bluuebunny/crossref_metadata_2025 huggingface dataset:
Upper cervical spinal cord cross‐sectional area in relapsing remitting multiple sclerosis: Application of a new technique for measuring cross‐sectional area on magnetic resonance images
Authors: Mann Ranbir S. , Constantinescu Cris S. , Tench Christopher R.
Published: July 2007

Purpose

To measure accurately the upper cervical cord cross‐sectional area (CSA) in patients with relapsing remitting multiple sclerosis (RRMS), and normal control subjects, to address the paradox that longitudinal reduction in CSA has been detected in RRMS while reduction compared to controls has not. We hypothesized that a lack of statistical power and/or measurement sensitivity due to partial volume averaging in previous studies contributed to this paradox.

Materials and Methods

Using a technique that corrects for partial volume averaging, we measured the CSA in 35 normal controls and 35 RRMS patients. We used the total intracranial volume (TICV) to normalize the CSA and therefore reduce the normal variance and improve the statistical power.

Results

The mean TICV did not differ between groups. Statistical power analysis indicated that a 5% reduction in CSA in the patients could be detected with an estimated power of 0.74 before normalization and 0.9 after. The mean CSA in the patients was not reduced compared to controls after (P = 0.928) or before (P = 0.881) normalization.

Conclusion

Using a sensitive analysis method, and apparently appropriate statistical power, we did not detect reduced CSA in RRMS patients. We hypothesize that this may be due to inflammation. J. Magn. Reson. Imaging 2007;26:61–65. © 2007 Wiley‐Liss, Inc.
Uterus‐like mass: MRI appearance of a very rare entity
Authors: Menn Kirsten A. , Qin Lihui , Fedoriw George D. , Gillette Mary E. , McCarthy Shirley
Published: July 2007

We describe a 37‐year‐old patient who presented with right lower quadrant pain and intermenstrual bleeding. MRI demonstrated a 5 × 5 cm lobulated mass centered in the right uterine wall interpreted as suspicious for malignancy. A total hysterectomy was performed, and the gross and histologic features were consistent with the diagnosis of a uterus‐like mass. Uterus‐like mass is a benign entity that can be found in a variety of organs, and is characterized by endometrium surrounded by smooth muscle. It is an extremely rare lesion with only approximately 15 cases reported in the current literature. There is a lack of imaging literature on this entity, which is primarily described in the pathology literature. Its histogenesis is uncertain, but is theorized to be metaplastic change, congenital anomaly, and/or heterotopia. However, given the MRI appearance in this case, we feel that uterus‐like mass could be prospectively diagnosed or listed in a differential diagnosis. J. Magn. Reson. Imaging 2007;26:162–164. © 2007 Wiley‐Liss, Inc.
Quantitative magnetization transfer imaging in postmortem multiple sclerosis brain
Authors: Schmierer Klaus , Tozer Daniel J. , Scaravilli Francesco , Altmann Daniel R. , Barker Gareth J. , Tofts Paul S. , Miller David H.
Published: July 2007

Purpose

To investigate the relationship of myelin content, axonal density, and gliosis with the fraction of macromolecular protons (fB) and T2 relaxation of the macromolecular pool (T2B) acquired using quantitative magnetization transfer (qMT) MRI in postmortem brains of subjects with multiple sclerosis (MS).

Materials and Methods

fB and T2B were acquired in unfixed postmortem brain slices of 20 subjects with MS. The myelin content, axonal count, and severity of gliosis were all quantified histologically. t‐Tests and multiple regression were used for analysis.

Results

MR indices obtained in unfixed postmortem MS brains were consistent with in vivo values reported in the literature. A significant correlation was detected between Trmyelin (inversely proportional to myelin content) and 1) fB (r = –0.80, P < 0.001) and 2) axonal count (r = –0.79, P < 0.001). fB differed between 1) normal‐appearing white matter (NAWM) and remyelinated WM lesions (rWMLs) (mean: fB 6.9 [SD 2] vs. 4.0 [1.8], P = 0.01), and 2) rWMLs and demyelinated WMLs (mean: 4.2 [2.2] vs. 2.5 [1.3], P = 0.016). No association was detected between T2B and any of the histological measures.

Conclusion

fB in MS WM is dependent on myelin content and may be a tool to monitor patients with this condition. J. Magn. Reson. Imaging 2007;26:41–51. © 2007 Wiley‐Liss, Inc.
Design, construction and evaluation of an anthropomorphic head phantom with realistic susceptibility artifacts
Authors: Shmueli Karin , Thomas David L. , Ordidge Roger J.
Published: July 2007

Purpose

To design and construct an anthropomorphic head phantom using materials of appropriate magnetic susceptibility and air spaces of realistic dimensions, with the aim of reproducing the susceptibility artifacts found in the human brain.

Materials and Methods

The phantom is based on a plastic skull filled with MnCl2‐doped water. Materials to mimic soft tissue (wax) and bone (plastic skull) were chosen based on mass susceptibility measurements using a superconducting quantum interference device (SQUID) magnetometer. The phantom was designed for and evaluated at 4.7T using field mapping and echo‐planar imaging (EPI).

Results

The main magnetic field (B0) maps of the phantom resemble those of four volunteers' brains and have similar standard deviations (SDs). Maps of the B0 field gradients in the phantom and real brains are also similar. The phantom has relaxation times close to those of brain tissue at 4.7T. Gradient‐echo (GE)‐EPI images of the phantom suffer from susceptibility artifacts comparable to those in real heads and at anatomically realistic locations.

Conclusion

The phantom is a useful tool for evaluating and comparing different susceptibility artifact reduction techniques. The phantom could also be used to test CT‐MRI coregistration in the presence of susceptibility artifacts since the water‐filled brain cavity is both CT‐ and MR‐visible. J. Magn. Reson. Imaging 2007;26:202–207. © 2007 Wiley‐Liss, Inc.
Correlations between MR and endothelial hyperplasia in low‐grade gliomas
Authors: Callot Virginie , Galanaud Damien , Figarella‐Branger Dominique , Lefur Yann , Metellus Philippe , Nicoli François , Cozzone Patrick
Published: July 2007

Purpose

To investigate the capacity of multimodal MR to detect endothelial hyperplasia (EH), which has been linked to the aggressiveness of gliomas and which is so far only detected by biopsy, an invasive technique that prevents repeated measurements and early detection.

Materials and Methods

A total of 26 patients with low‐grade gliomas participated in the study. All underwent a histopathological analysis and a multimodal MR examination (spectroscopic, anatomic, diffusion, perfusion, and postcontrast imaging).

Results

EH was present (EH+) in 15 patients and absent (EH–) in 11. No differences were observed between EH– and EH+ groups when comparing spectroscopic and diffusion parameters. Perfusion measurements, however, allowed us to distinguish EH+ from EH–: the relative regional cerebral blood flow (rCBF) was found equal to 3.23 ± 2.05 for EH+ and 1.33 ± 0.46 for EH– (P = 0.006).

Conclusion

We have observed a strong correlation between the presence of EH and the increase of rCBF. Compared to conventional imaging, MR perfusion provides additional and complementary information that may be used for biopsy guidance, early detection of tumor aggressiveness, and noninvasive follow‐ups. J. Magn. Reson. Imaging 2007;26:52–60. © 2007 Wiley‐Liss, Inc.
Can isotropic fast gradient echo imaging be substituted for conventional T1 weighted sequences in shoulder MR arthrography at 3 Tesla?
Authors: Magee Thomas
Published: July 2007

Purpose

To assess the practical utility of isotropic shoulder imaging in patients undergoing MR arthrography. Isotropic shoulder imaging can be performed in less than three minutes with use of fast gradients.

Materials and Methods

Two experienced musculoskeletal radiologists retrospectively interpreted MR images of the shoulder in 100 consecutive patients undergoing MR arthrography of the shoulder. All patients underwent MRI of the shoulder in oblique coronal, oblique sagittal, and axial planes on a 3.0‐Tesla MRI system. All patients had conventional fast spin‐echo T1‐weighted imaging. All patients also had thin section (0.4 mm) isotropic spoiled gradient echo images performed. A total of 67 of the 100 patients underwent subsequent arthroscopy and results were compared with MR interpretations.

Results

There were 41 full‐thickness supraspinatus tendon tears, nine partial‐thickness supraspinatus tendon tears (seven articular surface and two bursal surface), 21 superior labral, 18 anterior labral, and seven posterior labral tears demonstrated by consensus retrospective reading of the 100 shoulder MR exams. There was no difference in interpretation of the isotropic images as compared to the conventionally acquired images in the oblique coronal, oblique sagittal, and axial planes. Some patients had more than one finding on each exam. A total of 67 patients went on to arthroscopy. There were 41 full‐thickness supraspinatus tendon tears, nine partial‐thickness supraspinatus tendon tears, 21 superior labral, 18 anterior labral, and seven posterior labral tears demonstrated on arthroscopy. All full‐ and partial‐thickness supraspinatus tendon tears seen at arthroscopy were seen on consensus MR reading. A total of 19 out of the 21 patients with superior labral anterior posterior (SLAP) tears at arthroscopy were seen on consensus MR reading. A total of 16 of the 18 anterior labral tears and six of the seven posterior labral tears seen at arthroscopy were seen on consensus MR reading. Some of the 67 patients had more than one finding on arthroscopy.

Conclusion

Isotropic imaging of the shoulder is practical in clinical imaging when performed with use of fast gradients on a 3‐Tesla system. Isotropic imaging provides the same clinical information as conventional imaging and can be acquired in less than three minutes. J. Magn. Reson. Imaging 2007;26:118–122. © 2007 Wiley‐Liss, Inc.
FTIR‐spectroscopic characterization of humic acids and humin fractions obtained by advanced NaOH, Na4P2O7, and Na2CO3 extraction procedures
Authors: Tatzber Michael , Stemmer Michael , Spiegel Heide , Katzlberger Christian , Haberhauer Georg , Mentler Axel , Gerzabek Martin H.
Published: July 2007

Aim of our study was the development of the methodological basis for the characterization of humic fractions of a long‐term field experiment. Humic acids (HAs) were extracted from three layers of a nontilled soil using three different extractants (1 M NaOH, 0.1 M Na4P2O7, 1 M Na2CO3), and the humin fraction was enriched. NaOH as extractant for FTIR analysis of humic substances yields higher resolved IR spectra, especially in the important regions of stretching vibrations including aromatic and aliphatic groups and in the fingerprint area including amides, aliphats, and aromats than the other extractants. The NaOH extraction has lower extraction yields as compared to Na4P2O7 and Na2CO3 and represents a different part of the soil organic matter (SOM). This is reflected by lower C : N ratios and higher E4 : E6 and fulvic acid–to–humic acid ratios as compared to the other extractants. The FTIR band areas of HA fraction obtained by NaOH showed an increase of the aromatic and carbonyl groups and a decrease of amide groups with increasing soil depth. Aliphatic groups showed contradicting results: The bands of the stretching vibrations increased, and the band of the bending vibrations decreased. We assume that band interactions in the bending vibrations were responsible for that phenomenon under the assumption of an increase of aliphatic groups with increasing soil depth. The IR bands of the enriched humin fraction showed a decreasing trend in case of both aliphatic bands deriving from stretching vibrations and an increase of aromatic characteristics with depth. Our study led to the conclusion that HA fractions obtained by 1 M NaOH represent a small and dynamic fraction indicated by the measured yields in combination with values of Nt, C : N, E4 : E6 ratios, and ratios of fulvic acids (FA) to HA. The humin fraction has a high contribution to the total organic C and represents a more stabilized fraction of SOM which still shows changes in its aromatic and aliphatic characteristics with soil depth.
Effects of soil flooding on P transformations in soils of the Mesopotamia region, Argentina
Authors: Quintero Cesar Eugenio , Hernán Gutiérrez‐Boem Flavio , Befani Romina María , Boschetti Norma Graciela
Published: July 2007

In the Mesopotamia region (Argentina), rice is cropped on a wide range of soil types, and the response of rice to fertilizer application has been inconsistent even in soils with very low levels of available phosphorus. Phosphorus transformations in flooded soils depend on soil characteristics that may affect phosphorus availability. This study was conducted to determine which soil characteristics were related to the changes in P fractions during soil flooding. Soils were chosen from ten sites within the Mesopotamia region that are included in five different soil orders: Oxisols, Ultisols, Alfisols, Mollisols, and Vertisols. Soil phosphorus (P) was fractionated by a modified Hedley method before and after a 45 d anaerobic‐incubation period. Changes in the inorganic P extracted with resin depended on soil pH and were related to the exchangeable‐Fe concentration of soils (extracted with EDTA). Inorganic P extracted with alkaline extractants (NaHCO3 and NaOH) increased due to soil flooding. This increase was related to the organic‐C (OC) percentage of soils (r2 = 0.62, p < 0.01), and ranged from 13 to 55 mg kg–1. Even though previous studies showed that P associated with poorly crystalline Fe played an important role in the P nutrition of flooded rice, in this study, there was no relationship between ammonium oxalate–extractable Fe and P changes in soils due to flooding. Our results suggest that in the Mesopotamia region, changes in P fractions due to soil flooding are related to soil OC, soil pH, and soluble and weakly adsorbed Fe.
Extraction of water‐soluble organic matter from mineral horizons of forest soils
Authors: Rennert Thilo , Gockel Kai F. , Mansfeldt Tim
Published: July 2007

Dissolved organic matter (DOM) is involved in many important biogeochemical processes in soil. As its collection is laborious, very often water‐soluble organic matter (WSOM) obtained by extracting organic or mineral soil horizons with a dilute salt solution has been used as a substitute of DOM. We extracted WSOM (measured as water‐soluble organic C, WSOC) from seven mineral horizons of three forest soils from North‐Rhine Westphalia, Germany, with demineralized H2O, 0.01 M CaCl2, and 0.5 M K2SO4. We investigated the quantitative and qualitative effects of the extractants on WSOM and compared it with DOM collected with ceramic suction cups from the same horizons. The amounts of WSOC extracted differed significantly between both the extractants and the horizons. With two exceptions, K2SO4extracted the largest amounts of WSOC (up to 126 mg C kg–1) followed by H2O followed by CaCl2. The H2O extracts revealed by far the highest molar UV absorptivities at 254 nm (up to 5834 L mol–1 cm–1) compared to the salt solutions which is attributed to solubilization of highly aromatic compounds. The amounts of WSOC extracted did not depend on the amounts of Fe and Al oxides as well as on soil organic C and pH. Water‐soluble organic matter extracted by K2SO4bore the largest similarity to DOM due to relatively analogue molar absorptivities. Therefore, we recommend to use this extractant when trying to obtain a substitute for DOM, but as WSOM extraction is a rate‐limited process, the suitability of extraction procedures to obtain a surrogate of DOM remains ambiguous.
Hyperbranched Fluoropolymers and their Hybridization into Complex Amphiphilic Crosslinked Copolymer Networks
Authors: Bartels Jeremy W. , Cheng Chong , Powell Kenya T. , Xu Jinqi , Wooley Karen L.
Published: July 2007

This feature article highlights three types of hyperbranched fluoropolymers (HBFPs) with different structural features, which were synthesized by either polycondensation of fluorinated ABx monomers or self‐condensing vinyl (co)polymerization of fluorinated inimers and/or fluorinated comonomers. Amphiphilic crosslinked networks with hybridization of these hydrophobic HBFPs and linear hydrophilic poly(ethylene glycol)s are also discussed. As microphase‐segregated materials with nanoscale surface heterogeneities, these networks possessed unusual anti‐biofouling abilities, atypical sequestration and release behaviors for guest molecules, and special mechanical properties.

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

A 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

Self‐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

A 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

Spinal 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

Fully 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

As 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

Three‐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

Metabolic 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

A 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

The 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

A 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

The 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.
Near‐infrared reflectance measurement of moisture, protein and oil content of ground crambe seed
Authors: Hartwig R. A. , Hurburgh Charles R.
Published: July 2007

Crambe moisture, protein and oil percentages were predicted by fixed‐filter near‐infrared reflectance with standard errors of prediction (SEP) of 0.26, 0.59 and 0.86 percentage points, respectively. Crambe had a large range of protein and oil percentages, 17.4%–25.0% and 17.7%–36.4% respectively. Calibration samples were selected on the basis of relative spectral data, with no advance knowledge of protein and oil content. This procedure selected samples representing the full range of constituent values, and resulted in calibrations that had lower SEP's than standard errors of calibration.
Identification of adduct radiolysis products from ethyl palmitate and ethyl oleate
Authors: Vajdi Mehran , Nawar W. W. , Merritt Charles
Published: July 2007

Radiolysis 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

The 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

Engineers 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

Block 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

This 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

A 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

Kinetics 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.
Changes in volatile constituents of bell peppers immediately and 3o minutes after stir frying
Authors: Wu Chung‐May , Liou Shu‐Er , Wang Ming‐Chin
Published: July 2007

Bell peppers(Capsicum annuum var. grossum. Sendt) were stir fried for two min, and their volatile constitu‐ents were analyzed immediately and 30 min after stir frying. Autoxidation of unsaturated fatty acids in stir frying and aging is the main cause of changes in volatile compounds.
Hydrogenation of linolenate. XI. Nuclear magnetic resonance investigation
Authors: Johnston A. E. , Glass C. A. , Dutton H. J.
Published: July 2007

Nuclear magnetic resonance (NMR) spectra have been obtained during the hydrogenation of methyl linolenate with platinum, nickel and sulfur‐poisoned‐nickel catalysts and during the reduction of linolenic acid with hydrazine. Structural changes have been studied by 舠proton counting舡 techniques and include those for the total unsaturation (olefinic protons), 15,16‐double bond (ॆ‐olefinic methyl protons), 1,4‐pentadienes (di‐ॅ‐olefinic methylene protons) and allylic methylene (ॅ‐olefinic methylene protons).

The number of olefinic protons is inversely related to the degree of saturation as determined by iodine value, GLC and hydrogen absorption. Amounts of double bonds in the 15,16‐position and in the 1,4‐pentadiene structures decrease linearly with increasing saturation, but the slopes of lines differ for specific catalysts. Sulfur‐poisoned pickel has the most negative slope, followed by electrolytic nickel, and then platinum and hydrazine. Amounts of ॅ‐olefinic structures with increasing saturation are roughly constant for hydrazine and platinum during reduction with the first mole of hydrogen; they fall to zero at complete saturation. For the two nickel catalysts, the ॅ‐olefinic structures increase during absorption of the first mole and a half of hydrogen before dropping to zero. The possibility of substituting NMR measurements for iodine value, alkali‐isomerization spectrophotometric determination and other structural analyses is discussed.
Performance of straight‐chain alkylbenzene sulfonates (LAS) in heavy‐duty detergents
Authors: Sweeney W. A. , Olson A. C.
Published: July 2007

The foamability (dishwashing and washing machine) and detergency of LAS in heavy‐duty detergents is directly compared with polypropylenɹ ABS (PPABS) at various mol wt, conen, water hardnesses and temp. In every case a peak in performance is obtained in the C11 to C17 side chain range. The peak is shifted to lower mol wt as water hardness is increased, especially at low detergent conen. LAS opt performance is generally equal to PPABS, except in dishwashing foam in soft water. The LAS peaks, however, are shifted to ca. one carbon lower mol wt than the PPABS. Therefore, best over‐all performance is obtained for LAS whose average mol wt corresponds to a 12.5 carbon side chain, whereas PPABS is best with an average 13.5 carbon side chain.

Dishwashing foamability is markedly different for the different isomers contained in LAS. When the phenyl group it attached to the middle of the alkyl chain, surprisingly high results are obtained. This dishwashing difference is great enough to be noticeable when the isomer distribution changes in whole products made using different alkylation catalysts. Detergency and washing machine foam are not affected enough to see differences between whole alkylates.

LAS solubility is greater than PPABS and is influenced by isomer distribution.
Factors influencing vegetable oil bleaching by adsorption
Authors: Stout Lawrence E. , Chamberlain Donald F. , McKelvey James M.
Published: July 2007

Vegetable oil bleaching by adsorption involves the removal of color particles which are either dissolved or colloidally dispersed in the oil. This type of adsorption follows an exponential relationship and the Freundlich equation was utilized in correlating the data. In utilizing this equation, the color of the oil was assumed proportional to the concentration of the color particles, and a color measurement system based on the Beer‐Lambert Law was devised. This system involves a measurement of the transmittance of light of 475 millimicrons wave length through the oil. A Coleman, Model 11, Spectrophotometer was used for the transmittance measurements. Spectral transmittance curves for cottonseed and soybean oil, bleached and unbleached, are given.

The effect of the variables of temperature, time of contact, and particle size on the activity of several adsorbents was determined. It was found that the activity of each adsorbent is at a maximum at some particular temperature. The adsorbents were grouped into three general classes: acid‐activated clays, natural earths, and materials high in silica content, and it was found that adsorbents in the same class have a temperature of maximum activity within the same range.

The effectiveness of 16 different adsorbents in bleaching a refined cottonseed oil was determined by utilizing the Freundlich equation and plotting adsorption isotherms for each adsorbent. Similar data are given for 10 different adsorbents in bleaching a refined soybean oil. On the basis of adsorbent activity, acid‐activated clays were 11/s to 2 times as effective as natural earths.
Design of a 5500 lb/hr solar steam plant
Authors: Allen D. J. , Gangadharan A. C. , Kumar S.
Published: July 2007

Solar thermal systems capable of providing process heat to the industries that make up the Food and Kindred Products Group are now commercially available. Whether or not they will be adopted by these industries will depend not only upon further reductions in capital costs, but also upon the costs and availability of alternative fossil fuels, the operating and maintenance costs of solar thermal systems, and tax incentives.
Determination of tocopherols and sterols by capillary gas chromatography
Authors: Slover H. T. , Thompson R. H. , Merola G. V.
Published: July 2007

A method is described for simultaneously determining tocopherols and sterols in fats and oils by quantitative capillary gas chromatography. Samples containing ca. 100 mg of lipid were saponified in capped tubes with aqueous KOH by heating for 8 min at 80 C; the unsaponifiable fraction was extracted with cyclohexane, freed of solvent, derivatized to form the trimethylsilyl ethers of both tocopherols and sterols, and chromatographed on a 50 m×0.25 mm glass capillary column coated with Dexsil 400. Most of the individual tocopherols and common sterols were well separated, although interfering peaks were seen in some samples, which for better specificity should be subjected to an initial purification. For most samples, however, the simplified sample preparation, without preliminary purification, was adequate when combined with capillary gas chromatography. Recovery, method and gas liquid chromatographic precision, and applications are discussed.