bluuebunny/crossref_metadata_2025_split huggingface dataset:
Future directions for in‐situ product removal (ISPR)
Authors: Woodley John M , Bisschops Marc , Straathof Adrie J J , Ottens Marcel 
Published: September 2007

AbstractThis paper summarizes the main findings of a round‐table discussion held to examine the key bottlenecks in the further application and industrial implementation of in‐situ product removal (ISPR) techniques.** It is well established that ISPR can yield great benefits for processes limited by inhibitory or toxic products, as well as unstable products or reactions that are thermodynamically unfavorable. However, several issues for industrial implementation were revealed in the discussion. Most notably implementation will be dependent on (1) research into the appropriate process structure, (2) methods to achieve process robustness, (3) systematic selection methods for separation operations and (4) the nature of the product market. Here, these four issues will be discussed as a basis for future work in this area. Copyright © 2007 Society of Chemical Industry
Synthesis of isotopically labelled compounds at Schering‐Plough, an historical perspective
Authors: Hesk D. , McNamara P. 
Published: September 2007

AbstractThe use of isotopically labelled compounds at Schering‐Plough (S‐P) has substantially increased over the past 30 years. Since the formation of the S‐P Radiochemistry section in the early 1970s, the group has expanded its role from supplying 14C‐ and 3H‐labelled compounds for ADME studies for compounds in development, to providing 3H‐labelled compounds for drug discovery and also to provide stable isotope‐labelled compounds that are used as LC/MS internal standards. Other isotopes used by the group have included 125I and 35S, which have been used to label both small molecules and proteins. Copyright © 2007 John Wiley & Sons, Ltd.
Isotope incorporation via organoboranes
Authors: Kabalka George W. 
Published: September 2007

AbstractOrganoboranes can be used as precursors to a wide variety of functionally substituted, isotopically labeled compounds. Straightforward boron‐based methods for incorporating short‐lived and stable isotopes of carbon, nitrogen, oxygen, and the halogens have been developed over a period of 20 years. Application of these methods to biology, agriculture, and medicine has been slowed by the limited availability of boronated precursors containing functional groups appropriate to those fields. The situation has changed markedly with the advent of metal catalyzed boron‐based reactions, which now produce a variety of important boronated materials readily available in the laboratory and from commercial sources. This is especially important in the medical and pharmaceutical communities where short‐lived isotopes of carbon, nitrogen, and the halogens are demonstrating great value in positron and single photon emission tomographic procedures. Copyright © 2007 John Wiley & Sons, Ltd.
Amersham radiochemistry to GE Healthcare
Authors: Kitson Sean L. 
Published: September 2007

AbstractI was invited by Professor John R. Jones (University of Surrey) to write a paper to celebrate 50 years of the Journal of Labelled Compounds and Radiopharmaceuticals. The aim of this paper is to outline briefly the history of radiochemistry from The Radiochemical Centre at Amersham in the 1940s to the acquisition by General Electric in 2004 and the formation of GE Healthcare. Copyright © 2007 John Wiley & Sons, Ltd.
Carbon‐14 labelling of acarbose – a challenge over more than 20 years
Authors: Seidel D. , Wehlmann H. , Lenz J. 
Published: September 2007

AbstractAcarbose is a potent α‐glucosidase inhibitor which is used successfully as a drug for the treatment of type II diabetes. The compound prevents enzymes of the α‐glucosidase group from cleaving carbohydrates. For the investigation of pharmacokinetics and drug metabolism a first carbon‐14 labelling synthesis was performed in 1981. According to the pharmaceutical production process, the radiosynthesis was performed by fermentation. Due to limited radiolytic stability, repeated radiosyntheses were necessary. Finally, carbon‐14 labelling was optimized to prepare [14C]acarbose on a gram scale with a significant increase of the radiochemical yield. The aspects of the fermentation over a period of about 20 years are described focussing the attention on the optimized radiosynthesis. Copyright © 2007 John Wiley & Sons, Ltd.
The imaging continuum: bench to biomarkers to diagnostics
Authors: Frank Richard A. , Långström Bengt , Antoni Gunnar , Montalto Michael C. , Agdeppa Eric D. , Mendizabal Marivi , Wilson Ian A. , Vanderheyden Jean‐Luc 
Published: September 2007

AbstractInnovation in basic and applied science has brought radiotracers to fruition as diagnostics. Non‐invasive, longitudinal, and quantifiable molecular imaging is the key to diagnosing and monitoring numerous illnesses, with more to come from characterization of the clinical relevance of findings from genomics research. Radiotracers enable real‐time in vivo studies of the effects of drug candidates on receptors, pathways, pharmacodynamics, and clinically relevant endpoints, thereby providing both early detection of pathophysiology to enable early intervention, and then monitoring of treatment responses to enable individualization of treatment regimens. We review developments which have translated imaging from ‘bench to bedside’, or ‘biomarkers to diagnostics’. Notable developments include (1) synthesis methods for rapid 11C labeling of biomolecules to high specific radioactivity; (2) ligand‐binding assays for screening molecular imaging agents rather than drugs; (3) in vivo imaging of radiotracers in animals; (4) discovering the imaging advantages of 99mTc, 11C, and 18F; (5) co‐registration and automated quantitative assessment of high spatial resolution CT and MR images with molecular images from PET for longitudinal studies of treatment effect. Copyright © 2007 John Wiley & Sons, Ltd.
Solid‐phase reactions as approach to the synthesis of organic compounds labelled with tritium
Authors: Myasoedov Nikolay F. 
Published: September 2007

AbstractThe solid‐phase method for hydrogenolysis, hydrogenation and isotope exchange reactions is described. Its potential for tritium labelling of organic compounds including lipids, nucleotides, amino acids, peptides and pharmaceuticals is demonstrated. The influence of the reaction conditions on the yield and specific radioactivity of the labelled compounds is considered. It is shown that results can be interpreted by the dependence of tritium spillover reactions on the nature of the initial compound and other factors. Copyright © 2007 John Wiley & Sons, Ltd.
Proton MR spectroscopic imaging of the medulla and cervical spinal cord
Authors: Edden Richard A.E. , Bonekamp David , Smith Mari A. , Dubey Prachi , Barker Peter B. 
Published: September 2007

AbstractPurposeTo demonstrate the feasibility of quantitative, one‐dimensional proton MR spectroscopic imaging (1D‐MRSI) of the upper cervical spine and medulla at 3.0 Tesla.Materials and MethodsA method was developed for 1D‐point‐resolved spectroscopy sequence (PRESS)‐MRSI, exciting signal in five voxels extending from the pontomedullary junction to the level of the C3 vertebra, and performed in 10 healthy volunteers to generate control data.ResultsHigh‐resolution 1D‐MRSI data were obtained from all 10 subjects. Upper cervical spine concentrations of choline, creatine, and N‐acetyl aspartate were estimated to be 2.8 ± 0.5, 8.8 ± 1.8, and 10.9 ± 2.7 mM, respectively, while in the medulla they were 2.6 ± 0.5, 9.1 ± 1.7, and 10.8 ± 0.9 mM.ConclusionQuantitative 1D‐MRSI of the upper cervical spine has been shown to be feasible at 3.0 Tesla. J. Magn. Reson. Imaging 2007;26:1101–1105. © 2007 Wiley‐Liss, Inc.
Temporal evolution of spinal cord infarction in an in vivo experimental study of canine models characterized by diffusion‐weighted imaging
Authors: Zhang Jin Song , Huan Yi , Sun Li Jun , Ge Ya Li , Zhang Xue Xin , Chang Ying Juan 
Published: September 2007

AbstractPurposeTo determine the temporal evolution of diffusion abnormalities of in vivo experimental spinal cord infarction.Materials and MethodsGuided by a digital subtract angiography (DSA) monitor, an agent of 1:1 match of lipiodol and diatrizoate meglumine was injected into bilateral T9‐11 intercostal arteries of six dogs to embolize the spinal branches of intercostal arteries and establish the canine spinal cord infarction models. The progression of experimental spinal cord infarction was followed by dynamic MRI, including diffusion‐weighted imaging (DWI) on a 1.5 Tesla MR system from one hour to 168 hours postembolization. Apparent diffusion coefficient (ADC) values were calculated and analyzed. At the end of the MRI experiments, the spinal cords of the animals were fixed for histology.ResultsA total of six experimental models were successfully established. In all cases, DWI images showed slight hyperintensity within one hour postembolization, whereas only four cases presented slight hyperintensity on T2‐weighted images. ADC values of spinal cord infarction lesions decreased rapidly at early stage (several hours to 24 hours) and then increased gradually.ConclusionThe temporal evolution of diffusion abnormality of experimental spinal cord infarction may help us better understand various DWI signals in the process of spinal cord infarction. J. Magn. Reson. Imaging 2007;26:848–854. © 2007 Wiley‐Liss, Inc.
Quantification of rodent cerebral blood flow (CBF) in normal and high flow states using pulsed arterial spin labeling magnetic resonance imaging
Authors: Wegener Susanne , Wu Wen‐Chau , Perthen Joanna E. , Wong Eric C. 
Published: September 2007

AbstractPurposeTo implement a pulsed arterial spin labeling (ASL) technique in rats that accounts for cerebral blood flow (CBF) quantification errors due to arterial transit times (dt)—the time that tagged blood takes to reach the imaging slice—and outflow of the tag.Materials and MethodsWistar rats were subjected to air or 5% CO2, and flow‐sensitive alternating inversion‐recovery (FAIR) perfusion images were acquired. For CBF calculation, we applied the double‐subtraction strategy (Buxton et al., Magn Reson Med 1998;40:383–396), in which data collected at two inversion times (TIs) are combined.ResultsThe ASL signal fell off more rapidly than expected from TI = one second onward, due to outflow effects. Inversion times for CBF calculation were therefore chosen to be larger than the longest transit times, but short enough to avoid systematic errors caused by outflow of tagged blood. Using our method, we observed a marked regional variability in CBF and dt, and a region dependent response to hypercapnia.ConclusionEven when flow is accelerated, CBF can be accurately determined using pulsed ASL, as long as dt and outflow of the tag are accounted for. J. Magn. Reson. Imaging 2007;26:855–862. © 2007 Wiley‐Liss, Inc.
Interleaved water and fat imaging and applications to lipid quantitation using the gradient reversal technique
Authors: Tang Haiying , Wu Ed X. , Kennan Richard , Liu Haiying , Williams Donald S. 
Published: September 2007

AbstractPurposeTo implement and evaluate the gradient reversal‐based chemical shift imaging technique to obtain qualitative and quantitative spatially‐registered fat and water images with high imaging efficiency at very high field.Materials and MethodsA multiecho gradient reversal‐based sequence allowing interleaved water–fat imaging during a single acquisition and quantitation of fat/water content is presented. The sequence was optimized and implemented at 11.7T. The quantitation was verified with water–fat phantoms and applied to lipid measurement in an in vivo mouse model.ResultsResults from phantoms, in vivo lipid measurement in mouse liver and hind limb muscle, and ex vivo rat knee imaging experiments demonstrated the robustness and high selectivity of this technique for interleaved and quantitative water and fat imaging at very high field.ConclusionThe proposed MRI technique permits interleaved water and fat imaging, with which spectrally well‐separated water and fat images at the identical slice locations could be obtained in a single acquisition without increasing scan time. The technique could be used for in vivo quantitative mapping of lipid content and applied to investigations using small animal experiment models. J. Magn. Reson. Imaging 2007;26:1064–1070. © 2007 Wiley‐Liss, Inc.
Whole‐body diffusion‐weighted imaging: Technical improvement and preliminary results
Authors: Li Shuo , Sun Fei , Jin Zheng‐yu , Xue Hua‐dan , Li Ming‐li 
Published: September 2007

AbstractPurposeTo optimize the free‐breathing whole‐body diffusion‐weighted imaging (WB‐DWI) protocol by using the short TI inversion‐recovery diffusion‐weighted echo‐planar imaging (STIR‐DWEPI) sequence and the built‐in body coil. Additionally, to evaluate the feasibility of tumor screening using high‐resolution three‐dimensional (3D) maximum intensity projection (MIP) images.Materials and MethodsThe prescan procedure of STIR‐DWEPI was modified using the data from 30 volunteers. During each exam, an optimized center frequency (CF) was used to minimize the slice offsets in consecutive scan stations. Prescan time was reduced from 50 seconds to 20 seconds with improved station profile. Total scan time was 30 minutes for five stations and 1.2 m coverage. A total of 30 patients with histologically‐proven malignant disease were scanned under the final protocol using a built‐in body coil. The image quality and the degree of background body signal suppression were assessed.ResultsFree‐breathing WB‐DWI was 100% successfully performed in all patients, without slice misregistration, fat contamination, significant distortion, or nonuniformity. The reconstructed 3D‐MIP images were adequate to depict malignant lesions in all 30 patients. The results of WB‐DWI were found to be comparable to those of single‐photon emission computed tomography (SPECT) and positron emission tomography (PET).ConclusionStable and high‐resolution WB‐DWI is feasible using the technical improvements described in this study. WB‐DWI might have important clinical value for the detection of primary and metastatic malignancies within the whole body. The potential for diagnosis and therapeutic assessment of tumors should be further assessed in a larger patient cohort. J. Magn. Reson. Imaging 2007;26:1139–1144. © 2007 Wiley‐Liss, Inc.
Time course of diffusion imaging in acute brainstem infarcts
Authors: Axer Hubertus , Gräβel David , Brämer Dirk , Fitzek Sabine , Kaiser Werner A. , Witte Otto W. , Fitzek Clemens 
Published: September 2007

AbstractPurposeTo study the time course of diffusion imaging at the lesion site in brainstem infarcts.Materials and MethodsSequential MR scans were acquired from 24 patients with brainstem infarcts. Diffusion‐weighted images (DWI), T2‐weighted images (T2w), maps of apparent diffusion coefficient, and maps of fractional anisotropy were generated from each MR scan. A trend function was fitted to these measurements to model an objective, general time course of the studied parameters.ResultsApparent diffusion coefficient (ADC) continuously decreased over time until a transition time around 45 hours; afterwards a continuous increase took place. After the 14th day ADC reached values similar to the ADC of the intact contralateral side (pseudonormalization) and then further increased. Fractional anisotropy (FA) decreased continuously over 3 to 6 months.ConclusionTimes of transition and pseudonormalization of ADC were longer than described for territorial hemispheric infarcts and describe the acute to subacute phase of brainstem ischemia. In contrast, the continuous decline of FA over 3 to 6 months indicates a chronic process of change of histological structures in brainstem ischemia, and may be regarded as an indicator of the chronic phase. J. Magn. Reson. Imaging 2007;26:905–912. © 2007 Wiley‐Liss, Inc.
Multiecho reconstruction for simultaneous water‐fat decomposition and T2* estimation
Authors: Yu Huanzhou , McKenzie Charles A. , Shimakawa Ann , Vu Anthony T. , Brau Anja C.S. , Beatty Philip J. , Pineda Angel R. , Brittain Jean H. , Reeder Scott B. 
Published: September 2007

AbstractPurposeTo describe and demonstrate the feasibility of a novel multiecho reconstruction technique that achieves simultaneous water‐fat decomposition and T2* estimation. The method removes interference of water‐fat separation with iron‐induced T2* effects and therefore has potential for the simultaneous characterization of hepatic steatosis (fatty infiltration) and iron overload.Materials and MethodsThe algorithm called “T2*‐IDEAL” is based on the IDEAL water‐fat decomposition method. A novel “complex field map” construct is used to estimate both R2* (1/T2*) and local B0 field inhomogeneities using an iterative least‐squares estimation method. Water and fat are then decomposed from source images that are corrected for both T2* and B0 field inhomogeneity.ResultsIt was found that a six‐echo multiecho acquisition using the shortest possible echo times achieves an excellent balance of short scan and reliable R2* measurement. Phantom experiments demonstrate the feasibility with high accuracy in R2* measurement. Promising preliminary in vivo results are also shown.ConclusionThe T2*‐IDEAL technique has potential applications in imaging of diffuse liver disease for evaluation of both hepatic steatosis and iron overload in a single breath‐hold. J. Magn. Reson. Imaging 2007;26:1153–1161. © 2007 Wiley‐Liss, Inc.
Range of ventricular dimensions and function by steady‐state free precession cine MRI in repaired tetralogy of Fallot: Right ventricular outflow tract patch vs. conduit repair
Authors: Samyn Margaret M. , Powell Andrew J. , Garg Ruchira , Sena Laureen , Geva Tal 
Published: September 2007

AbstractPurposeTo characterize the range of biventricular size and function evaluated by steady‐state free precession (SSFP) cine magnetic resonance (MR) in a large cohort of patients with repaired tetralogy of Fallot (TOF), and to compare these measurements in those with a right ventricular outflow tract (RVOT) patch vs. a right ventricle‐to‐pulmonary artery (RV‐PA) conduit.Materials and MethodsAnalysis of ventricular size and function in 300 consecutive examinations in patients with repaired TOF evaluated by SSFP cine MR.ResultsOf the 300 examinations performed in 256 patients, 69% had undergone repair with a RVOT patch and 31% with a RV‐PA conduit. Compared to patients with RV‐PA conduit, those with a RVOT patch had significantly more pulmonary regurgitation (PR) (38 ± 17 vs. 23 ± 16%, P < 0.0001), larger indexed RV end‐diastolic volume (154 ± 53 vs. 133 ± 51 mL/m2, P = 0.002), similar indexed end‐systolic volume (80 ± 39 vs. 74 ± 46 mL/m2, P = 0.31), higher ejection fraction (EF) (50 ± 9 vs. 47 ± 12%, P = 0.037), and lower mass‐to‐volume ratio (0.29 ± 0.08 vs. 0.36 ± 0.13, P < 0.0001). Pulmonary regurgitation fraction correlated positively with RV end‐diastolic volume index in the RVOT patch group (r = 0.51, P < 0.0001) but not in the RV‐PA conduit.ConclusionThis study provides the range and distribution of biventricular size and function, and PR measured by MRI in a large contemporary cohort of patients with repaired TOF, and demonstrates important variations in RV mechanics between patients repaired with a RVOT patch and those with an RV‐PA conduit. J. Magn. Reson. Imaging 2007;26:934–940. © 2007 Wiley‐Liss, Inc.
Intercenter agreement of brain atrophy measurement in multiple sclerosis patients using manually‐edited SIENA and SIENAX
Authors: Jasperse Bas , Valsasina Paola , Neacsu Veronica , Knol Dirk L. , De Stefano Nicola , Enzinger Christian , Smith Stephen M. , Ropele Stefan , Korteweg Tijmen , Giorgio Antonio , Anderson Valerie , Polman Chris H. , Filippi Massimo , Miller David H. , Rovaris Marco , Barkhof Frederik , Vrenken Hugo 
Published: September 2007

AbstractPurposeTo investigate intercenter agreement of brain volume (change) measurement in multiple sclerosis (MS) using structural image evaluation using normalization of atrophy (SIENA) and the cross‐sectional version of SIENA (SIENAX) with additional manual editing to correct for inadequate brain extraction.Materials and MethodsBaseline and follow‐up T1‐weighted MR images of 20 MS patients were dispatched to five centers. Each center performed fully‐automated and manually‐edited analyses for SIENAX, yielding normalized brain volume (NBV), and SIENA, yielding percentage brain volume change (PBVC). Intercenter agreement was assessed with the concordance correlation coefficient (CCC).ResultsIntercenter agreement was perfect for fully automated NBV and PBVC (both CCC = 1.0), and remained substantial upon manual editing (CCC = 0.94 for NBV, CCC = 0.95 for PBVC). Mean NBV values for each center decreased significantly after manual editing (overall mean NBV = 1605.3 cm3 vs. 1651.1 cm3 without manual editing; t = –4.58, P < 0.001). Total variance in PBVC decreased significantly by a factor of 1.8 after manual editing (σ2 = 2.82 before, and σ2 = 1.54 after manual editing, P < 0.05).ConclusionSubstantial intercenter agreement was found for manually‐edited SIENAX and SIENA, suggesting that measurements from multiple centers may be pooled. Manual editing reduces overestimation of NBV, and is likely to increase statistical power for PBVC. J. Magn. Reson. Imaging 2007;26:881–885. © 2007 Wiley‐Liss, Inc.
Evaluation of regional myocardial function using automated wall motion analysis of cine MR images: Contribution of parametric images, contraction times, and radial velocities
Authors: Kachenoura Nadjia , Redheuil Alban , Balvay Daniel , Ruiz‐Dominguez Cinta , Herment Alain , Mousseaux Elie , Frouin Frédérique 
Published: September 2007

AbstractPurposeTo develop fast and robust procedures for a clinical evaluation of regional myocardial contractile function.Materials and MethodsParametric analysis of main motion was applied to steady‐state free‐precession (SSFP) cine MR images. From the time–signal intensity curve associated with each pixel, parametric maps of mean high and low amplitudes and transition times between muscle and cavity were automatically computed. Then, regional time to first contraction, Tfc, mean contraction time, Tmc and radial component of the endocardial velocity, Vm were estimated from these parametric maps and a user‐defined endocardial end‐diastolic contour. The method was applied to short‐axis slices in 22 subjects: eight controls, 13 myocardial infarctions (MIs), and one left bundle branch block (LBBB).ResultsTypical patterns of normality and pathology on parametric maps are indicated. For controls, the mean values ± standard deviations (SDs) of Tfc, Tmc, and Vm were: 70 ± 25 msec, 318 ± 43 msec, and 4.6 ± 1.8 cm second–1. An apex to base gradient of Tfc, a significant septal delay in Tfc and Tmc, and a decrease of Vm between the lateral and septal walls were observed. For MI, Tfc and Tmc increased and Vm decreased significantly in pathological segments. For LBBB, large delays were estimated in the septal wall.ConclusionThe proposed method is promising for clinical assessment of regional wall contraction. J. Magn. Reson. Imaging 2007;26:1127–1132. © 2007 Wiley‐Liss, Inc.