bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel applications of highly sensitive liquid chromatography/mass spectrometry/mass spectrometry for the direct detection of ultra‐trace levels of contaminants in water
Authors: Seitz Wolfram , Schulz Wolfgang , Weber Walter H. 
Published: June 2006

AbstractRecent advances in the sensitivity of liquid chromatography/mass spectrometry (LC/MS) instrument technology provide the basis for the direct detection, i.e. without sample pre‐concentration, of organic contaminants in water in the ng/L range. Novel applications for the analysis of atrazine and some of its desalkylated and hydroxylated degradation products, the pharmaceutical compounds diclofenac and carbamazepine, sulfonylurea herbicides, and iodinated X‐ray contrast media have been developed. For each analyte a specific tandem mass spectrometric (MS/MS) transition has been selected and the corresponding mass spectrometric parameters optimised. All analytes could be analysed within three specific analytical runs including different high‐performance liquid chromatography (HPLC) conditions. Detection limits were determined to be better than 10 ng/L for the direct analysis of the compounds in water except for X‐ray contrast media, for which detection limits were found to be up to one order of magnitude higher. The methods have been successfully utilised for the analysis of natural waters. Matrix effects frequently occurring in LC/MS have shown to be low to moderate in the case of X‐ray contrast media. This work demonstrates that for the analysis of a large number of water contaminants, the sample pre‐concentration step could possibly be omitted. Copyright © 2006 John Wiley & Sons, Ltd.
Quantification of tizanidine in human plasma by liquid chromatography coupled to tandem mass spectrometry
Authors: Nirogi Ramakrishna V. S. , Kandikere Vishwottam N. , Shukla Manoj , Mudigonda Koteshwara , Maurya Santosh 
Published: June 2006

AbstractA simple, sensitive and rapid high‐performance liquid chromatography/positive ion electrospray tandem mass spectrometry (MS/MS) method was developed and validated for the assay of tizanidine in human plasma. Following liquid‐liquid extraction, the analytes were separated using an isocratic mobile phase on a reversed‐phase column and analyzed by MS/MS in the selected reaction monitoring mode. The assay exhibited a linear dynamic range of 50–5000 pg/mL for tizanidine in human plasma. The lower limit of quantification was 50 pg/mL with a relative standard deviation of less than 13%. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. A run time of 2.5 min for each sample made it possible to analyze more than 300 human plasma samples per day. The validated method has been successfully used to analyze human plasma samples for application in pharmacokinetic, bioavailability or bioequivalence studies. Copyright © 2006 John Wiley & Sons, Ltd.
A multivariate test for population bioequivalence
Authors: Chervoneva Inna , Hyslop Terry , Hauck Walter W. 
Published: June 2006

AbstractIn this article, we propose a multivariate generalization of the criteria for testing univariate population bioequivalence. Recently, a number of approaches for testing multivariate equivalence have appeared in the literature. Most of them consider a multivariate equivalence region, which implies simultaneous comparison of means in each dimension. In contrast, our proposal combines a comparison of means and a comparison of variances into a single aggregate criterion, using the trace of the covariance matrix as a scalar measure of the total variability. We use a confidence interval approach to multivariate population bioequivalence testing, similar to the univariate case. Two versions of the modified large‐sample confidence interval for the linearized multivariate criterion are constructed. In a simulation study, we evaluate the empirical coverage of these confidence intervals and rejection rates of the corresponding tests in finite samples. The proposed methodology is illustrated with an example of testing equivalence of the spray pattern of nasal sprays. Copyright © 2006 John Wiley & Sons, Ltd.
Functional regression analysis using anFtest for longitudinal data with large numbers of repeated measures
Authors: Yang Xiaowei , Shen Qing , Xu Hongquan , Shoptaw Steven 
Published: June 2006

AbstractLongitudinal data sets from certain fields of biomedical research often consist of several variables repeatedly measured on each subject yielding a large number of observations. This characteristic complicates the use of traditional longitudinal modelling strategies, which were primarily developed for studies with a relatively small number of repeated measures per subject. An innovative way to model such ‘wide’ data is to apply functional regression analysis, an emerging statistical approach in which observations of the same subject are viewed as a sample from a functional space. Shen and Faraway introduced anFtest for linear models with functional responses. This paper illustrates how to apply thisFtest and functional regression analysis to the setting of longitudinal data. A smoking cessation study for methadone‐maintained tobacco smokers is analysed for demonstration. In estimating the treatment effects, the functional regression analysis provides meaningful clinical interpretations, and the functionalFtest provides consistent results supported by a mixed‐effects linear regression model. A simulation study is also conducted under the condition of the smoking data to investigate the statistical power for theFtest, Wilks' likelihood ratio test, and the linear mixed‐effects model using AIC. Copyright © 2006 John Wiley & Sons, Ltd.
Improving point predictions of random effects for subjects at high risk
Authors: Lyles Robert H. , Manatunga Amita K. , Moore Reneé H. , DuBois Bowman F. , Cook Curtiss B. 
Published: June 2006

AbstractThe prediction of random effects corresponding to subject‐specific characteristics (e.g. means or rates of change) can be very useful in medical and epidemiologic research. At times, one may be most interested in obtaining accurate and/or precise predictions for subjects whose characteristic places them in a tail of the distribution. While the typical posterior mean predictor dominates others in terms of overall mean squared error of prediction (MSEP), its tendency to ‘overshrink’ has motivated research into alternatives emphasizing other criteria. Here, we specifically target MSEP within a certain region (e.g. above a known cut‐off for high risk or a specified percentile of the random effect distribution), and we consider minimizing this quantity with and without constraints on overall MSEP efficiency. We use the normal‐theory random intercept model to derive prediction methods with potential to yield markedly better performance for subjects in the specified region, given a well‐controlled and (if desired) modest concession of overall MSEP. Criteria geared toward classification as well as overall and regional prediction unbiasedness are also provided. We evaluate the proposed techniques and illustrate them using repeated measures data on fasting blood glucose from type 2 diabetes patients. A simulation study verifies that theoretical properties and relative performances of the proposed predictors are essentially maintained when calculating them in practice based on estimated mixed linear model parameters. Straightforward extensions to incorporate covariates and additional random effects are briefly outlined. Copyright © 2006 John Wiley & Sons, Ltd.
A practical approach to computing power for generalized linear models with nominal, count, or ordinal responses
Authors: Lyles Robert H. , Lin Hung‐Mo , Williamson John M. 
Published: June 2006

AbstractData analysts facing study design questions on a regular basis could derive substantial benefit from a straightforward and unified approach to power calculations for generalized linear models. Many current proposals for dealing with binary, ordinal, or count outcomes are conceptually or computationally demanding, limited in terms of accommodating covariates, and/or have not been extensively assessed for accuracy assuming moderate sample sizes. Here, we present a simple method for estimating conditional power that requires only standard software for fitting the desired generalized linear model for a non‐continuous outcome. The model is fit to an appropriate expanded data set using easily calculated weights that represent response probabilities given the assumed values of the parameters. The variance–covariance matrix resulting from this fit is then used in conjunction with an established non‐central chi square approximation to the distribution of the Wald statistic. Alternatively, the model can be re‐fit under the null hypothesis to approximate power based on the likelihood ratio statistic. We provide guidelines for constructing a representative expanded data set to allow close approximation of unconditional power based on the assumed joint distribution of the covariates. Relative to prior proposals, the approach proves particularly flexible for handling one or more continuous covariates without any need for discretizing. We illustrate the method for a variety of outcome types and covariate patterns, using simulations to demonstrate its accuracy for realistic sample sizes. Copyright © 2006 John Wiley & Sons, Ltd.
Klebetechnik für den schnellen und wirtschaftlichen Bau von Verbundbrücken
Authors: Dauner Hans‐Gerhard 
Published: June 2006

AbstractDieser Beitrag behandelt eine neue Technik für den Verbundbrückenbau. Dabei wird die Fahrbahnplatte aus untereinander verklebten Fertigteilen hergestellt. Der Verbund mit den Stahlträgern wird teilweise mittels einer Haftschicht auf Epoxydharzbasis erreicht. Damit ermöglichen auf der Klebetechnik beruhende Verfahren ein schnelles, wirtschaftlich vorteilhaftes und qualitativ hochwertiges Bauen von Verbundbrücken. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bestimmung der Wölbspannungen von doppeltsymmetrischen Kastenquerschnitten mit Diagrammen
Authors: Rubin Helmut 
Published: June 2006

AbstractBei torsionsbeanspruchten Stäben mit Kastenquerschnitten ist es in der Regel ausreichend, die Wölbkrafttorsion nur an den Stellen eines Einzeltorsionsmoments (Auflager‐ oder eingeprägtes Moment) zu untersuchen, und dies auch nur, wenn das Moment nicht an einem frei verwölbbaren Stabende angreift. Außerdem dürfen bei statisch unbestimmten Systemen die Auflagertorsionsmomente vereinfachend unter vollständiger Vernachlässigung der Wölbkrafttorsion bestimmt werden, weil deren Einfluß von der Stelle des Einzeltorsionsmoments aus rasch abklingt und somit die Torsionsdrehwinkel nur unwesentlich beeinflußt. Der vorliegende Beitrag erlaubt die Ermittlung der Wölbnormal‐ und ‐schubspannungen an den genannten Stellen mit Hilfe von Diagrammen oder alternativ mit Hilfe von Formeln, die nur von zwei Querschnittsparametern abhängen; dabei brauchen weder sekundäres Torsionsmoment noch Wölbmoment bestimmt zu werden. Die verwendete Theorie berücksichtigt die sekundären Schubverformungen, was bei geschlossenen Querschnitten stets erforderlich ist. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cell Wall Degrading Enzymes and Proteases Improve Starch Yields of Sorghum and Maize
Authors: Pérez‐Carrillo Esther , Serna‐Saldívar Sergio O. 
Published: June 2006

AbstractThe effects of a commercial cell‐wall‐degrading enzyme (CWDE) complex and/or commercial protease on yield and quality of starch extracted from white regular sorghum (RSOR), white waxy sorghum (WSOR) and yellow maize (YMZ) were determined. A bifactorial experiment with a level of confidence of P<0.05 was performed to study the effect of CWDE and/or protease addition to coarsely ground grains for 4 h after 20 h of regular SO2 steeping of whole kernels. Calcium oxide (CaO) or lactic acid were used to adjust the pH solution to 5.5 prior to grinding. YMZ yielded the highest amount of starch, whereas RSOR gave higher starch yield than WSOR. All enzyme treatments significantly (P<0.05) improved starch yields. Protease alone and CWDE plus protease treatments were the most effective treatments in terms of starch yields. These enzyme treatments allowed the recovery of more than 90% of the starch. The two types of sorghum starches contained higher amounts of residual protein and ash when compared with maize starch. The various enzymes treatments did not affect starch composition or Visco Analyser properties of each type of kernel. As expected, the WSOR starch had lower pasting temperature and retrogradation when compared with the regular starches.
From Starch to Starch Microspheres: Factors Controlling the Microspheres Quality
Authors: Elfstrand Lidia , Eliasson Ann‐Charlotte , Jönsson Monica , Reslow Mats , Wahlgren Marie 
Published: June 2006

AbstractStarch microparticle is a dosage form suitable for encapsulation of protein drugs. The microparticle characteristics can be influential factors for consecutive sustained drug release from the starch matrix and impact its ability to be coated by poly(D,L‐lactide‐co‐glycolide). In this study, six types of starch microparticles were investigated and characterized. Desired qualities of the microspheres such as spherical form of the particles, well‐defined and sharp particle contours were coincident with coarse surface morphology, sharp and distinct peaks in DSC and X‐ray graphs. It was concluded that the quality of the starch microparticles was influenced by molecular properties of the starch material as well as type of buffer, and these factors were related to recrystallization kinetics, amount and quality of ordered/crystalline structure of final starch microspheres and their microscopic appearance.
Chemical and Physical Properties of Kiwifruit (Actinidia deliciosa) Starch
Authors: Stevenson David G. , Johnson Scott R. , Jane Jay‐lin , Inglett George E. 
Published: June 2006

AbstractChemical and physical properties of kiwifruit (Actinidia deliciosa var. ‘Hayward’) starch were studied. Kiwifruit starch granules were compound, irregular or dome‐shaped with diameters predominantly 4–5 µm or 7–9 µm. Kiwifruit starch exhibited B‐type X‐ray diffraction pattern, an apparent amylose content of 43.1% and absolute amylose content of 18.8%. Kiwifruit amylopectins, relative to other starches, had low weight‐average molecular weight (7.4×107), and gyration radius (200 nm). Average amylopectin branch chain‐length was long (DP 28.6). Onset and peak gelatinization temperatures were 68.9°C and 73.0°C, respectively, and gelatinization enthalpy was high (18.5 J/g). Amylose‐lipid thermal transition was observed. Starch retrograded for 7 d at 4°C had a very high peak melting temperature (60.7°C). Peak (250 RVU), final (238 RVU) and setback (94 RVU) viscosity of 8% kiwifruit starch paste was high relative to other starches and pasting temperature (69.7°C) was marginally higher than onset gelatinization temperature. High paste viscosities and low pasting temperature could give kiwifruit starch some advantages over many cereal starches.
Study of Protein Detection and Ultrastructure of Brazilian Rice Starch during Alkaline Extraction
Authors: Cardoso Mateus B. , Samios Dimitrios , Silveira Nádya P. 
Published: June 2006

AbstractAlkaline extraction of Brazilian rice starch was studied. UV/Vis and fluorescence spectroscopy were employed as an innovative way for protein detection during the extraction. Moreover, the results were compared to the traditional biuret colorimetric test. In parallel, the ultrastructure of starch was monitored by small angle X‐ray scattering (SAXS) during every extraction step. A progressive reduction of the granules organization was observed, which was also detected by the loss of birefringence under polarized light. The external integrity of starch granules after complete removal of proteins was maintained, as verified by scanning electron microscopy (SEM). The size of the granules, determined by the Mie scattering method varied between 3 and 8 µm.
Three‐dimensional ultrasound assessment of the cervix for predicting time to spontaneous onset of labor and time to delivery in prolonged pregnancy
Authors: Rovas L. , Sladkevicius P. , Strobel E. , De Smet F. , De Moor B. , Valentin L. 
Published: June 2006

AbstractObjectivesTo determine whether three‐dimensional (3D) ultrasound including power Doppler examination of the cervix is useful for predicting time to spontaneous onset of labor or time to delivery in prolonged pregnancy.MethodsA prospective study was conducted in 60 women who went into spontaneous labor. All underwent transvaginal 3D power Doppler ultrasound examination of the cervix immediately before a prolonged‐pregnancy check‐up at ≥ 41 + 5 gestational weeks. Univariate and multivariate logistic regression analysis was used to determine which of the following variables predicted spontaneous onset of labor > 24 h and > 48 h and vaginal delivery > 48 h and > 60 h: length, anteroposterior (AP) diameter and width of the cervix and of any cervical funneling; cervical volume (cm3); vascularization index (VI); flow index (FI); vascularization flow index (VFI); parity; and Bishop score. Multivariate logistic regression analysis was carried out both with and without Bishop score as a predictive variable. Receiver–operating characteristics (ROC) curves were used to describe the diagnostic performance of the tests.ResultsThe areas under the ROC curves for Bishop score, cervical length, and logistic regression models did not differ significantly (areas ranging from 0.72 to 0.82). If Bishop score was not included in the logistic regression model, cervical length, VI and FI independently predicted delivery > 48 h, the likelihood increasing with increasing cervical length, decreasing VI and increasing FI.ConclusionsIn prolonged pregnancy cervical vascularization as estimated by 3D power Doppler ultrasound is related to time to delivery > 48 h, but the likelihood of delivery > 48 h can be predicted equally well using Bishop score alone or sonographic cervical length alone Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Portable EDXRF surface mapping of sulfate concentration on Michelangelo's David
Authors: Castellano Alfredo , Buccolieri Giovanni , Quarta Stefano , Donativi Marina 
Published: June 2006

AbstractThe study presented in this paper was carried out within a large international project founded in the context of the Michelangelo's David's 500th anniversary celebration. A group of experts analysed Michelangelo's masterpiece with several techniques with the aim of helping restorers to choose the most suitable treatment for cleaning of the statue. The task of the present team was to map the possible presence of sulfur (as sulfates) on the surface of the sculpture due to pollution effects. A portable energy‐dispersive x‐ray fluorescence (EDXRF) system was used. The EDXRF technique is not only non‐destructive, sensitive and capable of simultaneous multi‐elemental analysis but also, in its portable version, it allows the analysis of many areas before, during and after restoration. A large number of measurements were made to obtain an overall picture of the sulfur distribution on the sculpture and then further measurements were made at selected strategic points. After applying different removal procedures at each of these points, the measurements were repeated to obtain a quantitative evaluation of the effectiveness of each cleaning procedures. The results are presented and discussed. Copyright © 2006 John Wiley & Sons, Ltd.
Modern Laparoscopy and the Archery Episode in the Greatest Epic of India: Mahabarata1
Authors: Natarajan K. 
Published: June 2006

AbstractThe laparoscopic surgeon is trained to acquire advanced skills to perform the complicated laparoscopic surgery of the target tissue in a three‐dimensional (3D) space by viewing its two‐dimensional (2D) video image. This technique finds its parallel in a very ancient archery episode portrayed in the longest and the greatest Indian epic, Mahabarata. In this epic, Arjuna, the master archer, is required to employ the strategy of aiming at the eye of a target fish rotating above his head by viewing its reflected image below in water; of course, all this to win the hand of a beautiful princess! Arjuna is so trained that he cannot but excel in focusing his attention on his target. A comparative study of the laparoscopic surgeon and the ancient master archer is done in this paper with a view to throwing light on the interesting similarities between the archer and the modern laparoscopic surgeon with respect to training methods, skills, and techniques.
Improvement in serial cardiopulmonary exercise testing following enzyme replacement therapy in Fabry disease
Authors: Bierer Gregory , Balfe David , Wilcox William R. , Mosenifar Zab 
Published: June 2006

SummaryBackground. Fabry disease is an X‐linked genetic disorder resulting in the accumulation of glycosphingolipids in various organs, leading to exercise intolerance and early mortality. Enzyme replacement therapy (ERT) has recently been approved for use in Fabry patients. Goals of study. To assess baseline cardiopulmonary exercise characteristics in both invasive and noninvasive tests and to study the impact of ERT on exercise. Methods. A total of 15 patients with Fabry disease underwent baseline cardiopulmonary exercise tests. Six patients were randomized 2:1 to receive either ERT or placebo. We performed serial cardiopulmonary exercise tests at baseline and every 3 months over a period of at least 18 months. The baseline test was compared to the last two exercise tests for each patient. Results. Mean age was 32 years. Mean VO2 max was 1.680 ± 0.67 L/min and increased by 0.459 ± 0.64 L/min in the patients receiving ERT. Mean VO2 max was 1.462 ± 0.25 L/min and decreased by 0.116 ± 0.44 L/min in patients on placebo. Mean oxygen pulse (VO2/HR) increased by 1.71 with enzyme, but increased only 0.025 in patients taking placebo. Estimated stroke volume (SV) increased by 10 ml in patients on ERT. Conclusions. In this small cohort, exercise tolerance increased in patients receiving enzyme replacement therapy. Cardiopulmonary exercise testing is a useful test in measuring the response to therapy in Fabry disease patients.
Long-term computed tomography follow-up after open surgical repair of abdominal aortic aneurysms
Authors: Mantoni M. , Neergaard K. , Christoffersen J. K. , Lambine T. L. , BÆkgaard N. 
Published: June 2006

Purpose: To describe the findings on computed tomography (CT) of the aortic sac (AS) in patients operated on for abdominal aortic aneurysm (AAA) with insertion of a coated Dacron prosthesis. Material and Methods: A prospective study of 36 consecutive patients operated on for AAA over 2 years and followed longitudinally with CT for up to 10 years. Results: All patients had a fluid-filled AS on CT 7–10 days postoperatively. At 6 months, the AS had decreased in most patients, mainly in the antero-posterior diameter, and in two had disappeared completely. In five patients with complications, the AS increased in size. The AS disappeared completely at 10 years' follow-up in 13 patients. When present, a retroperitoneal hematoma always disappeared after 6 months. Conclusion: These data indicate that the AS after graft implantation will diminish gradually but will persist for at least 6 months. Usually the transverse diameter is bigger than the antero-posterior diameter. If the AS enlarges and becomes rounded and distended with an inhomogeneous interior, it might be a sign of graft infection. In these cases an ultrasound-guided or CT-guided puncture is recommended.