bluuebunny/crossref_metadata_2025 huggingface dataset:
Gold(I)‐Catalyzed Bis‐Spiroketalization: Synthesis of the Trioxadispiroketal‐Containing A—D Rings (II) of Azaspiracid.
Authors: Li Yongfeng , Zhou Feng , Forsyth Craig J.
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Hydrothermal Synthesis of Single‐Crystalline Antimony Telluride Nanobelts.
Authors: Shi Weidong , Yu Jiangbo , Wang Haishui , Zhang Hongjie
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Direct Observation of the Ferromagnetic Spin Polarization in Gold Nanoparticles: A Review
Authors: Yamamoto Y. , Hori H.
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Carbon Nanomaterials with Controlled Macroscopic Shapes as New Catalytic Materials
Authors: Pham‐Huu Cuong , Ledoux Marc‐Jacques
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Platinum Complexes Featuring Terminally Bound Ga+ and In+ Ions
Authors: Aldridge Simon
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Chemistry of Ru(η6‐1,3,5‐cyclooctatriene)(η2‐dimethyl Fumarate)2
Authors: Mitsudo Take‐Aki , Ura Yasuyuki , Kondo Teruyuki
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Cluster Rhenium(III) Complexes with Adamantanecarboxylic Acids: Synthesis and Properties
Authors: Golichenko A. A. , Shtemenko A. V.
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Enamine‐Based Aldol Organocatalysis in Water: Are They Really “All Wet”?
Authors: Brogan Andrew P. , Dickerson Tobin J. , Janda Kim D.
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
In Water or in the Presence of Water?
Authors: Hayashi Yujiro
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Potassium Metal
Authors: Venturello P. , Barbero M.
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of Heterocyclic Ring Systems Using Organometallic Reagents
Authors: Agarwal Sameer , Knoell Jan , Krahl Micha P. , Knoelker Hans‐Joachim
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Advances in the Synthesis of H‐Phosphinic Acids and Esters
Authors: Montchamp Jean‐Luc
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Electrochemistry in Preparing Organophosphorus Compounds
Authors: Peruzzini Maurizio
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Chemistry and Biological Activities of 2‐Azetidinones
Authors: Ilyas Babar , Ajmal Mohammad , Imran Mohammad , Khan S. A.
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Recent Developments in the Chemistry and Biology of Epothilones
Authors: Altmann Karl‐Heinz , Cachoux Frederic , Caravatti Giorgio , Isarno Thomas , Wartmann Markus
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis by Substitution of Carbon Functionalities
Authors: Carroll M. A.
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Total Asymmetric Synthesis of Monosaccharides and Analogues
Authors: Vogel Pierre
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Optimization of in vivo Gene Transfer Through Regulating Biological Response to Vectors
Authors: Nishikawa Makiya
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Fluorescent DNA Base Replacements: Reporters and Sensors for Biological Systems
Authors: Wilson James N. , Kool Eric T.
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Electrospray Mass Spectrometry (ESI‐MS) in the Study of Metal—Ligand Solution Equilibria
Authors: Di Marco Valerio B. , Bombi G. Giorgio
Published: March 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Chirality as a tool in nucleic acid recognition: Principles and relevance in biotechnology and in medicinal chemistry
Authors: Corradini Roberto , Sforza Stefano , Tedeschi Tullia , Marchelli Rosangela
Published: March 2007

The understanding of the interaction of chiral species with DNA or RNA is very important for the development of new tools in biology and of new drugs. Several cases in which chirality is a crucial point in determining the DNA binding mode are reviewed and discussed, with the aim of illustrating how chirality can be considered as a tool for improving the understanding of mechanisms and the effectiveness of nucleic acid recognition. The review is divided into two parts: the former describes examples of chiral species interacting with DNA: intercalators, metal complexes, and groove binders; the latter part is dedicated to chirality in DNA analogs, with discussion of phosphate stereochemistry and chirality of ribose substitutes, in particular of peptide nucleic acids (PNAs) for which a number of works have been published recently dealing with the effect of chirality in DNA recognition. The discussion is intended to show how enantiomeric recognition originates at the molecular level, by exploiting the enormous progresses recently achieved in the field of structural characterization of complexes formed by nucleic acid with their ligands by crystallographic and spectroscopic methods. Examples of application of the DNA binding molecules described and the role of chirality in DNA recognition relevant for biotechnology or medicinal chemistry are reported. Chirality, 2007. © 2007 Wiley‐Liss, Inc.
Enantioselective and diastereoselective Michael addition of ketone/aldehyde to trans‐nitroolefins catalyzed by a novel chiral pyrrolidine‐thiourea
Authors: Shen Zongxuan , Zhang Yongqiang , Jiao Chongjun , Li Bin , Ding Juan , Zhang Yawen
Published: March 2007

The direct Michael addition reaction of cyclohexanone/aliphatic aldehydes with nitroolefins, catalyzed by a novel chiral pyrrolidine‐thiourea catalyst 1a, is described. The desired 1,4‐adducts were obtained in moderate yields with enantioselectivities up to 99% ee and dr up to 99:1 of the syn product. Chirality, 2007. © 2007 Wiley‐Liss, Inc.
Categorical selection of the antibody repertoire in splenic B cells
Authors: Schelonka Robert L. , Tanner Jason , Zhuang Yingxin , Gartland G. Larry , Zemlin Michael , Schroeder Harry W.
Published: March 2007

In the bone marrow, the passage of developing B cells through critical checkpoints of differentiation is associated with a reduction of specific categories of CDR3 of the Ig heavy chain (CDR‐H3), particularly those with excessive hydrophobic or charged amino acids and those with a length of eight or fewer residues. To gain insight into the role of CDR‐H3 content in the development of B cells in the spleen, we compared the sequences of VH7183DJCμ transcripts from sorted transitional T1, marginal zone, and follicular B cell subsets to those expressed by immature IgM+IgD– and mature IgMloIgDhi B cells in the bone marrow. Although differences in VH utilization were noted, the T1 CDR‐H3 repertoire showed extensive similarity to that of immature bone marrow B cells, and the follicular CDR‐H3 repertoire most resembled that of mature bone marrow B cells. Unlike the splenic follicular and bone marrow mature B cell CDR‐H3 repertoires, the marginal zone B cell CDR‐H3 repertoire retained both short and highly charged amino acid motifs, including those with two arginines. Our findings suggest that antigen binding sites containing specific categories of CDR‐H3 sequence content may inhibit, permit, or even facilitate passage of the host B cell through critical checkpoints in peripheral as well as central development.
Analysis of dust pollution in slate and granite transformation plants
Authors: Ordóñez Celestino , Saavedra Angeles , Taboada Javier , Alejano Leandro
Published: March 2007

The production of dust in natural stone transformation plants causes respiratory illnesses in workers that, over time, may seriously affect their physical health. In this article we study dust contamination in a number of ornamental slate and granite transformation plants located in Galicia, in northwest Spain. Using dust concentration measures combined with other factors that increase or decrease the noxious effects of dust (noise, duration over time, etc.), and applying multivariate and geostatistical techniques, we were able to construct dust concentration and associated environmental impact maps. The results were integrated in a GIS (Geographical Information System), which allows us to view the contamination maps, as also information on the machinery used, the associated work stations, the most contaminated areas of each plant, etc. This information was then used to analyze the problem in each plant and to compare results between plants. We propose a method designed to reduce worker exposure to dust using an individualised dust capture system at each of the work stations. The pollution control system and its characteristics were finally incorporated into the GIS to allow interested parties such as the managers of the plants studied or people interested in designing a new plant to consult the available information. © 2007 American Institute of Chemical Engineers Environ Prog, 2007.
Assessing mid‐continent area power pool capacity adequacy including transmission limitations
Authors: Chowdhury A. A. , Glover B. P. , Brusseau L. E. , Hebert S. , Jarvenpaa F. , Jensen A. , Stradley K. , Turanli H. , Haringa G. E.
Published: March 2007

This paper presents the results of a multi‐area generating capacity adequacy assessment performed by the Composite System Reliability Working Group (CSRWG) for the Mid‐Continent Area Power Pool's (MAPP's) United States (US) thermal system. The impact of transmission resource limitations within the MAPP region on the system reserve margin has been studied. In addition, the generating unit forced outage rate uncertainty, extreme hot summer loading conditions and the load forecast uncertainty are explicitly modelled in the study. The basic objective of this study was to determine the Reserve Capacity Obligation (RCO) for the MAPP‐US thermal system for the years 2003, 2006, 2009 and 2012. Similar studies have been performed in 1991 and 1994, and one of the purposes of this study was to determine whether or not the recommendations from the previous studies were still valid. The results of the study confirmed the current RCO level for the MAPP‐US thermal system. Copyright © 2007 John Wiley & Sons, Ltd.
Acute oral toxicity of colchicine in rats: effects of gender, vehicle matrix and pre‐exposure to lipopolysaccharide
Authors: Wiesenfeld Paddy L. , Garthoff Larry H. , Sobotka Thomas J. , Suagee Jessica K. , Barton Curtis N.
Published: March 2007

The oral toxicity of a single administration by gavage (10, 20 or 30 mg kg−1 body weight) of colchicine (COL) was determined in young, mature male and female Sprague‐Dawley rats. The effect of COL was evaluated in the presence or absence of additional treatment variables that included vehicle and lipopolysaccharide (LPS) pre‐exposure. The vehicle for COL was either Half and Half cream (H & H) or saline, and each group included pretreatment with either saline or a low, minimally toxic dose (83 µg kg−1 body weight) of LPS. Colchicine toxicity in both male and female age‐matched rats was characterized by progressively more severe dose‐related clinical signs of toxicity. These included mortality, decreased body weight and feed intake during the first several days after dosing, with recovery thereafter in surviving animals. There were differences in the severity of the toxic response to COL between male and female rats. The most notable sex‐related difference was in COL lethality. Female rats were two times more susceptible to the lethal effects of COL than male rats. Saline or H & H delivery vehicles did not result in any apparent qualitative or quantitative differences in COL toxicity. LPS pretreatment significantly potentiated COL lethality in both males and females, although the potentiation in males was greater than in females. LPS pretreatment modestly increased the COL induced anorexic effect in surviving males, but not in surviving female animals. LPS did not appear to modulate either the body weights or clinical signs of COL induced toxicity in surviving males or females. Copyright © 2007 John Wiley & Sons, Ltd.
Palladium‐nanoparticle intercalated vermiculite for selective hydrogenation of α,β‐unsaturated aldehydes
Authors: Divakar Duraiswami , Manikandan Dhanagopal , Rupa Valentine , Preethi Esther Leena , Chandrasekar Revathi , Sivakumar Thiripuranthagan
Published: March 2007

Palladium nanoparticles were generated in the interlamellar region of swelling 2:1 type vermiculite clay using an adsorption excess isotherm. An adsorption excess isotherm was constructed for vermiculite after exchanging the exchangeable Na+ ions in the interlamellar region using a binary liquid mixture (ethanol:toluene). Based on adsorption excess isotherm, 1% w/w palladium was intercalated into the interlamellar space of vermiculite. The Pd‐intercalated vermiculite was characterized by X‐ray diffraction, transmission electron microscopy and atomic absorption spectroscopy. The 1% w/w Pd‐intercalated vermiculite was tested for its catalytic activity towards selective hydrogenation reactions involving some α,β‐unsaturated carbonyl compounds using a pulse reactor and its catalytic activity was compared with commercial 1% Pd/C. The intercalated catalyst was found to be very selective towards the desired product of unsaturated alcohols. Copyright © 2007 Society of Chemical Industry
Phytoremediation: the state of rhizosphere ‘engineering’ for accelerated rhizodegradation of xenobiotic contaminants
Authors: Dzantor E. Kudjo
Published: March 2007

Phytoremediation has emerged as the method of choice for cleaning up a broad range of environmental contaminants. One process through which plants render some xenobiotic organic contaminants innocuous in soil involves plant–microbe interactions in which root exudates stimulate entire microbial communities, or induce specific enzymes in competent individuals to cause enhanced rhizodegradation. For some contaminants these inherent processes can be slow; however, potentials exist for their improvement through rhizosphere manipulations. Although this requires a greater understanding than currently exists with respect to plant and microbe components and interactions involved in the biodegradation of xenobiotic contaminants, improved understanding is being achieved by advances in biochemical and molecular characterization, and visualization of rhizosphere phenomena. In combination with earlier knowledge of naturally‐occurring plant–microbe interactions such as the opine concept, this new knowledge considerably improves the opportunities for manipulating rhizosphere interactions to greatly accelerate rhizodegradation for routine practical implementation in the field. Copyright © 2007 Society of Chemical Industry
Separation of scandium(III) from lanthanides(III) with room temperature ionic liquid based extraction containing Cyanex 925
Authors: Sun Xiaoqi , Wu Dongbei , Chen Ji , Li Deqian
Published: March 2007

The separation of Sc(III) from Y(III), La(III) and Yb(III) in [C8mim][PF6] containing Cyanex 925 has been investigated, and is reported in this paper. A cation exchange mechanism of Sc(III) in [C8mim][PF6] and Cyanex 925 is proposed by study of the influence of anionic and cationic species on the extraction. The coefficient of the equilibrium equation of Sc(III) was confirmed by slope analysis of log DSc vs log [Cyanex 925], and the loading capacity also confirmed the stoichiometry of Cyanex 925 to Sc(III) was close to 3:1. Infrared data for Cyanex 925 saturated with Sc(III) in [C8mim][PF6] indicated strong interaction between PO of Cyanex 925 and Sc(III). In addition, the relationship between log DSc and temperature showed that temperature had little influence on the extraction process, and the resulting thermodynamic parameters indicated that an exothermic process was involved. Copyright © 2007 Society of Chemical Industry
The effect of substrate on the composition of polyhydroxyalkanoates in enhanced biological phosphorus removal
Authors: Yagci Nevin , Cokgor Emine Ubay , Artan Nazik , Randall Clifford , Orhon Derin
Published: March 2007

This paper primarily evaluates the effect of external substrate type on the composition of polyhydroxyalkanoates in enhanced biological phosphorus removal (EBPR). Two sets of sequencing batch reactors (SBRs) are operated for this purpose, one with acetate and the other with propionate as the sole carbon source at different influent COD/phosphate ratios in the range 6.7–20 mgCOD mg−1P. Results indicate that propionate is a more efficient substrate for EBPR, enabling total phosphate removal regardless of the change in COD/phosphate ratio. Total polyhydroxyalkanoates formation of 267–291 mgCOD L−1 with a slight increase at higher influent phosphorus levels is observed for acetate experiments, and a slightly lower level of 250–280 mgCOD L−1, with a similar trend for propionate experiments. The volatile fatty acid type and composition in the influent induces a significant difference in the polyhydroxyalkanoates composition of the two sets of activated sludge sustained in corresponding SBR systems. Propionate is mostly stored as 3‐hydroxy‐2‐methylvalerate and polyhydroxyvalerate, while acetate is stored as polyhydroxybutyrate. The P uptake rate in SBRs fed with propionate is considerably higher than that in the acetate reactors. Parallel batch experiments yield different results, especially for systems fed with acetate, indicating that the enzymatic system to metabolize propionate is not rapidly established, always yielding a dominant polyhydroxybutyrate fraction in the generated polyhydroxyalkanoates regardless of the level of propionate in the feed. Copyright © 2007 Society of Chemical Industry
Inoculum strategies for Penicillium simplicissimum lipase production by solid‐state fermentation using a residue from the babassu oil industry
Authors: Gutarra Melissa L. E. , Godoy Mateus G. , Castilho Leda R. , Freire Denise M. G.
Published: March 2007

Two alternative inoculation strategies for lipase production by the fungus Penicillium simplicissimum were tested in solid‐state fermentation using a residue from the babassu oil industry (babassu cake). Conventional spore inoculation was compared with fungal pellets grown in liquid medium and with inocula consisting of fermented cake. Fungal pellets delayed lipase production whereas fermented cake accelerated enzyme synthesis, yielding a productivity of 0.45 U g−1 h−1, which is equivalent to the highest values obtained with conventional inocula. Therefore, a 22 factorial design was used to determine the best conditions for lipase production with fermented cake as inoculum strategy, varying the inoculum propagation time and inoculum concentration. Lipase activity and productivity reached 30 U g−1 and 0.63 U g−1 h−1, respectively, with 10% inoculum and 36 h. Thus, fermented cake inocula increased production 1.5‐fold with 10 times fewer spores than in conventional inoculation, indicating that fermented solids are an interesting alternative for inoculum development in solid‐state fermentation, mainly for large‐scale processes. Copyright © 2007 Society of Chemical Industry
A hybrid neural model (HNM) for the on‐line monitoring of lipase production by Candida rugosa
Authors: Boareto Álvaro J M , De Souza Maurício B , Valero Francisco , Valdman Belkis
Published: March 2007

A mechanistic model was proposed by Gordillo for the representation of lipase production by Candida rugosa, with the bioreactor in batch and fed‐batch operation. However, the model was not able to represent the lipolytic activity. The objective of the present study is to propose an efficient hybrid neural‐phenomenological model (HNM) for this process. The experimental data used corresponded to fed‐batch operation with constant substrate feed rate at 2.8 × 10−7; 5.6 × 10−7 and 9.7 × 10−7 kg s−1. Artificial neural networks (ANNs) were trained to represent the aqueous and intracellular lipase activity and were further associated with a reduced version of the mechanistic model of the proposed HNM. When compared to the experimental data, the HNM exhibited higher accuracy. The HNM can be employed in process monitoring using only on‐line measurements of CO2 and substrate feed rate to infer enzyme activities and also substrate and biomass concentrations. Copyright © 2007 Society of Chemical Industry
Submillimeter isotropic resolution carotid wall MRI with swallowing compensation: Imaging results and semiautomated wall morphometry
Authors: Koktzoglou Ioannis , Li Debiao
Published: March 2007

Purpose

To assess a swallowing‐compensated, three‐dimensional (3D) diffusion‐prepared segmented steady‐state free precession (3D Nav‐D‐SSFP) technique for carotid wall MRI with 0.6‐mm isotropic spatial resolution, and its utility for semiautomated carotid wall morphometry.

Materials and Methods

The carotid arteries of seven healthy volunteers (N = 14) were imaged with 3D Nav‐D‐SSFP and black‐blood T2‐weighted (T2w) two‐dimensional (2D) fast spin‐echo (FSE). Carotid wall‐lumen contrast‐to‐noise ratio (CNR) was measured with both sequences. Measurement of carotid wall area (WA) and lumen area (LA) made in a semiautomated manner off of the 3D Nav‐D‐SSFP images were compared to those made manually.

Results

Adjusted for voxel volume and number of slices, a near six‐fold improvement in CNR per unit time was achieved with 3D Nav‐D‐SSFP relative to 2D T2w FSE (P < 0.001). Manual and semiautomated measurements of carotid WA and LA on the 3D Nav‐D‐SSFP images were highly correlated (intraclass correlation coefficient (ICC) = 0.961 and 0.996, respectively; P < 0.001).

Conclusion

3D Nav‐D‐SSFP is a time‐efficient, swallowing‐compensated, black‐blood technique that lends itself for semiautomated measurements of carotid WA and LA that are in good agreement with manual measurements. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
A dendrimer‐based nanosized contrast agent dual‐labeled for magnetic resonance and optical fluorescence imaging to localize the sentinel lymph node in mice
Authors: Koyama Yoshinori , Talanov Vladimir S. , Bernardo Marcelino , Hama Yukihiro , Regino Celeste A.S. , Brechbiel Martin W. , Choyke Peter L. , Kobayashi Hisataka
Published: March 2007

Purpose

To preoperatively and intraoperatively localize the sentinel lymph node (SLN), a single hybrid probe for MR and near infrared (NIR) optical imaging was synthesized and tested.

Materials and Methods

A macromolecular MR/NIR optical contrast agent was synthesized based on a ∼191 gadolinium‐labeled contrast agent using generation‐6 polyamidoamine dendrimer (G6), which is also labeled with 2 Cy5.5, an NIR fluorophore. After establishing the optimal dose, the agent was injected into mammary glands of 10 normal mice to examine the lymphatic drainage from the breast using a 3T clinical scanner. Immediately after the MRI scan, NIR optical imaging and image‐guided surgery were performed to compare the two imaging modalities.

Results

To consistently identify the SLNs, we needed to inject 25 μL of 30 mM [Gd] G6‐Cy5.5. All SLNs could be easily identified and resected under NIR optical imaging‐guided surgery. Although external NIR optical imaging failed to identify SLNs close to the injection site due to shinethrough, MR lymphography (MRL) consistently identified all SLNs regardless of their location.

Conclusion

We have successfully synthesized and tested a dual labeled MR/NIR optical hybrid contrast agent, G6‐Cy5.5 for reoperative and intraoperative localization of SLNs. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Time‐resolved 3D MR velocity mapping at 3T: Improved navigator‐gated assessment of vascular anatomy and blood flow
Authors: Markl Michael , Harloff Andreas , Bley Thorsten A. , Zaitsev Maxim , Jung Bernd , Weigang Ernst , Langer Mathias , Hennig Jürgen , Frydrychowicz Alex
Published: March 2007

Purpose

To evaluate an improved image acquisition and data‐processing strategy for assessing aortic vascular geometry and 3D blood flow at 3T.

Materials and Methods

In a study with five normal volunteers and seven patients with known aortic pathology, prospectively ECG‐gated cine three‐dimensional (3D) MR velocity mapping with improved navigator gating, real‐time adaptive k‐space ordering and dynamic adjustment of the navigator acceptance criteria was performed. In addition to morphological information and three‐directional blood flow velocities, phase‐contrast (PC)‐MRA images were derived from the same data set, which permitted 3D isosurface rendering of vascular boundaries in combination with visualization of blood‐flow patterns.

Results

Analysis of navigator performance and image quality revealed improved scan efficiencies of 63.6% ± 10.5% and temporal resolution (<50 msec) compared to previous implementations. Semiquantitative evaluation of image quality by three independent observers demonstrated excellent general image appearance with moderate blurring and minor ghosting artifacts. Results from volunteer and patient examinations illustrate the potential of the improved image acquisition and data‐processing strategy for identifying normal and pathological blood‐flow characteristics.

Conclusion

Navigator‐gated time‐resolved 3D MR velocity mapping at 3T in combination with advanced data processing is a powerful tool for performing detailed assessments of global and local blood‐flow characteristics in the aorta to describe or exclude vascular alterations. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Time‐resolved, high‐resolution contrast‐enhanced MR angiography of dialysis shunts using the CENTRA keyhole technique with parallel imaging
Authors: Mende Katja A. , Froehlich Johannes M. , von Weymarn Constantin , Hoogeveen Romhild , Kistler Thomas , Zollikofer Christoph L. , Wentz Klaus U.
Published: March 2007

Purpose

To evaluate the use of a dynamic keyhole magnetic resonance angiography (MRA) sequence combined with sensitivity encoding (SENSE) for hemodialysis shunts, because surveillance with conventional contrast‐enhanced MRA (CE‐MRA) is limited by its low temporal resolution, resulting in arteriovenous overlay.

Materials and Methods

A total of 12 patients with Brescia‐Cimino shunts were investigated prospectively using the new technique. During the contrast passage (gadoterate, Gd‐DOTA) a series of five to nine dynamic central k‐space measurements (10% for upper‐arm shunt, 25% for lower‐arm shunt) followed by a full reference data set were acquired. The outer k‐space data of the single reference scan were used to complete the dynamic data sets.

Results

All studies were diagnostic (17 stenoses, three aneurysms) without complications. The acquisition times for a single dynamic scan of the upper‐ and lower‐arm shunts were 2.2 and 3.2 seconds, respectively, while the reference scan needed 13 and 22.4 seconds, respectively. The dynamic angiograms allowed the differentiation of arterial and venous filling despite a mean peak delay time of only 4.2 seconds in the shoulder region. Image quality qualified in consensus by two experienced readers was rated “good” in 19 cases and “intermediate” in five cases with high mean values for signal‐to‐noise ratios (SNRs) and contrast‐to‐noise‐ratios (CNRs).

Conclusion

We have successfully implemented a fast, dynamic, CE‐MRA technique with CE timing robust angiography (CENTRA) keyhole and SENSE in clinical routine. High spatial and temporal resolution improve the diagnostics of dialysis shunts and allow the assessment of detailed, dynamic, four‐dimensional (4D) information. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Interaction between rod and cone inputs in mixed‐input bipolar cells in goldfish retina
Authors: Joselevitch Christina , Kamermans Maarten
Published: March 2007

One class of goldfish bipolar cells, the mixed‐input bipolar cell, contacts both rods and cones. Although the morphology of the different mixed‐input bipolar cell subtypes has been described, insight into the interaction between rods and cones at the bipolar cell level is scarce. The aim of this study was to characterize this interaction in the different physiological types of mixed‐input bipolar cells. We found mixed‐input bipolar cells that depolarized, hyperpolarized, or showed a combination of the two types of response after center stimulation. The relative contributions of rod and cone inputs varied strongly in these cell populations. Depolarizing mixed‐input bipolar cells are rod‐dominated, having the highest sensitivity and the smallest dynamic range. Hyperpolarizing mixed‐input bipolar cells, on the other hand, have a more balanced rod‐cone input ratio. This extends their dynamic range and decreases their sensitivity. Finally, opponent mixed‐input bipolar cells seem to be mostly cone‐dominated, although some rod input is present. The antagonistic photoreceptor inputs form a push‐pull system that makes these mixed‐input bipolar cells very sensitive to changes in light intensity. Our finding that spectral tuning changes with light intensity conflicts with the idea that the separate nonopponent and opponent channels are related to coding of brightness and color, respectively. The organization of mixed‐input bipolar cells into various classes with different dynamic ranges and absolute sensitivities might be a strategy to transmit information about all visual aspects most efficiently, given the sustained nature of bipolar cell responses and their limited voltage range. © 2007 Wiley‐Liss, Inc.
Prognostic value of tumor thickness in patients with merkel cell carcinoma
Authors: Goldberg Stephanie R. , Neifeld James P. , Frable William J.
Published: March 2007

Background and Objectives

Merkel cell carcinoma is an aggressive skin malignancy that often presents with tumor metastases. We hypothesized that tumor thickness might correlate with both regional and metastatic tumor spread and could, therefore, be used as an independent prognostic variable. The purpose of this study was to see if depth of tumor invasion would predict prognosis independent of tumor stage.

Methods

Data pertaining to clinical presentation, pathology, treatment, and survival were collected for patients diagnosed with Merkel cell carcinoma from 1972 to 2005. Patients were staged according to AJCC guidelines. Pathologic specimens were evaluated for tumor thickness. The relationship between tumor thickness and disease‐free survival or overall survival was analyzed using Kaplan–Meier survival analyses.

Results

Sixty patients were identified. Five‐year disease‐free survivals for Stages 1, 2, and 3 patients were 20%, 33%, and 0%, respectively. Five‐year overall survivals for Stages 1, 2, and 3 patients were 33.3%, 60%, and 16.7%, respectively. There was no correlation between tumor thickness and either disease‐free survival or overall survival.

Conclusions

This study suggests that tumor thickness is not an independent risk factor for survival. Mean tumor thickness did increase with the AJCC stages, but this most likely represents more advanced stage of disease. J. Surg. Oncol. 2007;95:618–622. © 2007 Wiley‐Liss, Inc.
Barriers to rehabilitation of patients with extremity sarcomas
Authors: Custodio Christian M.
Published: March 2007

The treatment of most extremity bone or soft tissue sarcomas involves either limb salvage surgery with adjuvant chemoradiation therapy or amputation. The rehabilitation of patients with extremity sarcomas is challenging, and the approach differs depending on the choice of surgical procedure as well as potential‐associated medical complications. Early, interdisciplinary rehabilitation involvement is helpful in lessening the impact of expected impairments and disability. There is a lack of evidence examining specific rehabilitation interventions in this patient population. Functional outcomes and quality of life studies suggest overall similar findings between limb salvage patients and amputees, but with differences in various subscales. Rehabilitation interventions are therefore individualized; based on the assessment of medical limitations, functional goals and expectations, and modification of environmental factors. Overcoming medical and oncologic barriers to rehabilitation; as well as psychological, structural, cultural, political, and economic barriers; can serve to lessen the degree of disability. J. Surg. Oncol. 95:393–399. © 2007 Wiley‐Liss, Inc.
Serum insulin‐like growth factor I/free prostate specific antigen (IGF‐I/fPSA) ratio enhances prostate cancer detection in men with total PSA 4.0–10.0 ng/ml
Authors: Zhigang Zhao , Jieming Liu , Su Li , Wenlu Shen
Published: March 2007

Background

Recent studies have suggested that IGF‐I and IGFBP‐3, in combination with PSA, may enhance PCa detection. This study was to investigate the use of serum IGF‐I and IGFBP‐3, and their combinations with prostate volume and fPSA in enhancing the discriminatory diagnosis of PCa in men with tPSA of 4.0–10.0 ng/ml.

Methods

Serum IGF‐I and IGFBP‐3 were determined by ELISA from 586 men with tPSA between 4.0 and 10.0 ng/ml. Of them, 281 were diagnosed with PCa and 305 without. ROC, univariate and multivariate logistic regression analyses were performed to evaluate the predictive performance of those parameters.

Results

IGF‐I, IGFD, IGF‐I/fPSA, and IGFBP‐3/fPSA were significantly higher in PCa cases than benign controls, whereas the differences of IGFBP‐3 and IGFBPD were statistically insignificant between the two groups, respectively. The AUC values indicated enhanced performance of IGF‐I/fPSA ratio (AUC = 0.753) in PCa detection compared with the currently used f/tPSA (AUC = 0.689). Multivariate logistic regression confirmed the observed relationships and identified IGF‐I/fPSA as independent factor in PCa presence.

Conclusion

Our data show that IGF‐I/fPSA as a promising marker can enhance PCa detection in ambiguous cases often found in the tPSA between 4.0 and 10.0 ng/ml. J. Surg. Oncol. 2007;96:54–61. © 2007 Wiley‐Liss, Inc.
Intergenerational transmission of trauma: Exploring mother–infant prenatal attachment
Authors: Schwerdtfeger Kami L. , Goff Briana S. Nelson
Published: March 2007

Early childhood attachment and bonding and the intergenerational transmission of trauma are two key areas to address to understand the connection between parental trauma and the parent–child relationship. The purpose of the current study was to explore the relationship between trauma and past parental attachment behaviors of 41 expectant mothers and the subsequent development of attachment and bonding with their unborn child. Results of the current study suggest that trauma history, in general, does not negatively impact expectant mothers' current prenatal attachment with their unborn child. However, interpersonal trauma history does appear to have negative effects on prenatal attachment. These results point to the importance of understanding the role of interpersonal trauma exposure on prenatal attachment.
The increasing internationalization of mainstream posttraumatic stress disorder research: A bibliometric study
Authors: Figueira Ivan , Luz Mariana da , Braga Raphael J. , Cabizuca Mariana , Coutinho Evandro , Mendlowicz Mauro V.
Published: March 2007

The aim of this study was to quantify changes in the national contributions to research related to posttraumatic stress disorder (PTSD) from 1983 through 2002. Using the Web of Science database (Thomson Scientific, Philadelphia, PA), we classified articles according to the year of publication and the country of the authors. The number of publishing countries increased from 7 between 1983 and 1987 to 39 between 1998 and 2002. Meanwhile, the U.S. output share declined from 87.6% in the first period to 62.4%. Although the number of countries publishing on PTSD has steadily increased, research is still dominated qualitatively and quantitatively by developed countries. These findings suggest a growing international acceptance of this diagnostic category. However, the immaturity of PTSD research is demonstrated by the concentration of publications in a few countries.
The consistency of combat exposure reporting and course of PTSD in Vietnam War veterans
Authors: Koenen K. C. , Stellman S. D. , Dohrenwend B. P. , Sommer J. F. , Stellman J. M.
Published: March 2007

Self‐reports of traumatic events are often used in clinical and epidemiologic studies. Nevertheless, research suggests combat exposure reports may be biased by posttraumatic stress disorder (PTSD) symptom severity, leading to an inflated dose‐response relation between combat exposure and PTSD. The authors examined the consistency in combat exposure reports and their relation to PTSD symptoms in Vietnam Veteran American Legionnaires who responded to two mailed surveys (1984, 1998; N = 1,462). Combat exposure reports were highly reliable (test–retest correlation = 0.87). However, changes in exposure reporting were related to changes in PTSD symptoms, specifically reexperiencing symptoms. The effect size of the dose‐response relation attributable to changes in reporting was smaller for continuous than categorical measures. Findings are discussed in relation to recent controversies over veterans' combat exposure reports.
Intimate partner psychological aggression and child behavior problems
Authors: Clarke Stephanie B. , Koenen Karestan C. , Taft Casey T. , Street Amy E. , King Lynda A. , King Daniel W.
Published: March 2007

The present study examined the relationship between intimate partner psychological aggression and children's behavior problems in a community sample of families (N = 470 children). The results showed that psychological aggression experienced by the mother has adverse effects on children's externalizing and internalizing behavior problems over and above the effects of physical aggression. The association between psychological aggression and child behavior problems was partially mediated by maternal distress. Exposure to psychological aggression appears to have unique direct and indirect adverse effects on children.
Kinetic studies on the reactions of 3‐isothiazolones with 2‐methyl‐2‐propanethiol
Authors: Morley John O. , Kapur A. Jayne Oliver , Charlton Michael H.
Published: March 2007

The kinetics of the ring‐opening reactions of the 3‐isothiazolones (1a–d) with aqueous 2‐methyl‐2‐propanethiol has been explored at pH 4. The results strongly suggest that the reaction is second order in thiol and third order overall. Extrapolation of the kinetic data gives third‐order rate constants that lie in the order (1a) > (1b) > (1c) > (1d) in line with the known biological activity of these derivatives. The mechanism of the reaction is thought to involve attack by one thiol at the sulfur atom of the isothiazolone with the concomitant hydrogen bonding of a second thiol to the amide nitrogen. Calculations of the structure and electronic properties of the isothiazolones at the RHF 6‐31G** level are supportive. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 39: 254–260, 2005
Homogeneous, unimolecular gas‐phase elimination kinetics of ethyl esters of glyoxylic, 2‐oxo‐propanoic, and 3‐methyl‐2‐oxo‐butanoic acids
Authors: Reyes Andreina , Dominguez Rosa M. , Tosta Maria , Herize Armando , Chuchani Gabriel
Published: March 2007

The rates of elimination of several ethyl esters of 2‐oxo‐carboxylic acid were determined in a seasoned static reaction vessel over the temperature range 350–430°C and pressure range 33–240 Torr. The reactions, in the presence of a free‐radical inhibitor, are homogeneous, unimolecular, and follow a first‐order rate law. The overall and partial rate coefficients are expressed by the Arrhenius equation.

Ethyl glyoxalate

equation image

Ethyl 2‐oxo‐propionate

equation image

Ethyl 3‐methyl‐2‐oxo‐butyrate

equation image

The mechanisms of these elimination reactions are described in terms of concerted cyclic transition state structures. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 39: 268–275, 2007
Effect of medical and surgical interventions on health‐related quality of life in Parkinson's disease
Authors: Martinez‐Martin Pablo , Deuschl Günther
Published: March 2007

Motor‐related parameters are the standard outcome parameters for treatment interventions. Nonetheless, subjective appraisals about the consequences of treatment on health‐related quality of life (HRQoL) are meanwhile established and may uncover important aspects of interventions. We have reviewed the literature with a defined search strategy and collected 61 clinical trials, which have used HRQoL as a planned outcome parameter. The articles were rated similarly as for the Task Force report of the Movement Disorder Society on interventions for Parkinson's disease (PD), but the relevant outcome parameter was HRQoL. We found that unilateral pallidotomy, deep brain stimulation of the subthalamic nucleus, and rasagiline are efficacious to improve the HRQoL of PD patients. For many other interventions, the efficacy to improve HRQoL in the PD setting cannot be considered to be proven so far. HRQoL should be part of future trial designs and more research is necessary to understand the determinants of QoL in PD. © 2007 Movement Disorder Society
Poroelastic model for pile–soil interaction in a half‐space porous medium due to seismic waves
Authors: Lu Jian‐Fei , Jeng Dong‐Sheng
Published: March 2007

In this paper, frequency domain dynamic response of a pile embedded in a half‐space porous medium and subjected to P, SV seismic waves is investigated. According to the fictitious pile methodology, the problem is decomposed into an extended poroelastic half‐space and a fictitious pile. The extended porous half‐space is described by Biot's theory, while the fictitious pile is treated as a bar and a beam and described by the conventional 1‐D structure vibration theory. Using the Hankel transformation method, the fundamental solutions for a half‐space porous medium subjected to a vertical or a horizontal circular patch load are established. Based on the obtained fundamental solutions and free wave fields, the second kind of Fredholm integral equations describing the vertical and the horizontal interaction between the pile and the poroelastic half‐space are established. Solution
of the integral equations yields the dynamic response of the pile to plane P, SV waves. Numerical results show the parameters of the porous medium, the pile and incident waves have direct influences on the dynamic response of the pile–half‐space system. Significant differences between conventional single‐phase elastic model and the poroelastic model for the surrounding medium of the pile are found. Copyright © 2007 John Wiley & Sons, Ltd.
Models and branch‐and‐cut algorithms for pickup and delivery problems with time windows
Authors: Ropke Stefan , Cordeau Jean‐François , Laporte Gilbert
Published: March 2007

In the pickup and delivery problem with time windows (PDPTW), capacitated vehicles must be routed to satisfy a set of transportation requests between given origins and destinations. In addition to capacity and time window constraints, vehicle routes must also satisfy pairing and precedence constraints on pickups and deliveries. This paper introduces two new formulations for the PDPTW and the closely related dial‐a‐ride problem (DARP) in which a limit is imposed on the elapsed time between the pickup and the delivery of a request. Several families of valid inequalities are introduced to strengthen these two formulations. These inequalities are used within branch‐and‐cut algorithms which have been tested on several instance sets for both the PDPTW and the DARP. Instances with up to eight vehicles and 96 requests (194 nodes) have been solved to optimality. © 2007 Wiley Periodicals, Inc. NETWORKS, Vol. 49(4), 258–272 2007
New planar chromatographic techniques in natural product analysis
Authors: Erdelmeier C. A. J. , Körig G. M.
Published: March 2007

Planar chromatography (PLC) is gaining importance in the analysis of natural products. Sophisticated instrumentation has become available in this field. Major progress in planar chromatography has been achieved through the development of forced‐flow techniques. Progress has also been made in the capillary‐controlled flow techniques with the use of modified development chambers. A large variety of stationary phases is available and strategies to optimize mobile phase compositions in PLC have been developed. The detection and quantitation in PLC has improved through direct coupling of PLC with spectroscopic methods with and the use of modern, computerized scanning densitometers.