bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrafast electron transfer processes studied by pump‐repump‐probe spectroscopy
Authors: Fischer Martin K. , Gliserin Alexander , Laubereau Alfred , Iglev Hristo
Published: October 2010

The photodetachment of Br–, I– and OH– in aqueous solution is studied by 2‐ and 3‐pulse femtosecond spectroscopy. The UV excitation leads to fast electron separation followed by formation of a donor‐electron pairs. An additional repump pulse is used for secondary excitation of the intermediates. The 3‐pulse technique allows distinguishing the pair‐intermediate from the fully separated electron. Using this method we observe a novel geminate recombination channel of.OH with adjacent hydrated electrons. The process leads to an ultrafast quenching (0.7 ps) of almost half the initial number of radicals. The phenomenon is not observed in Br– and I–. Our results demonstrate the potential of the 3‐pulse spectroscopy to elucidate the mechanism of ultrafast ET reactions. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
2010 Financial reform: A guide for corporate treasurers
Authors: Ehrlich Michael
Published: October 2010

The Dodd‐Frank Financial Reform Bill of 2010 is the most ambitious piece of financial reform legislation since the Great Depression. Every U.S. corporation and citizen will be affected. For treasurers of financial firms like banks and brokers, the entire regulatory universe will be upended. But what will it mean for the corporate treasurer of a nonfinancial firm? The author provides a road map of what to expect, including future legislative changes and expected implementation problems. There is also a checklist for treasurers to help them handle the key issues. © 2010 Wiley Periodicals, Inc.
Maximizing cash through operational analysis
Authors: Reider Rob
Published: October 2010

The author looks at cash management by considering the principles needed to maintain your company in the most economical, efficient, and effective manner possible. If you keep these principles in mind, you can analyze operations and identify areas that need improvement—and then apply best practices that maximize cash inflow and minimize cash outflow. The author guides you through this process with a wealth of valuable bullet‐point checklists. © 2010 by Rob Reider
Cash management initiatives for your accounts payable operations
Authors: Schaeffer Mary S.
Published: October 2010

Accounts payable definitely affects your company's cash flow and cash management. The author explains several tactics your firm can use to improve its cash position‐as well as one or two that will inadvertently harm it.

This article is excerpted from Controller and CFO's Guide to Accounts Payable (John Wiley & Sons). © 2007 by Mary S. Schaeffer
A quick guide to bank lines of credit
Authors: Sagner James S.
Published: October 2010

Bank lines of credit are an important form of corporate borrowing. As banks cut back on business loans and other forms of credit, it pays to reexamine bank credit lines—and how your company can use them. The author discusses current implications for corporate borrowers and provides a list of action steps your firm should take. © 2010 Wiley Periodicals, Inc.
New revenue‐recognition model
Authors: Olsen Lori , Weirich Thomas R.
Published: October 2010

On June 24, 2010, the Financial Accounting Standards Board (FASB) and the International Accounting Standards Board (IASB) issued a joint exposure draft on revenue recognition. It marks a significant step toward international convergence. But the new revenue model may have a significant impact on the way some entities recognize revenue—and new disclosure guidance as to the amount, timing, and uncertainty of revenues and cash flows arising from customer contracts. Therefore, cash and treasury management should carefully analyze the impact that this new model can have on their particular entity. The authors explain how to apply the new model. © 2010 Wiley Periodicals, Inc.
Gen Y's addiction to web 2.0: Problem or strategy?
Authors: Mooney J. Lowell , Wright Jr. Harry R. , Higgins Leslee N.
Published: October 2010

Looming on the horizon is a long‐term threat that could endanger your company's very existence. That threat is a coming shortage of workers. But there's more bad news: the employees now entering the workplace, dubbed Generation Y, will be very difficult and expensive to retain.

What must your company do to attract and keep this newest generation of workers? And is their addiction to Web social networking a problem or a strategy? © 2010 Wiley Periodicals, Inc.
The final bleaching of eucalypt kraft pulps with hydrogen peroxide: relationship with industrial ECF bleaching history and cellulose degradation
Authors: Loureiro Pedro E. G. , Evtuguin Dmitry V. , Carvalho M. Graça V. S.
Published: October 2010

BACKGROUND: The process of chemical pulp bleaching is based for the most part in chlorine dioxide within elemental chlorine free (ECF) technologies. The use of greener alternatives such as bleaching with hydrogen peroxide (P stage) is not widely used owing to selectivity concerns related to transition metal‐catalyzed decomposition reactions. Even at the final stage where peroxide is recognized to boost brightness and improve the brightness stability of the bleached pulp, cellulose degradation often overcomes these advantages. This paper presents the results of studies intended to optimize final peroxide bleaching performance considering two standard ECF industrial bleaching sequences: the conventional DED and the ECF‐light OQ(PO)D (stages name: D—chlorine dioxide; E—alkaline extraction; O—oxygen; Q—chelation, (PO)—hydrogen peroxide pressurized with oxygen).

RESULTS: The addition of sodium diethylenetriaminepentaacetate (DTPA) was the most effective option in terms of DED pulp bleachability and selectivity with hydrogen peroxide, as well as in terms of brightness reversion. As regards the OQ(PO)D pulp, a blend of DTPA and magnesium was the most beneficial in those properties.

CONCLUSIONS: The choice of the best hydrogen peroxide stabilizer, among the different tested combinations of magnesium and chelants (EDTA and DTPA) studied, in terms of pulp bleachability, bleaching selectivity and brightness reversion is dependent on the impact of the previous bleaching stages on metallic nature and content. The pulp Mg/(Fe + Cu) ratio was highlighted as a process parameter controlling cellulose degradation in peroxide bleaching. Copyright © 2010 Society of Chemical Industry
Influence of preparation method and boron addition on the metal function properties of RuSn catalysts for selective carbonyl hydrogenation
Authors: Sánchez Maria A. , Mazzieri Vanina A. , Sad Mario R. , Grau Ricardo , Pieck Carlos L.
Published: October 2010

BACKGROUND: Improvements in the selective hydrogenation of unsaturated fatty acid methyl esters in order to obtain unsaturated fatty alcohols have been attempted through the preparation and modification of supported group VIII metallic catalysts. Suitable catalysts appear to be those based on supported Ru modified by Sn. The influence of preparation and activation methods on the structural and electronic properties of the metallic phase and the effect of modifications to these properties on the catalytic performance of RuSn/Al2O3 catalysts was studied regarding selective hydrogenation of carbonyl groups.

RESULTS: Preparation methods have a marked influence on the electronic state of Ru and its interaction with Sn. Temperature‐programmed reduction (TPR), Fourier transform infrared spectroscopy of chemisorbed CO (FTIR‐CO) and X‐ray photoelectron spectroscopy (XPS) results clearly show that the incorporation of sodium borohydride in the preparation leads to a greater RuSn interaction when compared with catalysts prepared by co‐impregnation without B. The activation of catalysts without B (either by direct reduction or calcinations‐reduction) does not produce a strong RuSn interaction. B‐containing catalysts exhibit higher hydrogenolytic and lower dehydrogenating activities. Selectivity towards oleyl alcohol formation was 37% for this catalyst, while catalysts without B were not suitable for obtaining fatty alcohols.

CONCLUSION: The degree of interaction between Ru and Sn strongly depends on catalyst preparation and activation method where strong interaction promotes selectivity with respect to oleyl alcohol formation. On the contrary, catalysts with a weak RuSn interaction do not show significant selectivity for the unsaturated alcohol. Copyright © 2010 Society of Chemical Industry
A shRNA library constructed through the generation of loop‐stem‐loop DNA
Authors: Nishikawa Yuji , Sugiyama Tomoyasu
Published: October 2010

Background

Short hairpin RNA (shRNA) libraries are considered to comprise a powerful tool in genetic screening. Several library construction methods have been proposed; these methods require between four and nine tedious reaction steps to construct the library. In the present study, we describe a method of generating shRNA‐coding DNA efficiently from randomized oligonucleotides based on four reaction steps.

Methods

Blunt end 29 nucleotides (nt) stem‐loop DNA was synthesized with a DNA polymerase I Klenow fragment from randomized oligonucleotides. The stem‐loop DNA was ligated with a 5′ phosphorylated hairpin linker to obtain novel loop‐stem‐loop DNA. Next, the complementary sequence, forming an 86 nt inverted repeat‐containing stem‐loop DNA, was synthesized using Klenow fragment. The stem‐loop DNA was digested and cloned into a small RNA expression vector. Luciferase activity in cells co‐transfected with a Renilla luciferase‐targeting shRNA plasmid and the luciferase expression plasmid was analyzed for the purpose of evaluating their specificity and efficiency for RNA interference (RNAi).

Results

shRNA‐coding DNA was generated from randomized oligonucleotides. The average GC content in the random sequence was 46.6%. Each sequence was unique. A shRNA generated by this method suppressed luciferase activity at a lower dose compared to a typical shRNA that contain a sequence perfectly matched to the target.

Conclusions

We constructed a shRNA library through four reaction steps, including the generation of loop‐stem‐loop DNA, without the polymerase chain reaction. A shRNA generated by this method retained its specificity of RNAi; however, the shRNA contained a target‐irrelevant 7 nt sequence adjacent to the loop. This method could be valuable in the area of functional genomics. Copyright © 2010 John Wiley & Sons, Ltd.
Binding of CDR‐derived peptides is mechanistically different from that of high‐affinity parental antibodies
Authors: Timmerman Peter , Shochat Susana G. , Desmet Johan , Barderas Rodrigo , Casal Jose Ignacio , Meloen Rob H. , Altschuh Danièle
Published: October 2010

We present data that reveal crucial differences between the binding mode of anti‐gastrin17 (G17, pyroEGPWLEEEEEAYGWMDF‐NH2) monoclonal antibodies (mAbs) and their CDR‐derived synthetic binders (SBs) with G17. The mAbs recognize the N‐terminal sequence of G17 (pyroEGPWL) with nanomolar affinity and high sequence selectivity. Molecular simulations suggest that G17 recognition is based primarily on a multitude of weak antibody–ligand interactions (H‐bonding, van der Waals, etc.) inside a structurally well‐defined cleft‐like binding pocket. Relatively small structural changes (e.g. G‐2 to A for G17) have a drastic impact on affinity, which is characteristic for antibody‐like binding. In contrast, SBs recognize various sequences, including G17‐unrelated targets with affinities of 1:1 complexes estimated in the 0.1–1.0 mM range. In most cases however, the G17/SB complex stoichiometries are not well‐defined, giving rise to multimer aggregate formation with high apparent complex stabilities. Mutational studies on both G17 and SBs reveal the importance of positively charged (K/R) and aromatic residues (W/Y/F) for G17/SB complex formation. We propose that the synthetic binders use combinations of electrostatic, hydrophobic, and/or cation–π interactions in a variety of ways due to their intrinsic flexibility. This may also be the reason for their relatively low target specificity. We speculate that our findings are of general relevance, in showing that high‐affinity mAbs do not necessarily provide the optimal basis for functional mimics design. Copyright © 2010 John Wiley & Sons, Ltd.
Warfarin: an environment‐dependent switchable molecular probe
Authors: Nicholls Ian A. , Karlsson Björn C. G. , Rosengren Annika M. , Henschel Henning
Published: October 2010

The complex nature of the structure of the anticoagulant warfarin is reflected in the diversity of binding modes observed in warfarin–protein recognition systems. A series of theoretical, 1H‐NMR and steady state and time resolved fluorescence spectroscopic studies, have been used to establish correlations between the molecular environment provided by various solvent systems and the relative concentrations of the various members of warfarin's ensemble of isomers. A consequence of these observations is that the judicious choice of solvent system or molecular environment of warfarin allows for manipulation of the position of the equilibrium between isomeric structures such as the hemiacetal and open phenol‐keto forms, the latter even possible in a deprotonated form, where in each case unique spectroscopic properties are exhibited by the respective structures. Collectively, warfarin's capacity to adapt its structure as a function of environment in conjunction with the fluorescence behaviours of the various isomers together provide an environment‐dependent molecular switch with reporter properties, which allows for the simultaneous detection of warfarin in different states with lifetimes spanning the range < 0.10–5.5 ns. These characteristics are here used to examine warfarin binding domains in a series of materials (solvents, protein, inorganic matrix and synthetic polymer). Moreover, these studies demonstrate the potential for using warfarin, or other switchable analogues thereof, as a tool for studying molecular level characteristics, for example local dielectricity. Copyright © 2010 John Wiley & Sons, Ltd.
Extension of the selection of protein chromatography and the rate model to affinity chromatography
Authors: Sandoval G. , Shene C. , Andrews B. A. , Asenjo J. A.
Published: October 2010

The rational selection of optimal protein purification sequences, as well as mathematical models that simulate and allow optimization of chromatographic protein purification processes have been developed for purification procedures such as ion‐exchange, hydrophobic interaction and gel filtration chromatography. This paper investigates the extension of such analysis to affinity chromatography both in the selection of chromatographic processes and in the use of the rate model for mathematical modelling and simulation. Two affinity systems were used: Blue Sepharose and Protein A. The extension of the theory developed previously for ion‐exchange and HIC chromatography to affinity separations is analyzed in this paper. For the selection of operations two algorithms are used. In the first, the value of η, which corresponds to the efficiency (resolution) of the actual chromatography and, Σ, which determines the amount of a particular contaminant eliminated after each separation step, which determines the purity, have to be determined. It was found that the value of both these parameters is not generic for affinity separations but will depend on the type of affinity system used and will have to be determined on a case by case basis. With Blue Sepharose a salt gradient was used and with Protein A, a pH gradient. Parameters were determined with individual proteins and simulations of the protein mixtures were done. This approach allows investigation of chromatographic protein purification in a holistic manner that includes ion‐exchange, HIC, gel filtration and affinity separations for the first time. Copyright © 2010 John Wiley & Sons, Ltd.
Magnetic resonance imaging findings in extrauterine malignant mixed mullerian tumors: Report of two cases
Authors: Yoon Jeong‐Hee , Cho Jeong Yeon , Hwang Sung Il , Lee Hak‐jong , Kim Seung‐Hyup
Published: October 2010

This report describes two cases of women who presented with huge abdominal masses. Those lesions were large, invasive, extrauterine masses, which showed inhomogeneous signal intensities at magnetic resonance image (MRI). After work‐up and surgery, the masses were identified as extremely rare malignant mixed Mullerian tumors that did not originate from the uterus. We have focused on the MRI findings of the tumors, with a review of the literature. J. Magn. Reson. Imaging 2010;32:1238–1241. © 2010 Wiley‐Liss, Inc.
Feasibility and precision of cerebral blood flow and cerebrovascular reactivity MRI measurements using a computer‐controlled gas delivery system in an anesthetised juvenile animal model
Authors: Winter Jeff D. , Fierstra Jorn , Dorner Stephanie , Fisher Joseph A. , Lawrence Keith S. , Kassner Andrea
Published: October 2010

Purpose:

To demonstrate the feasibility and repeatability of cerebrovascular reactivity (CVR) imaging using a controlled CO2 challenge in mechanically ventilated juvenile pigs.

Materials and Methods:

Precise end‐tidal partial pressure CO2 (PETCO2) control was achieved via a computer‐controlled model‐driven prospective end‐tidal targeting (MPET) system integrated with mechanical ventilation using a custom‐built secondary breathing circuit. Test‐retest blood‐oxygen level dependent (BOLD) CVR images were collected in nine juvenile pigs by quantifying the BOLD response to iso‐oxic square‐wave PETCO2 changes. For comparison, test‐retest baseline arterial spin labeling (ASL) cerebral blood flow (CBF) images were collected. Repeatability was quantified using the intra‐class correlation coefficient (ICC) and coefficient of variation (CV).

Results:

The repeatability of the PETCO2 (CV < 2%) step changes resulted in BOLD CVR ICC > 0.94 and CV < 6% for cortical brain regions, which was similar to ASL CBF repeatability (ICC > 0.96 and CV < 4%).

Conclusion:

This study demonstrates the feasibility and precision of CVR imaging with an MPET CO2 challenge in mechanically ventilated subjects using an animal model. Translation of this method into clinical imaging protocols may enable CVR imaging in young children with cerebrovascular disease who require general anesthesia. J. Magn. Reson. Imaging 2010;32:1068–1075. © 2010 Wiley‐Liss, Inc.
MRI of the neck at 3 Tesla using the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) (BLADE) sequence compared with T2‐weighted fast spin‐echo sequence
Authors: Ohgiya Yoshimitsu , Suyama Jumpei , Seino Noritaka , Takaya Shu , Kawahara Masaaki , Saiki Makoto , Sai Syouei , Hirose Masanori , Gokan Takehiko
Published: October 2010

Purpose:

To evaluate motion artifacts, tissue contrasts, and lesion detectability in the neck with the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) (BLADE) technique.

Materials and Methods:

A total of 46 patients referred for MRI of the neck were included in a comparison of T2‐weighted BLADE (T2W‐BLADE) sequence and T2W fast spin‐echo (T2W‐FSE) sequence. All examinations were performed at 3T using the same parameters. Two observers evaluated unlabelled images for motion artifacts, the preferred image quality, and lesion detectability. Region of interest (ROI)‐based quantitative measurements were performed to assess tissue contrasts. The frequency of occurrence of the different assessed artifacts and the lesion detectability was tested using McNemar's test. Tissue contrasts were compared using the Wilcoxon paired test. Reader agreement was assessed using kappa test.

Results:

T2W‐BLADE showed less ghosting and pulsation artifacts than T2W‐FSE (P < 0.01). T2W‐BLADE images were rated as better than or equal to T2W‐FSE images in majority cases (93.5%; kappa = 0.64). There was not significant difference in tissue contrasts between T2W‐BLADE and T2W‐FSE. A total of 32 lesions were present in 32 patients and equally well seen on T2W‐BLADE and T2W‐FSE.

Conclusion:

T2W‐BLADE can reduce motion artifacts and provide tissue contrasts and lesion detectability equivalent to T2W‐FSE. J. Magn. Reson. Imaging 2010;32:1061–1067. © 2010 Wiley‐Liss, Inc.
Spiral water–fat imaging with integrated off‐resonance correction on a clinical scanner
Authors: Börnert Peter , Koken Peter , Eggers Holger
Published: October 2010

Purpose

To integrate water‐fat–resolved spiral gradient‐echo imaging with off‐resonance correction into a clinical MR scanner and to evaluate its basic feasibility and performance.

Materials and Methods

Three‐point chemical shift imaging was implemented with forward and strongly T2*‐weighted reverse spiral sampling and with off‐resonance correction after water–fat separation. It was applied in a volunteer study on single breathhold abdominal imaging, which included a brief comparison with Cartesian sampling.

Results

Water‐fat–resolved, off‐resonance–corrected forward and reverse three‐dimensional interleaved spiral imaging was found to be feasible on a clinical MR scanner with only minor changes to the existing data acquisition and reconstruction, and to provide good image quality. Three‐point chemical shift encoded data thus support both, water–fat separation and off‐resonance correction with high accuracy.

Conclusion

The combination of chemical shift encoding and appropriate postprocessing could pave the way for water‐fat–resolved spiral imaging in clinical applications. J. Magn. Reson. Imaging 2010;32:1262–1267. © 2010 Wiley‐Liss, Inc.
Acute abdominal pain: Is there a potential role for MRI in the setting of the emergency department in a patient with renal calculi?
Authors: Kalb Bobby , Sharma Puneet , Salman Khalil , Ogan Kenneth , Pattaras John G. , Martin Diego R.
Published: October 2010

Acute flank pain is a frequent clinical presentation encountered in emergency departments, and a work‐up for obstructive urolithiasis in this setting is a common indication for computed tomography (CT). However, imaging alternatives to CT for the evaluation of renal colic are warranted in some clinical situations, such as younger patients, pregnancy, patients that have undergone multiple prior CT exams and also patients with vague clinical presentations. MRI, although relatively insensitive for the direct detection of urinary calculi, has the ability to detect the secondary effects of obstructive urolithiasis. Using rapid, single shot T2‐weighted sequences without and with fat saturation provides an abdominopelvic MR examination that can detect the sequelae of clinically active stone disease, in addition to alternate inflammatory processes that may mimic the symptoms of renal colic. In addition, MR nephro‐urography (MRNU) has the ability to provide quantitative analysis of renal function that has the potential to direct clinical management in the setting of obstructing calculi. This review describes the potential utility and limitations of MRI in the emergency setting for diagnosing causes of flank pain and renal colic, particularly in patients with unusual presentations or when an alternative to CT may be warranted. J. Magn. Reson. Imaging 2010;32:1012–1023. © 2010 Wiley‐Liss, Inc.
Combined use of neuroradiology and 1H‐MR spectroscopy may provide an intervention limiting diagnosis of glioblastoma multiforme
Authors: Fellows Greg A. , Wright Alan J. , Sibtain Naomi A. , Rich Phil , Opstad Kirstie S. , McIntyre Dominick J.O. , Bell B. Anthony , Griffiths John R. , Howe Franklyn A.
Published: October 2010

Purpose

To evaluate the accuracy of 1H‐MR spectroscopy (1H‐MRS) as an intervention limiting diagnostic tool for glioblastoma multiforme. GBM is the most common and aggressive primary brain tumor, with mean survival under a year. Oncological practice currently requires histopathological diagnosis before radiotherapy.

Materials and Methods

Eighty‐nine patients had clinical computed tomography (CT) and MR imaging and 1.5T SV SE 1H‐MRS with PRESS localization for neuroradiological diagnosis and tumor classification with spectroscopic and automated pattern recognition analysis (TE 30 ms, TR 2000 ms, spectral width 2500 Hz and 2048 data points, 128–256 signal averages were acquired, depending on voxel size (8 cm3 to 4 cm3). Eighteen patients from a cohort of 89 underwent stereotactic biopsy.

Results

The 18 stereotactic biopsies revealed 14 GBM, 2 grade II astrocytomas, 1 lymphoma, and 1 anaplastic astrocytoma. All 14 biopsied GBMs were diagnosed as GBM by a protocol combining an individual radiologist and an automated spectral pattern recognition program.

Conclusion

In patients undergoing stereotactic biopsy combined neuroradiological and spectroscopic evaluation diagnoses GBM with accuracy that could replace the need for biopsy. We do not advocate the replacement of biopsy in all patients; instead our data suggest a specific intervention limiting role for the use of 1H‐MRS in brain tumor diagnosis. J. Magn. Reson. Imaging 2010;32:1038–1044. © 2010 Wiley‐Liss, Inc.
Prospective comparison of image quality and diagnostic accuracy of 0.5 molar gadobenate dimeglumine and 1.0 molar gadobutrol in contrast‐enhanced run‐off magnetic resonance angiography of the lower extremities
Authors: Achenbach Marina , Figiel Jens H. , Burbelko Mykhaylo , Heverhagen Johannes T.
Published: October 2010

Purpose

To compare image quality and diagnostic accuracy of 0.5 molar gadobenate dimeglumine and 1.0 molar gadobutrol in contrast‐enhanced (CE) magnetic resonance angiography (MRA) of the lower extremities interindividually.

Materials and Methods

The study was approved by our Institutional Review Board. Written informed consent was obtained from all patients before enrollment in the study. We prospectively included 74 patients (21 women, 53 men; mean age ± SD: 67.9 ± 11.0 years) with suspected peripheral occlusive vascular disease. All patients underwent a contrast‐enhanced MRA of both lower extremities with either 0.1 mL/kg body weight gadobutrol or gadobenate dimeglumine. Image quality, stenosis grade, and artifacts were assessed by two blinded, independent investigators. Signal intensity (SI), signal‐to‐noise ratio (SNR), and contrast‐to‐noise ratio (CNR) were measured by a third investigator. Contrast agent groups were compared to each other using a two‐sided Student's t‐test.

Results

The results did not show significant differences for SI, SNR, or CNR. Both investigators were in significant accordance (P < 0.05) with regard to stenosis detection.

Conclusion

We conclude that application of standard clinical doses (0.1 mL/kg body weight) of both contrast agents provides similar diagnostic results and gadolinium dose could be reduced by the application of a single dose of gadobenate dimeglumine for CE run‐off MRA. J. Magn. Reson. Imaging 2010;32:1166–1171. © 2010 Wiley‐Liss, Inc.
Distribution of cardiac iron measured by magnetic resonance imaging (MRI)‐R*2
Authors: Yamamura Jin , Grosse Regine , Graessner Joachim , Janka Gritta E. , Adam Gerhard , Fischer Roland
Published: October 2010

Purpose

To assess regional iron distribution by magnetic resonance imaging (MRI)‐R2* within the heart of patients with β‐thalassemia major (TM) and other iron overload diseases.

Materials and Methods

Breathhold electrocardiogram (ECG)‐gated MRI (1.5 T) of the heart was used for the measurement of transverse relaxation rates R2* in 32 patients (11–79 years). In a mid‐papillary short‐axis slice divided into septal, anterior, lateral, and posterior quadrants, R2* was analyzed from region of interest (ROI)‐based signal intensities from 12 echo times (TE = 1.3–26 msec). Typical boundary effects were evaluated in detail.

Results

The segmentation of the cardiac wall resulted in highly significant correlations of R2* between septal and all other quadrants. In the patient group with R2* < 50 s−1 (normal), all quadrants show higher normalized median rates (126%–174%) than the septum (P < 10−4), while this was relatively smaller in the group with septal R2* > 50 s−1. Typical boundary effects on segmental R2* from blood, lung tissue, epicardial fat, and hepatic iron could not be easily separated from segmental iron distribution.

Conclusion

The measurement of MRI‐R2* in the interventricular septum is the least affected method by boundary effects to detect patients with iron overload at risk of developing heart failure. J. Magn. Reson. Imaging 2010;32:1104–1109. © 2010 Wiley‐Liss, Inc.
Lower brain glutamate is associated with cognitive deficits in HIV patients: A new mechanism for HIV‐associated neurocognitive disorder
Authors: Ernst Thomas , Jiang Caroline S. , Nakama Helenna , Buchthal Steven , Chang Linda
Published: October 2010

Purpose

To determine whether subjects with human immunodeficiency virus (HIV)‐associated neurocognitive disorder (HAND) show altered concentrations of brain glutamate (GLU), and whether lower GLU levels correlate with cognitive deficits.

Materials and Methods

GLU concentrations were measured in the basal ganglia, frontal gray and white matter, and parietal gray matter of 45 HIV‐positive and 46 age‐and‐education‐matched HIV‐negative subjects using echo‐time averaged proton magnetic resonance spectroscopy (1H MRS).

Results

Compared to controls, HIV subjects with cognitive deficits had lower GLU in the parietal gray matter, while those without cognitive deficits tended to show higher basal ganglia GLU. Lower parietal and frontal gray matter GLU were associated with a greater number of nucleoside reverse transcriptase inhibitors, and were predictive of poorer cognitive performance. Correlations between GLU and cognitive performance, but not the other findings, remained significant after correction for multiple comparisons.

Conclusion

Parietal gray matter GLU is lower in HIV subjects with cognitive deficits. This reduction might result from reduced astrocytic reuptake of GLU, secondary excitotoxicity, and mitochondrial toxicity from antiretroviral treatments. The glutamatergic system may play an important role in the pathophysiology of HAND, and brain GLU on 1H MRS may provide an early surrogate marker for monitoring disease severity and treatment effects. J. Magn. Reson. Imaging 2010;32:1045–1053. © 2010 Wiley‐Liss, Inc.
Faster dynamic imaging of speech with field inhomogeneity corrected spiral fast low angle shot (FLASH) at 3 T
Authors: Sutton Bradley P. , Conway Charles A. , Bae Youkyung , Seethamraju Ravi , Kuehn David P.
Published: October 2010

Purpose

To evaluate the impact of magnetic field inhomogeneity correction on achievable imaging speeds for magnetic resonance imaging (MRI) of articulating oropharyngeal structures during speech and to determine if sufficient acquisition speed is available for visualizing speech structures with real‐time MRI.

Materials and Methods

We designed a spiral fast low angle shot (FLASH) sequence that combines several acquisition techniques with an advanced image reconstruction approach that includes magnetic field inhomogeneity correction. A simulation study was performed to examine the interaction between imaging speed, image quality, number of spiral shots, and field inhomogeneity correction. Six volunteer subjects were scanned to demonstrate adequate visualization of articulating structures during simple speech samples.

Results

The simulation study confirmed that magnetic field inhomogeneity correction improves the available tradeoff between image quality and speed. Our optimized sequence co‐acquires magnetic field maps for image correction and achieves a dynamic imaging rate of 21.4 frames per second, significantly faster than previous studies. Improved visualization of anatomical structures, such as the soft palate, was also seen from the field‐corrected reconstructions in data acquired on volunteer subjects producing simple speech samples.

Conclusion

Adequate temporal resolution of articulating oropharyngeal structures during speech can be obtained by combining outer volume suppression, multishot spiral imaging, and magnetic field corrected image reconstruction. Correcting for the large, dynamic magnetic field variation in the oropharyngeal cavity improves image quality and allows for higher temporal resolution. J. Magn. Reson. Imaging 2010;32:1228–1237. © 2010 Wiley‐Liss, Inc.
4D time‐resolved magnetic resonance angiography for noninvasive assessment of pulmonary arteriovenous malformations patency
Authors: Boussel Loic , Cernicanu Alexandru , Geerts Liesbeth , Gamondes Delphine , Khouatra Chahera , Cottin Vincent , Revel Didier , Douek Philippe
Published: October 2010

Purpose

To assess the capability of four‐dimensional (4D) time‐resolved magnetic resonance angiography (MRA) to assess pulmonary arteriovenous malformations (PAVMs) patency by analyzing pulmonary arterial and venous enhancement kinetics.

Materials and Methods

Seven patients with eight documented patent PAVMs underwent a 4D‐MRA with keyhole and viewsharing compression at 3T with the following parameters: spatial resolution 0.87 × 0.87 × 1.4 mm3; field of view 500 × 350 × 238 mm3; dynamic scan time (temporal resolution) 1.2 seconds; total acquisition time 18.1 seconds for six dynamic datasets (6 × 1.2 sec + reference scan: 10.9 sec). All images were reviewed by two experienced radiologists. Image quality was rated on a qualitative 5‐point scale (1: not assessable to 5: excellent). Signal value was measured on cross‐sectional planes for the afferent arteries and efferent veins of the PAVM, and for normal reference healthy arteries and veins. The difference in time to peak for each coupled artery/vein (dTTPav) was calculated and compared with a Mann–Whitney test between PAVMs and reference vessels.

Results

Mean image quality was 3.2 ± 0.9. dTTPav was significantly smaller in PAVMs (0.15 ± 0.76 sec) than in reference vessels (3.75 ± 1.62 sec), P < 0.001.

Conclusion

4D‐MRA is a promising tool for noninvasive assessment of PAVM patency. J. Magn. Reson. Imaging 2010;32:1110–1116. © 2010 Wiley‐Liss, Inc.
Analysis of deprotonated acids with silicon nanoparticle‐assisted laser desorption/ ionization mass spectrometry
Authors: Hua Yimin , Dagan Shai , Wickramasekara Samanthi , Boday Dylan J. , Wysocki Vicki H.
Published: October 2010

Chemically modified silicon nanoparticles were applied for the laser desorption/negative ionization of small acids. A series of substituted sulfonic acids and fatty acids was studied. Compared to desorption ionization on porous silicon (DIOS) and other matrix‐less laser desorption/ionization techniques, silicon nanoparticle‐assisted laser desorption/ionization (SPALDI) mass spectrometry allows for the analysis of acids in the negative ion mode without the observation of multimers or cation adducts. Using SPALDI, detection limits of many acids reached levels down to 50 pmol/µl. SPALDI of fatty acids with unmodified silicon nanoparticles was compared to SPALDI using the fluoroalkyl silylated silicon powder, with the unmodified particles showing better sensitivity for fatty acids, but with more low‐mass background due to impurities and surfactants in the untreated silicon powder. The fatty acids exhibited a size‐dependent response in both SPALDI and unmodified SPALDI, showing a signal intensity increase with the chain length of the fatty acids (C12‐C18), leveling off at chain lengths of C18‐C22. The size effect may be due to the crystallization of long chain fatty acids on the silicon. This hypothesis was further explored and supported by SPALDI of several, similar sized, unsaturated fatty acids with various crystallinities. Fatty acids in milk lipids and tick nymph samples were directly detected and their concentration ratios were determined by SPALDI mass spectrometry without complicated and time‐consuming purification and esterification required in the traditional analysis of fatty acids by gas chromatography (GC). These results suggest that SPALDI mass spectrometry has the potential application in fast screening for small acids in crude samples with minimal sample preparation. Copyright © 2010 John Wiley & Sons, Ltd.
Non‐covalent interactions of alkali metal cations with singly charged tryptic peptides
Authors: Rožman Marko , Gaskell Simon J.
Published: October 2010

The complexes formed by alkali metal cations (Cat+ = Li+, Na+, K+, Rb+) and singly charged tryptic peptides were investigated by combining results from the low‐energy collision‐induced dissociation (CID) and ion mobility experiments with molecular dynamics and density functional theory calculations. The structure and reactivity of [M + H + Cat]2+ tryptic peptides is greatly influenced by charge repulsion as well as the ability of the peptide to solvate charge points. Charge separation between fragment ions occurs upon dissociation, i.e. b ions tend to be alkali metal cationised while y ions are protonated, suggesting the location of the cation towards the peptide N‐terminus. The low‐energy dissociation channels were found to be strongly dependant on the cation size. Complexes containing smaller cations (Li+ or Na+) dissociate predominantly by sequence‐specific cleavages, whereas the main process for complexes containing larger cations (Rb+) is cation expulsion and formation of [M + H]+. The obtained structural data might suggest a relationship between the peptide primary structure and the nature of the cation coordination shell. Peptides with a significant number of side chain carbonyl oxygens provide good charge solvation without the need for involving peptide bond carbonyl groups and thus forming a tight globular structure. However, due to the lack of the conformational flexibility which would allow effective solvation of both charges (the cation and the proton) peptides with seven or less amino acids are unable to form sufficiently abundant [M + H + Cat]2+ ion. Finally, the fact that [M + H + Cat]2+ peptides dissociate similarly as [M + H]+ (via sequence‐specific cleavages, however, with the additional formation of alkali metal cationised b ions) offers a way for generating the low‐energy CID spectra of ‘singly charged’ tryptic peptides. Copyright © 2010 John Wiley & Sons, Ltd.
Oxaliplatin‐based hyperthermic intraperitoneal chemotherapy in primary or recurrent epithelial ovarian cancer: A pilot study of 31 patients
Authors: Frenel Jean‐Sebastien , Leux Christophe , Pouplin Luc , Ferron Gwenael , Berton‐Rigaud Dominique , Bourbouloux Emmanuelle , Dravet François , Jaffre Isabelle , Classe Jean‐Marc
Published: October 2010

Background

The feasibility and safety of oxaliplatin‐based hyperthermic intraperitoneal chemotherapy (HIPEC) associated with cytoreductive surgery (CRS) was assessed in patients with peritoneal carcinomatosis resulting from primary advanced or relapsing epithelial ovarian cancer (EOC).

Methods

Thirty‐one patients received neoadjuvant platin‐based chemotherapy followed by oxaliplatin‐based HIPEC associated with CRS as consolidation of primary therapy (n = 19) or for relapsing disease (n = 12). Grade 3/4 complications were recorded according to National Cancer Institute definitions.

Results

Median peritoneal carcinomatosis index (PCI) was 2.7 after neoadjuvant chemotherapy. Mean duration of surgery was 352 min (range 105–614) and median hospital stay was 11 days (range 6–87). Grade 3 toxicity was observed in nine patients: five required repeat surgery, two an invasive procedure, four rehospitalization, and three a return to the ICU. No grade 4 toxicity occurred, excepted one hypokalemia. Median progression‐free survival (PFS) for primary advanced EOC was 13.2 months and 1‐year PFS was 59.3%. Median PFS for relapsing patients was 14.3 months and 1‐year PFS was 54.4%.

Conclusion

CRS with oxaliplatin‐based HIPEC is feasible and relatively safe in recurrent and primary EOC. HIPEC after neoadjuvant chemotherapy reduces the PCI and decreases the number of surgical procedures and morbidity. Further evaluations of this procedure are required to assess the survival benefits. J. Surg. Oncol. 2011;103:10–16. © 2010 Wiley‐Liss, Inc.
Adverse prognosis of clustered‐cell versus single‐cell micrometastases in pN0 early gastric cancer
Authors: Cao Liang , Hu Xiang , Zhang Yi , Huang Gang
Published: October 2010

Background and Objectives

The clinical significance of lymph node micrometastasis (MM) for pN0 early gastric cancer is not well documented. The aim of this study is to clarify the risk factors of lymph node MM and the prognostic significance of the type of lymph node MM in patients with pN0 early gastric cancer.

Methods

We investigated the lymph node MM with using an anticytokeratin immunohistochemical stain in 160 patients with pN0 early gastric cancer who underwent curative resection between 2000 and 2005.

Results

We identified lymph node MM in 34 of 160 patients (21.3%), and in 84 of 1,656 lymph nodes (5.1%). MM occurred as single‐cell type in 10 patients and as cell cluster type in 24 patients. MM was significantly associated with tumor size (P = 0.041) and lymphatic invasion (P = 0.008). The statistically significant prognostic factors affecting 5‐year survival rates were depth of tumor invasion (P = 0.020), tumor size (P = 0.035), lymphatic invasion (P = 0.018), MM (P < 0.001), and type of MM (P < 0.001). Cox regression survival analysis revealed that the presence of MM, and particularly the cluster‐type MM (P < 0.001), were independent prognostic factors in pN0 early gastric cancer patients.

Conclusions

The incidence of lymph node MM in patients with node negative early gastric cancer was 21.3%, and cancer cell cluster type of MM proved a primary independent prognostic factor for pN0 early gastric cancer patients. J. Surg. Oncol. 2011;103:53–56. © 2010 Wiley‐Liss, Inc.
Analysis of 151 consecutive gastric submucosal tumors according to tumor location
Authors: Lee Han Hong , Hur Hoon , Jung Hun , Jeon Hae Myung , Park Cho Hyun , Song Kyo Young
Published: October 2010

Background

The aim of the present study was to evaluate the histopathological characteristics of gastric submucosal tumors (SMTs) according to their location.

Methods

A retrospective analysis of a prospective database of 151 consecutive patients who underwent surgery for gastric SMTs between 2001 and 2009 was performed.

Results

Of 151 gastric SMTs, 100 (66.2%) were gastrointestinal stromal tumors, 21 (13.9%) were leiomyomas, and 30 (19.9%) were other benign tumors. Leiomyoma was the most common neoplasm at the cardia (55.2%; P < 0.05), and the incidence of endophytic cardia tumors was higher compared with other locations (65.5%; P < 0.05). SMTs located at the cardia were significantly smaller than those found in the upper third (2.6 ± 1.0 vs. 4.1 ± 3.0; P < 0.05) and middle third (2.6 ± 1.0 vs. 3.9 ± 3.3; P < 0.05) of the stomach.

Conclusions

The characteristics of gastric SMTs located at the cardia differ significantly from those of gastric SMTs located in other regions of the stomach. These findings suggest that treatment strategy should be tailored by the location of tumors. J. Surg. Oncol. 2011;104:72–75. © 2010 Wiley‐Liss, Inc.
A matrix solid‐phase dispersion–gel permeation chromatography–programmed temperature vaporisation–GC‐MS procedure for the analysis of polycyclic aromatic hydrocarbons in mussel samples
Authors: Fernández‐González Verónica , Concha‐Graña Estefanía , Muniategui‐Lorenzo Soledad , López‐Mahía Purificación , Fernández‐Fernández Esther , Prada‐Rodríguez Dario
Published: October 2010

A simultaneous matrix solid‐phase dispersion extraction‐gel permeation chromatography cleanup with programmed temperature vaporisation GC‐MS determination is proposed for the analysis of parent and alkylated polycyclic aromatic hydrocarbons (PAHs) in mussel samples. The parameters affecting the extraction and elution efficiency were studied. Final conditions were: 0.5 g of mussel sample, 0.5 g diatomaceous earth as dispersant; and 4 g of Bio‐Beads S‐X3 for the gel permeation chromatography. Ethyl acetate/hexane (1:1, v/v) was selected for the elimination of the lipid fraction and the elution of PAHs. The detection and quantification limits achieved with this procedure were between 0.01 μg/kg and 0.67 μg/kg and 0.02 μg/kg and 1.93 μg/kg, respectively. The linearity of the method ranged between 5 μg/kg and 1000 μg/kg for most of the studied PAHs. The method was validated by the analysis of mussel tissue reference material (SRM 2977). The repeatability, intermediate precision and accuracy of the method obtained are in excellent agreement with the certified values. The proposed method is simple, precise and robust; no special instruments or costly equipment are required, and a reduction in the total time of analysis, sample handling and solvent consumption is achieved in comparison with classic procedures.
Molecular‐imprinted polymer extraction combined with dispersive liquid–liquid micro‐extractionfor ultra‐preconcentration of mononitrotoluene
Authors: Ebrahimzadeh Homeira , Abedi Hamid , Yamini Yadollah , Adlnasab Laleh
Published: October 2010

Molecular‐imprinted polymer (MIP) combined with dispersive liquid–liquid micro‐extraction (DLLME) were developed for ultra‐preconcentration and determination of mononitrotoluenes in wastewater samples using gas chromatography–flame ionization detector. MIP was synthesized by copolymerization of methacrylic acid–ethylene glycole dimethacrylate–2,2‐azobisisobutyronitrile as the initiator that imprinted with 3‐nitrotoluene as the template molecule. Effects of several factors, such as type and volume of eluent, adsorption, and desorption times of the analyte on the polymer, and breakthrough volume were investigated. Optimization of 3‐nitrotoluene extraction from MIP was studied forward followed by DLLME. Preconcentration factor of MIP‐DLLME method was about 2800 under the optimum conditions. The LOD of the proposed method was 0.02 μg/L and a linear dynamic range in the range of 0.04–20 μg/L was obtained. The performance of the present method was evaluated for extraction and determination of nitrotoluene compounds in wastewater samples in the range of microgram per liter and satisfactory results were achieved (RSD<13%).
Financial cost–benefit analysis of bench terraces in Rwanda
Authors: Bizoza A. R. , de Graaff J.
Published: October 2010

Bench terracing has received considerable attention from soil and water conservation (SWC) programmes involved in soil erosion control in Rwanda. It is questioned, however, whether enough attention is paid to the suitability of the soils and to the eventual financial profitability. Terraces may reduce soil erosion and increase production but they should also provide sufficient financial gains at farm level. A plot level financial cost–benefit analysis was undertaken to examine under which social and economic conditions bench terraces are financially viable in Northern and Southern Rwanda. Farmers' estimates of respective costs and potato yields from plots with subsidized and un‐subsidized bench terraces, progressive terraces and plots with no terraces at all were obtained for the analysis. Costs of labour and manure were found to be the most influential for the profitability of bench and progressive terraces. While the cost–benefit analysis, using market prices, showed that bench terraces would be hardly profitable, an analysis with opportunity costs for labour and manure indicated that bench terraces and even more progressive terraces can be financially profitable. Extra measures and incentives may be required to facilitate use of labour and access to manure, as now achieved with the one cow per family policy. This paper suggests that further studies should be undertaken to determine costs and benefits of bench terraces beyond private perspective in Rwanda. Copyright © 2010 John Wiley & Sons, Ltd.