrogen (H2) and argon (Ar) by a plasma‐enhanced chemical vapor deposition (PECVD) method. Basing on the structural characterization of nc‐Si:H, we have found that Ar affects the growth of films deposited at two substrate temperatures (Ts = 250 and 120 °C) in different ways. At Ts = 250 °C, the Ar gas deteriorates the crystallinity of nc‐Si:H, whereas, at Ts = 120 °C, the crystallization of nc‐Si:H films is promoted with increasing argon flow rate (Hf) from 10 to 30 sccm; however, the extremely high Ar dilution adversely affects the ordered structure of films. Meanwhile, the hydrogen concentration in the films is also controlled by Hf. Finally, the effects of Ar in the SiCl4/H2/Ar system have been discussed in related to the equilibrium of atomic hydrogen and ionized argon.
Development of a methodology using gas chromatography‐combustion‐isotope ratio mass spectrometry for the determination of the carbon isotope ratio of caffeine extracted from tea leaves (Camellia sinensis)
Authors: Wu Chen , Yamada Keita , Sumikawa Osamu , Matsunaga Akiko , Gilbert Alexis , Yoshida Naohiro 
Published: March 2012

RATIONALECompound‐specific isotope analysis (CSIA) of the extracted caffeine can be used to determine the authenticity of the origin of tea. Elemental analysis‐isotope ratio mass spectrometry (EA‐IRMS), which is widely used to measure the carbon isotope ratio of caffeine, has a strict requirement for the purity of the extracted caffeine. To obtain high‐purity caffeine from tea leaves, the conventional extraction process has to be repeated and usually takes about 5–6 h. To improve the measurement of the carbon isotope ratio of caffeine, a more rapid and accurate measuring method is needed.METHODSAn analytical protocol was developed for the determination of the carbon isotope ratio of caffeine from tea leaves using gas chromatography‐combustion‐isotope ratio mass spectrometry (GC‐C‐IRMS) combined with our extraction process. The procedure to extract caffeine and determine its carbon isotope ratio takes around 1.5 h.RESULTSThe standard deviation of the method is less than 0.1‰ (1σ). The measured carbon isotope ratios were not influenced by the amount of caffeine injected (0.08–0.62 µg) or by the extraction yield of caffeine from the tea leaves.CONCLUSIONSThe carbon isotope ratios of caffeine from eight tea cultivars were determined using the protocol. Copyright © 2012 John Wiley & Sons, Ltd.
Proton‐transfer reaction mass spectrometry (PTRMS) in combination with thermal desorption (TD) for sensitive off‐line analysis of volatiles
Authors: Crespo Elena , Devasena Samudrala , Sikkens Cor , Centeno Raymund , Cristescu Simona M. , Harren Frans J. M. 
Published: March 2012

RATIONALEWhen performing trace gas analysis, it is not always possible to bring the source of volatiles and the gas analyzer together. In these cases, volatile storage containers, such as thermal desorption (TD) tubes, can be used for off‐line measurement. TD is routinely combined with gas chromatography/mass spectrometry (GC/MS), but so far not with proton‐transfer reaction mass spectrometry (PTRMS), which has a faster response.METHODSA PTR‐quadrupole‐MS instrument and a PTR‐ion‐trap‐MS instrument were separately coupled to a TD unit for off‐line analysis of trace volatiles in air. Carbograph 1TD/Carbopack X sorbent tubes were filled with different concentrations of a trace gas mixture containing low molecular weight volatiles (32 g/mol up to 136 g/mol) and measured with the above‐mentioned combinations. The carrier gas in the TD unit was changed from helium to nitrogen to be able to combine this instrument with the mass spectrometer.RESULTSGood linearity and reproducibility with the amount of gas stored were obtained. The storage capacity over time (up to 14 days) showed larger variability (<11% for all compounds, except for acetone 27%). Several tubes were filled with breath of different persons, and the breath of a smoker showed increased levels of acetonitrile and benzene. The combination of the PTR ion‐trap instrument with the TD unit was also investigated. Due to its higher sampling rate, the ion‐trap system showed higher throughput capabilities than the quadrupole system.CONCLUSIONSThe combination of TD with PTRMS using both a quadrupole and an ion trap for off‐line volatile analysis has been validated. TD tubes can be a robust and compact volatile storage method when the mass spectrometry and the sampling cannot be performed in the same place, for example in large screening studies. In addition, a higher measurement throughput than with GC/MS could be obtained. Copyright © 2012 John Wiley & Sons, Ltd.
Subdivision algorithm for optimal control
Authors: Taraba Peter 
Published: March 2012

SUMMARYWe present a novel algorithm for optimal control of nonlinear systems based on a subdivision algorithm. The algorithm presented in this paper is an alternative to a set‐oriented approach for optimal feedback stabilization. We compare the proposed algorithm to the set‐oriented approach, contrast these two approaches, and use examples to show that the new algorithm produces comparable results. Also, we demonstrate by example that we receive a precomputed optimal solution. The main contribution of the paper is understanding how cost function improves with further subdivision of state space and smaller memory footprint of the final solution in comparison with set‐oriented approach. Copyright © 2012 John Wiley & Sons, Ltd.
Exponential H ∞  filtering for singular systems with Markovian jump parameters
Authors: Wang Guoliang , Zhang Qingling , Yang Chunyu 
Published: March 2012

SUMMARYThis paper is concerned with the H ∞  filter design for continuous‐time singular systems with Markovian jump parameters, whose system mode is transmitted through an unreliable network. In contrast to the traditionally mode‐dependent or mode‐independent filtering method, a new partially mode‐dependent filter is established via using a mode‐dependent Lyapunov function, where the stochastic property of mode available to a filter is considered. Sufficient conditions for the existence of H ∞  filter are obtained as strict linear matrix inequalities. Finally, numerical examples are used to show the effectiveness of the given theoretical results. Copyright © 2012 John Wiley & Sons, Ltd.