bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radiosynthesis of 3‐(3‐[18F]fluoropropoxy)‐4‐(benzyloxy)‐N‐[(1‐dimethylaminocyclopentyl)methyl]‐5‐methoxybenzamide, a potential PET radiotracer for the glycine transporter GlyT‐2
Authors: Tian Haibin , Vogel Rebecca , Amici Louis , Tamagnan Gilles , Baldwin Ronald M. 
Published: December 2006

AbstractThe recently described selective and potent GlyT2 antagonist, 4‐benzyloxy‐3,5‐dimethoxy‐N‐[(1‐dimethylaminocyclopentyl) methyl]benzamide (IC50=16 nM) provided an important additional tool to further characterize GlyT2 pharmacology. In order to identify an effective PET radioligand for in vivo assessment of the GlyT‐2 transporter, 3‐(3‐[18F]fluoropropoxy)‐4‐(benzyloxy)‐N‐((1‐dimethylaminocyclopentyl) methyl)‐5‐methoxybenzamide ([18F]3), a novel analog of 4‐benzyloxy‐3,5‐dimethoxy‐N‐[(1‐dimethylaminocyclopentyl) methyl]benzamide was synthesized using a one‐pot, two‐step method. The NCA radiofluorination of 1,3‐propanediol di‐p‐tosylate in the presence of K2CO3 and Kryptofix‐222 in acetonitrile gave 81% 3‐[18F]fluoropropyl tosylate, which was subsequently coupled with 4‐benzyloxy‐3‐hydroxy‐5‐methoxy‐N‐[(1‐dimethylaminocyclopentyl) methyl]benzamide in the same reaction vessel. Solvent extraction and HPLC (Eclipse XDB‐C8 column, 80/20/0.1 MeOH/H2O/Et3N, 3.0 ml/min) gave [18F]3 in 98.5% radiochemical purity. The radiochemical yield was determined to be 14.0–16.2% at EOS, and the specific activity was 1462±342 GBq/µmol. The time of synthesis and purification was 128 min. The final product was prepared as a sterile saline solution suitable for in vivo use. Copyright © 2006 John Wiley & Sons, Ltd.
Cine phase contrast MRI to measure continuum Lagrangian finite strain fields in contracting skeletal muscle
Authors: Zhou Hehe , Novotny John E. 
Published: December 2006

AbstractPurposeTo measure the complex mechanics and Lagrangian finite strain of contracting human skeletal muscle in vivo with cine phase contrast MRI (CPC‐MRI) applied to the human supraspinatus muscle of the shoulder.Materials and MethodsProcessing techniques are applied to transform velocities from CPC‐MRI images to displacements and planar Lagrangian finite strain. An interpolation method describing the continuity of the velocity field and forward‐backward and Fourier transform methods were used to track the displacement of regions of interest during a cyclic abduction motion of a subject's arm. The components of the Lagrangian strain tensor were derived during the motion and principal and maximum in‐plane shear strain fields calculated.ResultsDerived displacement and strain fields are shown that describe the contraction mechanics of the supraspinatus. Strains vary over time during the cyclic motion and are highly nonuniform throughout the muscle.ConclusionThis method presented overcomes the physical resolution of the MRI scanner, which is crucial for the detection of detailed information within muscles, such as the changes that might occur with partial tears of the supraspinatus. These can then be used as input or validation data for modeling human skeletal muscle. J. Magn. Reson. Imaging 2007. © 2006 Wiley‐Liss, Inc.
Assessment of bolus injection protocol with appropriate concentration for quantitative assessment of pulmonary perfusion by dynamic contrast‐enhanced MR imaging
Authors: Ohno Yoshiharu , Murase Kenya , Higashino Takanori , Nogami Munenobu , Koyama Hisanobu , Takenaka Daisuke , Kawamitu Hideaki , Matsumoto Sumiaki , Hatabu Hiroto , Sugimura Kazuro 
Published: December 2006

AbstractPurposeTo determine the appropriate concentration for quantitative assessment of dynamic contrast‐enhanced pulmonary MR imaging.Materials and MethodsA total of 40 consecutive patients with small bronchioalveolar carcinoma underwent perfusion single‐photon emission tomography (SPECT) and three‐dimensional (3D) dynamic MR imaging with a 3D radiofrequency spoiled gradient‐echo sequence. In each patient, 5 mL of contrast media with 0.1, 0.3, and 0.5 mmol/mL were administered at a rate of 5 mL/second. All patients were divided into two groups (<70 kg and ≥70 kg) for assessment of appropriate concentration to quantitatively assess regional perfusion parameter in routine clinical practice. Pulmonary blood flow (PBF) in each protocol was calculated from a signal intensity (SI)–time course curve. Differences and limits of agreement of PBF between dynamic MR imaging (PBFMR) using three different concentrations and perfusion SPECT (PBFSPECT) were statistically compared in both patient groups.ResultsPBFMR using 0.3 mmol/mL in the <70‐kg group and 0.5 mmol/mL in the ≥70‐kg group showed no significant difference compared with PBFSPECT (P > 0.05). Limits of agreements in 0.3 mmol/mL in the <70‐kg group and 0.5 mmol/mL in the ≥70‐kg group were smaller than those of the other concentrations and small enough for clinical purposes.ConclusionAppropriate concentrations provide accurate and reproducible assessments of regional pulmonary perfusion parameters on 3D dynamic MR perfusion imaging. We suggest using 5 mL of contrast media with 0.3 mmol/mL for patients weighing less than 70 kg and 0.5 mmol/mL for patients weighing 70 kg or more. J. Magn. Reson. Imaging 2007. © 2006 Wiley‐Liss, Inc.
Small hepatic lesions found on single‐phase helical CT in patients with malignancy: Diagnostic capability of breath‐hold, multisection fluid‐attenuated inversion‐recovery (FLAIR) MR imaging using a half‐fourier acquisition single‐shot turbo spin‐echo (HASTE) sequence
Authors: Sasaki Katsumi , Ito Katsuyoshi , Fujita Takeshi , Shimizu Ayame , Yasui Masayasu , Hayashida Minoru , Tanabe Masahiro , Matsunaga Naofumi 
Published: December 2006

AbstractPurposeTo evaluate the diagnostic capability of breath‐hold, multisection fluid‐attenuated inversion‐recovery (FLAIR) imaging using a half‐Fourier acquisition single‐shot turbo spin‐echo (HASTE) sequence in combination with T2‐weighted fast spin‐echo (FSE) magnetic resonance (MR) sequences for small hepatic lesions found on CT in patients with malignancy.Materials and MethodsThis study included 48 patients with extrahepatic malignancy who underwent both CT and MR examinations. There were a total of 112 small hepatic lesions (73 cysts and 39 liver metastases, <2 cm in diameter) that showed low attenuation on enhanced CT. Three radiologists independently reviewed the CT and MR (FLAIR‐HASTE and T2‐weighted FSE) images and assigned a confidence level to their evaluation (cyst or metastasis) on a five‐point scale.ResultsAll three reviewers were significantly better able (P < 0.05) to differentiate small hepatic cyst from liver metastasis with combined FLAIR‐HASTE and T2‐weighted FSE images (Az values = 0.997–0.999) than with CT (0.917–0.932). The mean values of sensitivity, specificity, and accuracy were significantly higher (P < 0.001) for T2‐weighted FSE with FLAIR‐HASTE (96.6%, 96.8%, and 96.7%, respectively) than for CT (76.9%, 61.6%, and 67.3%, respectively). A confident diagnosis was rendered in 12 of 112 lesions (10.7%) on the basis of CT, and this rate increased to 83 of 112 (74.1%) on the basis of T2‐weighted FSE and FLAIR‐HASTE imaging.ConclusionFLAIR‐HASTE is considered to be an effective sequence for differentiating hepatic cysts from liver metastases without the use of a contrast agent. With FLAIR‐HASTE one can confidently diagnose small hepatic lesions found on CT in patients with a malignancy. J. Magn. Reson. Imaging 2007. © 2006 Wiley‐Liss, Inc.
Negative‐charge driven fragmentations for evidencing zwitterionic forms from doubly charged coppered peptides
Authors: Boutin Michel , Bich Claudia , Afonso Carlos , Fournier Françoise , Tabet Jean‐Claude 
Published: December 2006

AbstractIn aqueous solution, amino acids (AA) and peptides are known to exist as zwitterions over a large pH range. However, in the gas phase, i.e. in electrospray (ESI), the zwitterionic form becomes unfavorable owing to the absence of stabilizing effects from intermolecular solvation. Nevertheless, during mass spectrometry experiments, the presence of a metallic cation can reinforce the zwitterionic character of the molecule and thus influence its fragmentation under low energy collision‐induced dissociation (CID) conditions. The [M + CuII]2+ complexes of six pentapeptides (YGGFL, YGGFL(NH2), YGGFK, YGGFQ, KYGGF and QYGGF) were analyzed by collision to highlight the presence of zwitterions. The experiments were performed on a 3D‐ion trap equipped with an orthogonal ESI source. For each peptides studied, negative‐charge driven fragmentations on globally positively charged ions were observed. These fragmentation mechanisms, generally observed in the negative mode, suggest the competitive deprotonation of the C‐terminal carboxylic acid or of the tyrosine side‐chain residue for each peptide studied and thus a zwitterionic form to preserve the charge balance. Moreover, the specific loss of (CH3C6H4O)• characterizes YGGFK compared to YGGFQ and the specific loss of styrene characterizes KYGGF compared to QYGGF. These results allow the differentiation of the two couples of isobaric pentapeptides. An unusual loss of NH4+, which occurred from the N‐terminus, was also observed for YGGFL, YGGFL(NH2), YGGFK and YGGFQ. Finally, the reduction of CuII to CuI, concomitant with the (CH3C6H4O)• release, was pointed out for YGGFK. Copyright © 2006 John Wiley & Sons, Ltd.
Direct analysis of alkaloid profiling in plant tissue by using matrix‐assisted laser desorption/ionization mass spectrometry
Authors: Wu Wei , Liang Zhitao , Zhao Zhongzhen , Cai Zongwei 
Published: December 2006

AbstractA method for the direct determination of alkaloid profiling in plant tissues by using matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) was developed. The alkaloid profiles of the herbs were obtained without the need for complicated sample preparation. Experimental results demonstrated that the direct MALDI‐TOFMS analysis allowed rapid and reliable characterization of the components in plant tissues. Four commonly used Chinese medicinal herbs were studied, including Aconitum Carmichaeli Debx. (Fuzi in Chinese) and Processed Fuzi, for herb differentiation and explanation of the significant difference in their toxicities. The direct analysis method proved valuable for the preliminary study of plant component profiles. The rapid collection of information from the direct analysis on plant tissues could be valuable for supporting the discovery of new compounds and for the quality control of medicinal herbs. Copyright © 2006 John Wiley & Sons, Ltd.
Tandem mass spectrometry of kahalalides: identification of two new cyclic depsipeptides, kahalalide R and S from Elysia grandifolia
Authors: Tilvi Supriya , Naik C. G. 
Published: December 2006

AbstractSpectra obtained using electrospray ionization mass spectrometry (ESI‐MS) of the mollusk Elysia grandifolia showed a cluster of molecular ion peaks centered at a molecular mass of 1478 Da (kahalalide F, an anticancer agent). Two new molecules, kahalalide R (m/z 1464) and S (m/z 1492) were characterized using tandem mass spectrometry. The mass differences of 14 Da suggest that they are homologous molecules. In addition, previously identified kahalalide D and kahalalide G are also reported. However, the ESI‐MS of the mollusk's algal diet Bryopsis plumosa showed the presence of only kahalalide F. The amino acid sequences of kahalalide R and S are proposed using collision‐induced dissociation (CID) experiments of singly and doubly charged molecular ions and by comparison with the amino acid sequence of kahalalide F. The pathway is presented for the loss of amino acid residues in kahalalide F. It is observed that there is sequential loss of amino acids in the linear peptide chain, but in the cyclic part the ring opens at the amide bond rather than at the lactone linkage, and the loss of amino acid residues is not sequential. The CID experiment of the alkali‐metal‐cationized molecular ions shows that the sodium and potassium ions coordinate to the amide nitrogen/oxygen in the linear peptide chain of the molecule and not to the lactone oxygen of the lactone. In the case of kahalalide D, CID of the protonated peptide opens the depsipeptide ring to form a linear peptide with acylium ion, and fragment ion signals indicate losses of amino acids in sequential order. In this study, tandem mass spectrometry has provided the detailed information required to fully characterize the new peptides. Copyright © 2006 John Wiley & Sons, Ltd.
The tropopause at southern extratropical latitudes: Argentine operational rawinsonde climatology
Authors: Bischoff Susana A. , Canziani Pablo O. , Yuchechen Adrián E. 
Published: December 2006

AbstractArgentine operational rawinsonde records spanning a 30‐year period (1968–1997) were used to study the climatology of the tropopause from the subtropics to the southern mid‐latitudes, approximately along the 60°W meridian. The thermal tropopause annual cycle as well as its variability was analyzed at three sites: Resistencia (RES), Ezeiza (EZE), and Comodoro Rivadavia (CRD). Single and double tropopause observations were studied, given the comparatively frequent occurrence of double tropopause events at all three sites. The tropopause behavior at RES and CRD is distinct, whereas at EZE it shows a winter evolution similar to the one at CRD and a summer evolution closer to the one at RES, in agreement with the annual evolution of the subtropical jet. The tropopause evolution is discussed under the light of the dynamic climatology of southern South America. In the presence of double tropopause events and in terms of potential temperature, it should be noted that the upper tropopause temperature is close to the 380 K isentropic, i.e. the tropical tropopause layer. Moreover, the lower tropopause and single tropopause events are fairly close together, i.e. coincident with the lowermost stratosphere. Considering previous research and results from the present analysis, a definition of Extratropical Tropopause Layer (ExTL) is introduced in this work. It is proposed that the lowermost stratosphere should be regarded as the ExTL. Copyright © 2006 Royal Meteorological Society
Drought index evaluation for assessing future wheat production in Greece
Authors: Mavromatis T. 
Published: December 2006

AbstractThe main objectives of this study were (1) to evaluate the SPI, and three variations of the Palmer Drought Severity Index (PDSI) (the original PDSI (Orig‐PDSI), a self‐calibrated version (SC‐PDSI) and a modified scheme employing Priestlay–Taylor's approach to compute potential evapotranspiration (PET) instead of Thornthwaite's method) and their respective moisture anomaly indices for assessing rainfed common wheat and durum wheat yield in two pilot crop regions in north and central Greece, and (2) to assess the vulnerability of wheat production to climate change, using the most appropriate drought index, with future scenarios provided by the Hadley Centre regional climate model HadRM3. The yield models that performed best at high‐drought risk years (the Orig‐PDSI index in the northern region and the SC‐PDSI in the southern region, explaining 82.5 to 84.7% and 92% of the measured yield variability, respectively) were also the most effective at predicting the observed wheat yields when soil moisture was not an important yield‐limiting factor. However, the strength of the relationship between the drought indices and the crop yields was much weaker. Improving the representation of PET in the PDSI algorithm did not improve the model's performance. The sensitivity of the two types of wheat to HadRM3 projections for the high‐drought risk years differed dramatically between the two pilot districts, with extremely decreased yields of 3.14 tn ha−1 expected in the southern district and much smaller changes expected in the northern district (−4.6 vs + 6.7% for durum wheat and common wheat, respectively). For the low‐drought risk years, the yield models in the northern region predicted lower yields by 30 to 60 kg ha−1. A positive yield response by 30 kg ha−1 was found for the southern district. Copyright © 2006 Royal Meteorological Society
Detecting trends in tropical rainfall characteristics, 1979–2003
Authors: Lau K.‐M. , Wu H.‐T. 
Published: December 2006

AbstractAnalyses of two state‐of‐the‐art, blended space‐based and ground‐based global rainfall data sets from the Global Precipitation Climatology Project (GPCP) and the Climate Prediction Center Merged Analysis Product (CMAP) reveal that there was a significant shift in the probability distribution functions of tropical rainfall during the period 1979–2003. This shift features a positive trend in the occurrence of heavy (top 10% by rain amount) and light (bottom 5%) rain events in the tropics during 1979–2003 and a negative trend in moderate (25–75%) rain events. These trends are consistent in both data sets and are in overall agreement with the Climate Research Unit's (CRU) gauge‐only rainfall data over land. The relationships among the trends and the possible long‐term changes in rainfall characteristics are discussed. Copyright © 2006 Royal Meteorological Society
A lacustrine record of early Holocene watershed events and vegetation history, Corvara in Badia, Dolomites (Italy)
Authors: Borgatti Lisa , Ravazzi Cesare , Donegana Marta , Corsini Alessandro , Marchetti Mauro , Soldati Mauro 
Published: December 2006

AbstractThe early–middle Holocene lacustrine succession of Corvara in Badia (Italian Dolomites, 1521 m a.s.l.) records landslides and other watershed events before the onset of human pressure. The sensitivity of this archive to relate climate change, watershed processes and vegetation dynamics in the catchment has been explored through a stratigraphic study, including the analysis of sedimentological features, magnetic properties, palaeobotanical records and radiocarbon dating. A palaeolake existed between 10.1 k and 7 k cal. yr BP and was surrounded by a dense conifer forest. Long‐term forest dynamics driven by ecological processes and by climatic conditions favourable to upward forest expansion is recorded throughout the pollen record. Within the fine clastic sedimentation, distinct layers enriched in organic debris of terrestrial origin have been attributed to instant events produced by mass movements. Their age fits the chronology of large landslide events already known in the catchment, enabling correlation of the field evidence of landslides with the lacustrine record. Landslide frequency is controlled by geological and structural factors, but it is significantly modulated by the centennial–millennial climatic phases that characterise the Holocene in the Alps. The taphonomical properties of pollen and macroremains provided valuable insight on the mechanism of watershed processes. Copyright © 2006 John Wiley & Sons, Ltd.
Food additives characterization by infrared, Raman, and surface‐enhanced Raman spectroscopies
Authors: Podstawka Edyta , Światłowska Małgorzata , Borowiec Ewa , Proniewicz Leonard M. 
Published: December 2006

AbstractFourier‐transform infrared (FT‐IR), Raman (RS), and surface‐enhanced Raman scattering (SERS) spectra of β‐hydroxy‐β‐methylobutanoic acid (HMB), L‐carnitine, and N‐methylglycocyamine (creatine) have been measured. The SERS spectra have been taken from species adsorbed on a colloidal silver surface. The respective FT‐IR and RS band assignments (solid‐state samples) based on the literature data have been proposed. The strongest absorptions in the FT‐IR spectrum of creatine are observed at 1398, 1615, and 1699 cm−1, which are due to νs(COOH) + ν(CN) + δ(CN), ρs(NH2), and ν(CO) modes, respectively, whereas those of L‐carnitine (at 1396/1586 cm−1 and 1480 cm−1) and HMB (at 1405/1555/1585 cm−1 and 1437–1473 cm−1) are associated with carboxyl and methyl/methylene group vibrations, respectively. On the other hand, the strongest bands in the RS spectrum of HMB observed at 748/1442/1462 cm−1 and 1408 cm−1 are due to methyl/methylene deformations and carboxyl group vibrations, respectively. The strongest Raman band of creatine at 831 cm−1 (ρw(RNH2)) is accompanied by two weaker bands at 1054 and 1397 cm−1 due to ν(CN) + ν(RNH2) and νs(COOH) + ν(CN) + δ(CN) modes, respectively. In the case of L‐carnitine, its RS spectrum is dominated by bands at 772 and 1461 cm−1 assigned to ρr(CH2) and δ(CH3), respectively.The analysis of the SERS spectra shows that HMB interacts with the silver surface mainly through the COO−, hydroxyl, and CH2 groups, whereas L‐carnitine binds to the surface via COO− and N+(CH3)3 which is rarely enhanced at pH = 8.3. On the other hand, it seems that creatine binds weakly to the silver surface mainly by NH2, and CO from the COO− group. Copyright © 2006 John Wiley & Sons, Ltd.
Detailed 1D/2D NMR Analyses of Benzophenone‐Related Reaction Products from a Photopolymerization System of Vinyl Acetate and Benzophenone
Authors: Kong Lingbing , Deng Jianping , Yang Wantai 
Published: December 2006

AbstractSummary: A new reaction system was designed in order to allow the reaction between benzophenone (BP) and poly(vinyl acetate) chain/radical or monomer to progress under UV irradiation with relatively constant intensity of absorbed light. After the reaction, most BP‐related products were successfully separated and were directly and particularly studied for the first time by a 600 MHz solution‐state NMR spectrometer. 13C, 1H, DEPT‐135, and 2D 1H‐13C HSQC, 1H‐13C HMBC NMR spectra were utilized for the analyses. In the mixed products, two new structures with new ether groups were detected and confirmed, besides detailed confirmation of benzopinacol and semi‐benzopinacol‐connected poly(vinyl acetate).Structures 1 and 2magnified imageStructures 1 and 2
White‐Light Emission from a Single Polymer with Singlet and Triplet Chromophores on the Backbone
Authors: Zhen Hongyu , Xu Wei , Yang Wei , Chen Qiliang , Xu Yunhua , Jiang Jiaxing , Peng Junbiao , Cao Yong 
Published: December 2006

AbstractSummary: A strategy to generate an efficient white‐light emission has been developed by mixing fluorescence and phosphorescence emission from a single polymer. Fluorene is used as the blue‐emissive component, benzothiadiazole (BT) and the iridium complex [(btp)2Ir(tmd)] are incorporated into a polyfluorene backbone, respectively, as green‐ and red‐emissive chromophores by Suzuki polycondensation. By changing the contents of BT and [(btp)2Ir(tmd)] in the polymer, the electroluminescence spectrum from a single polymer can be adjusted to achieve white‐light emission. A white polymeric light‐emitting diode (WPLED) with a structure of ITO/PEDOT:PSS/PVK/PFIrR1G03/CsF/Al shows a maximum external quantum efficiency of 3.7% and the maximum luminous efficiency of 3.9 cd · A−1 at the current density of 1.6 mA · cm−2 with the CIE coordinates of (0.33, 0.34). The maximum luminance of 4 180 cd · m−2 is achieved at the current density of 268 mA · cm−2 with the CIE coordinates of (0.31, 0.32). The white‐light emissions from such polymers are stable in the white‐light region at all applied voltages, and the electroluminescence efficiencies decline slightly with the increasing current density, thus indicating that the approach of incorporating singlet and triplet species into the polymer backbone is promising for WPLEDs.Structure of PFIrR1G04 and the EL spectra of its devices under various voltages. Device structure: ITO/PEDOT:PSS/PVK/polymer/CsF/Al.magnified imageStructure of PFIrR1G04 and the EL spectra of its devices under various voltages. Device structure: ITO/PEDOT:PSS/PVK/polymer/CsF/Al.