bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel N‐Succinylchitosan‐graft‐Polyacrylamide/Attapulgite Composite Hydrogel Prepared through Inverse Suspension Polymerization
Authors: Li Ping , Zhang Junping , Wang Aiqin 
Published: July 2007

AbstractA novel N‐succinylchitosan‐graft‐polyacrylamide/attapulgite composite hydrogel was prepared by using N‐succinylchitosan, acrylamide and attapulgite through inverse suspension polymerization. The result from FTIR spectra showed that OH of attapulgite, OH and NHCO of N‐succinylchitosan participated in graft polymerization with acrylamide. The introduced attapulgite could enhance thermal stability of the hydrogel. Scanning electron microscopy observation indicates that the composite hydrogel has a microporous surface. The volume ratio of heptane to water, weight ratio of acrylamide to N‐succinylchitosan and attapulgite content have great influence on swelling ability of the composite hydrogel. The composite hydrogel shows higher swelling rate and pH‐sensitivity compared to that of without attapulgite.magnified image
Nitroxide‐Mediated Aqueous Dispersion Polymerization: From Water‐Soluble Macroalkoxyamine to Thermosensitive Nanogels
Authors: Delaittre Guillaume , Save Maud , Charleux Bernadette 
Published: July 2007

AbstractSelf‐stabilized nanoparticles with a temperature‐responsive poly[(N,N‐diethylacrylamide)‐co‐(N,N′‐methylenebisacrylamide)] microgel core and a covalently attached hairy shell were synthesized via a simple nitroxide‐mediated controlled free‐radical aqueous dispersion polymerization, using a poly(sodium acrylate) alkoxyamine macroinitiator. With this method, high solid content, surfactant‐free particle suspensions were prepared, with diameter ranging from 49 to 118 nm at high temperature, and able to reversibly swell with water at low temperature. The proposed method requires a limited number of reagents in a simple polymerization procedure and thus avoids many drawbacks generally encountered in the synthesis of thermally responsive microgel particles.magnified image
Analysis of LRRK2 Gly2385Arg genetic variant in non‐Chinese Asians
Authors: Tan Eng‐King , Zhao Yi , Tan Louis , Lim Hui‐Qin , Lee Jasinda , Yuen Yih , Pavanni Ratnagopal , Wong Meng‐Cheong , Fook‐Chong Stephanie , Liu Jian‐Jun 
Published: July 2007

AbstractA common LRRK2 missense variant, Gly2385Arg, has been found to be a genetic risk factor for Parkinson's disease (PD) in ethnic Chinese and Japanese. However, the presence of the variant in other non‐Chinese Asian patients has not been fully clarified. We performed genetic analysis of the Gly2385Arg variant in 472 non‐Chinese Asian subjects in Singapore (comprising of 166 PD and 306 controls of Malay/Indian ethnicity). The frequency of the heterozygous Gly2385Arg genotype was not significantly different in PD compared with controls (1.2% vs. 0.8%, odds ratio = 2.83, 95% CI 0.40, 20.2, P = 0.3). No subjects carried the homozygous genotype. Stratification by Malay and Indian ethnicity revealed that there were two carriers each among 98 (2.0%) Malay PD and 173 (1.2%) Malay controls (odds ratio = 1.78, 95% CI 0.25, 12.8, P = 0.6), but there were no carriers among 66 Indian PD and 133 Indian controls. We demonstrated that the Gly2385Arg variant could be detected in our Malay subjects. However, its frequency was much lower than the 8 to 10% prevalence previously reported in our Singaporean and Taiwanese Chinese PD population. The relevance of Gly2385Arg as a genetic risk factor may be restricted to selected Asian races, and more studies will be needed to confirm our observations. © 2007 Movement Disorder Society
Investigation of human cervical and upper thoracic spinal cord motion: Implications for imaging spinal cord structure and function
Authors: Figley C.R. , Stroman P.W. 
Published: July 2007

AbstractSpinal cord (SC) motion is thought to be the dominant source of error in current diffusion and spinal functional MRI (fMRI) methods. However, until now, such motion has not been well characterized in three dimensions. While previous studies have predominantly examined motion in the superior/inferior (S/I) direction, the foci of the present study were the anterior/posterior (A/P) and right/left (R/L) components of human cervical and upper thoracic SC motion. Cardiac‐gated, turbofast low‐angle shot (turbo‐FLASH) cinematic MRI was employed at 3T to acquire images of the cord at 24 phases throughout the cardiac cycle. Time‐dependent signal fluctuations within voxels adjacent to the cord/cerebrospinal fluid (CSF) interface were then used to measure SC motion, which was found to occur predictably as a function of cardiac activity. Cord movement was largest in the A/P direction, for which principal components of motion were calculated, thereby indicating consistent patterns of SC oscillation that can potentially be used to improve SC imaging. Magn Reson Med 58:185–189, 2007. © 2007 Wiley‐Liss, Inc.
Phase‐sensitive cardiac tagging—REALTAG
Authors: Derbyshire J. Andrew , Sampath Smita , McVeigh Elliot R. 
Published: July 2007

AbstractFully inverting spins, instead of merely saturating them, provides superior contrast for tagging procedures. The resulting improvement in tag contrast‐to‐noise ratio (CNR) yields higher‐precision tag detection. Also, thinner slices and hence reduced tag separations can be employed, providing displacement and strain measurements with better spatial resolution. Alternatively, the improved tag contrast can be used to obtain cine images covering a greater portion of the cardiac cycle. The use of standard magnitude reconstruction for images of these inversion tags causes rectification of the negative‐valued signals from the tags, confounding the image interpretation. Therefore, a phase‐sensitive reconstruction scheme of the inverted tags must be employed. Here we demonstrate the implementation of inverted tags with phase‐sensitive reconstruction in a ramped‐flip‐angle, steady‐state free precession (SSFP) sequence. Magn Reson Med 58:206–210, 2007. © 2007 Wiley‐Liss, Inc.
Correction of frequency and phase variations induced by eddy currents in localized spectroscopy with multiple echo times
Authors: Zhang Yan , Marenco Stefano , Shen Jun 
Published: July 2007

AbstractAs a consequence of the time‐varying magnetic field induced by eddy currents, frequency drifting occurs when the sampling window of localized spectroscopy continuously shifts. The frequency drifting and the concomitant phase variations can severely affect spectroscopy results when data are acquired with multiple echo times (TEs), such as in the measurement of glutamate (Glu) concentration using the TE‐averaged method. Specifically, the averaged spectra are further broadened and distorted in the presence of residual eddy currents, and editing of the coupled spins of Glu C4 protons is affected, resulting in errors in the measured relative intensity ratio. Postacquisition correction using unsuppressed water as reference can effectively minimize this detrimental effect, as manifested by the significantly enhanced signal intensity. Also, it is demonstrated that the methyl signals of creatine (Cr) at 3.0 ppm and choline (Cho) at 3.2 ppm can be used as internal references in finding frequency and phase disparities between different TEs. Magn Reson Med 58:174–178, 2007. © 2007 Wiley‐Liss, Inc.
Three‐dimensional magnetic resonance myocardial motion tracking from a single image plane
Authors: Abd‐Elmoniem Khaled Z. , Osman Nael F. , Prince Jerry L. , Stuber Matthias 
Published: July 2007

AbstractThree‐dimensional imaging for the quantification of myocardial motion is a key step in the evaluation of cardiac disease. A tagged magnetic resonance imaging method that automatically tracks myocardial displacement in three dimensions is presented. Unlike other techniques, this method tracks both in‐plane and through‐plane motion from a single image plane without affecting the duration of image acquisition. A small z‐encoding gradient is subsequently added to the refocusing lobe of the slice‐selection gradient pulse in a slice following CSPAMM acquisition. An opposite polarity z‐encoding gradient is added to the orthogonal tag direction. The additional z‐gradients encode the instantaneous through plane position of the slice. The vertical and horizontal tags are used to resolve in‐plane motion, while the added z‐gradients is used to resolve through‐plane motion. Postprocessing automatically decodes the acquired data and tracks the three‐dimensional displacement of every material point within the image plane for each cine frame. Experiments include both a phantom and in vivo human validation. These studies demonstrate that the simultaneous extraction of both in‐plane and through‐plane displacements and pathlines from tagged images is achievable. This capability should open up new avenues for the automatic quantification of cardiac motion and strain for scientific and clinical purposes. Magn Reson Med 58:92–102, 2007. © 2007 Wiley‐Liss, Inc.
Characterization of bovine patellar cartilage by NMR
Authors: Ling Wen , Regatte Ravinder R. , Schweitzer Mark E. , Jerschow Alexej 
Published: July 2007

AbstractMetabolic and structural changes in cartilage tissue are thought to be at the root of degenerative joint disease. We identify here the NMR resonances in bovine patellar cartilage tissue by static and high‐resolution magic angle spinning (HRMAS) NMR spectroscopy, 1H‐13C heteronuclear single‐quantum correlation (HSQC) spectroscopy, total correlation spectroscopy (TOCSY), and saturation transfer experiments. Some differences between the patellar cartilage samples studied here and earlier nasal cartilage and intervertebrate disc studies were found. In addition, we show assignments downfield of the water signal, which also includes the assignment of amide and hydroxy protons on the basis of their exchangeability with water. These results will allow an identification of spectroscopic markers of cartilage degradation using techniques such as chemical exchange saturation transfer imaging. Copyright © 2007 John Wiley & Sons, Ltd.
A novel computational strategy for the pKa estimation of drugs by non‐linear regression of multiwavelength spectrophotometric pH‐titration data exhibiting small spectral changes
Authors: Meloun Milan , Bordovská Sylva , Syrový Tomáš 
Published: July 2007

AbstractA new computational procedure for the protonation model building of a multiwavelength and multivariate spectra treatment is proposed for the special case of small changes in spectra. The absorbance change Δi for the ith spectrum divided with the instrumental standard deviation sinst(A) represents the signal‐to‐error ratio SER of the spectra studied. The determination of the number of chemical components in a mixture is the first important step for further quantitative analysis in all forms of spectral data treatment. Most index‐based methods of the factor analysis can always predict the correct number of components, and even the presence of a minor one, when the SER is higher than 10. The Wernimont–Kankare procedure in the program INDICES performs reliable determinations of the instrumental standard deviation of the spectrophotometer used sinst(A), correctly predicts the number of light‐absorbing components present, and also solves ill‐defined problems with severe collinearity in spectra or very small changes in spectra. The mixed dissociation constants of three drugs, haemanthamine, lisuride, and losartan, including diprotic molecules at ionic strengths of I = 0.5 and 0.01 and at 25°C were determined using two different multiwavelength and multivariate treatments of the spectral data, SPECFIT32 and SQUAD(84) non‐linear regression analyses and INDICES factor analysis, even in the case of small absorbance changes in spectra. The dissociation constant pKa was estimated by non‐linear regression of {pKa, I} data at 25°C: for haemanthamine pKa = 7.28(1) at I = 0.50, for lisuride pKa = 7.86(1) and for losartan pKa,1 = 3.60(1), pKa,2 = 4.73(1) at I = 0.01. Goodness‐of‐fit tests for the various regression diagnostics enabled the reliability of the parameter estimates found to be proven. PALLAS and MARVIN predict pKa being based on the structural formulae of the drug compounds in agreement with the experimental value. Copyright © 2007 John Wiley & Sons, Ltd.
Band structure and optical properties of SbSeI: density‐functional calculation
Authors: Akkus Harun , Kazempour Ali , Akbarzadeh Hadi , Mamedov Amirullah M. 
Published: July 2007

AbstractThe electronic structure and linear optical properties of the ferroelectric semiconductor SbSeI are calculated in the nonpolar phase using the density functional methods in the generalized gradient approximation. The obtained electronic band structure shows that SbSeI has an indirect forbidden gap of 1.65 eV. The linear photon‐energy‐dependent dielectric functions and some optical functions such as absorption and extinction coefficients, refractive index, energy‐loss function, reflectivity and optical conductivity are calculated. Moreover, some important optical parameters such as the effective number of valence electrons and the effective optical dielectric constant are calculated. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Liquid chromatography/electrospray ionization tandem mass spectrometry assay for determination of nicotine and metabolites, caffeine and arecoline in breast milk
Authors: Pellegrini Manuela , Marchei Emilia , Rossi Silvia , Vagnarelli Federica , Durgbanshi Abhilasha , García‐Algar Óscar , Vall Oriol , Pichini Simona 
Published: July 2007

AbstractA procedure based on liquid chromatography/tandem mass spectrometry (LC/MS/MS) is described for the determination of nicotine and its principal metabolites cotinine,trans‐3‐hydroxycotinine and cotinine‐N‐oxide, caffeine and arecoline in breast milk, usingN‐ethylnorcotinine as internal standard. Liquid/liquid extraction with chloroform/isopropanol (95:5, v/v) was used for nicotine, cotinine,trans‐3‐hydroxycotinine, cotinine‐N‐oxide and caffeine under neutral conditions and for arecoline under basic conditions. Chromatography was performed on a C8reversed‐phase column using a gradient of 50 mM ammonium formate, pH 5.0, and acetonitrile as a mobile phase at a flow rate of 0.5 mL/min. Separated analytes were determined by electrospray ionization tandem mass spectrometry in the positive ion mode using multiple reaction monitoring. Limits of quantification were 5 µg/L for nicotine, cotinine,trans‐3‐hydroxycotinine, cotinine‐N‐oxide and caffeine, and 50 µg/L for arecoline using 1 mL human milk per assay. Calibration curves were linear over the calibration ranges for all the substances under investigation, with a minimumr2 > 0.998. At three concentrations spanning the linear dynamic range of the assay, mean recoveries from breast milk ranged between 71.8 and 77.4% for different analytes. This method was applied to the analysis of analytes in human milk to assess substance exposure in breast‐fed infants in relation to eventual clinical outcomes. This LC/MS/MS assay provides adequate sensitivity and performance characteristics for the simultaneous quantification of biomarkers of three of the drugs most commonly used worldwide (tobacco, caffeine and areca nut). Copyright © 2007 John Wiley & Sons, Ltd.
Successful artificial insemination in the corn snake, Elaphe gutatta, using fresh and cooled semen
Authors: Mattson Kelli J. , De Vries Alyse , McGuire Susie M. , Krebs Jessi , Louis Edward E. , Loskutoff Naida M. 
Published: July 2007

AbstractThe design and implementation of assisted reproductive technology to improve genetic diversity and augment captive populations is an important but rarely applied research field in reptiles. Using the corn snake (Elaphe gutatta) as a model, the Henry Doorly Zoo recently produced offspring born as a result of artificial insemination using both fresh, diluted semen, and diluted semen stored at refrigeration for 3 days. Semen was collected noninvasively from sexually mature male corn snakes using a gentle massaging technique, extended in medium then inseminated into the oviducts of adult females. Using molecular genetic techniques to confirm or refute the success of the insemination using primers developed for the black rat snake, Elaphe obsolete, all possible parents and offspring genotypes were evaluated. A paternity‐by‐exclusion analysis verified that the offspring were in fact a result of artificial insemination. Zoo Biol 26:363–369, 2007. © 2007 Wiley‐Liss, Inc.
Crystal structures and melting points of saturated triacylglycerols in the β‐3 phase
Authors: van Soest T. C. , de Jong S. , Roijers E. C. 
Published: July 2007

A comprehensive packing analysis is presented of the crystal structures of a large number of saturated triacylglycerols in the β‐3 phase. The triacylglycerolsp.q.r have been grouped into four classes:r=p,p+2,p+4 andp+6. The length of the middle chain,q, dictates whether a β‐2 or β‐3 packing occurs. The latter packing arrangement is adopted whenq differs at least 4 fromp orr.The model‐building approach starts from the known molecular conformation of β‐210.10.10 and the T‖ subcell packing mode of the hydrocarbon chains. Purely geometrical model‐building allows a preliminary assignment of crystal structures. Crystal lattice energy calculations using the atom‐atom potential method support these tentative assignments and clarify some details regarding the stacking of layers. In common with the β‐2 phase crystal structures, the structure of the terrace‐like arrangement of the terminal methyl groups plays a crucial role. Triacylglycerols with chains 1 and 3 differing 2 or 4 carbon atoms have a common arrangement of the end‐methyl groups (type β‐3A). Those with a difference of 0 (i.e. symmetrical) or 6 carbon atoms have a different, less favorable methyl terrace (type β‐3B). The available experimental evidence (x‐ray powder diffraction, unit‐cell data and melting points) is entirely compatible with these proposals.
Identification of adduct radiolysis products from ethyl palmitate and ethyl oleate
Authors: Vajdi Mehran , Nawar W. W. , Merritt Charles 
Published: July 2007

AbstractRadiolysis induced adduct products have been separated and identi‐fied from irradiated ethyl palmitate, ethyl α‐d2‐palmitate and ethyl oleate. In the saturated compounds, adduct formation was observed mainly at the position α to the carbonyl group. The three major adduct products identified in irradiated ethyl palmitate were ethyl α‐tetradecylpalmitate, ethyl α‐pentadecylpalmitate and the α,α′‐ dimer of ethyl palmitate. Corresponding compounds were identified from the irradiated ethyl α‐deuteropalmitate. Adduct radiolysis products formed in ethyl oleate were identified as the monoene and diene dimers.
Quantitation of estolide triglycerides in sapium seeds by high performance liquid chromatography with infrared detection
Authors: Payne‐Wahl Kathleen , Kleiman Robert 
Published: July 2007

AbstractThe kernel oil of Chinese tallow(Sapium sebiferum) seed contains tetraester triglycerides composed oftrans‐2, cis‐4‐decadienoic acid joined in an estolide linkage to 8‐hydroxy‐5, 6‐octadienoic acid. A rapid (< 10 min) method of separation and quantitation of the tri‐glyceride and estolide triglyceride fractions of the oil has been devel‐oped using high performance liquid chromatography with infrared detection.
An edible oil deodorizer with a direct‐fired heater
Authors: Kuroda Zenzyuro , Young Chao 
Published: July 2007

AbstractEngineers have long believed a direct‐fired heater (DFH) for deodorization is always in danger of over‐heating. Commercial tests done in recent years have proved this danger can be avoided by proper furnace design. At least ten commercial deodorizers with this system are now used in Asia. A new deodorizer with a DFH was designed and built in 1986 in Taiwan. It features a single‐shell design and steam‐stripping of deep oil layers. It has been operated successfully for several years. The deodorized oil was compared with oil produced by conventional deodorizers. The new deodorizer with a DFH revealed several advantages.
Block polymer nonionic surfactants in textiles
Authors: Schmolka Irving R. 
Published: July 2007

AbstractBlock polymer surfactants have wide acceptance in the textile industry. These products are characterized by low‐to‐moderate foam, low levels of toxicity, and a variety of other desirable physical properties. This paper reviews their use as lubricants, texturizers, antistats, softeners, dyes, rayon processing agents, emulsifiers, defoamers and bleaching agents.
Chemical inactivation of soybean protease inhibitors
Authors: Sessa David J. , Nelsen Terry C. 
Published: July 2007

AbstractThis study aimed to optimize chemical treatments to destroy Kunitz (KTI) and Bowman‐ Birk (BBI) type protease inhibitors in model systems, and to destroy total trypsin inhibitor activity in soy flour. Time, temperature, and reagent concentration were studied and 40 to more than 85% inactivation of KTI and BBI were observed by treatment with 0.6 mM Na2S2O5,10 mM ascorbic acid + 0.8 mM CuSO4 or 20 mM H2O2 + 0.8 mM CuSO4 at 65‐ 90°C for 0.5‐ 1 hr. Upon treatment with Na2S2O5, KTI and BBI amino acid composition had no significant change. In contrast, AH + CU2+ treatment of both KTI and BBI markedly increased aspartic acid + asparagine and glutamic acid + glutamine contents, and significantly decreased histidine, tyrosine, and methionine. With soy flour, only Na2S2O5 effectively inactivated both protease inhibitors. Steeping soybean flour in 50 mM Na2S2O5 at 65°C for 1 hr inactivated about 98% BBI and 95% KTI. The information conveyed is basic to developing chemical methodology needed to inactivate both KTI and BBI protease inhibitors in soy protein products.
Measurement of oxidative interactions of cholesterol
Authors: Nawar W. W. , Kim S. K. , Li Y. J. , Vajdi M. 
Published: July 2007

AbstractA simple analytical technique, using a silicic acid minicolumn and capillary gas chromatography, was used for measuring the oxidative interactions of cholesterol with other compounds. When triacylglycerols were added to cholesterol before heating at 180°C, the latter oxidized faster than cholesterol heated alone, and a relatively high amount of epoxides was found.Dipahnitoylphosphatidylethanolamine and all the amino acids tested showed a protective effect, with cysteine and alanine being the most effective. The results of this study indicate that the varius compounds added not only influenced the rate of cholesterol oxidation, but also exerted different influences on its oxidative pathway.
Kinetics of staining and bleaching
Authors: Kissa Erik , Dohner Jenny M. , Gibson Ward R. , Strickman Donna 
Published: July 2007

AbstractKinetics of staining and stain removal have been studied with food dyes and natural colorants. Kinetics of staining indicate that the staining agent is adsorbed on the fiber surface and diffuses into the interior of the fibers. Similarities exist between staining and dyeing mechanisms of cotton, polyester and nylon fibers. Stain removal by nonoxidative detergency involves diffusion of the staining agent from the interior of fibers and desorption from the fiber surface. The kinetics of stain removal by bleaching with peroxyacids or activated sodium perborate depend on the affinity of the stain to fibers. When desorption of stain is rapid, bleaching of the stain in solution is the rate‐ determining step and stain removal obeys pseudo‐ first‐ order kinetics. When the stain is washfast, the concentration of the stain in fibers decreases with the square root of time, indicating a diffusion process. The peroxygen bleaching agent is sorbed in the subsurface of fibers or diffuses into the interior of fibers. If bleaching occurs in the outer perimeter of fibers, the rate‐ determining step may be the diffusion of stain molecules from the interior of fibers to the location of the bleaching agent. On the other hand, if bleaching occurs within fibers, the rate‐ determining step may be diffusion of the bleaching agent to the stain located within the fibers.