bluuebunny/crossref_metadata_2025_split huggingface dataset:
Syntheses with Aliphatic Dialdehydes, XLVI. Synthesis and Reactions of 2,2‐Dialkyl‐Substituted Malonaldehydes and Their Semi(Ethylene Acetals)
Authors: Appelhans Dietmar , Reichardt Christian 
Published: July 2007

AbstractAttempts to synthesize the 2,2‐disubstituted malonaldehydes 3a–h by Swern oxidation of the propane‐1,3‐diols 4a–h led only to polymers of unknown structure, with the exception of 3d,e,f,h, which could be isolated in low yields (ca. 5%) as monomeric compounds. The more stable and hence easier to isolate half‐protected semi(ethylene acetals) of these malonaldehydes, 7a–g, were synthesized from the 2,2‐disubstituted 3‐hydroxypropanals 5a–g via the semiacetals 6a–g. Modified Wittig‐Horner olefination reactions of the malonaldehyde semiacetals 7, followed by hydrolysis, led to derivatives of butane‐1,4‐dial, 9b–e,g, and pent‐3‐ene‐1,5‐dial, 10a–e,g, thus demonstrating the synthetic utility of the new malonaldehyde derivatives 7.
Molecular Bowls and Capsules with an Endohedral Functionality: The Stabilization of Highly Reactive Species in Their Inner Phase
Authors: Goto Kei , Okazaki Renji 
Published: July 2007

AbstractEndohedral phases of molecular bowls and capsules have great potential for serving as a reaction environment for the internal functionality as well as a complexing site for the guest molecule. The reactivity of a functional group covalently fixed in the interior of such molecules can be regulated in a unique fashion by the surrounding framework. This article gives an account of the design of novel molecular bowls and capsules bearing an endohedral functionality and the stabilization of highly reactive species by covalent fixation in the interior of such molecules. The target species include a sulfenic acid, a selenenic acid, and a monosubstituted simple enol, which have been recognized as important but elusive intermediates in organic and enzymatic reactions.
Polyhalogenated Cyclopentadienes in [4+2] Cycloadditions: Preparative Aspects
Authors: Eibler Ernst , Burgemeister Thomas , Höcht Peter , Prantl Bernhard , Roßmaier Henry , Schuhbauer Hans Markus , Wiest Hubert , Sauer Jürgen 
Published: July 2007

Abstract[4+2] Cycloadditions of cyclopentadienes1a–1iwith arylsubstituted cyclic and open‐chain dienophiles usually gave singleendo‐cycloadducts in high yield. Assignment of the product structures involved1H‐NMR spectroscopy including (1H,1H) long‐range coupling and (1H,19F)through‐bondandthrough‐spacecoupling.
7‐Nitro‐7‐deaza‐2′‐deoxyadenosine and 8‐Methyl‐7‐deaza‐2′‐deoxyguanosine: Pyrrolo[2,3‐d]pyrimidine Nucleosides with Different Sugar Conformations
Authors: Seela Frank , Rosemeyer Helmut , Zulauf Matthias , Chen Yaoming , Kastner Guido , Reuter Hans 
Published: July 2007

AbstractThe crystal structures of 7‐nitro‐7‐deaza‐2′ ‐deoxyadenosine (3) and 8‐methyl‐7‐deaza‐2′ ‐deoxyguanosine (5) have been determined and were compared with those of the parent 7‐deaza‐2′ ‐deoxyadenosine (2) and other 7‐substituted 7‐deazapurine 2′ ‐deoxynucleosides 4 and 6. The sugar pucker of compound 3 is N (3′T2′) whereas compound 5 shows 2′E conformation (S‐type). Despite the methyl group, compound 5 exhibits anti conformation about the N‐glycosylic bond as in all other cases. The predominant conformations of 3 and 5 in aqueous solution, determined by 1H NMR spectroscopy, is consistent with those in the solid state.
Studies on Metabolites of Mycoparasitic Fungi, 6. 15‐Hydroxyacorenone: New Acorane‐Type Sesquiterpene from the Culture Broth of the Mycoparasitic Fungus Trichoderma harzianum
Authors: Tezuka Yasuhiro , Tasaki Miyuki , Huang Qing , Hatanaka Yasumaru , Kikuchi Tohru 
Published: July 2007

AbstractA new acorane‐type sesquiterpene, 15‐hydroxyacorenone, has been isolated from the culture broth of Trichoderma harzianum, which in turn was isolated from the fruiting body of a medicinal mushroom, Ganoderma lucidum (Fr.) Karst. (the oriental crude drug “Lin‐Chi”). The structure of 15‐hydroxy‐acorenone was determined by spectroscopic methods to be (1S,4S,5S)‐8‐hydroxymethyl‐1‐isopropyl‐4‐methylspiro[4.5]‐dec‐8‐en‐7‐one (1).
Functionalized Ozonides by Substitution Reactions of Chlorinated Ozonides with Difunctional Alcohols
Authors: Griesbaum Karl , Quinkert Ralf‐Olaf 
Published: July 2007

AbstractSubstitution of 3‐chloro‐3,5‐bis(chloromethyl)‐5‐methyl‐1,2,4‐trioxolane (3) with allyl alcohol gave the corresponding diastereomeric allyloxy‐substituted ozonides 4, which were converted into diozonides 7 by ozone treatment. Substitutions of 3 with ethanediol or with 1,3‐propanediol gave the corresponding hydroxyalkoxy‐substituted ozonides 8, 14, which were oxidized to the corresponding aldehydes 10, 16. Reaction of 3,5‐dichloro‐3,5‐bis(chloromethyl)‐1,2,4‐trioxolane (1a) with ethanediol gave the corresponding bis(hydroxy)‐substituted ozonide 19 as well as a bicyclic ozonide 18 by reaction of 1a with ethanediol in a ratio of 1:1.
MR imaging of testicular torsion: Features of testicular hemorrhagic necrosis and clinical outcomes
Authors: Watanabe Yuji , Nagayama Masako , Okumura Akira , Amoh Yoshiki , Suga Tsuyoshi , Terai Akihito , Dodo Yoshihiro 
Published: July 2007

AbstractPurposeTo determine whether emergency subtraction dynamic contrast‐enhanced MR imaging (DCE‐MRI) in combination with T2‐ and T2*‐weighted imaging of the testis is useful in the evaluation of patients with testicular torsion.Materials and MethodsFourteen patients with surgically proven testicular torsion were examined using preoperative emergency MRI, including T2‐weighted, T2*‐weighted, and DCE‐MRI. The affected testis was examined histologically in eight patients who underwent orchiectomy, and by postoperative follow‐up MRI in six patients who underwent orchiopexy. The diagnostic criteria for testicular torsion and detection of hemorrhagic necrosis in the affected testis in emergency MRI were decreased or no perfusion in DCE‐MRI and a spotty and/or streaky pattern of low or very low signal intensity in T2‐ and T2*‐weighted images. The intraoperative findings and clinical outcomes were also compared.ResultsThe histological findings and follow‐up MR images revealed total or partial necrosis of the affected testis in 10 of the 14 patients. In the diagnosis of complete torsion, the sensitivities were 100% for DCE‐MRI and 75% for T2‐ and T2*‐weighted imaging. In the detection of testicular necrosis, T2‐ and T2*‐weighted imaging showed the highest accuracy (100%), followed by 12‐hour time from onset (93%), intraoperative findings (79%), and DCE‐MRI (71%).ConclusionEmergency MRI can help diagnose testicular torsion and detect testicular necrosis when DCE‐MRI is used in combination with T2‐ and T2*‐weighted images. J. Magn. Reson. Imaging 2007;26:100–108. © 2007 Wiley‐Liss, Inc.
Upper cervical spinal cord cross‐sectional area in relapsing remitting multiple sclerosis: Application of a new technique for measuring cross‐sectional area on magnetic resonance images
Authors: Mann Ranbir S. , Constantinescu Cris S. , Tench Christopher R. 
Published: July 2007

AbstractPurposeTo measure accurately the upper cervical cord cross‐sectional area (CSA) in patients with relapsing remitting multiple sclerosis (RRMS), and normal control subjects, to address the paradox that longitudinal reduction in CSA has been detected in RRMS while reduction compared to controls has not. We hypothesized that a lack of statistical power and/or measurement sensitivity due to partial volume averaging in previous studies contributed to this paradox.Materials and MethodsUsing a technique that corrects for partial volume averaging, we measured the CSA in 35 normal controls and 35 RRMS patients. We used the total intracranial volume (TICV) to normalize the CSA and therefore reduce the normal variance and improve the statistical power.ResultsThe mean TICV did not differ between groups. Statistical power analysis indicated that a 5% reduction in CSA in the patients could be detected with an estimated power of 0.74 before normalization and 0.9 after. The mean CSA in the patients was not reduced compared to controls after (P = 0.928) or before (P = 0.881) normalization.ConclusionUsing a sensitive analysis method, and apparently appropriate statistical power, we did not detect reduced CSA in RRMS patients. We hypothesize that this may be due to inflammation. J. Magn. Reson. Imaging 2007;26:61–65. © 2007 Wiley‐Liss, Inc.
Uterus‐like mass: MRI appearance of a very rare entity
Authors: Menn Kirsten A. , Qin Lihui , Fedoriw George D. , Gillette Mary E. , McCarthy Shirley 
Published: July 2007

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

AbstractPurposeTo investigate the relationship of myelin content, axonal density, and gliosis with the fraction of macromolecular protons (fB) and T2 relaxation of the macromolecular pool (T2B) acquired using quantitative magnetization transfer (qMT) MRI in postmortem brains of subjects with multiple sclerosis (MS).Materials and MethodsfB and T2B were acquired in unfixed postmortem brain slices of 20 subjects with MS. The myelin content, axonal count, and severity of gliosis were all quantified histologically. t‐Tests and multiple regression were used for analysis.ResultsMR indices obtained in unfixed postmortem MS brains were consistent with in vivo values reported in the literature. A significant correlation was detected between Trmyelin (inversely proportional to myelin content) and 1) fB (r = –0.80, P < 0.001) and 2) axonal count (r = –0.79, P < 0.001). fB differed between 1) normal‐appearing white matter (NAWM) and remyelinated WM lesions (rWMLs) (mean: fB 6.9 [SD 2] vs. 4.0 [1.8], P = 0.01), and 2) rWMLs and demyelinated WMLs (mean: 4.2 [2.2] vs. 2.5 [1.3], P = 0.016). No association was detected between T2B and any of the histological measures.ConclusionfB in MS WM is dependent on myelin content and may be a tool to monitor patients with this condition. J. Magn. Reson. Imaging 2007;26:41–51. © 2007 Wiley‐Liss, Inc.
Design, construction and evaluation of an anthropomorphic head phantom with realistic susceptibility artifacts
Authors: Shmueli Karin , Thomas David L. , Ordidge Roger J. 
Published: July 2007

AbstractPurposeTo design and construct an anthropomorphic head phantom using materials of appropriate magnetic susceptibility and air spaces of realistic dimensions, with the aim of reproducing the susceptibility artifacts found in the human brain.Materials and MethodsThe phantom is based on a plastic skull filled with MnCl2‐doped water. Materials to mimic soft tissue (wax) and bone (plastic skull) were chosen based on mass susceptibility measurements using a superconducting quantum interference device (SQUID) magnetometer. The phantom was designed for and evaluated at 4.7T using field mapping and echo‐planar imaging (EPI).ResultsThe main magnetic field (B0) maps of the phantom resemble those of four volunteers' brains and have similar standard deviations (SDs). Maps of the B0 field gradients in the phantom and real brains are also similar. The phantom has relaxation times close to those of brain tissue at 4.7T. Gradient‐echo (GE)‐EPI images of the phantom suffer from susceptibility artifacts comparable to those in real heads and at anatomically realistic locations.ConclusionThe phantom is a useful tool for evaluating and comparing different susceptibility artifact reduction techniques. The phantom could also be used to test CT‐MRI coregistration in the presence of susceptibility artifacts since the water‐filled brain cavity is both CT‐ and MR‐visible. J. Magn. Reson. Imaging 2007;26:202–207. © 2007 Wiley‐Liss, Inc.
Correlations between MR and endothelial hyperplasia in low‐grade gliomas
Authors: Callot Virginie , Galanaud Damien , Figarella‐Branger Dominique , Lefur Yann , Metellus Philippe , Nicoli François , Cozzone Patrick 
Published: July 2007

AbstractPurposeTo investigate the capacity of multimodal MR to detect endothelial hyperplasia (EH), which has been linked to the aggressiveness of gliomas and which is so far only detected by biopsy, an invasive technique that prevents repeated measurements and early detection.Materials and MethodsA total of 26 patients with low‐grade gliomas participated in the study. All underwent a histopathological analysis and a multimodal MR examination (spectroscopic, anatomic, diffusion, perfusion, and postcontrast imaging).ResultsEH was present (EH+) in 15 patients and absent (EH–) in 11. No differences were observed between EH– and EH+ groups when comparing spectroscopic and diffusion parameters. Perfusion measurements, however, allowed us to distinguish EH+ from EH–: the relative regional cerebral blood flow (rCBF) was found equal to 3.23 ± 2.05 for EH+ and 1.33 ± 0.46 for EH– (P = 0.006).ConclusionWe have observed a strong correlation between the presence of EH and the increase of rCBF. Compared to conventional imaging, MR perfusion provides additional and complementary information that may be used for biopsy guidance, early detection of tumor aggressiveness, and noninvasive follow‐ups. J. Magn. Reson. Imaging 2007;26:52–60. © 2007 Wiley‐Liss, Inc.
Can isotropic fast gradient echo imaging be substituted for conventional T1 weighted sequences in shoulder MR arthrography at 3 Tesla?
Authors: Magee Thomas 
Published: July 2007

AbstractPurposeTo assess the practical utility of isotropic shoulder imaging in patients undergoing MR arthrography. Isotropic shoulder imaging can be performed in less than three minutes with use of fast gradients.Materials and MethodsTwo experienced musculoskeletal radiologists retrospectively interpreted MR images of the shoulder in 100 consecutive patients undergoing MR arthrography of the shoulder. All patients underwent MRI of the shoulder in oblique coronal, oblique sagittal, and axial planes on a 3.0‐Tesla MRI system. All patients had conventional fast spin‐echo T1‐weighted imaging. All patients also had thin section (0.4 mm) isotropic spoiled gradient echo images performed. A total of 67 of the 100 patients underwent subsequent arthroscopy and results were compared with MR interpretations.ResultsThere were 41 full‐thickness supraspinatus tendon tears, nine partial‐thickness supraspinatus tendon tears (seven articular surface and two bursal surface), 21 superior labral, 18 anterior labral, and seven posterior labral tears demonstrated by consensus retrospective reading of the 100 shoulder MR exams. There was no difference in interpretation of the isotropic images as compared to the conventionally acquired images in the oblique coronal, oblique sagittal, and axial planes. Some patients had more than one finding on each exam. A total of 67 patients went on to arthroscopy. There were 41 full‐thickness supraspinatus tendon tears, nine partial‐thickness supraspinatus tendon tears, 21 superior labral, 18 anterior labral, and seven posterior labral tears demonstrated on arthroscopy. All full‐ and partial‐thickness supraspinatus tendon tears seen at arthroscopy were seen on consensus MR reading. A total of 19 out of the 21 patients with superior labral anterior posterior (SLAP) tears at arthroscopy were seen on consensus MR reading. A total of 16 of the 18 anterior labral tears and six of the seven posterior labral tears seen at arthroscopy were seen on consensus MR reading. Some of the 67 patients had more than one finding on arthroscopy.ConclusionIsotropic imaging of the shoulder is practical in clinical imaging when performed with use of fast gradients on a 3‐Tesla system. Isotropic imaging provides the same clinical information as conventional imaging and can be acquired in less than three minutes. J. Magn. Reson. Imaging 2007;26:118–122. © 2007 Wiley‐Liss, Inc.
FTIR‐spectroscopic characterization of humic acids and humin fractions obtained by advanced NaOH, Na4P2O7, and Na2CO3 extraction procedures
Authors: Tatzber Michael , Stemmer Michael , Spiegel Heide , Katzlberger Christian , Haberhauer Georg , Mentler Axel , Gerzabek Martin H. 
Published: July 2007

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

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

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

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