bluuebunny/crossref_metadata_2025_split huggingface dataset:
Shell curvature as an initial deformation: A geometrically exact finite element approach
Authors: Pimenta P. M. , Campello E. M. B. 
Published: January 2009

AbstractAn alternative approach for the analysis of arbitrarily curved shells is developed in this paper based on the idea of initial deformations. By ‘alternative’ we mean that neither differential geometry nor the concept of degeneration is invoked here to describe the shell surface. We begin with a flat reference configuration for the shell mid‐surface, after which the initial (curved) geometry is mapped as a stress‐free deformation from the plane position. The actual motion of the shell takes place only after this initial mapping. In contrast to classical works in the literature, this strategy enables the use of only orthogonal frames within the theory and therefore objects such as Christoffel symbols, the second fundamental form or three‐dimensional degenerated solids do not enter the formulation. Furthermore, the issue of physical components of tensors does not appear. Another important aspect (but not exclusive of our scheme) is the possibility to describe exactly the initial geometry. The model is kinematically exact, encompasses finite strains in a totally consistent manner and is here discretized under the light of the finite element method (although implementation via mesh‐free techniques is also possible). Assessment is made by means of several numerical simulations. Copyright © 2009 John Wiley & Sons, Ltd.
Energy conservation of atomistic/continuum coupling
Authors: Aubertin Pascal , Réthoré Julien , de Borst René 
Published: January 2009

AbstractThe efficient and accurate coupling of two dissimilar domains presents a major challenge, especially when wave propagation is considered. Overlap coupling methods are promising in the sense that spurious wave reflections can be avoided and loss of energy due to the coupling scheme can be minimized. However, the conservation properties and the proper physical representation of the forces depend on the precise formulation of the algorithm for coupling such dissimilar models. This is unlike that of coupling similar domains. We will demonstrate this with the help of numerical studies in continuum‐to‐continuum coupling and continuum‐to‐discrete coupling. Copyright © 2009 John Wiley & Sons, Ltd.
Identification of random shapes from images through polynomial chaos expansion of random level set functions
Authors: Stefanou G. , Nouy A. , Clement A. 
Published: January 2009

AbstractIn this paper, an efficient method is proposed for the identification of random shapes in a form suitable for numerical simulation within the extended stochastic finite element method (X‐SFEM). The method starts from a collection of images representing different outcomes of the random shape to identify. The key point of the method is to represent the random geometry in an implicit manner using the level set technique. In this context, the problem of random geometry identification is equivalent to the identification of a random level set function, which is a random field. This random field is represented on a polynomial chaos (PC) basis and various efficient numerical strategies are proposed in order to identify the coefficients of its PC decomposition. The performance of these strategies is evaluated through some ‘manufactured’ problems and useful conclusions are provided. The propagation of geometrical uncertainties in structural analysis using the X‐SFEM is finally examined. Copyright © 2009 John Wiley & Sons, Ltd.
Rapid capillary electrophoresis analysis of glutathione and glutathione disulfide in roots and shoots of plants exposed to copper
Authors: Mendoza Jorge , Garrido Tatiana , Riveros Raúl , Parada José 
Published: January 2009

AbstractIntroductionGlutathione and glutathione disulfide can be determined by capillary zone electrophoresis; however, the frequent use of acidic precipitation of protein from samples prior to analysis generates an acidic matrix of strength and pH that may cause changes in the method sensitivity, comigration of species or changes in the equilibria that relate both species in cells or fluids.ObjectiveTo optimise electrophoretic conditions for glutathione and glutathione disulfide determination, and to improve pre‐analytical treatment for better visualization of the signals of both peptides in an acidic matrix.MethodologyThe method consisted of direct photometric detection at 185 nm and 300 mm borate at pH 7.6 as background electrolyte. The variables under study were voltage applied, injection time, capillary length and electrolyte pH. Seedlings were hydroponically grown and the peptides were extracted with metaphosphoric acid.ResultsThe resulting acidic matrix was previously treated with the same background electrolyte to prevent comigration and to improve signal resolution. The optimised method showed good reproducibility and linearity, with correlation coefficients above 0.999 and detection limits below 3 µm, and determination of both analytes in less than 3 min. Analyte recovery in the process was in the 88–104% range. The concentration range found in hydroponically grown tomato plants, irrespective of copper level, was 45–100 nmol/g fresh weight for glutathione and below 56 nmol/g fresh weight for glutathione disulfide.ConclusionThe results obtained here support the applicability of the method to the fast and simultaneous determination of glutathione and glutathione disulfide in tissue of shoots and roots of plants grown under either normal or stressful conditions. Copyright © 2009 John Wiley & Sons, Ltd.
Phytochemistry of cimicifugic acids and associated bases in Cimicifuga racemosa root extracts
Authors: Gödecke Tanja , Nikolic Dejan , Lankin David C. , Chen Shao‐Nong , Powell Sharla L. , Dietz Birgit , Bolton Judy L. , van Breemen Richard B. , Farnsworth Norman R. , Pauli Guido F. 
Published: January 2009

AbstractIntroductionEarlier studies reported serotonergic activity for cimicifugic acids (CA) isolated from Cimicifuga racemosa. The discovery of strongly basic alkaloids, cimipronidines, from the active extract partition and evaluation of previously employed work‐up procedures has led to the hypothesis of strong acid/base association in the extract.ObjectiveRe‐isolation of the CAs was desired to permit further detailed studies. Based on the acid/base association hypothesis, a new separation scheme of the active partition was required, which separates acids from associated bases.MethodologyA new 5‐HT7 bioassay guided work‐up procedure was developed that concentrates activity into one partition. The latter was subjected to a new two‐step centrifugal partitioning chromatography (CPC) method, which applies pH zone refinement gradient (pHZR CPC) to dissociate the acid/base complexes. The resulting CA fraction was subjected to a second CPC step. Fractions and compounds were monitored by 1H NMR using a structure‐based spin‐pattern analysis facilitating dereplication of the known acids. Bioassay results were obtained for the pHZR CPC fractions and for purified CAs.ResultsA new CA was characterised. While none of the pure CAs was active, the serotonergic activity was concentrated in a single pHZR CPC fraction, which was subsequently shown to contain low levels of the potent 5‐HT7 ligand, Nω‐methylserotonin.ConclusionThis study shows that CAs are not responsible for serotonergic activity in black cohosh. New phytochemical methodology (pHZR CPC) and a sensitive dereplication method (LC‐MS) led to the identification of Nω‐methylserotonin as serotonergic active principle. Copyright © 2009 John Wiley & Sons, Ltd.
Ultra‐performance liquid chromatography/time‐of‐flight mass spectrometry as a chemotaxonomic tool for the analysis of Gentianaceae species
Authors: Urbain Aurélie , Marston Andrew , Marsden‐Edwards Emma , Hostettmann Kurt 
Published: January 2009

AbstractIntroductionThe segregation between the genera Gentiana and Gentianella among the Gentianaceae family is poorly defined. In order to clarify the classification of these genera, some researchers have tried to incorporate data about the chemical constitution, but this has not yet been achieved in a comprehensive way.ObjectiveTo develop a fast and reproducible analytical method for the observation of characteristic fingerprints of secondary metabolites of each genus.MethodologySeven species were investigated, three Gentianella and four Gentiana selected for their close taxonomic links within each genus. Ten xanthones previously isolated from one of these species were used as chemotaxonomic markers. A UPLC/ESI‐TOF‐MS method was developed to analyse the methanolic extracts.Results The UPLC/TOF‐MS provided clear metabolic fingerprints and elemental composition of the compounds. The profiles of the three Gentianella species were strikingly similar. On the contrary, metabolic profiles of Gentiana species were very different from the Gentianella chromatograms and also from each other. Several compounds were unique to each genus and therefore could be used as biomarkers.Conclusion UPLC/TOF‐MS can be applied as a chemotaxonomic tool for the rapid screening of Gentianaceae species and for the distinction between closely related taxa from the Gentianaceae family. Copyright © 2009 John Wiley & Sons, Ltd.
An optimised, small‐scale preparation of high‐quality RNA from dry seeds of Davidia involucrata
Authors: Qi G. , Li J. T. , Ruan Q. P. , Yang J. , Su Z. X. 
Published: January 2009

AbstractIntroduction The dormancy of Davidia involucrata seeds normally lasts for an extended period of time and because of this unique property the species is an excellent model for studying the molecular mechanisms of plant dormancy. The use of minimal plant material is desirable for RNA extraction since D. involucrata is a rare plant and it is relatively difficult to collect large amounts of seeds in order to perform molecular biology studies.Objective To improve the quality of RNA obtained from seeds of D. involucrata by eliminating the oxidation of polyphenols during extraction and by preventing polysaccharides and other impurities from being extracted.MethodsA previously described method was modified by the addition of 4% (w/v) poly(N‐vinyl‐2‐pyrrolidone) to the dry seeds during grinding and by adding 5% (v/v) β‐mercaptoethanol and 28% (v/v) ethanol to the extraction buffer. Two further centrifugation steps (5000 and 8000 rpm) were utilised and one‐seventh volume of ethanol was incubated with the supernatant at 4°C for 2–3 h prior to the precipitation of RNA.ResultsFollowing these modifications, an effective method was established for total RNA extraction from a small amount of dry seeds of D. involucrata. The isolated RNA was shown to have high purity and integrity by gel electrophoresis and spectrophotometry, and was confirmed to be suitable for RT‐PCR and the construction of cDNA libraries.ConclusionThe modified method reduced the amount of seeds required for extraction of total DNA and was beneficial for preserving the endangered species. Copyright © 2008 John Wiley & Sons, Ltd.
Isolation and purification of acid‐labile carotenoid 5,6‐epoxides on modified silica gels
Authors: Nagy Veronika , Agócs Attila , Turcsi Erika , Deli József 
Published: January 2009

AbstractIntroductionThe acid‐labile carotenoid 5,6‐epoxides occur in all green plants and in most fruits, but their isolation or purifica‐tion is complicated and expensive because they decompose on normal silica gels. Alkaline stationary phases in open column chromatography (OCC) have low capacities, which makes them unsuitable for preparative scale.ObjectiveTo find a simple high‐capacity stationary phase for OCC that does not induce transformations of acid‐labile compounds.MethodologyCommercially available silica gel was treated with aqueous sodium bicarbonate solution to neutralise its slightly acidic character, and was then washed and dried. The effect of the treated gel (named silica‐9) on violaxanthin was studied. The modified gel was also applied to the OCC of different complex natural extracts (maple leaves and fruits of yellow paprika). Carotenoids were examined by HPLC‐PAD both before and after chromatography on the modified gel.ResultsViolaxanthin decomposed rapidly on normal silica gels but not on the modified gel. Chromatography of plant extracts showed that the modified gel had a similar capacity to the untreated gel but did not effect epoxy‐carotenoids, which could be separated or enriched readily on a large scale.ConclusionThe modified gel does not induce any transformation or decomposition of epoxy‐carotenoids but still exhibits a high capacity, suggesting that it can be used in preparative organic chemistry as an additional and convenient tool in the OCC for the separation of other acid‐labile compounds. Copyright © 2009 John Wiley & Sons, Ltd.
Gas chromatographic analysis of dimethyltryptamine and β‐carboline alkaloids in ayahuasca, an amazonian psychoactive plant beverage
Authors: Pires Ana Paula Salum , De Oliveira Carolina Dizioli Rodrigues , Moura Sidnei , Dörr Felipe Augusto , Silva Wagner Abreu E. , Yonamine Mauricio 
Published: January 2009

AbstractIntroductionAyahuasca is obtained by infusing the pounded stems of Banisteriopsis caapi in combination with the leaves of Psychotria viridis. P. viridis is rich in the psychedelic indole N,N‐dimethyltryptamine, whereas B. caapi contains substantial amounts of β‐carboline alkaloids, mainly harmine, harmaline and tetrahydroharmine, which are monoamine‐oxidase inhibitors. Because of differences in composition in ayahuasca preparations, a method to measure their main active constituents is needed.ObjectiveTo develop a gas chromatographic method for the simultaneous determination of dimethyltryptamine and the main β‐carbolines found in ayahuasca preparations.MethodologyThe alkaloids were extracted by means of solid phase extraction (C18) and detected by gas chromatography with nitrogen/phosphorous detector.ResultsThe lower limit of quantification (LLOQ) was 0.02 mg/mL for all analytes. The calibration curves were linear over a concentration range of 0.02–4.0 mg/mL (r2 > 0.99). The method was also precise (RSD < 10%).ConclusionA simple gas chromatographic method to determine the main alkaloids found in ayahuasca was developed and validated. The method can be useful to estimate administered doses in animals and humans for further pharmacological and toxicological investigations of ayahuasca. Copyright © 2009 John Wiley & Sons, Ltd.
Social adjustment among Chinese women following breast cancer surgery
Authors: Lam Wendy WT , Chan Miranda , Hung Wai Ka , Or Amy , Fielding Richard 
Published: January 2009

AbstractBackground: How breast cancer surgery affects social adjustment among Chinese women is unknown, as are factors predicting such adjustment.Methods: 405 Chinese women receiving surgery for localized breast cancer completed Social Adjustment Scales (Ch‐SAS) at 1‐, 4‐ and 8‐months post‐operatively. Subscale scores were regressed on baseline (days 3–12 post‐operatively) measures of treatment decision‐making difficulty (TDMD), self‐efficacy (GSeS), consultation satisfaction (C‐MISS‐R), psychological (CHQ‐12) and physical distress (PD), and 1‐month follow‐up optimism (C‐LOT‐R), and disappointment (E‐OI), fully adjusted for demographic and clinical factors.Results: All Ch‐SAS subscales except appearance & sexuality changed significantly over 8‐months follow‐up: Enjoyment of social activities (F=27.38, df 2, p<0.001) and self‐image (F=3.63, df 2, p=0.027) improved slightly. Family interaction (F=26.63, df 2, p<0.001) and interaction with friends (F=3.37, df 2, p=0.035) declined slightly. Family and friends interaction subscales were predominantly predicted by high self‐efficacy and optimism, whereas self‐image and appearance & sexuality subscales were predominantly predicted by low treatment outcome disappointment, TDM difficulties, baseline psychological morbidity and high self‐efficacy. Enjoyment of social activities was predicted by low baseline psychological distress and concurrent physical symptom distress.Conclusion: High self‐efficacy and optimism predicted women who have better social relationships with friends and family. Higher self‐efficacy, low TDM difficulties, less disappointment with treatment outcome and low psychological and physical distress predicted better adjustment to self‐image and body image. Copyright © 2009 John Wiley & Sons, Ltd.
Distress in couples approached for genetic counseling and BRCA1/2 testing during adjuvant radiotherapy
Authors: Schlich‐Bakker Kathryn J. , ten Kroode Herman F. J. , Wárlám Rodenhuis Carla C. , Ausems Margreet G. E. M. , van den Bout Jan 
Published: January 2009

AbstractObjective: Breast cancer patients mostly rely on their partners for support in dealing with their cancer diagnosis and treatment. Genetic counseling and BRCA1/2 testing during primary treatment may add to demands made on their partners. This study aimed to gain insight into the extent of psychological distress in partners of recently diagnosed patients and to find factors to help identify couples vulnerable to high psychological distress after an active approach for genetic counseling.Methods: Breast cancer patients and their partners (n=110) completed psychological distress measures (HADS and IES) prior to the approach for counseling (T0), after the approach (T1), and after leaving the genetic counseling protocol (T2). Couples not approached for counseling (n=85) completed similar questionnaires.Results: Partners reported an equal or lower level of distress than patients, with a positive correlation between the two, although partners and patients differed in the course of their distress. Couples approached for genetic counseling did not differ in the level or course of either distress measure from not approached couples. A high baseline distress best predicts long‐term high distress in patients and their partners. Younger patients were found to be particularly vulnerable.Conclusions: The approach for genetic counseling during adjuvant radiotherapy was not associated with extra psychological distress in partners or patients in the first year following the breast cancer diagnosis. A partner's long‐term level of distress was significantly associated with that of the patient. Highly distressed patients with highly distressed partners were most likely to experience high distress in the long term. Copyright © 2009 John Wiley & Sons, Ltd.
Intrusive cognitions and their appraisal in anxious cancer patients
Authors: Whitaker Katriina L. , Watson Maggie , Brewin Chris R. 
Published: January 2009

AbstractObjective: Previous research found that anxious cancer patients experience uncontrollable negative intrusive cognitions that have an impact on coping and are associated with significant psychological distress. This is the first study to examine the appraisal of intrusive cognitions in an anxious group of cancer patients.Methods: A sample of 139 anxious cancer patients was assessed for evidence of intrusive phenomena, including memories, images and thoughts. Patients completed the Response to Intrusions Questionnaire and the Impact of Event Scale in relation to intrusive cognitions.Results: Forty‐eight percent (67/139) reported frequent, uncontrollable intrusive cognitions. Intrusive thoughts and images were equally as common and images were associated with increased distress and uncontrollability. A significant positive linear relationship was found between the number of intrusions and anxiety severity (P<0.05). Negative appraisal of intrusive cognitions was associated with anxiety (P<0.01) and depression severity (P<0.01), intrusion‐specific distress (P<0.01), rumination (P<0.01) and cognitive avoidance (P<0.01), after controlling for intrusion frequency.Conclusion: Negative appraisal of intrusive cognitions plays a significant role in psychological distress and intrusion‐specific distress in anxious cancer patients. Finding similarities in the types of intrusive cognitions reported by cancer patients and other anxious populations highlights the potential applicability of psychological therapies developed to reduce the frequency and impact of intrusive cognitions. Copyright © 2009 John Wiley & Sons, Ltd.
Ammonia solutions explosivity
Authors: Dupont Laurent 
Published: January 2009

AbstractExplosion risks resulting from the industrial handling of aqueous ammonia solutions are often not taken into account in risk assessments, especially for dilute solutions, although accidental explosions implying ammonia vapors are reported in the literature. In fact, ammonia solutions do not show any flash point, but are able to form an explosive atmosphere. In this study, explosivity characteristics of several ammonia solutions, more or less diluted, were determined in a 20‐L sphere device.It appears that the explosion range of ammonia solutions depends on the temperature and on the ammonia concentration. The explosion severity is smaller than for pure ammonia because of the presence of water and it tends to decrease slightly with dilution. However, the maximal explosion pressure is still above 3 bar with the 10% solution. Hence, such aqueous solutions, even diluted, handled in enclosed spaces can generate great disasters. © 2009 American Institute of Chemical Engineers Process Saf Prog, 2009
Contraceptive method switch and discontinuation among women migrants in indonesia
Authors: Liew Hui‐Peng 
Published: January 2009

AbstractUsing the 2000 wave of the Indonesian Family Life Survey (IFLS3), this study attempts to examine the relationship between migration and contraceptive method switch and discontinuation in Indonesia. The major conclusion from the multinomial logistic regression is that repeated migrants are more likely than one‐time migrants to discontinue use of the same method. However, the differentials in the likelihood of discontinuing use of the same method among women migrants is eliminated after controlling for the quality of health centre/family planning programme and the degree of infrastructure development in a community. The results of this study will contribute important foundational knowledge about the extent of contraceptive use dynamics by women of different migration experiences in Indonesia. This knowledge will provide guidance to policymakers to employ effective means to incorporate migration and issues that are sensitive to women migrants in their family planning and reproductive health programmes. Copyright © 2009 John Wiley & Sons, Ltd.
The use of neem for controlling gastric hyperacidity and ulcer
Authors: Maity Pallab , Biswas Kaushik , Chattopadhyay Ishita , Banerjee Ranajit K. , Bandyopadhyay Uday 
Published: January 2009

AbstractH2‐receptor blockers and proton pump inhibitors are now used extensively to control gastric and duodenal ulcer, inflammation and pain, but these drugs have limitations and are not always affordable. The development of novel nontoxic antiulcer drugs, including from medicinal plants, is therefore desirable, and Azadirachta indica A. Juss, commonly known as Neem, is known to have potent gastroprotective and antiulcer effects. This review deals with the pharmacological and biochemical studies carried out regarding the antiulcer activities of Neem extracts and their mechanism of action, including the inhibition of acid secretion. A comparison with ranitidine and omeprazole in some animal models has been included and clinical studies, where available, have also been incorporated, along with a safety evaluation. Neem bark extract has the potential for the development of novel medicines for the therapeutic control of gastric hyperacidity and ulcer. Copyright © 2009 John Wiley & Sons, Ltd.