bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inherently Chiral Molecular Clips: Synthesis, Chiroptical Properties, and Application to Chiral Discrimination
Authors: Fukuhara Gaku , Madenci Süreyya , Polkowska Jolanta , Bastkowski Frank , Klärner Frank‐Gerrit , Origane Yumi , Kaneda Masayuki , Mori Tadashi , Wada Takehiko , Inoue Yoshihisa 
Published: January 2007

AbstractInherently chiral molecular clips (MCs), pseudoenantiomeric anti‐1 and anti‐2, as well as mesoid syn‐3, were synthesized by diastereodifferentiating repetitive Diels–Alder reactions of the achiral bisdienophile 6 with chiral diene 5 generated in situ from (−)‐menthyl 3,4‐bis(dibromomethyl)benzoate 4. These MCs were successfully separated by chiral HPLC to give optically active anti‐1 and anti‐2 and almost optically inactive syn‐3. The structures of anti‐1, anti‐2, and syn‐3 were assigned by high‐resolution NMR and the absolute configurations of anti‐1 and anti‐2 were determined by the exciton‐chirality method. Optically active anti‐2 can serve as a chiral host. It binds the HCl adduct of D‐tryptophan methyl ester (D‐TrpOMe⋅HCl) 3.5 times stronger than the L‐enantiomer (KD/KL=3.5).
An interpolation‐based local differential quadrature method to solve partial differential equations using irregularly distributed nodes
Authors: Ma Hang , Qin Qing‐Hua 
Published: January 2007

AbstractTo circumvent the constraint in application of the conventional differential quadrature (DQ) method that the solution domain has to be a regular region, an interpolation‐based local differential quadrature (LDQ) method is proposed in this paper. Instead of using regular nodes placed on mesh lines in the DQ method (DQM), irregularly distributed nodes are employed in the LDQ method. That is, any spatial derivative at a nodal point is approximated by a linear weighted sum of the functional values of irregularly distributed nodes in the local physical domain. The feature of the new approach lies in the fact that the weighting coefficients are determined by the quadrature rule over the irregularly distributed local supporting nodes with the aid of nodal interpolation techniques developed in the paper. Because of this distinctive feature, the LDQ method can be consistently applied to linear and nonlinear problems and is really a mesh‐free method without the limitation in the solution domain of the conventional DQM. The effectiveness and efficiency of the method are validated by two simple numerical examples by solving boundary‐value problems of a linear and a nonlinear partial differential equation. Copyright © 2007 John Wiley & Sons, Ltd.
Attention‐like processes underlying optomotor performance in a Drosophila choice maze
Authors: van Swinderen Bruno , Flores Kristopher A. 
Published: January 2007

AbstractThe authors present a novel paradigm for studying visual responses in Drosophila. An eight‐level choice maze was found to reliably segregate fly populations according to their responses to moving stripes displayed on a computer screen. Visual responsiveness was robust in wild‐type flies, and performance depended on salience effects such as stimulus color and speed. Analysis of individual fly choices in the maze revealed that stereotypy, or choice persistence, contributed significantly to a strain's performance. On the basis of these observations, the authors bred wild‐type flies for divergent visual phenotypes by selecting individual flies displaying extreme stereotypy. Selected flies alternated less often in the sequential choice maze than unselected flies, showing that stereotypy could evolve across generations. The authors found that selection for increased stereotypy impaired flies' responsiveness to competing stimuli in tests for attention‐like behavior in the maze. Visual selective attention was further investigated by electrophysiology, and it was found that increased stereotypy also impaired responsiveness to competing stimuli at the level of brain activity. Combined results present a comprehensive approach to studying visual responses in Drosophila, and show that behavioral performance involves attention‐like processes that are variable among individuals and thus sensitive to artificial selection. © 2006 Wiley Periodicals, Inc. Develop Neurobiol 67: 129–145, 2007.
The serotonin receptor SER‐1 (5HT2ce) contributes to the regulation of locomotion in Caenorhabditis elegans
Authors: Dernovici Serge , Starc Tanja , Dent Joseph A. , Ribeiro Paula 
Published: January 2007

AbstractSerotonin (5‐hydroxytryptamine: 5HT) is an important neuroactive substance in the model roundworm, Caenorhabditis elegans. Aside from having effects in feeding and egg‐laying, 5HT inhibits motility and also modulates several locomotory behaviors, notably food‐induced slowing and foraging. Recent evidence showed that a serotonergic 5HT2‐like receptor named SER‐1 (also known as 5HT2ce) was responsible for the effect of 5HT on egg‐laying. Here we confirm this observation and show that SER‐1 also plays an important role in locomotion. A mutant lacking SER‐1 was found to be highly resistant to exogenous 5HT in the absence of food and this resistant phenotype was rescued by reintroducing the SER‐1 gene in a mutant background. Pharmacological studies showed that the same antagonists that blocked the activity of recombinant SER‐1 invitro also inhibited the effect of 5HT on motility, suggesting the same receptor was responsible for both effects. When tested for locomotory behaviors, the SER‐1 mutant was found to be moderately defective in food‐induced slowing. In addition, the mutant changed direction more frequently than the wildtype when searching for food, suggesting that SER‐1 may play a role in navigational control during foraging. Both these effects required the presence of MOD‐1, a 5HT gated chloride channel, and the results indicate that SER‐1 and MOD‐1 modulate these behaviors through a common pathway. On the basis of expression analysis of a ser‐1::GFP translational fusion, SER‐1 is prominently located in central, integrating neurons of the head ganglia (RIA and RIC) but not the body wall musculature. The evidence suggests that SER‐1 controls locomotion through indirect modulation of neuromuscular circuits and has effects both on speed and direction of movement. © 2006 Wiley Periodicals, Inc. Develop Neurobiol 67: 189–204, 2007.
Channel change following European settlement: Gilmore Creek, southeastern Australia
Authors: Page Ken , Frazier Paul , Pietsch Timothy , Dehaan Remy 
Published: January 2007

AbstractEuropean settlement in southeastern Australia led to rapid changes in the morphology of many upland streams. However, our knowledge of the nature of these changes is limited as historical records and preserved palaeochannels are rare. In this study we compare a well‐preserved section of the late Holocene palaeochannel of Gilmore Creek to its present channel. We used a combination of map and aerial photograph interpretation, field survey, OSL dating and discharge analysis to describe and compare the modern and palaeochannels and establish a firm date for the timing of channel change. In common with many other streams in southeastern Australia Gilmore Creek's late Holocene channel meandered across a stable well‐vegetated and frequently inundated floodplain. After about 1830 European settlers quickly modified the catchment by clearing riparian and hillslope vegetation, introducing grazing animals and other exotic species and mining for alluvial gold in the headwaters. The OSL dates show that between about 1850 and 1880 the small meandering channel aggraded with coarse sands and then up to about 1 m of silty sand was deposited over the floodplain. Declining sediment input from upstream channel avulsion before 1890 resulted in the establishment of a straighter, larger capacity channel that incised to the level of basal cobbles and, in places, to bedrock. The dramatic change in channel pattern resembles that described on the Cann River in eastern Victoria following the removal of riparian vegetation and within‐channel coarse woody debris. At Gilmore Creek increased channel capacity has greatly reduced the average frequency of floodplain inundation. High values of specific stream power suggest that channel morphology is now well adjusted to the present flow regime. Copyright © 2007 John Wiley & Sons, Ltd.
Improved genetic algorithm for multi‐objective reactive power dispatch problem
Authors: Devaraj D. 
Published: January 2007

AbstractThis paper presents an improved genetic algorithm (GA) approach for solving the multi‐objective reactive power dispatch problem. Loss minimization and maximization of voltage stability margin are taken as the objectives. Maximum L‐index of the system is used to specify the voltage stability level. Generator terminal voltages, reactive power generation of capacitor banks and tap changing transformer setting are taken as the optimization variables. In the proposed GA, voltage magnitudes are represented as floating point numbers and transformer tap‐setting and reactive power generation of capacitor bank are represented as integers. This alleviates the problems associated with conventional binary‐coded GAs to deal with real variables and integer variables with total number of permissible choices not equal to 25. Crossover and mutation operators which can deal with mixed variables are proposed. The proposed method has been tested on IEEE 30‐bus system and is compared with conventional methods and binary‐coded GA. The proposed method has produced the loss which is less than the value reported earlier and is well suitable for solving the mixed integer optimization problem. Copyright © 2007 John Wiley & Sons, Ltd.
Removing pharmaceuticals and endocrine‐disrupting compounds from wastewater by photocatalysis
Authors: Dalrymple Omatoyo K , Yeh Daniel H , Trotz Maya A 
Published: January 2007

AbstractWidespread concerns continue to be raised about the increasing presence of emerging contaminants in the environment. Such compounds include a wide range of persistent organic chemicals, including pharmaceuticals and endocrine‐disrupting compounds whose effects are poorly known, often because they have only begun to enter the environment and are showing up in wastewater treatment plants. The occurrence and behavior of these compounds in wastewater are key issues with regard to water reclamation and reuse. Treatment plants are now faced with the challenge of removing the compounds from their effluent before they enter natural waterways. In this regard, photocatalysis is a promising technology for wastewater treatment that offers many advantages over conventional and some advanced treatment options. The application of photocatalysis for the removal of pharmaceuticals and endocrine‐disrupting compounds for wastewater is comprehensively surveyed in this paper. This treatment technology is not intended to replace conventional systems but to supplement for higher‐quality effluent. The assessment places emphasis on the process fundamentals, advantages, and disadvantages of the technology. It also focuses on the current limitations and future research needs. Copyright © 2007 Society of Chemical Industry
Kinetics of reactions between chlorine or bromine and the herbicides diuron and isoproturon
Authors: Acero Juan L , Real Francisco J , Benitez F Javier , Gonzalez Manuel 
Published: January 2007

AbstractThe chemical oxidation of two herbicide derivatives of the phenylurea group—diuron and isoproturon—has been carried out by means of chlorine, in the absence and in the presence of bromide ion. Apparent second‐order rate constants for the reactions between chlorine and the herbicides were determined to be below 0.45 L mol−1 s−1. Hypobromous acid reacts faster with the investigated herbicides, especially with isoproturon (kapp = 24.8 L mol−1 s−1 at pH 7). While pH exerts a negative effect on the bromination rate, the maximum chlorination rate was found to be at circumneutral pH. In a second stage, the oxidation of each compound was conducted in different natural waters, in order to simulate the processes which take place in water purification plants. Again, chlorine was used as an oxidant, and bromide ion was added in some experiments with the aim of producing the more reactive HOBr oxidant. The herbicide oxidation rate was inversely proportional to the organic matter content of the natural water. However, the formation of trihalomethanes (THMs) was directly proportional to the organic matter content and constitutes a limitation for the application of chlorine during drinking water treatment. Finally, the evolution of herbicide concentration was modeled and predicted by applying a kinetics approach based on the rate constants for the reactions between the herbicides and the active oxidants. Copyright © 2007 Society of Chemical Industry
Anticipating rotavirus vaccines in Brazil: Detection and molecular characterization of emerging rotavirus serotypes G8 and G9 among children with diarrhoea in Recife, Brazil
Authors: Montenegro Fernanda M.U. , Correia Jailson B. , Rodrigues Falbo Ana , Dove Winifred , Nakagomi Toyoko , Nakagomi Osamu , Cuevas Luis E. , Cunliffe Nigel A. , Hart C. Anthony 
Published: January 2007

AbstractIn 2006, Brazil will initiate universal immunization of its 4‐million infants with a live attenuated serotype G1P[8] human rotavirus vaccine. In anticipation of the national immunization program, this study was undertaken to characterize rotavirus strains circulating among children in Recife, one of the largest cities in the northeast region of Brazil. Group A rotaviruses were detected in 102 (35%) of 290 faecal specimens collected from children under 5 years of age who presented with acute diarrhoea during a 1‐year period between May 2004 and April 2005. In addition to the globally common G1P[8] serotype that accounted for 49% of strains, emerging rotavirus serotypes G8P[6] and G9P[8] represented 2% and 29% of strains, respectively. Following cell culture adaptation, RNA‐RNA hybridization demonstrated that two Brazilian G8P[6] rotavirus strains shared a high level of genomic RNA homology with Malawian G8P[6] strains, and a Brazilian G9P[8] strain was related most closely to a G9P[8] strain from India. The results suggest that certain rotavirus strains have a much wider global circulation than generally appreciated. Continued global spread of such strains might challenge the efficacy of current rotavirus vaccines. J. Med. Virol. 79:335–340, 2007. © 2007 Wiley‐Liss, Inc.
The Brazilian experience with biofuels
Authors: Segall Sergio D. , Artz William E. 
Published: January 2007

AbstractBrazil leads the world in ethanol production and ethanol use for fuel and the government has decided recently to implement a programme to blend biodiesel with diesel. In 2004, the government created the National Program for Production and Use of Biodiesel to reduce Brazil's dependence on imported diesel and to supply a fuel that has low environmental impact. The Program allows the use of 17 other oil sources for biodiesel production. This article describes the background to biodiesel and bioethanol production and use, details the Brazilian alcohol and biodiesel programmes, and examines the prospects for these biofuels and their potential effects on agriculture and oilseed crops.
Physically and Chemically Cross‐Linked Poly{[(maleic anhydride)‐alt‐styrene]‐co‐(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid)}/Poly(ethylene glycol) Proton‐Exchange Membranes
Authors: Devrim Yılser G. , Rzaev Zakir , Pişkin Erhan 
Published: January 2007

AbstractNovel proton exchange membranes were solvent‐cast from DMF solutions of the terpolymers poly[(MA‐alt‐S)‐co‐AMPS], containing hydrophobic phenyl and reactive hydrophilic carboxylic and organo‐sulfonic acid fragments with different compositions, and PEGs with different molecular weights and amounts. These membranes were formed as a result of physical (via H‐bonding) and chemical (via PEG) cross‐linking. The structures of membranes were confirmed by FT‐IR and 1H‐ and 13C NMR spectroscopy. Mechanical and thermal properties, swellability, and proton conductivity of these membranes were significantly affected both by the chemical composition of the terpolymers (mainly the AMPS content) and also the cross‐linker (PEG) molecular weight and content in the final form of the membranes. It was concluded that the membranes prepared by using the terpolymer with an AMPS content of 36.84 mol‐% and PEG with a molecular weight of 1 450 and with an initial PEG content of 30 wt.‐% are the most suitable ones for fuel cell applications.magnified image
Fluorescence studies on the interaction between pyrene‐labelled poly(acrylic acid) and cyclodextrins
Authors: de Melo J Sérgio Seixas , Costa Telma , Oliveira Noémia , Schillén Karin 
Published: January 2007

AbstractThe interactions, in aqueous media, between a pyrene‐labelled polyelectrolyte poly(acrylic acid) (PAAMePy) with two different degrees of labelling and β‐ and γ‐cyclodextrins (β‐ and γ‐CD) were studied using absorption and fluorescence (steady‐state and time‐resolved) techniques. In addition to qualitative and quantitative parameters obtained from absorption and steady‐state fluorescence spectra, time‐resolved fluorescence data are presented, allowing additional important observations regarding the nature of the interactions. From the overall data it was possible to conclude that in the case of interaction with γ‐CD the efficient encapsulation of two pyrene units into the cavity of the cyclodextrin molecule leads to a decrease in the number of available free monomers and an increase in the number of preformed ground‐state dimers (GSDs) of pyrene. It was also shown that contrary to the situation in water, where only intramolecular interactions are present, the addition of γ‐CD leads to new interpolymeric interactions. The absence of significant changes is noted when the interactions of PAAMePy polymers take place with β‐CD. The excimer‐to‐monomer fluorescence intensity ratio (IE/IM) was found to increase with the added amount of γ‐CD but not with β‐CD. This increase is justified on the basis of the increase of the GSD contribution. The photophysical behaviour was found to be dependent on the pH of the media, but with the absence of relevant interactions between CD and PAAMePy polymer at alkaline values. Copyright © 2007 Society of Chemical Industry
Duration and distance of exposure are important predictors of transmission among community contacts of Ontario SARS cases
Authors: REA E. , LAFLÈCHE J. , STALKER S. , GUARDA B. K. , SHAPIRO H. , JOHNSON I. , BONDY S. J. , UPSHUR R. , RUSSELL M. L. , ELIASZIW M. 
Published: January 2007

SUMMARYWe report attack rates and contact-related predictors among community contacts of severe acute respiratory syndrome (SARS) cases from the 2003 Toronto-area outbreak. Community contact data was extracted from public health records for single, well-defined exposures to a SARS case. In total, 8662 community-acquired exposures resulted in 61 probable cases; a crude attack rate of 0·70% [95% confidence interval (CI) 0·54–0·90]. Persons aged 55–69 years were at higher risk of acquiring SARS (1·14%) than those either younger (0·60%) or older (0·70%). In multivariable analysis exposures for at least 30 min at a distance of ⩽1 m increased the likelihood of becoming a SARS case 20·4-fold (95% CI 11·8–35·1). Risk related to duration of illness in the source case at time of exposure was greatest for illness duration of 7–10 days (rate ratio 3·4, 95% CI 1·9–6·1). Longer and closer proximity exposures incurred the highest rate of disease. Separate measures of time and distance from source cases should be added to minimum datasets for the assessment of interventions for SARS and other emerging diseases.
Osteotome Technique for Removal of Symptomatic Ear Canal Exostoses
Authors: Hetzler Douglas G. 
Published: January 2007

AbstractObjectives/Hypothesis: This study was undertaken to assess a transcanal osteotome technique for removing symptomatic ear canal exostoses. Outcome measures included healing rates and the rate of complications.Study Design: Prospective study in a private practice.Methods: A straight 1‐mm osteotome and a curved 1‐mm osteotome were used by way of a transcanal approach to incrementally remove obstructive ear canal exostoses. If anterior or superior bone growths were closely approximating the tympanic membrane, they were partially removed with a 1.5 mm cylindrical end‐ and side‐cutting burr. Healing rates were monitored with weekly postoperative visits.Results: Two hundred twenty‐one ear canals (140 patients) were consecutively treated with this technique. Healing was achieved at 2 to 8 (average 3.50) weeks, with 90% healed by 4 weeks. There were 4 mobilizations of a full‐thickness segment of anterior bony canal wall; 3 exposures of periosteum anterior to the anterior bony wall; 1 tear of the tympanic membrane requiring a tympanoplasty; 18 anterior and 11 posterior tympanic membrane tears that healed spontaneously; 3 instances of sensorineural hearing decrease; 3 cases of new‐onset postoperative tinnitus; and 1 instance of postoperative positioning vertigo. There were no lacerations of the tympanic membrane by an osteotome, no facial nerve injuries, no soft tissue stenoses of an ear canal, and no skin grafting of an ear canal.Conclusions: The described technique of using osteotomes transcanal for removal of symptomatic obstructive ear canal exostoses promoted rapid healing and was effective and safe.
Identifying children with neurological impairment and disability in resource‐poor countries
Authors: Mung’ala‐Odera V. , Newton C. R. J. C. 
Published: January 2007

AbstractBackground  The burden of neurological impairment (NI) in children living in resource‐poor countries (RPCs) is unknown. This lack of data is caused by inappropriate case detection techniques. In RPCs, the most appropriate method should be inexpensive, simple, rapid and accurate. This article reviews methods used to identify children with NI and disability in RPCs, evaluating their effectiveness and suitability.Methods  A search of relevant articles was performed using the National Library of Medicine via PubMed and Medline search engines. In addition, bibliographies of reviews were also browsed to identify additional articles, particularly those from World Health Organization and United Nations sources and from government and unpublished reports. Key phrases used included impairment, disability or handicap and the following terms: identification, screening, prevalence and developing countries. Studies included were those that fulfilled the following criteria; performed in RPCs, presented data in detail to allow reanalysis and provided data on cost and validity of the methods.Results  Use of the national census, key informants and methods using rapid rural appraisal have low sensitivity and are not able to provide adequate information on diagnostic categories or risk factors. House‐to‐house surveys using questionnaires have high sensitivities (63–100%) in the detection of impairment, but this approach remains relatively expensive and cannot be applied to an entire population (e.g. a region or country) and is thus less useful for assessing the needs of disability. Furthermore, the sensitivity is decreased in the detection of some domains, e.g. cognition.Conclusions  Most of the approaches used for identifying individuals with NI or disability suffer from inadequacies, the main ones being low sensitivity and underreporting. To assess the burden, nationwide censuses combined with surveys in selected areas of the country may be useful. These systems, however, require validation to establish their suitability.