bluuebunny/crossref_metadata_2025_split huggingface dataset:
Amperometric Flow‐Biosensor for Cyanide Based on an Inhibitory Effect upon Bioelectrocatalytic Reduction of Oxygen by Peroxidase‐Modified Carbon‐Felt
Authors: Wang Yue , Hasebe Yasushi 
Published: May 2011

AbstractA novel, simple and relative highly sensitive amperometric flow biosensor for cyanide was developed by using horseradish peroxidase (HRP)‐adsorbed carbon‐felt (CF), based on an inhibitory effect on the HRP‐catalyzed O2 reduction. The HRP‐CF showed a sufficient bioelecrocatalytic activity for O2 reduction in the potential region from 0 to −0.5 V at pH 5.0, due to a direct electron transfer‐based O2 reduction process via ferrous‐HRP and compound III. This HRP‐catalyzed O2 reduction was reversibly inhibited by cyanide, which enabled to fabricate a novel and simple reagentless (i.e., no requirement of the ordinary substrate, H2O2, and the electron transfer mediators) flow‐biosensor for cyanide. When air‐saturated 0.1 M phosphate buffer (pH 5.0) was used as a carrier under the applied potential of −0.2 V vs. Ag/AgCl, the steady‐state base‐current due to the HRP‐catalyzed O2 reduction was reversibly inhibited by the cyanide injection (200 µL), resulting in peak‐shape current responses. The magnitude of the inhibition peak currents linearly increased with increasing concentrations of cyanide up to 1 µM, and the detection limit was found to be 0.04 µM (S/N=2). The apparent inhibition constant Ki′ was estimated to be 0.87 µM.
Application of Contactless Impedance Detection to Determination of Substances in Gaseous Phase
Authors: Pavlíček V. , Opekar F. , Štulík K. 
Published: May 2011

AbstractA simple cell, consisting of two insulated wire electrodes placed in a PTFE tube through which the test gaseous phase flows, has been applied to capacitively coupled contactless conductometric detection (C4D) and determination of water vapour in the air, to examine the possibilities of the use of C4D for analyses of gaseous samples. It has been found that the measurement is sufficiently sensitive and reliable for determinations of common concentrations of water in the air. The dynamic characteristics and the signal stability demonstrate that the cell will be suitable for long‐term continuous monitoring of the air humidity. Qualitative tests indicate that vapours of organic solvents can also be monitored. To the authors knowledge, this is the first attempt to use C4D in gas analyses.
Evaluation of the risk of mixtures of paddy insecticides and their transformation products to aquatic organisms in the Sakura River, Japan
Authors: Iwafune Takashi , Yokoyama Atsushi , Nagai Takashi , Horio Takeshi 
Published: May 2011

Abstract
To assess the risk of mixtures of six paddy insecticides and their transformation products (TPs) to aquatic organisms in the Sakura River, Japan, their concentrations in the river water were monitored during the rice cultivation season in 2008 and 2009, and acute toxicity tests for Cheumatopsyche brevilineata (caddisflies) and Daphnia magna (daphnids), surrogate test species for caddisflies and cladocerans, respectively, were conducted. The mixture of fipronil, applied in the rice nursery box, and its desulfinyl, sulfide, and sulfone TPs were detected in the river for several months after transplanting, and they were more toxic to C. brevilineata than the other tested compounds. The toxicities of the parent compound and its TPs, such as fipronil and its TPs, may be related to their hydrophobicities. Risk quotients for mixtures (RQmix) of only parent compounds did not exceed 1, but, in mid-June 2009, the RQmix of parent compounds and TPs for caddisflies exceeded 1. Diazinon, fenitrothion, and fenthion sprayed on the rice crop and their TPs posed a sporadic risk for cladocerans, depending on the application timing, whereas fipronil TPs contributed to the RQmix for caddisflies for several months after transplanting. The risk of mixtures of insecticides and their TPs differed seasonally between caddisflies and cladocerans, depending on insecticide application timing and the persistence and toxicity of TPs. Environ. Toxicol. Chem. 2011; 30:1834–1842. © 2011 SETAC
Copper and zinc contamination in oysters: Subcellular distribution and detoxification
Authors: Wang Wen-Xiong , Yang Yubo , Guo Xiaoyu , He Mei , Guo Feng , Ke Caihuan 
Published: May 2011

Abstract
Metal pollution levels in estuarine and coastal environments have been widely reported, but few documented reports exist of severe contamination in specific environments. Here, we report on a metal-contaminated estuary in Fujian Province, China, in which blue oysters (Crassostrea hongkongensis) and green oysters (Crassostrea angulata) were discovered to be contaminated with Cu and other metals. Extraordinarily high metal concentrations were found in the oysters collected from the estuary. Comparison with historical data suggests that the estuary has recently been contaminated with Cr, Cu, Ni, and Zn. Metal concentrations in blue oysters were as high as 1.4 and 2.4% of whole-body tissue dry wt for Cu and Zn, respectively. Cellular debris was the main subcellular fraction binding the metals, but metal-rich granules were important for Cr, Ni, and Pb. With increasing Cu accumulation, its partitioning into the cytosolic proteins decreased. In contrast, metallothionein-like proteins increased their importance in binding with Zn as tissue concentrations of Zn increased. In the most severely contaminated oysters, only a negligible fraction of their Cu and Zn was bound with the metal-sensitive fraction, which may explain the survival of oysters in such contaminated environments. Environ. Toxicol. Chem. 2011; 30:1767–1774. © 2011 SETAC
PCB-induced changes of a benthic community and expected ecosystem recovery following in situ sorbent amendment
Authors: Janssen Elisabeth M.-L , Thompson Janet K , Luoma Samuel N , Luthy Richard G 
Published: May 2011

Abstract
The benthic community was analyzed to evaluate pollution-induced changes for the polychlorinated biphenyl (PCB)-contaminated site at Hunters Point (HP) relative to 30 reference sites in San Francisco Bay, California, USA. An analysis based on functional traits of feeding, reproduction, and position in the sediment shows that HP is depauperate in deposit feeders, subsurface carnivores, and species with no protective barrier. Sediment chemistry analysis shows that PCBs are the major risk drivers at HP (1,570 ppb) and that the reference sites contain very low levels of PCB contamination (9 ppb). Different feeding traits support the existence of direct pathways of exposure, which can be mechanistically linked to PCB bioaccumulation by biodynamic modeling. The model shows that the deposit feeder Neanthes arenaceodentata accumulates approximately 20 times more PCBs in its lipids than the facultative deposit feeder Macoma balthica and up to 130 times more than the filter feeder Mytilus edulis. The comparison of different exposure scenarios suggests that PCB tissue concentrations at HP are two orders of magnitude higher than at the reference sites. At full scale, in situ sorbent amendment with activated carbon may reduce PCB bioaccumulation at HP by up to 85 to 90% under favorable field and treatment conditions. The modeling framework further demonstrates that such expected remedial success corresponds to exposure conditions suggested as the cleanup goal for HP. However, concentrations remain slightly higher than at the reference sites. The present study demonstrates how the remedial success of a sorbent amendment, which lowers the PCB availability, can be compared to reference conditions and traditional cleanup goals, which are commonly based on bulk sediment concentrations. Environ. Toxicol. Chem. 2011; 30:1819–1826. © 2011 SETAC
Embryotoxicity of weathered crude oil from the Gulf of Mexico in mallard ducks (Anas platyrhynchos)
Authors: Finch Bryson E , Wooten Kimberly J , Smith Philip N 
Published: May 2011

Abstract
Weathered crude oil in the Gulf of Mexico can result from oil spills such as the Deepwater Horizon incident that occurred on April 20, 2010 or from natural seeps. Adult waterbirds of the Gulf Coast region may become exposed to weathered crude oil while foraging, wading, or resting, and residues can then be transferred to nests, eggs, and hatchlings. Although the toxicity of many types of crude oil to avian embryos has been thoroughly studied, the effects of weathered crude oil on developing avian embryos are not well characterized. The objective of the present study was to examine embryotoxicity of weathered crude oil collected from the Gulf of Mexico in June 2010 using mallard ducks (Anas platyrhynchos) as a model species. Weathered crude oil was applied to fertilized mallard duck eggs by paintbrush in masses ranging from 0.1 to 99.9 mg on day 3 of incubation. Mortality occurred as early as day 7 and the conservatively derived median lethal application of weathered crude oil was 30.8 mg/egg (0.5 mg/g egg) or 30.7 µl/egg (0.5 µl/g egg). Body mass, liver and spleen mass, crown–rump and bill lengths, and frequency of deformities were not significantly different among hatchlings from oiled and control eggs. In comparison to published reports of fresh crude oil embryotoxicity, weathered crude oil was considerably less toxic. We conclude that avian toxicity varies according to the degree of crude oil weathering and the stage of embryonic development at the time of exposure. Results indicate bird eggs exposed to weathered crude oil from the Gulf of Mexico during summer 2010 may have had reduced hatching success. Environ. Toxicol. Chem. 2011; 30:1885–1891. © 2011 SETAC
Why don't older adults with subjective memory complaints seek help?
Authors: Hurt Catherine S. , Burns Alistair , Brown Richard G. , Barrowclough Christine 
Published: May 2011

BackgroundSubjective memory complaints (SMCs) are common among older adults, often causing significant distress and showing strong relationships to future cognitive decline. However, low rates of help‐seeking for memory complaints are well documented. Little is known about the reasons behind the decision to seek or not to seek help with memory problems. The common‐sense model of illness perception proposes that the beliefs people hold about their health underlie help‐seeking behaviour. The present study investigated factors underlying the decision to seek help in people with SMCs within the framework of the common‐sense model of illness perception.MethodsCognition, illness perceptions, coping styles, depression and anxiety were assessed in 98 adults with SMCs, aged 50 years and above, including 60 attending a memory clinic and 38 non‐help‐seekers.ResultsObjective cognitive performance did not differ between participants who had sought help and those who had not. Logistic regression revealed that illness perceptions including social comparison and causal attributions predict help‐seeking behaviour. More general coping style did not predict help‐seeking. Furthermore, participants who had sought help were more likely to have had a close relative with dementia.ConclusionsThe results suggest that beliefs about memory, rather than objective cognitive impairment, are associated with the decision to seek help for SMCs. The findings suggest that providing education regarding memory problems, in particular challenging causal attributions, may help to encourage help‐seeking in people with SMCs and improve care in the early stages of dementia. Copyright © 2011 John Wiley & Sons, Ltd.
Post‐stroke delirium in relation to dementia and long‐term mortality
Authors: Melkas Susanna , Laurila Jouko V. , Vataja Risto , Oksala Niku , Jokinen Hanna , Pohjasvaara Tarja , Leppävuori Antero , Kaste Markku , Karhunen Pekka J. , Erkinjuntti Timo 
Published: May 2011

BackgroundDelirium is a frequent post‐stroke complication that compromises effective rehabilitation and has been associated with poor outcome. We aimed to investigate whether delirium is associated with increased risk of post‐stroke dementia and long‐term mortality once confounding is taken into account.MethodsThe study comprised 263 consecutive acute ischemic stroke patients aged 55–85 years admitted to the emergency department of a university hospital. The cohort included three‐month survivors followed up for 10 years. The diagnosis of post‐stroke delirium during the first 7 days after stroke was based on the DSM‐IV criteria.FindingsOf all the patients, 50 (19.0%) were diagnosed with delirium. Low education, pre‐stroke cognitive decline, and severe stroke indicated by a Modified Rankin score between 3 and 5 were risk factors for post‐stroke delirium, which was also associated with diagnosis of dementia at 3 months post‐stroke. In the Kaplan–Meier analysis, delirium was associated with poor long‐term survival (6.1 versus 9.1 years). In the stepwise Cox regression proportional hazards analysis adjusted for demographic factors and risk factors, advanced age (hazard ratio [HR] 1.08) and stroke severity (HR 1.83), but not post‐stroke delirium, were associated with poor survival.InterpretationIn our well‐defined cohort of post‐stroke patients, acute stage delirium was diagnosed in one in five patients and associated with dementia at 3 months. Advanced age and stroke severity were related to the higher long‐term mortality among patients with post‐stroke delirium. Copyright © 2011 John Wiley & Sons, Ltd.
An efficient one‐pot three‐component reaction for synthesis of spirooxindole derivatives in water media under catalyst‐free condition
Authors: Zhao Li‐Qin , Zhou Bo , Li Yi‐Qun 
Published: May 2011

AbstractAn efficient, clean, and environmentally benign synthesis of spirooxindole derivatives by one‐pot three‐component reaction of isatins, malononitrile, and carbonyl compound in the absence of catalysis in water was described. A variety of spirooxindole derivatives were obtained with excellent yields within short reaction time. This novel protocol has the advantages of convenient operation, low cost, and environmental benign. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:673–677, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20723
THE DETERMINANTS OF CHINESE PROVINCIAL GOVERNMENT HEALTH EXPENDITURES: EVIDENCE FROM 2002–2006 DATA
Authors: Pan Jay , Liu Gordon G. 
Published: May 2011

SUMMARYThere is great divergence in provincial government health expenditures in China. Real per capita provincial government health expenditures (GHE) over the period 2002–2006 are examined using panel regression analysis. Key determinants of real per capita provincial GHE are real provincial per capita general budget revenue, real provincial per capita transfers from the central government, the proportion of provincial population under age 15, urban employee basic health insurance coverage, and proportion of urban population. Roughly equal and relatively low elasticities of budget revenue and transfers imply that the GHE is a necessity rather than a luxury good, and transfers have yet to become efficient instruments for the fair allocation of health resources by policy makers. Moreover, severe acute respiratory syndrome outbreak has increased the GHE, but we find no statistical evidence that provincial GHE have fluctuated according to the public health status. Copyright © 2011 John Wiley & Sons, Ltd.
Trichloroacetonitrile as a Source of Positive Chlorine Ion for Trapping Huisgen's Zwitterions
Authors: Yavari Issa , Nasiri‐Gheidari Samira 
Published: May 2011

AbstractThe zwitterionic 1 : 1 intermediates generated by addition of N‐heterocycles to activated acetylenes are trapped by trichloroacetonitrile to afford 1,2‐ or 1,4‐disubstituted N‐heterocycles in moderate to good yields under mild reaction conditions.
A Facile Synthesis of 2‐Imino‐4‐methylene‐1,3‐dithiolanes
Authors: Yavari Issa , Beheshti Saeideh 
Published: May 2011

AbstractA one‐pot synthesis of 2‐imino‐4‐methylidene‐1,3‐dithiolanes via a three‐component reaction of propargyl bromide (=3‐bromoprop‐1‐yne), primary amines, and carbon disulfide (CS2) is described.
On the Reactions of Furan‐2,3‐diones with Oxindole (=1,3‐Dihydro‐2H‐indol‐2‐one) and Lawesson Reagent. Synthesis of New 1,3‐Dihydro‐2H‐indol‐2‐ones, Bis‐furanones, and Bis‐pyrrolones
Authors: Korkusuz Elif , Yıldırım İsmail 
Published: May 2011

AbstractLactone analogues of 3‐substituted oxindoles (=1,3‐dihydro‐2H‐indol‐2‐ones) and nonbenzoid oxa‐analogous isoindigoid or nonbenzoid isoindigoid dyes were prepared by the reactions of furan‐2,3‐diones with oxindole and Lawesson reagent (Schemes 1 and 3), respectively. So, new derivatives of 2‐oxobutanoic acid, bis‐furanone, and bis‐pyrrolone, which are potentially biologically active compounds, were synthesized for the first time.
Novel Sesquiterpenes from the Mycelial Cultures of Dichomitus squalens
Authors: Xie Hai‐Hui , Xu Xin‐Ya , Dan Yang , Wei Xiao‐Yi 
Published: May 2011

AbstractFour novel sesquiterpenes, 5‐hydroxydichomitol (1), dichomilludol (2), 3β,13‐dihydroxyledol (3), and 2β,3β,13‐trihydroxyledol (4), were isolated along with 2β,13‐dihydroxyledol (5) from the AcOEt‐soluble fraction of the mycelial solid cultures of Dichomitus squalens. Their structures were determined on the basis of spectroscopic analyses. The previously assigned structure of dichomitol was revised.
Three New Medicagenic Acid Saponins from Polygala micranthaGuill. & Perr.
Authors: Kuiate Tabopda Turibio , Mitaine‐Offer Anne‐Claire , Miyamoto Tomofumi , Tanaka Chiaki , Tchaleu Ngadjui Bonaventure , Mirjolet Jean‐François , Duchamp Olivier , Lacaille‐Dubois Marie‐Aleth 
Published: May 2011

AbstractThree new medicagenic acid saponins, micranthosides A–C (1–3), were isolated from the roots of Polygala micrantha Guill. & Perr., along with six known presenegenin saponins. Their structures were elucidated on the basis of extensive 1D‐ and 2D‐NMR experiments (1H, 13C, DEPT, COSY, TOCSY, NOESY, HSQC, and HMBC) and mass spectrometry as 3‐O‐β‐D‐glucopyranosylmedicagenic acid 28‐[O‐β‐D‐galactopyranosyl‐(1→4)‐O‐β‐D‐xylopyranosyl‐(1→4)‐O‐α‐L‐rhamnopyranosyl‐(1→2)‐β‐D‐fucopyranosyl] ester (1), 3‐O‐β‐D‐glucopyranosylmedicagenic acid 28‐[O‐6‐O‐acetyl‐β‐D‐galactopyranosyl‐(1→4)‐O‐β‐D‐xylopyranosyl‐(1→4)‐O‐α‐L‐rhamnopyranosyl‐(1→2)‐β‐D‐fucopyranosyl] ester (2), and 3‐O‐{O‐β‐D‐glucopyranosyl‐(1→3)‐O‐[β‐D‐glucopyranosyl‐(1→6)]‐β‐D‐glucopyranosyl}medicagenic acid 28‐{O‐β‐D‐apiofuranosyl‐(1→3)‐O‐β‐D‐xylopyranosyl‐(1→4)‐O‐[β‐D‐apiofuranosyl‐(1→3)]‐O‐α‐L‐rhamnopyranosyl‐(1→2)‐β‐D‐fucopyranosyl} ester (3). Compounds 1–3 were evaluated against HCT 116 and HT‐29 human colon cancer cells, but they did not show any cytotoxicity.
Molybdenum‐ and Tungsten‐Based Coordination Polymers as Catalysts for an Efficient and Rapid Synthesis of Hexahydro‐5‐oxoquinoline‐3‐carboxylates and 1,4‐Dihydropyridine‐3,5‐dicarboxylates
Authors: Das Biswanath , Srilatha Malampati , Veeranjaneyulu Boyapati , Shashi Kanth Boddu 
Published: May 2011

AbstractHexahydro‐5‐oxoquinoline‐3‐carboxylates and 1,4‐dihydropyridine‐3,5‐dicarboxylates were synthesized efficiently and rapidly (2 min) in the presence of molybdenum‐ and tungsten‐based coordination polymers [M(Bu3Sn)2O4)]n (M=Mo or W) as catalysts (Schemes 1 and 2; Tables 2 and 3). The products were formed at room temperature in excellent yields (90–98%). The catalysts worked under heterogeneous conditions and were recyclable. The earlier reports for the application of these polymers to conduct organic synthesis are limited. The present method explores a new and useful application of these catalysts.
A Novel BriggsRauscher Oscillation with a Macrocyclic Nickel(II) Complex as Catalyst and Pentane‐2,4‐dione as the Substrate
Authors: Hu Gang , Zhao Fu‐Sheng , Lu Ming‐Ying , Zhu Ling , Guo Mi‐Mi , Liu Hai‐Yan , Hu Lin 
Published: May 2011

AbstractA new BriggsRauscher oscillating reaction with a tetraazamacrocyclic nickel(II) complex [NiL](ClO4)2 as catalyst and pentane‐2,4‐dione (pe) as the substrate is reported. The ligand L is 5,7,7,12,14,14‐hexamethyl‐1,4,8,11‐tetraazacyclotetradeca‐4,11‐diene. The experimental results indicate that iodine ion may be an important intermediate, and free radicals can be involved in the reaction. A tentative mechanism based on NoyesFurrow model (NF model) is proposed. Moreover, other factors, such as the variation of concentration of the components and temperature on the oscillator, are discussed.
Polyoxygenated Sterols from Freshwater Clam
Authors: Kong Zwe‐Ling , Chi Yu Siauo , Ai Dai Shu , Tu Cha‐Chung , Pan Min‐Hsiung , Liu Yeuk‐Chuen 
Published: May 2011

AbstractTwo new biologically active polyoxygenated sterols, 3,5,9‐trihydroxycholest‐7‐en‐6‐one (1) and cholest‐7‐ene‐3,6,9‐triol (3), together with one known sterone, topsentisterol D3 (2), were isolated from freshwater clam (Corbicula fluminea Muller; an important cultured edible shellfish in Taiwan). The structure elucidation of sterols 1–3 were accomplished by 1H‐ and 13C‐NMR, HMQC, and HMBC, and MS analyses. The sterols 1–3 displayed cytotoxicities against the human hepatoma Hep G2 cells (IC50: 6.04±0.07, 40.78±4.28, and 10.57±0.51 μg/ml, resp.).
Synthesis and Characterization of Enantiomerically Pure cis‐ and trans‐3‐Fluoro‐2,4‐dioxa‐9‐aza‐3‐phosphadecalin 3‐Oxides as Acetylcholine Mimetics and Inhibitors of Acetylcholinesterase
Authors: Lorenzetto Piergiorgio , Wächter Michael , Rüedi Peter 
Published: May 2011

AbstractThe title compounds, the P(3)‐axially and P(3)‐equatorially substituted cis‐ and trans‐configured 9‐benzyl‐3‐fluoro‐2,4‐dioxa‐9‐aza‐3‐phosphadecalin 3‐oxides (=9‐benzyl‐3‐fluoro‐2,4‐dioxa‐9‐aza‐3‐phosphabicyclo[4.4.0]decane 3‐oxides=7‐benzyl‐2‐fluorohexahydro‐4H‐1,3,2‐dioxaphosphorino[4,5‐c]pyridine 2‐oxides) were prepared (ee >99%) and fully characterized (Schemes 2 and 4). The absolute configurations were deduced from that of their precursors, the enantiomerically pure ethyl 1‐benzyl‐3‐hydroxypiperidine‐4‐carboxylates and 1‐benzyl‐3‐hydroxypiperidine‐4‐methanols which were unambiguously assigned. Being configuratively fixed and conformationally constrained phosphorus analogues of acetylcholine, the title compounds represent acetylcholine mimetics and are suitable probes for the investigation of molecular interactions with acetylcholinesterase. As determined by kinetic methods, all of the compounds are moderate irreversible inhibitors of the enzyme.