bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improved Synthesis and Mutagenicity of Oligonucleotides Containing 5‐Hydroxymethylcytosine, 5‐Formylcytosine and 5‐Carboxylcytosine
Authors: Münzel Martin , Lischke Ulrike , Stathis Dimitrios , Pfaffeneder Toni , Gnerlich Felix A. , Deiml Christian A. , Koch Sandra C. , Karaghiosoff Konstantin , Carell Thomas 
Published: November 2011

Abstract5‐Formylcytosine (fC or 5‐CHOdC) and 5‐carboxylcytosine (caC or 5‐COOHdC) have recently been identified as constituents of mammalian DNA. The nucleosides are formed from 5‐methylcytosine (mC or 5‐MedC) via 5‐hydroxymethylcytosine (hmC or 5‐HOMedC) and are possible intermediates of an active DNA demethylation process. Here we show efficient syntheses of phosphoramidites which enable the synthesis of DNA strands containing these cytosine modifications based on Pd0‐catalyzed functionalization of 5‐iododeoxycytidine. The first crystal structure of fC reveals the existence of an intramolecular H‐bond between the exocyclic amine and the formyl group, which controls the conformation of the formyl substituent. Using a newly designed in vitro mutagenicity assay we show that fC and caC are only marginally mutagenic, which is a prerequisite for the bases to function as epigenetic control units.
Selective Separation/Preconcentration of Silver Ion in Water by Multiwalled Carbon Nanotubes Microcolumn as a Sorbent
Authors: Biparva Pourya , Hadjmohammadi Mohammad Reza 
Published: November 2011

AbstractThe present paper proposes the application of multiwalled carbon nanotubes (MWCNTs) as a solid adsorbent for selective separation/preconcentration of silver(I) in water samples prior to flame atomic absorption spectrometry. The procedure is based on the solid phase extraction of Ag(I)–2‐mercaptobenzothiazole chelate on MWCNTs. The elution step is carried out with 5 mL of 2 mol L−1 HNO3 in acetone solution at a flow rate of 1.0 mL min−1. The influences of the various analytical parameters including pH of the solution, eluent type, sample volume, flow rates of eluent, matrix ions were investigated for optimization of the presented procedure. Tests of addition/recovery for analyte ion in real samples were performed with satisfactory results. Preconcentration factor and limit of detection for Ag(I) were 160 and 0.21 µg L−1, respectively. The synthesized MWCNT exhibited excellent stability in eluent solution and its adsorption capacity was 5.4 mg of silver per gram of sorbent. The proposed method was successfully applied to trace silver determination in a variety of environmental water samples.
Assessment of the Biosorption Characteristics of a Spent Cottonseed Husk Substrate for the Decolorization of Methylene Blue
Authors: Zhou Qi , Gong Wenqi , Yang Dongjiang , Xie Chuanxin , Li Yubiao , Liu Xiafang , Bai Cuiping , Wang Rui 
Published: November 2011

AbstractThis study concentrates on the possible application of the spent cottonseed husk substrate (SCHS), an agricultural waste used after the cultivation of white rot fungus Flammulina velutipes, to adsorb methylene blue (MB) from aqueous solutions. Batch studies were carried out with variable initial solution pH, adsorbent amount, reaction time, temperature, and initial MB concentration. MB uptake was favorable at pH ranging from 4.0 to 12.0, and the equilibrium adsorption capacity of 143.5 mg g−1 can be reached promptly within about 240 min. The combination analysis of FTIR and BET techniques revealed that the massive functional groups on the biosorbent surface, such as hydroxyl and carboxyl, were responsible for the biosorption of MB. It was found that adsorption data matched the pseudo‐second order kinetic and Langmuir isotherm models. Thermodynamic parameters of free energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°), obtained from biosorption MB ranging from 293 to 313 K, showed that the sorption experiment was a spontaneous and endothermic process. The study highlighted a new pathway to develop a new potential utilization of SCHS as a low‐cost sorbent for the removal of MB pollutants from wastewater.
Physiological Responses of Halophyte Suaeda salsa to Water Table and Salt Stresses in Coastal Wetland of Yellow River Delta
Authors: Guan Bo , Yu Junbao , Wang Xuehong , Fu Yuqin , Kan Xingyan , Lin Qianxin , Han Guangxuan , Lu Zhaohua 
Published: November 2011

AbstractSoil salinity and waterlogging are two major environmental problems in estuarine wetlands. The objective of this study was to investigate the effects of salt stress, water table, and their combination on growth, chlorophyll content, antioxidant system, and ion accumulation in Suaeda salsa plant, which is the pioneer plant in coastal wetland of the Yellow River Delta (YRD). The results showed that plant height, number of branches, and biomass were significantly affected by water table and salt stress. With enhanced salt stress, the ratio of leaf to total biomass increased and the ratio of root to total biomass decreased. The contents of Chl‐a, ‐b, Chl‐a + b, and carotenoids (Car) decreased significantly with increasing soil salinity and the water table level. Salt stress enhanced the activity of superoxide dismutase (SOD) and catalase (CAT), but reduced the content of protein. With the lowering water table level, the activity of CAT and protein content increased, and activity of SOD decreased. Na+ and Cl− content were up‐regulated with increasing salt stress (NaCl), whereas, the contents of other cations (K+, Ca2+, and Mg2+) and anions (${\rm SO}_{{\rm 4}}^{{\rm 2}- } $ and ${\rm NO}_{{\rm 3}}^{- } $) were decreased. In summary, the results indicated that the S. salsa plants could adapt to the adverse soil environments through modifying their growth and physiology status at the highly saline and intertidal zone, such as the YRD estuarine wetlands, and also could be used as a bio‐reclamation plant to decline the high salt in saline soils.
Toxic Effects of Copper‐Based and Synthetic Organic Pesticides on Activated Sludge
Authors: Nalbur Berrak Erol , Eleren Sevil Çalışkan , Şahin Semih , Alkan Ufuk 
Published: November 2011

AbstractToxic effects of five commonly used pesticides on the biomass of a municipal activated sludge system were determined on the basis of the reduction in the oxygen uptake rate (OUR) and specific oxygen uptake rate (SOUR). Toxicity levels of the selected pesticides were determined by employing a modified OECD 209 (Organisation for Economic Cooperation and Development) method which was performed as batch experiments using a respirometer. Copper sulphate (CuSO4 · 5 H2O), copper oxychloride (Cu2Cl(OH)3), copper calcium oxychloride (CaCu3Cl2(OH)6) as copper‐based pesticides and chlorsulphuron (C12H12ClN5O4S), 2,4‐dichlorophenoxyacetic acid (2,4‐D) (C8H6Cl2O3) as synthetic organic pesticides were selected for the experiments. The EC50 values were determined to be 78, 249 and 281 mg/L for CuSO4 · 5 H2O, Cu2Cl(OH)3 and CaCu3Cl2(OH)6, respectively. Corresponding values for C12H12ClN5O4S and 2,4‐D were 860 and 3664 mg/L, respectively. Results indicated that toxicity effects of copper‐based pesticides were higher than that of synthetic organic pesticides. CuSO4 · 5 H2O was found to exert the highest toxicity among the copper‐based pesticides, whereas, C12H12ClN5O4S was determined to be the most toxic among the organic pesticides on activated sludge biomass.
Assessing Spin‐Component‐Scaled Second‐Order Møller–Plesset Theory Using Anharmonic Frequencies
Authors: Domin Dominik , Benoit David M. 
Published: November 2011

AbstractFour common parametrisations of spin‐component‐scaled second‐order Møller–Plesset (MP2) theory are benchmarked by calculating the anharmonic vibrational frequencies of a test suite consisting of eighteen diatomic and five small molecules. Of the four methods, the scaled opposite‐spin MP2 (SOS‐MP2), the variable‐scaling opposite‐spin MP2 (VOS‐MP2) and the spin‐component‐scaled MP2 (SCS‐MP2) methods perform statistically better than standard MP2 theory, while the spin‐component scaled for nucleic bases MP2 (SCSN‐MP2) performs worse. Vibrations of closed‐shell diatomic molecules are slightly more accurately described by the SOS‐MP2 method of Head‐Gordon (εMAD=51 cm−1) than the SCS‐MP2 method of Grimme (εMAD=61 cm−1) or the size‐consistent parametrisation of VOS‐MP2 (εMAD=54 cm−1). For open‐shell diatomic molecules, the SOS‐MP2 (εMAD=83 cm−1) and SCS‐MP2 (εMAD=81 cm−1) methods are of similar accuracy, while VOS‐MP2 is slightly better (εMAD=77 cm−1). Since the VOS‐MP2 and SOS‐MP2 methods tend to have smaller deviations from experiment, and they can be made computationally more economical than the SCS‐MP2 or MP2 methods, we suggest that they should be the preferred ab initio method for computing vibrational frequencies in large molecules.
Practical Synthesis of Photochromic Diarylethenes in Integrated Flow Microreactor Systems
Authors: Asai Tatsuro , Takata Atsushi , Nagaki Aiichiro , Yoshida Jun‐ichi 
Published: November 2011

AbstractAn effective method for the synthesis of photochromic diarylethenes through the generation of heteroaryllithiums and subsequent reaction with octafluorocyclopentene has been developed by using integrated flow microreactor systems. Reactions can be conducted without using cryogenic conditions by virtue of effective temperature and residence time control, although much lower temperatures (<−78 °C) are needed for batch macroreactions. Moreover, the synthesis of unsymmetrical diarylethenes, which is difficult to achieve when using conventional batch macrosystems, has been accomplished based on the selective introduction of one aryl group to give arylheptafluorocyclopentene followed by the introduction of another aryl group. The productivity of the laboratory‐scale system is approximately 0.5 mmol min−1. Therefore, the present integrated flow microreactor method serves as a practical way of synthesizing various photochromic diarylethene derivatives.
(Methoxyborole)cobalt Complexes – Synthesis, Structures and Bonding
Authors: Loginov Dmitry A. , Pronin Andrey A. , Starikova Zoya A. , Vologzhanina Anna V. , Petrovskii Pavel V. , Kudinov Alexander R. 
Published: November 2011

AbstractHeating (η‐C4H4BCy)Co(CO)2I (Cy = cyclohexyl) in benzene in the presence of AlCl3 and subsequent methanolysis affords the cationic benzene complex [(η‐C4H4BOMe)Co(η‐C6H6)]+ (1). Under visible‐light irradiation, 1 reacts with MeCN and tBuNC to give the tris(ligand) complexes [(η‐C4H4BOMe)Co(L)3]+ [L = MeCN (2), tBuNC (4)]. A similar reaction with P(OMe)3 in MeCN affords [(η‐C4H4BOMe)Co(MeCN){P(OMe)3}2]+ (5). Cation 2 reacts with BPh4– in CH2Cl2 to give the zwitterionic arene complex (η‐C4H4BOMe)Co(η‐C6H5BPh3) (3). Reactions of 2 with TlCp and Tl(η‐9‐SMe2‐7,8‐C2B9H10) afford the sandwich compounds (η‐C4H4BOMe)CoCp (6) and (η‐C4H4BOMe)Co(η‐9‐SMe2‐7,8‐C2B9H10) (7). The structures of 3 and 7 were determined by X‐ray diffraction. The bonding in the borole complexes [(C4H4BR)Co(C6H6)]+ and (C4H4BR)CoCp (R = H, OMe) was compared with that in the cyclobutadiene analogues [(C4R4)Co(C6H6)]+ and (C4R4)CoCp (R = H, Me) using energy decomposition analysis.
Improved synthesis and characterization of saturated branched‐chain fatty acid isomers
Authors: Ngo Helen L. , Hoh Eunha , Foglia Thomas A. 
Published: November 2011

AbstractThe development of viable technologies for producing green products from renewable fats and oils is highly desirable since such materials can serve as replacements for non‐renewable and poorly biodegradable petroleum‐based products. Mixtures of saturated branched‐chain fatty acid isomers (sbc‐FAs), commonly referred to as isostearic acid, are important intermediates for the production of biodegradable lubricants, cosmetics, emollients, and hydraulic fluids. Present methods for producing sbc‐FAs, however, often give low yields of sbc‐FAs or sbc‐FA preparations with a high content of dimer acid fatty acid co‐products. This study reports an improved route to synthesizing sbc‐FAs from monounsaturated fatty acids using a modified H‐Ferrierite zeolite catalyst in conjunction with small amounts of triphenylphosphine additive. The yields of sbc‐FAs (up to 80 wt%) and co‐products (up to15 wt%) were determined using a modification of a previously reported GC method. A more detailed analysis of the distribution of sbc‐FA isomers in the products was made by the combined use of GC × GC‐TOF‐MS. Additionally, it was found that the H‐Ferrierite zeolite catalyst was recyclable and reusable up to 10 times without significant loss of activity and selectivity for sbc‐FAs.
Heat treatment effects on extraction of roselle (Hibiscus sabdariffa L) seed oil
Authors: Akinoso Rahman , Suleiman Abubarkar 
Published: November 2011

AbstractFatty acid composition of roselle (Hibiscus sabdariffa L) seed oil was determined and oil extraction was optimized using RSM. Five levels of the variables, roasting duration (10, 15, 20, 25, and 30 min), and temperature (80, 90, 100, 110, and 120°C) were used. Oil yield (OY), free fatty acid (FFA), anisidine value (AV), specific gravity (SG), and stability were responses and determined using standard methods. Major fatty acids found were oleic acid (37.92%), linoleic (35.01%), palmitic (19.65%), and stearic (6.07%). Myristic (0.16), myristoleic (0.17), palmitoleic (0.56), arachidic (0.14), and eicosatrienoic (0.20) were minor fatty acids content. OY, FFA, AV, SG, and stability varied from 18 to 23%, from 0.56 to 4.11%, from 6.93 to 35.7 mg/L, from 0.90 to 0.95, and from 0.68 to 5.42%, respectively. The treatment had significant (p<0.05) effect on OY, AV, and SG. However, non‐significant effect of treatment was recorded on FFA and stability at 5% level of significance. The best desirability of 0.46 was achieved at roasting duration and temperature of 25 min and 110°C, respectively, which gave OY of 22%, initial FFA of 1.95%, AV of 31.2 mg/L, SG of 0.92, and stability of 2.67%.Practical applications: Roselle seed is a by‐product from the processing of roselle calyces. Reports from literature have shown that the seed contains about 20% edible health‐promoting oil. Research into effect of pre‐heat treatment on quality and quantity of oil extracted from roselle seed will serve as a guide in recommending optimum heating duration and temperature. The models developed in this study can be a working tool for producers of roselle oil extraction equipment and potential investors into commercial production of roselle oil. Output of this work may change the status of the seeds from a waste material to a valuable product.
A progression of induration in Medusae Fossae Formation transverse aeolian ridges: evidence for ancient aeolian bedforms and extensive reworking
Authors: Kerber Laura , Head James W. 
Published: November 2011

ABSTRACTA progression of induration, erosion, and redeposition of transverse and networked transverse aeolian ridges (TARs) has been documented in the Medusae Fossae Formation (MFF), Mars. Cratered and eroded aeolian bedforms are rarely observed on Mars, indicating that those found in the MFF have been inactive for much longer than those found elsewhere. Indurated TARs are observed to grade into faceted MFF terrain, indicating a genetic relationship between the two. We propose that TAR deposition, induration and erosion have played a larger role in the surface morphology and evolution of the MFF than previously recognized. The deposition, induration, and erosion of TARs indicate that the MFF has undergone multiple cycles of reworking, and that much of its current surface morphology does not reflect the circumstances of its primary emplacement. Copyright © 2011 John Wiley & Sons, Ltd.
The beaver meadow complex revisited – the role of beavers in post‐glacial floodplain development
Authors: Polvi Lina E. , Wohl Ellen 
Published: November 2011

ABSTRACTWe evaluate the validity of the beaver‐meadow complex hypothesis, used to explain the deposition of extensive fine sediment in broad, low‐gradient valleys. Previous work establishes that beaver damming forms wet meadows with multi‐thread channels and enhanced sediment storage, but the long‐term geomorphic effects of beaver are unclear. We focus on two low‐gradient broad valleys, Beaver Meadows and Moraine Park, in Rocky Mountain National Park (Colorado, USA). Both valleys experienced a dramatic decrease in beaver population in the past century and provide an ideal setting for determining whether contemporary geomorphic conditions and sedimentation are within the historical range of variability of valley bottom processes. We examine the geomorphic significance of beaver‐pond sediment by determining the rates and types of sedimentation since the middle Holocene and the role of beaver in driving floodplain evolution through increased channel complexity and fine sediment deposition. Sediment analyses from cores and cutbanks indicate that 33–50% of the alluvial sediment in Beaver Meadows is ponded and 28–40% was deposited in‐channel; in Moraine Park 32–41% is ponded sediment and 40–52% was deposited in‐channel. Radiocarbon ages spanning 4300 years indicate long‐term aggradation rates of ~0.05 cm yr‐1. The observed highly variable short‐term rates indicate temporal heterogeneity in aggradation, which in turn reflects spatial heterogeneity in processes at any point in time. Channel complexity increases directly downstream of beaver dams. The increased complexity forms a positive feedback for beaver‐induced sedimentation; the multi‐thread channel increases potential channel length for further damming, which increases the potential area occupied by beaver ponds and the volume of fine sediment trapped. Channel complexity decreased significantly as surveyed beaver population decreased. Beaver Meadows and Moraine Park represent settings where beaver substantially influence post‐glacial floodplain aggradation. These findings underscore the importance of understanding the historical range of variability of valley bottom processes, and implications for environmental restoration. Copyright © 2011 John Wiley & Sons, Ltd.
Automated critical point identification for PIV data using multimodal particle swarm optimization
Authors: Cormier N. , Cormier G. , Poitras G. , Brizzi L.‐É. 
Published: November 2011

SUMMARYA hybrid sequential niche algorithm is used for the automated identification of critical points of velocity fields. This method combines an adaptive sequential niche technique with deterministic local optimization to detect critical points: focus, node and saddle points. A particle swarm algorithm performs a global search whereas vortex core identification functions compute the precise location as the extremum of the corresponding function. Once a critical point is found, a rectangular niche is constructed around the point. The particle swarm then proceeds to explore different regions of the velocity field. The process advances sequentially, avoiding areas near previously found critical points by blocking niches obtained from previous steps. The niche size is automatically adjusted each time a search enters inside an existing niche. Vortex core functions are used for critical point identification and calculating its precise location inside each niche. The procedure is validated on particle image velocimetry data obtained with two types of flows, an impinging jet flow and a flow downstream of a model building. The hybrid algorithm proved to be very efficient and robust for automated detection and identification of critical points. It can be used as a first step for studying the time‐dependent dynamic behavior of instantaneous velocity fields by tracking topological critical points. This is the first study that uses a multi‐modal particle swarm algorithm for critical point identification. Copyright © 2011 John Wiley & Sons, Ltd.
The meaning in life questionnaire: psychometric properties with individuals with serious mental illness in an inpatient setting
Authors: Schulenberg Stefan E. , Strack Kristen M. , Buchanan Erin M. 
Published: November 2011

AbstractObjectives: This study examined the psychometric properties of the Meaning in Life Questionnaire (MLQ) with individuals with serious mental illness (SMI) in an inpatient setting (N = 96). The 10‐item MLQ comprises Presence (perceived meaning) and Search (motivation to discover meaning) scales. Design: This study focused on the reliability and validity of the MLQ, reporting a range of data, including correlations and regression (predicting scores on a measure of psychopathology, the Brief Symptom Inventory). Results: Both MLQ scales yielded reliable scores. The current sample tended to report greater Presence, whereas Search means tended to be similar to those reported in other studies. The association between Presence and the Brief Symptom Inventory was not statistically significant. As for Search, people reporting greater motivation to discover meaning tended to report greater degrees of symptoms. The Presence and Search scales correlated at r =.12, which was unexpected given that most studies note an inverse relationship. However, this finding is considered in light of an interaction effect between Presence and Search when predicting psychological distress. Conclusions: The current findings are supportive of the MLQ's utility with individuals with SMI. Limitations and directions for research are offered. © 2011 Wiley Periodicals, Inc. J Clin Psychol 67:1–10, 2011.
Fourier analysis of STimulated echoes (FAST) for the quantitative analysis of left ventricular twist
Authors: Reyhan Meral , Natsuaki Yutaka , Ennis Daniel B. 
Published: November 2011

AbstractPurpose:To validate a novel method for the rapid and facile quantification of left ventricular (LV) twist from tagged magnetic resonance images and demonstrate the potential clinical utility in a series of 20 healthy volunteers.Materials and Methods:Cardiac magnetic resonance imaging (MRI) short‐axis images were acquired with tissue tagging in 20 healthy subjects and six canines. The tagged images were processed using a novel Fourier Analysis of the STimulated echoes (FAST) method, which uses a series of Fourier‐space operations to measure LV twist with limited user interaction. A subset of eight healthy subjects and the canine data were compared to results from previously validated “gold standard” software (FindTags). Interobserver and intraobserver coefficients of variation (CVINTER and CVINTRA), linear regression, and Bland–Altman analyses were used to assess agreement between observers and methods.Results:CVINTRA for peak systolic twist (2.9% and 2.6%) and CVINTER (4.3% and 4.2%) were all small. Linear regression analysis of the FAST and FindTags twist values indicated very good agreement in healthy subjects (R = 0.91) and in canines (R = 0.95). Bland–Altman comparison of the FAST and FindTags twist results indicated excellent agreement in healthy subjects (bias of −0.5°, 95% confidence intervals (−4.3°, 4.3°)) and canines (bias of 0.2°, 95% confidence intervals (−2.7°, 3.1°)). Peak systolic twist in healthy subjects averaged 10.5 ± 1.9° degrees.Conclusion:The FAST method for quantifying LV twist produces results that are not significantly different from the current “gold standard” in a fraction of the user interaction time and has demonstrated feasibility in human subjects. J. Magn. Reson. Imaging 2012;35:587‐593. © 2011 Wiley Periodicals, Inc.