bluuebunny/crossref_metadata_2025 huggingface dataset:
Morbidity in former sawmill workers exposed to pentachlorophenol (PCP): A cross‐sectional study in New Zealand
Authors: McLean David , Eng Amanda , Dryson Evan , Walls Chris , Harding Elizabeth , Wong Khoon Ching , Cheng Soo , Mannetje Andrea't , Ellison‐Loschmann Lis , Slater Tania , Shoemack Phil , Pearce Neil
Published: January 2009

Background

From 1950 to 1990 pentachlorophenol (PCP) was used widely in the New Zealand sawmill industry, and persistent claims of long‐term health effects have been made.

Methods

We surveyed surviving members of a cohort enumerated to study mortality in sawmill workers employed from 1970 to 1990. Estimates of historical exposure were based on job titles held, using the results of a PCP biomonitoring survey conducted in the 1980s. The survey involved interviews and clinical examinations, with interviewers and examiners blinded to exposure status.

Results

Of the 293 participants 177 had not been exposed, and of the 116 exposed all but 10% had low or short‐term PCP exposure. Nevertheless, a number of significant associations between PCP exposure and the prevalence of various symptoms were observed including associations between: (i) exposure levels and self‐reported tuberculosis, pleurisy or pneumonia (P < 0.01) and a deficit in cranial nerve function (P = 0.04); (ii) duration of employment and thyroid disorders (P = 0.04), and neuropsychological symptoms including often going back to check things (P = 0.04), low libido (P = 0.02) and heart palpitations (P = 0.02), and a strong dose–response trend for frequent mood changes without cause (P < 0.01); and (iii) cumulative exposure and frequent mood changes without cause (P = 0.02), low libido (P = 0.04), and in the overall number of neuropsychological symptoms reported (P = 0.03).

Conclusions

PCP exposure was associated with a number of physical and neuropsychological health effects that persisted long after exposure had ceased. Am. J. Ind. Med. 52:271–281, 2009. © 2009 Wiley‐Liss, Inc.
Differences in access to wage replacement benefits for absences due to work‐related injury or illness in Canada
Authors: Smith Peter M. , Kosny Agnieszka A. , Mustard Cameron A.
Published: January 2009

Background

The objective of this article is to examine the factors associated with differences in access to income replacement benefits for workers experiencing a work‐related injury or illness of 1‐week or longer in the Canadian labor force.

Methods

This study utilized data from the Survey of Labour and Income Dynamics, a representative longitudinal survey conducted by Statistics Canada. A total of 3,352 work‐related absences were identified. Logistic regression models examined factors at the individual, occupational, and geographic level that were associated with the probability of receiving compensation.

Results

The probability of not receiving employer or workers' compensation benefits was higher among women, immigrants in their first 10 years in Canada, younger workers, respondents who were in their first year of a job, those who were not members of a union or collective bargaining agreement, and part‐time workers.

Conclusions

More research is required to understand why almost 50% of respondents with 1‐week or longer work‐related absences did not report receiving workers' compensation payments following their absence. More importantly, research is required to understand why particular groups of workers are more likely to be excluded from any type of compensation for lost earnings after a work‐related injury and illness in Canada. Am. J. Ind. Med. 52:341–349, 2009. © 2009 Wiley‐Liss, Inc.
Consanguinity associated with increased risk for bipolar I disorder in Egypt
Authors: Mansour Hader , Klei Lambertus , Wood Joel , Talkowski Michael , Chowdari Kodavali , Fathi Warda , Eissa Ahmed , Yassin Amal , Salah Hala , Tobar Salwa , El‐Boraie Hala , Gaafar Hanan , Elassy Mai , Ibrahim Nahed E. , El‐Bahaei Wafaa , Elsayed Mohamed , Shahda Mohamed , Sheshtawy Eman El , El‐Boraie Osama , El‐Chennawi Farha , Devlin Bernie , Nimgaonkar Vishwajit L.
Published: January 2009

We aimed to contrast rates of consanguinity among patients with bipolar I disorder (BP1) and controls in a population with customary consanguineous marriages (i.e., marriage between related individuals). Consanguinity increases risk for numerous monogenic and polygenic diseases. Whether the risk for BP1 increases with consanguinity has not been investigated systematically. Two independent studies were conducted in Egypt: (1) Case–control study 93 patients with BP1, 90 screened adult control individuals, and available parents. The inbreeding coefficient/consanguinity rate was estimated in two ways: using 64 DNA polymorphisms (“DNA‐based” rate); and from family history data (“self report”); (2) Epidemiological survey: total of 1,584 individuals were screened, from whom self‐reported consanguinity data were obtained for identified BP1 cases (n = 35) and 150 randomly selected, unaffected control individuals. DNA‐based consanguinity rates showed significant case–control differences (P = 0.0039). Self‐reported consanguinity rates were also elevated among BP1 patients in both samples (Study #1 OR = 2.66, 95% confidence intervals, CI: 1.34, 5.29; Study #2: OR = 4.64, 95% CI: 2.01, 10.34). In conclusion, two independent, systematic studies indicate increased consanguinity among Egyptian BP1 patients in the Nile delta region. Self‐reported estimates of consanguinity are bolstered by DNA‐based estimates, and both show significant case–control differences for BP1. © 2009 Wiley‐Liss, Inc.
A family‐based association study of the glutamate transporter gene SLC1A1 in obsessive–compulsive disorder in 378 families
Authors: Shugart Y.Y. , Wang Y. , Samuels J.F. , Grados M.A. , Greenberg B.D. , Knowles J.A. , McCracken J.T. , Rauch S.L. , Murphy D.L. , Rasmussen S.A. , Cullen B. , Hoehn‐Saric R. , Pinto A. , Fyer A.J. , Piacentini J. , Pauls D.L. , Bienvenu O.J. , Riddle M.A. , Liang K.Y. , Nestadt G.
Published: January 2009

SLC1A encodes the neuronal and epithelial glutamate transporter and was previously tested as a candidate for obsessive–compulsive disorder (OCD) by several research groups. Recently, three independent research groups reported significant association findings between OCD and several genetic variants in SLC1A1. This study reports the results from a family‐based association study, which examined the association between 13 single nucleotide polymorphisms (SNPs) within or in proximity to the SLC1A1 gene. Although we did not replicate association findings for those significant SNPs reported by previous studies, our study indicated a strong association signal with the SNP RS301443 (P‐value = 0.000067; Bonferroni corrected P‐value = 0.0167) under a dominant model, with an estimated odds ratio of 3.5 (confidence interval: 2.66–4.50). Further, we conducted single SNP analysis after stratifying the full data set by the gender status of affecteds in each family. The P‐value for RS301443 in families with the male affecteds was 0.00027, and the P‐value in families with female affecteds was 0.076. The fact that we identified a signal which was not previously reported by the other research groups may be due to differences in study designs and sample ascertainment. However, it is also possible that this significant SNP may be part of a regulator for SLC1A1, given that it is roughly 7.5 kb away from the boundary of the SLC1A1 gene. However, this potential finding needs to be validated biologically. Further functional studies in this region are planned by this research group. © 2009 Wiley‐Liss, Inc.
Gebändigt: das hoch reaktive Oxoniumion
Authors: Haley Michael M.
Published: January 2009

Das dreiwertige Sauerstoffatom als Strukturelement im tricyclischen Gerüst von 1–3 verleiht dieser „ungewöhnlichen“ Klasse von tertiären Oxoniumionen beispiellose Stabilität. Das Kation 1 ist am wenigsten reaktiv, es kann ohne erkennbare Zersetzung 72 h in siedendem Wasser erhitzt werden.

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Selective Propene Epoxidation on Immobilized Au6–10 Clusters: The Effect of Hydrogen and Water on Activity and Selectivity
Authors: Lee Sungsik , Molina Luis M. , López María J. , Alonso Julio A. , Hammer Bjørk , Lee Byeongdu , Seifert Sönke , Winans Randall E. , Elam Jeffrey W. , Pellin Michael J. , Vajda Stefan
Published: January 2009

Epoxidation made easy: Subnanometer gold clusters immobilized on amorphous alumina result in a highly active and selective catalyst for propene epoxidation. The highest selectivity is found for gas mixtures involving oxygen and water, thus avoiding the use of hydrogen. Ab initio DFT calculations are used to identify key reaction intermediates and reaction pathways. The results confirm the high catalyst activity owing to the formation of propene oxide metallacycles. Al green, Au yellow, O red, and C gray.

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Synthesis and Biological Activity of Argiotoxin 636 and Analogues: Selective Antagonists for Ionotropic Glutamate Receptors
Authors: Nelson Jared K. , Frølund Sidsel U. , Tikhonov Dennis B. , Kristensen Anders S. , Strømgaard Kristian
Published: January 2009

More discerning than the parent: Analogues of the polyamine toxin argiotoxin 636 (shown docked in the ion channel of an ionotropic glutamate (iGlu) receptor; N blue, O red) distinguish subtypes of iGlu receptors. Depending on which of the two internal amine groups is replaced with a methylene group, the analogue inhibits one or other of two receptor subtypes as potently as the natural compound, which itself inhibits both subtypes nonselectively.

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Quality management and quality practice: Perspectives on their history and their future
Authors: Fisher N. I. , Nair V. N.
Published: January 2009

The purpose of this article and a companion article is to explore a number of topics in Statistics in Business and Industry. This article sketches the history of Quality Management, from its emergence in the late 19th and early 20th centuries through to the present day. Particular emphasis is placed on activities in Japan immediately following the end of the Second World War, and subsequent developments elsewhere in the world. We draw a careful distinction between Quality Management and various methodologies that aid in its implementation, such as Six Sigma. In the words of one management practitioner, Norbert Vogel, ‘TQM in its broadest sense examines all aspects of management and the alternative methodologies being promoted are merely sub‐sets of what should be an integrated management system.’ The article concludes with some speculative thoughts about the future of Quality Management from a statistician's point of view. Copyright © 2009 John Wiley & Sons, Ltd.
Syntrophic interactions among anode respiring bacteria (ARB) and Non‐ARB in a biofilm anode: electron balances
Authors: Parameswaran Prathap , Torres César I. , Lee Hyung‐Sool , Krajmalnik‐Brown Rosa , Rittmann Bruce E.
Published: January 2009

We demonstrate that the coulombic efficiency (CE) of a microbial electrolytic cell (MEC) fueled with a fermentable substrate, ethanol, depended on the interactions among anode respiring bacteria (ARB) and other groups of micro‐organisms, particularly fermenters and methanogens. When we allowed methanogenesis, we obtained a CE of 60%, and 26% of the electrons were lost as methane. The only methanogenic genus detected by quantitative real‐time PCR was the hydrogenotrophic genus, Methanobacteriales, which presumably consumed all the hydrogen produced during ethanol fermentation (∼30% of total electrons). We did not detect acetoclastic methanogenic genera, indicating that acetate‐oxidizing ARB out‐competed acetoclastic methanogens. Current production and methane formation increased in parallel, suggesting a syntrophic interaction between methanogens and acetate‐consuming ARB. When we inhibited methanogenesis with 50 mM 2‐bromoethane sulfonic acid (BES), the CE increased to 84%, and methane was not produced. With no methanogenesis, the electrons from hydrogen were converted to electrical current, either directly by the ARB or channeled to acetate through homo‐acetogenesis. This illustrates the key role of competition among the various H2 scavengers and that, when the hydrogen‐consuming methanogens were present, they out‐competed the other groups. These findings also demonstrate the importance of a three‐way syntrophic relationship among fermenters, acetate‐consuming ARB, and a H2 consumer during the utilization of a fermentable substrate. To obtain high coulombic efficiencies with fermentable substrates in a mixed population, methanogens must be suppressed to promote new interactions at the anode that ultimately channel the electrons from hydrogen to current. Biotechnol. Bioeng. 2009;103: 513–523. © 2009 Wiley Periodicals, Inc.
Alignment of skeletal muscle myoblasts and myotubes using linear micropatterned surfaces ground with abrasives
Authors: Shimizu Kazunori , Fujita Hideaki , Nagamori Eiji
Published: January 2009

Alignment of cells plays a significant key role in skeletal muscle tissue engineering because skeletal muscle tissue in vivo has a highly organized structure consisting of long parallel multinucleated myotubes formed through differentiation and fusion of myoblasts. In the present study, we developed an easy, simple, and low‐cost method for aligning skeletal muscle cells by using surfaces with linear microscale features fabricated by grinding. Iron blocks were ground in one direction with three kinds of abrasives (9 µm diamond suspension, #400 sandpaper, and #150 sandpaper) and then used as molds to make micropatterned polydimethylsiloxane (PDMS) substrates (type I, type II, and type III). Observation of the surface topography revealed that the PDMS substrates exhibited different degree of mean roughness (Ra), 0.03 µm for type I, 0.16 µm for type II, and 0.56 µm for type III, respectively. Murine skeletal muscle cell line C2C12 myoblasts were cultured and differentiated on the patterned PDMS substrates, and it was examined whether the alignment of C2C12 myoblasts and myotubes was possible. Although the cell growth and differentiation on the three types of patterned substrates were similar to those on the flat PDMS substrate as a control, the alignment of both C2C12 myoblasts and myotubes was obviously observed on types II and III, but not on type I or the control substrate. These results indicate that surfaces ground with abrasives will be useful for fabricating aligned skeletal muscle tissues. Biotechnol. Bioeng. 2009;103: 631–638. © 2009 Wiley Periodicals, Inc.
A Molecular Paddlewheel with a Sliding Organometallic Latch: Syntheses, X‐Ray Crystal Structures and Dynamic Behaviour of [Cr(CO)3{η6‐2‐(9‐triptycyl)indene}], and of [M(CO)3{η5‐2‐(9‐triptycyl)indenyl}] (M=Mn, Re)
Authors: Nikitin Kirill , Müller‐Bunz Helge , Ortin Yannick , McGlinchey Michael J.
Published: January 2009

Metal clamping in operation! Deprotonation of [η6‐2‐(9‐triptycyl)indene]tricarbonylchromium induces a haptotropic shift of the organometallic fragment from the six‐membered to the five‐membered ring, as in a→b. In the anion, rotation of the molecular paddlewheel is blocked by the bulky tripod. X‐ray crystal structures provide pictures of the system in both its “ON” and “OFF” states.

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In [η6‐2‐(9‐triptycyl)‐indene]tricarbonylchromium (2 a), the indenyl–chromium moiety is linked directly to the axis of the three‐bladed triptycene paddlewheel. However, the molecular structure of 2 a reveals that there is no steric interaction between these components, and the paddlewheel is free to rotate. Accordingly, its NMR spectrum indicates the full equivalence of the blades of the triptycene. Deprotonation of the indene induces a haptotropic shift of the organometallic fragment from the six‐membered to the five‐membered ring of the indene and, in the sodium [η5‐2‐(9‐triptycyl)‐indenyl]tricarbonylchromium salt (3 a), so formed, rotation of the three‐bladed molecular paddlewheel is now blocked by the bulky tripod. NMR data for 3 a, and also for the isostructural η5‐Mn(CO)3 and η5‐Re(CO)3 complexes, 3 b and 3 c, respectively, reveal a 2:1 splitting of the blades of the triptycyl moiety, thus breaking its original threefold symmetry. The X‐ray crystal structures of the chromium complex, 2 a, and of the manganese and rhenium complexes, 3 b and 3 c, provide pictures of the system in both its “ON” and “OFF” states, whereby the M(CO)3 tripod has moved about 2 Å towards the triptycene, thus blocking its rotation. Comparison of the rotational barriers in 2‐(9‐triptycyl)indene (1) and its complexes 2 and 3, suggests that rotation of the paddlewheel can be slowed by a factor of approximately 108.
1,3‐Dioxolane‐Based Ligands as Rigid Analogues of Naftopidil: Structure–Affinity/Activity Relationships at α1and 5‐HT1AReceptors
Authors: Sorbi Claudia , Franchini Silvia , Tait Annalisa , Prandi Adolfo , Gallesi Rossella , Angeli Piero , Marucci Gabriella , Pirona Lorenza , Poggesi Elena , Brasili Livio
Published: January 2009

Conformational restrictionof naftopidil led to the discovery of a new class of ligands with a 1,3‐dioxolane (1,3‐oxathiolane, 1,3‐dithiolane) structure that bind to α1adrenoceptor subtypes and 5‐HT1Areceptors. Adequate structural modifications address the selectivity toward one or the other receptor system.

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Conformational restriction of naftopidil proved to be compatible with binding at α1adrenoceptor subtypes and 5‐HT receptor 1A (5‐HT1A), and led to the discovery of a new class of ligands with a 1,3‐dioxolane (1,3‐oxathiolane, 1,3‐dithiolane) structure. Compound7shows the highest affinity toward α1aand α1dadrenoceptor subtypes (pKi α1a=9.58, pKi α1d=9.09) and selectivity over 5‐HT1Areceptors (α1a/5‐HT1A=100, α1d/5‐HT1A=26). In functional experiments it behaves as a potent competitive α1aand α1dadrenoceptor antagonist (pKb α1A=8.24, pKb α1D=8.14), whereas at 5‐HT1Areceptors it is a potent partial agonist (pD2=8.30). Compounds8and10display high affinity (pKi=8.29 and 8.26, respectively) and selectivity for 5‐HT1A(5‐HT1A/α1=18 and 10). In functional experiments at the 5‐HT1Areceptor, compound8appears to be neutral antagonist (pKb=7.29), whereas compound10is a partial agonist (pD2=6.27). Therefore, 1,3‐dioxolane‐based ligands are a versatile class of compounds useful for the development of more selective ligands for one (α1) or the other (5‐HT1A) receptor system.
SHOP: A Method For Structure‐Based Fragment and Scaffold Hopping
Authors: Fontaine Fabien , Cross Simon , Plasencia Guillem , Pastor Manuel , Zamora Ismael
Published: January 2009

We present a method for fragment/scaffold substitution based on protein–ligand interactions. This concept goes beyond bioisosteric replacement, which only uses the structure of the fragment to replace as query. The methodology is validated with more than 10 biological targets relevant for drug discovery.

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A new method for fragment and scaffold replacement is presented that generates new families of compounds with biological activity, using GRID molecular interaction fields (MIFs) and the crystal structure of the targets. In contrast to virtual screening strategies, this methodology aims only to replace a fragment of the original molecule, maintaining the other structural elements that are known or suspected to have a critical role in ligand binding. First, we report a validation of the method, recovering up to 95 % of the original fragments searched among the top‐five proposed solutions, using 164 fragment queries from 11 diverse targets. Second, six key customizable parameters are investigated, concluding that filtering the receptor MIF using the co‐crystallized ligand atom type has the greatest impact on the ranking of the proposed solutions. Finally, 11 examples using more realistic scenarios have been performed; diverse chemotypes are returned, including some that are similar to compounds that are known to bind to similar targets.
Ground plan of the insect mushroom body: Functional and evolutionary implications
Authors: Strausfeld Nicholas J. , Sinakevitch Irina , Brown Sheena M. , Farris Sarah M.
Published: January 2009

In most insects with olfactory glomeruli, each side of the brain possesses a mushroom body equipped with calyces supplied by olfactory projection neurons. Kenyon cells providing dendrites to the calyces supply a pedunculus and lobes divided into subdivisions supplying outputs to other brain areas. It is with reference to these components that most functional studies are interpreted. However, mushroom body structures are diverse, adapted to different ecologies, and likely to serve various functions. In insects whose derived life styles preclude the detection of airborne odorants, there is a loss of the antennal lobes and attenuation or loss of the calyces. Such taxa retain mushroom body lobes that are as elaborate as those of mushroom bodies equipped with calyces. Antennal lobe loss and calycal regression also typify taxa with short nonfeeding adults, in which olfaction is redundant. Examples are cicadas and mayflies, the latter representing the most basal lineage of winged insects. Mushroom bodies of another basal taxon, the Odonata, possess a remnant calyx that may reflect the visual ecology of this group. That mushroom bodies persist in brains of secondarily anosmic insects suggests that they play roles in higher functions other than olfaction. Mushroom bodies are not ubiquitous: the most basal living insects, the wingless Archaeognatha, possess glomerular antennal lobes but lack mushroom bodies, suggesting that the ability to process airborne odorants preceded the acquisition of mushroom bodies. Archaeognathan brains are like those of higher malacostracans, which lack mushroom bodies but have elaborate olfactory centers laterally in the brain. J. Comp. Neurol. 513:265–291, 2009. © 2009 Wiley‐Liss, Inc.
Transcriptional re‐programming of primary macrophages reveals distinct apoptotic and anti‐tumoral functions of IRF‐3 and IRF‐7
Authors: Goubau Delphine , Romieu‐Mourez Raphaëlle , Solis Mayra , Hernandez Eduardo , Mesplède Thibault , Lin Rongtuan , Leaman Douglas , Hiscott John
Published: January 2009

The immunoregulatory transcriptional modulators – IFN‐regulatory factor (IRF)‐3 and IRF‐7 – possess similar structural features but distinct gene‐regulatory potentials. For example, adenovirus‐mediated transduction of the constitutively active form of IRF‐3 triggered cell death in primary human MΦ, whereas expression of active IRF‐7 induced a strong anti‐tumoral activity in vitro. To further characterize target genes involved in these distinct cellular responses, transcriptional profiles of active IRF‐3‐ or IRF‐7‐transduced primary human MΦ were compared and used to direct further mechanistic studies. The pro‐apoptotic BH3‐only protein Noxa was identified as a primary IRF‐3 target gene and an essential regulator of IRF‐3, dsRNA and vesicular stomatitis virus‐induced cell death. The critical role of IRF‐7 and type I IFN production in increasing the immunostimulatory capacity of MΦ was also evaluated; IRF‐7 increased the expression of a broad range of IFN‐stimulated genes including immunomodulatory cytokines and genes involved in antigen processing and presentation. Furthermore, active IRF‐7 augmented the cross‐presentation capacity and tumoricidal activity of MΦ and led to an anti‐tumor response against the B16 melanoma model in vivo. Altogether, these data further highlight the respective functions of IRF‐3 and IRF‐7 to program apoptotic, immune and anti‐tumor responses.
Changes in triacylglycerol molecular species and thermal properties of blended and interesterified mixtures of coconut oil or palm oil with rice bran oil or sesame oil
Authors: Reena Malongil B. , Reddy Sunki R. Y. , Lokesh Belur R.
Published: January 2009

Blended oils were prepared by mixing appropriate amounts of coconut oil (CNO) or palm oil (PO) with rice bran oil (RBO) or sesame oil (SESO) to get approximately equal proportions of saturated/monounsaturated/polyunsaturated fatty acids in the oil. These blended oils were subjected to interesterification reactions using lipase to randomize the fatty acid distribution on the glycerol molecule. The fatty acid compositions of the modified oils were evaluated by gas chromatography while changes in triacylglycerol molecular species were followed by HPLC. The triacylglycerol molecular species of the blended oils reflected those present in the parent oil. Interesterification of the blended oils resulted in the exchange of fatty acids within and between the triacylglycerol molecules, resulting in alterations in the existing triacylglycerol molecules. Emergence of new triacylglycerol molecular species following interesterification was also observed. The thermal profiles of the native, blended and interesterified oils were determined by differential scanning calorimetry. Thermal behaviour, melting and crystallization properties of the modified oils showed significant changes reflecting the changes in the triacylglycerol molecules present in the oil. Therefore, interesterification of oils introduces significant changes in the physical properties of oils, even though the overall fatty acid composition of blended and interesterified oils remains the same.
Cyclic 2:1 and 1:2 Aldehyde‐to‐Acetone Byproduct Adducts in Aldol Reactions Promoted by Supported Proline‐Incorporated Catalysts
Authors: Tuchman‐Shukron Lital , Kehat Tzofit , Portnoy Moshe
Published: January 2009

Significant amounts of cyclic byproducts of aldol addition with stoichiometry deviating from a regular 1:1 addition pattern were formed when the reaction of acetone with aromatic aldehydes was promoted by polymer‐supported proline‐incorporated catalysts. These adducts, unprecedented in the context of the aldol reaction, are most probably formed via a multistep domino mechanism.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Genosensor for SARS Virus Detection Based on Gold Nanostructured Screen‐Printed Carbon Electrodes
Authors: Martínez‐Paredes Graciela , González‐García María Begoña , Costa‐García Agustín
Published: January 2009

A hybridization‐based genosensor is designed on a disposable gold nanostructured screen‐printed carbon electrode. Gold nanoparticles which are formed in situ by applying a constant current intensity during a fixed time, acts as an immobilization and transduction surface. The parameters affecting the methodology are studied, with special attention being placed on sensibility. Immobilization takes place through thiol‐gold interaction in a relatively fast way, and the genosensor response is found to be linearly to the biotinylated target concentration between 2.5 and 50 pmol/L; a detection limit of 2.5 pmol/L is calculated, and a sensitivity of 1.76 μA/pmol L−1 is achieved. These results improve significantly those described in literature, thus demonstrating the advantages offered by the use of gold‐nanostructured surfaces.
Cathodic Electrochemical Determination of Herbicides in Acid Media Using a Bismuth Film Electrode
Authors: Moreno Mónica , Bermejo Esperanza , Chicharro Manuel , Zapardiel Antonio , Arribas Alberto Sánchez
Published: January 2009

A revised procedure for the preparation of bismuth film electrodes (BiFEs), adapted to improve its performance in acid media, is presented and applied for the analysis of herbicides under these conditions. Common carbon‐based substrates have been studied for the preparation of ex situ BiFE as well as the influence of relevant parameters upon the bismuth film formation (plating solution, deposition potential and deposition time). A plating solution consisting of 0.60 mM Bi(NO3)3 in 0.10 M H2SO4 and a careful selection of the plating potential (equal to the cathodic peak potential in this solution) applied during 360 s yields to a suitable BiFE in terms of stability and electroanalytical performance. The applicability of the BiFE was investigated for the analysis of the herbicides metamitron, metribuzin, maleic hydrazide and atrazine in nondeaerated solutions by square‐wave voltammetry (SWV). In all cases the enhanced electrochemical performance of the BiFE over bare glassy carbon electrode (GCE) is evident. Herbicides signals at BiFE have improved sensitivity and a positive potential shift is observed when compared to bare GCE. The herbicide metribuzin (4‐amino‐6‐tert‐4,5‐dihydro‐3‐methyl‐thio‐1,2,4‐triazin‐5‐one) was determinated in nondeaerated solutions by square‐wave voltammetry (SWV) using BiFE. Under optimal conditions, the dynamic linear range of concentrations is comprised between 10 and 200 μM and the detection limit is 6 μM.
Current‐Free Deposition of Prussian Blue with Organic Polymers: Towards Improved Stability and Mass Production of the Advanced Hydrogen Peroxide Transducer
Authors: Borisova Anastasiya V. , Karyakina Elena E. , Cosnier Serge , Karyakin Arkady A.
Published: January 2009

We report on a novel approach for open‐circuit (current‐free) deposition of Prussian blue. Synthesis of Prussian blue is carried out by reduction of ferric ferricyanide with organic molecules, which are known to form polymers upon oxidation. The proposed interfacial deposition is a result of the synthesis in the presence of electrode support due to preconcentration of precursors at the interface. The resulting modified electrodes displayed the dramatically improved operational stability in hydrogen peroxide continuous monitoring with no loss of either electrochemical or analytical performance characteristics compared to electrodes with electrochemically deposited Prussian blue. The shown possibility to deposit stable films with regular structure in the absence of any external voltage could open new horizons for sensor science.
Resolution of Heavy Metal Mixtures from Highly Overlapped ASV Voltammograms Employing a Wavelet Neural Network
Authors: Gutiérrez Juan Manuel , Moreno‐Barón Laura , Céspedes Francisco , Muñoz Roberto , del Valle Manuel
Published: January 2009

This work describes the chemometric assisted ASV determination of three heavy metals in water (lead, copper and cadmium) in presence of thallium and indium as interfering species. Stripping was carried out in open atmosphere, employing a graphite‐epoxy transducer as working electrode, without any surface regeneration after each analysis. The concentration range studied was from 0.4 to 20 ppm for both analytes and interferents. Due to the overlapping nature of the signals, a wavelet neural network (WNN) was used for deconvolution of the voltammogram. In order to validate the resolution capability, a k‐fold cross validation procedure was performed. Mixtures of metals could be resolved with good prediction of their concentrations; obtained vs. expected comparison graphs exhibited, for a set of samples not employed for training, correlation values of 0.996 for lead, 0.989 for cadmium and 0.995 for copper.
System of Modular Design for Electroanalysis Extended to Thermoelectrochemical Studies
Authors: Gründler Peter
Published: January 2009

An instrument for electroanalysis extended to thermoelectrochemical studies is presented here consisting of easily available components. An analog potentiostat is combined with a microcontroller. The latter is controlled by an Excel sheet extended by macros written in VBA (visual basic for applications). The worksheet acts as a virtual instrument with front panel and command buttons. Thus, specialized, expansive measuring software packages are unnecessary. The design of new techniques is facilitated by a of graphical representation of pulse sequences or the exciting waveforms. The instrument has proved to be useful for design and performance of non conventional electrochemical techniques working with additional parameters like irradiation or heat. Examples are given for thermoelectrochemical measuring sequences like TPV (temperature pulse voltammetry).
Multivariate Analysis for the Electrochemical Discrimination and Quantitation of Nitroaromatic Explosives
Authors: Polsky Ronen , Stork Christopher L. , Wheeler David R. , Steen William A. , Harper Jason C. , Washburn Cody M. , Brozik Susan M.
Published: January 2009

A chemometric approach for the discrimination and quantification of nitroaromatic explosives is presented. The multivariate analysis of the square‐wave voltammetric data of trinitrotoluene, 2,6‐dinitrotoluene, 2,4‐dinitrotoluene, and 2‐nitrotoluene reduction was employed to extract subtle differences in the electrochemical response across multiple potentials on a bare glassy carbon, aminophenyl‐modified glassy carbon, and carboxylphenyl‐modified glassy carbon electrode surfaces allowing the electrochemical discrimination of the four different nitroaromatic analytes. A multivariate regression model was developed to differentiate and predict the concentrations of the structural isomers 2,6‐dinitrotoluene, and 2,4‐dinitrotoluene in mixture solutions.
Planform dynamics of braided streams
Authors: Bertoldi Walter , Zanoni Luca , Tubino Marco
Published: January 2009

The high dynamism and complexity of braided networks poses a series of open questions, significant for river restoration and management. The present work is aimed at the characterization of the morphology of braided streams, in order to assess whether the system reaches a steady state under constant flow conditions and, in that case, to determine how it can be described and on which parameters it depends. A series of 14 experimental runs were performed in a laboratory physical model with uniform sand, varying the discharge and the longitudinal slope. Planimetric and altimetric configurations were monitored in order to assess the occurrence of a steady state. A set of parameters was considered, such as the braid‐plain width and the number and typology of branches and nodes. Results point out that a relationship exists between braiding morphology and two dimensionless parameters, related to total water discharge and stream power. We found that network complexity increases at higher values of water discharge and a larger portion of branches exhibits morphological activity. Results are then compared to the outputs of a simple one‐dimensional model, that allows to easily predict the average network complexity, once the bed topography is known. Model computations permit also the investigation of the effect of water discharge variations and to compare different width definitions. The at‐a‐station variability of planimetric parameters shows a peculiar behaviour, both regarding number of branches and wetted width. In particular, the analysis of the relationship between width and discharge highlighted relevant differences in comparison to single thread channel. Copyright © 2009 John Wiley & Sons, Ltd.
Multi‐process Late Quaternary landscape evolution modelling reveals lags in climate response over small spatial scales
Authors: Temme A. J. A. M. , Veldkamp A.
Published: January 2009

Landscapes evolve in complex, non‐linear ways over Quaternary timespans. Integrated geomorphological field studies usually yield plausible hypotheses about timing and impact of process activity. Landscape Evolution Models (LEMs) have the potential to test and falsify these landscape evolution hypotheses. Despite this potential, LEMs have mainly been used with hypothetical data and rarely to simulate the evolution of an actual landscape.

In this paper, we use a LEM (LAPSUS: LandscApe ProcesS modelling at mUlti dimensions and scaleS) to explore if it is possible to test and falsify conclusions of an earlier field study on 50 ka landscape evolution in Okhombe Valley, KwaZulu Natal, South Africa. In this LEM, five landscape processes interact without supervision: water driven erosion and deposition, creep, solifluction, biological weathering and frost weathering. Calibration matched model results to three types of qualitative fieldwork observations: individual process activity over time, relative process activity over time and net landscape changes over time. Results demonstrate that landscape evolution of the Okhombe valley can be plausibly simulated.

A particularly interesting and persistent feature of model results are erosional and depositional phases that lag climatic drivers both by decades, and by several ka within a few hundred meters. The longer lag has not been reported for this spatial scale before and may be an effect of slow landscape‐soil‐vegetation feedbacks. The combined modelling and fieldwork results allow a more complete understanding of these responses to climate change and can fill in hiatuses in the stratigraphical record. Suggestions are made for methodological adaptations for future LEM studies. Copyright © 2009 John Wiley & Sons, Ltd.
Reduced‐complexity flow routing models for sinuous single‐thread channels: intercomparison with a physically‐based shallow‐water equation model
Authors: Nicholas A. P.
Published: January 2009

Reduced‐complexity models of fluvial processes use simple rules that neglect much of the underlying governing physics. This approach is justified by the potential to use these models to investigate long‐term and/or fundamental river behaviour. However, little attention has been given to the validity or realism of reduced‐complexity process parameterizations, despite the fact that the assumptions inherent in these approaches may limit the potential for elucidating the behaviour of natural rivers. This study presents two new reduced‐complexity flow routing schemes developed specifically for application in single‐thread rivers. Output from both schemes is compared with that from a more sophisticated model that solves the depth‐averaged shallow water equations. This comparison provides the first demonstration of the potential for deriving realistic predictions of in‐channel flow depth, unit discharge, energy slope and unit stream power using simple flow routing schemes. It also highlights the inadequacy of modelling unit stream power, shear stress or sediment transport capacity as a function of local bed slope, as has been common practice in a number of previous reduced‐complexity models. Copyright © 2009 John Wiley & Sons, Ltd.
Deformation history of the eclogite‐ and jadeitite‐bearing mélange from North Motagua Fault Zone, Guatemala: insights in the processes of a fossil subduction channel
Authors: Marroni Michele , Pandolfi Luca , Principi Gianfranco , Malasoma Alessandro , Meneghini Francesca
Published: January 2009

In Guatemala, along the northern side of the Motagua Valley, a mélange consisting of blocks of eclogite and jadeitite set in a metaserpentinitic and metasedimentary matrix crops out. The metasedimentary rocks display a complex deformation history that includes four tectonic phases, from D1 to D4. The D1 phase occurs only as a relic and is characterized by a mineral assemblage developed under pressure temperature (P–T) conditions of 1.00–1.25 GPa and 206–263°C. The D2 phase, characterized by isoclinal folds, schistosity and mineral/stretching lineation, developed at P–T conditions of 0.70–1.20 GPa and 279–409°C. The following D3 and D4 phases show deformations developed at shallower structural levels. Whereas the D1 phase can be interpreted as the result of underplating of slices of oceanic lithosphere during an intraoceanic subduction, the following phases have been acquired by the mélange during its progressive exhumation through different mechanisms. The deformations related to the D2 and D3 phases can be regarded as acquired by extrusion of the mélange within a subduction channel during a stage of oblique subduction. In addition, the structural evidences indicate that the coupling and mixing of different blocks occurred during the D2 phase, as a result of flow reverse and upward trajectory in the subduction channel. By contrast, the D4 phase can be interpreted as related to extension at shallow structural levels. In this framework, the exhumation‐related structures in the mélange indicate that this process, probably long‐lived, developed through different mechanisms, active in the subduction channel through time. Copyright © 2009 John Wiley & Sons, Ltd.
Evaluating a new ridge and furrow rainfall harvesting system with two types of mulches
Authors: Gosar Borut , Tajnšek Anton , Udovč Andrej , Baričevič Dea
Published: January 2009

A new, ridge–furrow–ridge rainfall harvesting (RFRRH) system covered with black polyethylene (PE) mulch and black perforated PE mulch was studied in the cultivation of purple coneflower (Echinacea purpurea Moench). In the RFRRH system, PE mulch covered two ridges and a furrow between them, which serve as a rainfall harvesting zone. Soil water content, crop yield and production cost effectiveness were evaluated. We conclude that the new RFRRH system could reduce yield and increase material costs, which results in reduced income per hectare. On the other hand, the RFRRH system reduced weed control time and may therefore increase profit per hectare. It supplies at least an equal amount of water in comparison to bare ground (control), and can be used in semi‐humid or humid regions without additional irrigation. Copyright © 2009 John Wiley & Sons, Ltd.
Extraction and recovery of cerium(IV) along with fluorine(I) from bastnasite leaching liquor by DEHEHP in [C8mim]PF6
Authors: Zuo Yong , Liu Yu , Chen Ji , Li De‐Qian
Published: January 2009

BACKGROUND: Ionic liquids (ILs) as environmentally benign solvents have been widely studied in the application of solvent extraction. However, few applications have been successfully industrialized because of the difficult stripping of metal ions or the loss of components of the ILs. More work needs to be done to investigate the extraction behaviour of IL‐based extraction systems. In this work, the extraction behaviour of Ce(IV), Th(IV) and some trivalent rare earth (RE) nitrates by di(2‐ethylhexyl) 2‐ethylhexylphosphonate (DEHEHP) in the IL, 1‐methyl‐3‐octylimidazolium hexafluorophosphate ([C8mim]PF6), was investigated and compared with that in the n‐heptane system. In particular, the effect of F(I) on the extraction mechanism for Ce(IV) and its separation from Th(IV) was investigated. Otherwise, the recovery efficiency of Ce(IV) and F(I) from a practical bastnasite leach liquor was examined using IL based extraction.

RESULTS: Similar selectivity (Ce(IV) > Th(IV) ≫ RE(III)) was observed in both the IL and n‐heptane systems. The existence of F(I) had a large negative impact on the extraction and separation of Ce(IV). An identical process for the extraction of Ce(NO3)4 containing F(I) by DEHEHP in both IL and n‐heptane was achieved under appropriate conditions. The Ce(IV) in the IL phase may be quantitatively back extracted and may be recovered as part of high purity CeF3 and cerium sulfate.

CONCLUSION: It is possible for IL to act as an environmentally benign solvent for the recovery of Ce(IV) and F(I) from bastnasite in rare earth hydrometallurgy. Copyright © 2009 Society of Chemical Industry
Targeted transduction of CD34+ hematopoietic progenitor cells in nonpurified human mobilized peripheral blood mononuclear cells
Authors: Liang Min , Pariente Nonia , Morizono Kouki , Chen Irvin S. Y.
Published: January 2009

Background

Conventional gene‐therapy applications of hematopoietic stem cells (HSCs) involve purification of CD34+ progenitor cells from the mobilized peripheral blood, ex vivo transduction of the gene of interest into them, and reinfusion of the transduced CD34+ progenitor cells into patients. Eliminating the process of purification would save labor, time and money, while enhancing HSCs viability, transplantability and pluripotency. Lentiviral vectors have been widely used in gene therapy because they infect both dividing and nondividing cells and provide sustained transgene expression. One of the exceptions to this rule is quiescent primary lymphocytes, in which reverse transcription of viral DNA is not completed.

Methods

In the present study, we tested the possibility of targeting CD34+ progenitor cells within nonpurified human mobilized peripheral blood mononuclear cells (mPBMCs) utilizing vesicular stomatitis virus G (VSV‐G) pseudotyped lentiviral vectors, based on the assumption that the CD34+ progenitor cells would be preferentially transduced. To further enhance the specificity of vector transduction, we also examined utilizing a modified Sindbis virus envelope (2.2) pseudotyped lentiviral vector, developed in our laboratory, that allows targeted transduction to specific cell receptors via antibody recognition.

Results

Both the VSV‐G and 2.2 pseudotyped vectors achieved measurable results when they were used to target CD34+ progenitor cells in nonpurified mPBMCs.

Conclusions

Overall, the data obtained demonstrate the potential of ex vivo targeting of CD34+ progenitor cells without purification. Copyright © 2009 John Wiley & Sons, Ltd.
On the inter‐instrument and the inter‐laboratory transferability of a tandem mass spectral reference library: 2. Optimization and characterization of the search algorithm
Authors: Oberacher Herbert , Pavlic Marion , Libiseller Kathrin , Schubert Birthe , Sulyok Michael , Schuhmacher Rainer , Csaszar Edina , Köfeler Harald C.
Published: January 2009

A sophisticated matching algorithm developed for highly efficient identity search within tandem mass spectral libraries is presented. For the optimization of the search procedure a collection of 410 tandem mass spectra corresponding to 22 compounds was used. The spectra were acquired in three different laboratories on four different instruments. The following types of tandem mass spectrometric instruments were used: quadrupole‐quadrupole‐time‐of‐flight (QqTOF), quadrupole‐quadrupole‐linear ion trap (QqLIT), quadrupole‐quadrupole‐quadrupole (QqQ), and linear ion trap‐Fourier transform ion cyclotron resonance mass spectrometer (LIT‐FTICR). The obtained spectra were matched to an established MS/MS‐spectral library that contained 3759 MS/MS‐spectra corresponding to 402 different reference compounds. All 22 test compounds were part of the library. A dynamic intensity cut‐off, the search for neutral losses, and optimization of the formula used to calculate the match probability were shown to significantly enhance the performance of the presented library search approach. With the aid of these features the average number of correct assignments was increased to 98%. For statistical evaluation of the match reliability the set of fragment ion spectra was extended with 300 spectra corresponding to 100 compounds not included in the reference library. Performance was checked with the aid of receiver operating characteristic (ROC) curves. Using the magnitude of the match probability as well as the precursor ion mass as benchmarks to rate the obtained top hit, overall correct classification of a compound being included or not included in the mass spectrometric library, was obtained in more than 95% of cases clearly indicating a high predictive accuracy of the established matching procedure. Copyright © 2009 John Wiley & Sons, Ltd.