bluuebunny/crossref_metadata_2025_split huggingface dataset:
Controlled Garegg Conditions for Selective Iodination on Pyranose Templates
Authors: Simao Ana‐Catarina , Silva Sandrina , Rauter Amelia P. , Rollin Patrick , Tatibouët Arnaud 
Published: March 2011

AbstractRegio‐ and stereoselective iodinations under controlled Garegg conditions were performed on vicinal diols and contiguous triols located on pyranose templates. β‐D‐Fructo‐ orpsicopyranose‐based diols were selectively iodinated at C‐5 or C‐4, respectively, to afford the L‐sorbo or D‐tagato iodohydrins. In contrast, the related triols only underwent selective iodination at C‐5. Application of the process to D‐gluco‐ and D‐galactopyranosides resulted in selective iodination at C‐3 or C‐4, respectively, to afford the D‐allo or D‐gluco iodohydrins.
An Easy Access to Carbazolones and 2,3‐Disubstituted Indoles
Authors: Janreddy Donala , Kavala Veerababurao , Bosco J. W. John , Kuo Chun‐Wei , Yao Ching‐Fa 
Published: March 2011

AbstractSynthesis of carbazol‐4‐ones, 3,4‐dihydrocyclopental‐indol‐1‐one, and indole derivatives by a Fe/AcOH‐mediated intramolecular reductive N‐heteroannulation of 3‐hydroxy‐2‐(2‐nitrophenyl)enones is demonstrated. The same protocol has been extended to access indolocarbazolone and indoloquinolone derivatives.
Highly Functionalized, Angularly Anellated Aromatic Compounds from Dendralenes
Authors: Hopf Henning , Yildizhan Şeref 
Published: March 2011

Abstract[3]Dendralene (2) has been converted into the benz[a]anthracene tetraester13in a protocol involving diene‐transmissive Diels–Alder addition of dimethyl acetylenedicarboxylate to2followed by a sequence of reduction–addition–aromatization reactions. Likewise, the next higher vinylog [4]dendralene (19) provided the phenanthrene hexaester21. An attempt to prepare the doubleo‐xylylene intermediate17failed.
Cyclodextrin Ketones with the Catalytic Group at the Secondary Rim and Their Effectiveness in Enzyme‐Like Epoxidation of Stilbenes
Authors: Fenger Thomas Hauch , Marinescu Lavinia G. , Bols Mikael 
Published: March 2011

AbstractSeveral new cyclodextrin ketones with a ketone attached to the secondary face of the cyclodextrin in the form of a 2,3‐O‐(2‐oxopropane‐1,3‐diyl) or 2‐oxo group are reported. These compounds and a selection of known cyclodextrin ketones having the ketone at the primary face were investigated as epoxidation catalysts for oxidation of stilbenes and styrene. A method for determination of kcat in these epoxidations is presented, which was used to determine the rate accelerations for the cyclodextrin ketones relative to background reaction. The highest rate acceleration obtained for epoxidation of 4‐methoxy‐4′‐nitro‐trans‐stilbene was 221. The highest enantioselectivity obtained was 76 % ee of (S)‐styrene oxide.
Determination of salidroside and tyrosol in Rhodiola by capillary electrophoresis with graphene/poly(urea‐formaldehyde) composite modified electrode
Authors: Chen Bo , Zhang Luyan , Chen Gang 
Published: March 2011

AbstractThis report describes the fabrication and application of a novel graphene/poly(urea‐formaldehyde) composite modified electrode as a sensitive amperometric detector of CE. The composite electrode was fabricated on the basis of the in situ polycondensation of a mixture of graphenes and urea–formaldehyde prepolymers on the surface of a platinum disc electrode. It was coupled with CE for the separation and detection of salidroside and tyrosol in Rhodiola, a traditional Chinese medicine, to demonstrate its feasibility and performance. Salidroside and tyrosol have been well separated within 6 min in a 40 cm long capillary at a separation voltage of 12 kV using a 50 mM borate buffer (pH 9.8). The prepared graphene‐based CE detector offered significantly lower detection potential, yielded enhanced signal‐to‐noise characteristics, and exhibited high resistance to surface fouling and enhanced stability. It showed long‐term stability and reproducibility with relative standard deviations of less than 5% for the peak current (n=15).
Some important combinations of detection techniques for electrophoresis in capillaries and on chips with emphasis on electrochemical principles
Authors: Opekar František , Štulík Karel 
Published: March 2011

AbstractAnalyses of very complex samples involving capillary and chip electrophoresis often require dual (multiple) detection to attain sufficient selectivity of determination. The present work reviews and critically evaluates selected combinations of electrochemical detection techniques among themselves and with absorption spectrometric, fluorescence and luminescence techniques. Amperometry, contact and contactless conductometry, UV photometry and fluorescence measurements are paid special attention. Some information is also given on combinations of spectrometric techniques with mass spectrometry. The properties of the detection systems are critically discussed, examples are illustrated in figures and some details on the characteristics of dual detectors and their applications are tabulated.
Imidazolium chloride‐based ionic liquid‐assisted improvement of lipase activity in organic solvents
Authors: Daneshjoo Somayeh , Akbari Neda , Sepahi Abbas Akhavan , Ranjbar Bijan , Khavarinejad Ramezan‐Ali , Khajeh Khosro 
Published: March 2011

AbstractThe activity of a lipase from a newly isolated Pseudomonas sp. was investigated in the presence of organic solvents and imidazolium chloride‐based ionic liquids (IL) such as BMIM[Cl] and HMIM[Cl]. The lipase activity in the presence of IL was higher compared to that in common organic solvents such as methanol and 2‐propanol. A possible explanation for the enzyme activation might be the structural changes induced in the protein in organic systems. Since IL quench the intensity of fluorescence emission, it was not possible to investigate the major factor that influences the enzyme behavior in these new organic salts. Furthermore, the enzyme exhibited excellent activity in buffer mixtures containing both organic solvent and IL. The stability of the lipase at 50°C was considerably increased in the presence of 20% BMIM[Cl] compared with the untreated lipase in aqueous medium. The light scattering method clearly showed that prevention of aggregation could be the reason for thermal stabilization at 50°C in reactions containing IL. Kinetic analysis of the enzyme in the presence of different concentrations of IL showed that the Km value increased from 0.45 mM in aqueous buffer to 2.4 mM in 50% v/v BMIM[Cl]/buffer. The increase in Km indicates that IL can significantly reduce the binding affinity of the substrate to the enzyme. Also, a linear correlation was observed between the BMIM[Cl] concentration and Vmax of the enzyme. As the concentration of BMIM[Cl] increased from 10 to 50% v/v, the Vmax value increased from 1.8 to 46 μM/min.
Cytogenetic biomonitoring on a group of petroleum refinery workers
Authors: Basso Emiliano , Cevoli Chiara , Papacchini Maddalena , Tranfo Giovanna , Mansi Antonella , Testa Antonella 
Published: March 2011

AbstractWorkers employed in petroleum refineries are exposed to a wide range of toxic compounds (benzene, polycyclic aromatic hydrocarbons, heavy metals, etc.) with known mutagenic and carcinogenic potential. In this study, we investigated by using the cytokinesis block micronucleus (CBMN) assay on human peripheral blood lymphocytes (PBL) whether general occupational exposure in petroleum refineries resulted in early biological effects, which would be indicative of adverse health effects in the long term. In this study, out of more 500 workers enrolled in the study, 79 male subjects (46 nonsmokers and 33 smokers), employed in two different Italian petroleum refineries, and a total of 50 male control subjects (34 nonsmokers and 16 smokers) were selected by using very strict selection criteria. The comparison of chromosome damage in PBL between exposed and control populations pointed out a significant increase of micronuclei in the exposed group, correlated with the length of employment. Results confirm that smoking is the principal confounding factor for the responses. In conclusion, our results are indicative of a potential genotoxic risk related to the complex occupational exposure in petroleum refineries, despite the measures adopted in the plants, and corroborate the need to increase safety measures to avoid exposure to chemical agents. Environ. Mol. Mutagen. 2011. © 2011 Wiley‐Liss, Inc.
Accumulation of K‐Rascodon 12 mutations in the F344 rat distal colon following azoxymethane exposure
Authors: McKinzie Page B. , Parsons and Barbara L. 
Published: March 2011

AbstractAzoxymethane (AOM) administration to F344 male rats is a widely used model of human colon carcinogenesis. The current study investigates quantitatively the accumulation of K‐Rascodon 12 mutations following AOM exposure. Male, 6‐week‐old F344 rats were treated subcutaneously with 30 mg/kg body weight of AOM, and colon tissue was collected at 1, 8, 24, and 32 weeks after treatment. The K‐Rascodon 12 GGT to GAT and GGT to GTT mutant fractions (MFs) were measured using allele‐specific competitive blocker polymerase chain reaction (ACB‐PCR). Between 1 and 32 weeks after AOM treatment, the K‐Rascodon 12 GGT to GAT geometric mean MF in the rat colon increased significantly from 12.9 × 10−5to 145 × 10−5, and the GGT to GTT geometric mean MF increased significantly from 5.26 × 10−5to 180 × 10−5. K‐Rascodon 12 GGT to GAT MF also increased significantly in AOM‐treated rat colon tissue at 1 week compared to controls (4.44 × 10−5). The accumulation of the GGT to GAT MF long after the DNA adduct repair phase suggests that a portion of cells containing this mutation have a proliferative advantage, allowing them to accumulate as nascent tumors progress. Also, the GGT to GAT background MF increased in untreated rats, indicating that there is accumulation with age. The ACB–PCR assay generates quantitative data of cancer‐related mutations and thus provides insight into pathological processes following carcinogen exposure. Environ. Mol. Mutagen., 2011. © Published 2011 Wiley‐Liss, Inc.
Quantitative evaluation of laboratory uptake rates for pesticides, pharmaceuticals, and steroid hormones using POCIS
Authors: Bartelt-Hunt Shannon L , Snow Daniel D , Damon-Powell Teyona , Brown DelShawn L , Prasai Gyanendra , Schwarz Matthew , Kolok Alan S 
Published: March 2011

Abstract
Polar organic chemical integrative samplers (POCIS) are useful in monitoring for a wide range of chemicals in aquatic systems; however, a lack of available uptake rate data for compounds of environmental interest is one limitation in the application of these samplers to environmental studies. In this study, laboratory calibration experiments were conducted with POCIS for 65 compounds at 25°C under flowing conditions to determine chemical-specific uptake rates (Rs). Experimental uptake rates measured in this study ranged from 0.034 to 1.33 L/d, and uptake rates were determined for 36 compounds with no previously reported values. Experimentally determined uptake rates were applied to data obtained from POCIS samplers deployed downstream of three wastewater treatment plant (WWTP) effluent discharges and in four surface waters influenced by agricultural runoff. Time-weighted average concentrations for atrazine and metolachlor determined using uptake rates generated in this study compare well with results from composited grab sampling previously conducted in agricultural watersheds in Nebraska, USA. Environ. Toxicol. Chem. 2011; 30:1412–1420. © 2011 SETAC
Ontogenetic patterns in bluefish (Pomatomus saltatrix) feeding ecology and the effect on mercury biomagnification
Authors: Szczebak Joseph T , Taylor David L 
Published: March 2011

Abstract
In this study, bluefish (Pomatomus saltatrix; age 0–7, n = 632) and their prey (forage fish, macroinvertebrates, zooplankton; n = 2,005) were collected from the Narragansett Bay estuary (RI, USA), and total Hg concentration was measured in white muscle and whole-body tissues, respectively. Bluefish Hg concentrations were analyzed relative to fish length, prey Hg content, and ontogenetic shifts in habitat use and foraging ecology, the latter assessed using stomach content analysis (n = 711) and stable nitrogen (δ15N) and carbon (δ13C) isotope measurements (n = 360). Diet and δ13C analysis showed that age 0 bluefish consumed both benthic and pelagic prey (silversides, sand shrimp, planktonic crustaceans; δ13C = − 16.52‰), whereas age 1 + bluefish fed almost exclusively on pelagic forage fish (Atlantic menhaden, herring; δ13C = − 17.33‰). Bluefish total Hg concentrations were significantly correlated with length (mean Hg = 0.041 and 0.254 ppm wet wt for age 0 and age 1 + bluefish, respectively). Furthermore, Hg biomagnification rates were maximal during bluefish early life stages and decelerated over time, resulting in relatively high Hg concentrations in age 0 fish. Rapid Hg accumulation in age 0 bluefish is attributed to these individuals occupying a comparable trophic level to age 1 + bluefish (δ15N = 15.58 and 16.09‰; trophic level = 3.55 and 3.71 for age 0 and age 1 + bluefish, respectively), as well as juveniles having greater standardized consumption rates of Hg-contaminated prey. Finally, bluefish larger than 30 cm total length consistently had Hg levels above the U.S. Environmental Protection Agency criterion of 0.3 ppm. As such, frequent consumption of bluefish could pose a human health risk, and preferentially consuming smaller bluefish may be an inadequate strategy for minimizing human dietary exposure to Hg. Environ. Toxicol. Chem. 2011; 30:1447–1458. © 2011 SETAC
TICKET-UWM: A coupled kinetic, equilibrium, and transport screening model for metals in lakes
Authors: Farley Kevin J , Carbonaro Richard F , Fanelli Christopher J , Costanzo Robert , Rader Kevin J , Di Toro Dominic M 
Published: March 2011

Abstract
The tableau input coupled kinetic equilibrium transport-unit world model (TICKET-UWM) has been developed as a screening model for assessing potential environmental risks associated with the release of metals into lakes. The model is based on a fully implicit, one-step solution algorithm that allows for simultaneous consideration of dissolved and particulate phase transport; metal complexation to organic matter and inorganic ligands; precipitation of metal hydroxides, carbonates, and sulfides; competitive interactions of metals and major cations with biotic ligands; a simplified description of biogeochemical cycling of organic carbon and sulfur; and dissolution kinetics for metal powders, massives, and other solid forms. Application of TICKET-UWM to a generalized lake in the Sudbury area of the Canadian Shield is presented to demonstrate the overall cycling of metals in lakes and the nonlinear effects of chemical speciation on metal responses. In addition, the model is used to calculate critical loads for metals, with acute toxicity of Daphnia magna as the final endpoint. Model results show that the critical loads for Cu, Ni, Pb, and Zn varied from 2.5 to 39.0 g metal/m2-year and were found to be one or more orders of magnitude higher than comparable loads for pesticides (lindane, 4,4′-DDT) and several polyaromatic hydrocarbon (PAH) compounds. In sensitivity calculations, critical metal-loading rates were found to vary significantly as a function of the hydraulic detention time, water hardness, and metal dissolution kinetic rates. Environ. Toxicol. Chem. 2011; 30:1278–1287. © 2011 SETAC
OFDM channel estimation and data detection with superimposed pilots
Authors: Cui Tao , Tellambura Chintha 
Published: March 2011

AbstractWe propose three iterative superimposed‐pilot based channel estimators for Orthogonal Frequency Division Multiplexing (OFDM) systems. Two are approximate maximum‐likelihood, derived by using a Taylor expansion of the conditional probability density function of the received signal or by approximating the OFDM time signal as Gaussian, and one is minimum‐mean square error. The complexity per iteration of these estimators is given by approximately O(NL2), O(N3) and O(NL), where N is the number of OFDM subcarriers and L is the channel length (time). Two direct (non‐iterative) data detectors are also derived by averaging the log likelihood function over the channel statistics. These detectors require minimising the cost metric in an integer space, and we suggest the use of the sphere decoder for them. The Cramér–Rao bound for superimposed pilot based channel estimation is derived, and this bound is achieved by the proposed estimators. The optimal pilot placement is shown to be the equally spaced distribution of pilots. The bit error rate of the proposed estimators is simulated for N = 32 OFDM system. Our estimators perform fairly close to a separated training scheme, but without any loss of spectral efficiency. Copyright © 2011 John Wiley & Sons, Ltd.
The inflammation hypothesis in geriatric depression
Authors: Alexopoulos George S. , Morimoto Sarah Shizuko 
Published: March 2011

AbstractBackgroundA large body of research has focused on “mediating mechanisms” and predisposing brain abnormalities to geriatric depression, but little is known about its etiology. This paper examines whether age‐related and comorbid disease‐related immune deregulation is an etiologic contributor to geriatric depression.MethodsThis article reviews findings on neuroinflammation during the aging process and depression as well as studies of anti‐inflammatory actions of classical antidepressants and antidepressant actions of anti‐inflammatory agents.ResultsAging results in increased peripheral immune responses, impaired peripheral‐CNS immune communication, and a shift of the CNS into a pro‐inflammatory state. These exaggerated and prolonged immune responses may lead to changes in the function of emotional and cognitive networks pertinent to geriatric depression and to behavioral changes reminiscent of the depressive and cognitive symptoms of geriatric depression. Some antidepressants may reduce the expression of inflammation markers. Limited data suggest that some anti‐inflammatory agents may have antidepressant properties.ConclusionsA synthesis of available findings suggests that aging‐related and comorbid disease‐related inflammatory processes may promote changes in the neural systems predisposing to geriatric depression or facilitating metabolic changes that mediate depressive syndromes. The “inflammation hypothesis” in geriatric depression cannot be tested in its entirety, but it can lead to testable hypotheses and data on mechanisms by which inflammatory processes promote geriatric depression. The significance of such an effort is that it may lead to a novel treatment development model bringing to bear recent advances of anti‐inflammatory pharmacology to the treatment of depressed elderly patients. Copyright © 2011 John Wiley & Sons, Ltd.
Loneliness and vascular biomarkers: the Dublin Healthy Ageing Study
Authors: O'Luanaigh C. , O'Connell H. , Chin A.V. , Hamilton F. , Coen R. , Walsh C. , Walsh J.B. , Coakley D. , Molloy A. , Scott J. , Cunningham C.J. , Lawlor B.A. 
Published: March 2011

AbstractBackgroundLoneliness has been associated with poor physical health and a link has been suggested between the presence of loneliness, cardiovascular health and inflammatory markers.ObjectiveTo investigate the association between vascular disease biomarkers and loneliness in a community‐dwelling non‐demented elderly population.Designcross‐sectional community based assessment.Participants466 subjects with mean age 75.45 (SD, 6.06) years. 208 (44.6%) were male.ResultsHigher levels of HbA1c, but not other vascular biomarkers were independently associated with being lonely.ConclusionLoneliness was associated with raised levels of HbA1c in a community dwelling elderly population. The mechanism for this association has yet to be elucidated but may reflect an abnormal stress response in people who are lonely. Copyright © 2011 John Wiley & Sons, Ltd.
Growth behavior of cochlear nucleus neuronal cells on semiconductor substrates
Authors: Rak Kristen , Wasielewski Natalia , Radeloff Andreas , Scherzed Agmal , Jablonka Sibylle , Hagen Rudolf , Mlynski Robert 
Published: March 2011

AbstractAuditory brainstem implants provide sound information by direct stimulation of the cochlear nucleus to patients with dysfunctional or absent cranial nerve VIII. In contrast to patients with cochlear implants, the use of the auditory brainstem implants is less successful. This cannot be fully explained by the difference location of stimulation but a rather unspecific neuronal stimulation. The aim of this study was to further examine neuronal cells of the cochlear nucleus and to test their interactions with semiconductor substrates as a potential electrode material for improved auditory brainstem implants. The cochlear nuclei of postnatal day 7 rats were microsurgically dissected. The tissue was dissociated enzymatically and plated on coverslips as control and on the semiconductor substrates silicon or silicon nitride. After 4 days in culture the morphology and growth of dissociated cells was determined by fluorescence and scanning electron microscopy. Dissociated cells of the cochlear nucleus showed reduced cell growth on semiconductor substrates compared with controls. SEM analysis demonstrated close contact of neurons with supporting cells in culture and good adherence of neuronal growth cones on the used materials. These findings present basic knowledge for the development of neuron–electrode interfaces for future auditory brainstem implants. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.
Green tea may be benefit to the therapy of atrial fibrillation
Authors: Zeng Xin , Li Qiao , Zhang Miao , Wang Wei , Tan Xuerui 
Published: March 2011

AbstractAtrial fibrillation (AF) is the most common cardiac arrhythmia in clinical practice. Systemic inflammatory state, oxidative stress injury, and atrial fibrosis are identified as the main mechanisms for AF. Considering the multifactorial mechanisms of AF, a novel therapeutic agent with multi‐bioactivities should be presented. Regular consumption of green tea has been associated with a reduced risk of coronary heart disease and against a large number of pathologic conditions. Recent results indicate that green tea extract, especially (‐)‐epigallocatechin‐3‐gallate, could effectively decrease inflammatory factors secretion, antagonize oxidation, and inhibit matrix metalloproteinase activities. Inhibition of inflammation, modulation of oxidative stress, and targeting tissue fibrosis represent new approaches in tackling AF; therefore, green tea may be an innovative therapeutic candidate to prevent the occurrence, maintenance, and recurrence of AF. J. Cell. Biochem. 112: 1709–1712, 2011. © 2011 Wiley‐Liss, Inc.
A challenging system: Free energy prediction for factor Xa
Authors: Wallnoefer Hannes G. , Liedl Klaus R. , Fox Thomas 
Published: March 2011

AbstractFactor Xa (fXa) is a promising target for antithrombotic drugs. Recently, we presented a molecular dynamics study on fXa, which highlighted the need for a careful system setup to obtain stable simulations. Here, we show that these simulations can be used to predict the free energy of binding of several fXa inhibitors. We tested molecular mechanics/Poisson–Boltzmann surface area, molecular mechanics/Generalized Born surface area, and linear interaction energy (LIE) on a small data set of fXa ligands. The continuum solvent approaches only yield satisfying correlations to the experimental results if some of the water molecules are explicitly included in the free energy calculations. LIE gave reasonable results if a sufficiently large data set is used. In general, our procedure of setting up the fXa simulation system enabled MD simulations, which produce adequate ensembles for free energy calculations. © 2011 Wiley Periodicals, Inc. J Comput Chem 2011