bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermodynamic Analysis of Receptors Based on Guanidinium/Boronic Acid Groups for the Complexation of Carboxylates, α‐Hydroxycarboxylates, and Diols: Driving Force for Binding and Cooperativity
Authors: Wiskur Sheryl L. , Lavigne John J. , Metzger Axel , Tobey Suzanne L. , Lynch Vincent , Anslyn Eric V. 
Published: June 2004

AbstractThe thermodynamics of guanidinium and boronic acid interactions with carboxylates, α‐hydroxycarboxylates, and diols were studied by determination of the binding constants of a variety of different guests to four different hosts (7–10). Each host contains a different combination of guanidinium groups and boronic acids. The guests included molecules with carboxylate and/or diol moieties, such as citrate, tartrate, and fructose, among others. The Gibbs free energies of binding were determined by UV/Vis absorption spectroscopy, by use of indicator displacement assays. The receptor based on three guanidinium groups (7) was selective for the tricarboxylate guest. The receptors that incorporated boronic acids (8–10) had higher affinities for guests that included α‐hydroxycarboxylate and catechol moieties over guests containing only carboxylates or alkanediols. Isothermal titration calorimetry revealed the enthalpic and entropic contributions to the Gibbs free energies of binding. The binding of citrate and tartrate was investigated with hosts 7–10, for which all the binding events were exothermic, with positive entropy. Because of the selectivity of hosts 8–10, a simple boronic acid (14) was also investigated and determined to be selective for α‐hydroxycarboxylates and catechols over amino acids and alkanediols. Further, the cooperativity of 8 and 9 in binding tartrate was also investigated, revealing little or no cooperativity with 8, but negative cooperativity with 9. A linear entropy/enthalpy compensation relationship for all the hosts 7–10, 14, and the carboxylate‐/diol‐containing guests was also obtained. This relationship indicates that increasing enthalpy of binding is offset by similar losses in entropy for molecular recognition involving guanidinium and boronic acid groups.
New 2,2′‐Substituted 4,4′‐Dimethoxy‐6,6′‐dimethyl[1,1′‐biphenyls], Inducing a Strong Helical Twisting Power in Liquid Crystals
Authors: Holzwarth Richard , Bartsch Richard , Cherkaoui Zoubair , Solladié Guy 
Published: June 2004

AbstractBased on the stabilisation of the molecular motion by the chiral residue, novel optically active biphenylic chiral dopants for nematic liquid crystals were developed. This molecular congestion was obtained by introducing mesogenic residues on the 2,2′‐positions of the chiral biphenyl; this led to a novel molecular architecture that was found to be efficient. The synthesised optically active biphenyls were characterised with very short cholesteric pitches when used as chiral dopants in nematic liquid crystals. The synthesis of the enatiomerically pure biphenyl dopants and their preliminary physicochemical characterisations are described.
The management of early breast carcinoma before and after the introduction of clinical practice guidelines
Authors: White Victoria , Pruden Myee , Giles Graham , Collins John , Jamrozik Konrad , Inglis Graeme , Boyages John , Hill David 
Published: June 2004

AbstractBACKGROUNDClinical practice guidelines for the management of breast carcinoma were introduced in Australia in October, 1995. This article describes the management of early‐stage breast carcinoma both before and after the introduction of these guidelines.METHODSAll cases of early breast carcinoma that were diagnosed over the same 6‐month period in 1995 and 1999 and registered with a state‐based cancer registry were identified. Treating surgeons completed a survey assessing tumor characteristics and primary treatment. In 1995, 95% of 188 surgeons who were approached participated and 96% of the surveys were returned. In 1999, 92% of 159 surgeons who were approached participated and 91% of the surveys were returned. Analyses are based on 1066 cases from 1995 and 1001 cases from 1999.RESULTSThe pathologic disease stage of the patients was similar in both study years. The proportion of patients who underwent breast‐conserving therapy (BCT) increased from 54% in 1995 to 69% in 1999. This increase was noted across most levels of disease characteristics but was not evident among those patients treated by the least active surgeons. The proportion of patients treated with BCT who received radiotherapy increased from 59% in 1995 to 80% in 1999. This trend was observed across most levels of tumor characteristics and surgeon caseload. The proportion of women with receptor‐positive tumors who were treated with endocrine therapy increased, whereas the proportion of patients with receptor‐negative tumors who received this therapy decreased from 39% in 1995 to 17% in 1999.CONCLUSIONSThe management of early breast carcinoma in the state of Victoria appeared to change between 1995 and 1999 in the direction expected if the national guidelines had been incorporated into the practice patterns of surgeons treating breast carcinoma patients. Cancer 2004. © 2004 American Cancer Society.
Bemessung von bewehrtem Mauerwerk Beispiele nach Eurocode 6 Teil 1‐1
Authors: Reeh Helmut 
Published: June 2004

AbstractNach Aufstellung der Berechnungsgrundlagen wird anhand von zwei Beispielen die Nachweisführung und die Bemessung von bewehrtem Mauerwerk nach dem Eurocode 6 gezeigt. Als Beispiele werden eine Außenwand und ein Sturz aus USchalen behandelt. Als Ergebnis wird festgestellt, daß stets der Nachweis der Verankerung der Bewehrung maßgebend wird. Die Forderung in /2/ von ℓü > 0, 3 ℓb führt zu großen Verankerungslängen, die insbesondere bei Verankerung in Mauermörtel Probleme bereiten dürfte und vermutlich die Anwendung von bewehrtem Mauerwerk nach Eurocode 6 stark einschränken wird.
Ringanker und Ringbalken
Authors: Böhme Helmut H. 
Published: June 2004

AbstractDie in den Vorschriften (DIN 1053‐1) aufgeführten Regeln stellen eine gute Grundlage dar. Es muß aber, vor allem bei Ringankern, die unbedingte Einhaltung der folgenden Kriterien verlangt werden!(1) Erfüllung DIN 1053‐1, 11.96, Abschn. 8.2.1(2) Einhaltung der Bewehrungsregeln (Überdeckung, Krümmungskreisdurchmesser usw.)(3) Konstruktive Sicherung der Richtungsänderungspunkte(4) Ausführung in der Deckenebene (in einer Ebene). Eine beliebige Führung eines Zugstabes ist möglich. Da sich aber die Herausführung aus der Deckenebene immer aus der Notwendigkeit der Gebäudekonstruktion ergibt, ist dann die Ableitung und Aufnahme der Umlenkkräfte konstruktiv oft überhaupt nicht machbar.(5) Eine Umleitung der Zugkräfte über eine Rahmenkonstruktion ist grundsätzlich möglich, wird aber durch die räumliche Ringankerführung über beliebige Gebäudeteile nicht erfüllt. Man denke nur an die für die Aufnahme von Biegemomenten ungeeigneten Abmessungen.
Konstruktive Bewehrung im Mauerwerkbau
Authors: Beer Ingo , Schmidt Ulf , Schubert Peter 
Published: June 2004

AbstractMit den Tabellen für die Stahlspannung am Riß und für die Mauerwerkzugfestigkeit sowie den vorgestellten Gleichungen können sehr einfach — wie die Bemessungsbeispiele belegen — die zur Rißbreitenbeschränkung erforderlichen Bewehrungsgehalte bestimmt werden. Dabei ist jedoch zu beachten, daß die Angaben zur Mauerwerkzugfestigkeit nur Anhaltswerte sind. Da die Mauerwerkzugfestigkeit eine wesentliche Einflußgröße für die Bemessung ist, sollte diese für den Einzelfall genauer berechnet werden. Nur dann ist eine zutreffende und wirtschaftliche Bemessung der Bewehrung für den Einzelfall möglich.
Fructose‐mediated non‐enzymatic glycation: sweet coupling or bad modification
Authors: Schalkwijk Casper G. , Stehouwer Coen D. A. , van Hinsbergh Victor W. M. 
Published: June 2004

AbstractThe Maillard reaction is a process in which reducing sugars react spontaneously with amino groups in proteins to advanced glycation endproducts (AGEs). Although an elevated level of glucose had been thought to play a primary role in the Maillard reaction, on a molecular basis, glucose is among the least reactive sugars within biological systems. The formation of AGEs is now also known to result from the action of various metabolites other than glucose, which are primarily located intracellularly and participate in the non‐enzymatic glycation reaction at a much faster rate, such as fructose, trioses and dicarbonyl compounds. In this review, we considered the glycation reaction with particular attention to the potential role of fructose and fructose metabolites. The two sources for fructose are an exogenous supply from the diet and the endogenous formation from glucose through the aldose reductase pathway. Despite its ∼eightfold higher reactivity, the contribution of extracellular glycation by fructose is considerably less than that by glucose, because of the low plasma concentration of fructose (5 mmol/L glucose vs 35 µmol/L fructose). Intracellularly, fructose is elevated in a number of tissues of diabetic patients in which the polyol pathway is active. In the cells of these tissues, the concentrations of fructose and glucose are of the same magnitude. Although direct evidence is not yet available, it is likely that the high reactivity of fructose and its metabolites may substantially contribute to the formation of intracellular AGEs and may contribute to alterations of cellular proteins, dysfunction of cells and, subsequently, to vascular complications. Copyright © 2004 John Wiley & Sons, Ltd.
Analysis of ambergris tincture
Authors: Awano K. , Ishizaki S. , Takazawa O. , Kitahara T. 
Published: June 2004

AbstractThis is a report of the detection of 13‐ethoxy‐8α,13‐epoxy‐14,15,16‐trinorlabdane (1) and 12‐ethoxy‐8α,12‐epoxy‐13,14,15,16‐tetranorlabdane (2), hitherto unidentiﬁed and considered as degradation products of ambrein, among 31 constituents found by analysis of ambergris tincture. Copyright © 2004 John Wiley & Sons, Ltd.
Note on projective graphs
Authors: Łuczak Tomasz , Nešetřil Jaroslav 
Published: June 2004

AbstractWe show that all graphs with a simple extension property are projective. As a consequence of this result we settle in the affirmative a conjecture of Larose and Tardif and characterize all homogeneous graphs which are projective. © 2004 Wiley Periodicals, Inc. J Graph Theory 47: 81–86, 2004
Tumor microvascular changes in antiangiogenic treatment: Assessment by magnetic resonance contrast media of different molecular weights
Authors: Turetschek Karl , Preda Anda , Novikov Viktor , Brasch Robert C. , Weinmann Hanns J. , Wunderbaldinger Patrick , Roberts Timothy P.L. 
Published: June 2004

AbstractPurposeTo test magnetic resonance (MR) contrast media of different molecular weights (MWs) for their potential to characterize noninvasively microvascular changes in an experimental tumor treatment model.Materials and MethodsMD‐MBA‐435, a poorly differentiated human breast cancer cell line, was implanted into 31 female homozygous athymic rats. Animals were assigned randomly to a control (saline) or drug treatment (monoclonal antibody vascular endothelial growth factor (Mab‐VEGF) antibody) group. In both groups, dynamic MR imaging (MRI) was performed in each animal using up to three different contrast media on sequential days at baseline and follow‐up examination. The MWs of the contrast media used ranged from 557 Da to 92 kDa. Using a bidirectional kinetic model, tumor microvessel characteristics, including the fractional plasma volume (fPV) and transendothelial permeability (KPS), were estimated for each contrast medium. These microvascular characteristics were compared between drug and control groups and between contrast media of different MWs.ResultsTumors grew significantly slower (P < 0.0005) in the drug treatment group than in the control group. Mean KPS and fPV values decreased significantly (P < 0.05) in the Mab‐VEGF antibody‐treated group compared to baseline values using intermediate or macromolecular contrast media (MMCM), but did not change significantly using small molecular contrast media (SMCM). In the control groups, mean KPS and mean fPV values did not reach statistical significance for any of the contrast media used.ConclusionTherapeutic effects of a Mab‐VEGF antibody on tumor microvessel characteristics can be monitored by dynamic MRI. Intermediate‐size agents, such as Gadomer‐17, offer a substantial dynamic range and are less limited by imaging precision and therefore should be considered a practical alternative to monitor antiangiogenesis treatment effects in a clinical setting. J. Magn. Reson. Imaging 2004;20:138–144. © 2004 Wiley‐Liss, Inc.
Early‐enhancing nonneoplastic lesions on gadolinium‐enhanced magnetic resonance imaging of the liver following partial hepatectomy
Authors: Goshima Satoshi , Kanematsu Masayuki , Matsuo Masayuki , Kondo Hiroshi , Yokoyama Ryujiro , Hoshi Hiroaki , Moriyama Noriyuki 
Published: June 2004

AbstractPurposeTo assess the frequency, imaging findings, and significance of early‐enhancing nonneoplastic (EN) lesions with gadolinium‐enhanced magnetic resonance imaging (MRI) of the liver following partial hepatectomy.Materials and MethodsWe retrospectively reviewed MR images after partial hepatectomy in 30 patients. Postoperative MRI was performed in 1–12 months (mean, 3.7 months) after partial hepatectomy. We defined the EN lesion as a lesion that was ill defined; irregular, wedge shaped, or serpiginous; located along the liver edge; not visible on unenhanced MR images; did not appear hypointense on portal venous‐ or equilibrium‐phase images; or a combination of those imaging findings.ResultsA total of 39 EN lesions (size range, 5–60 mm; mean, 25.2 mm) in 19 patients and 17 recurrent tumors (size range, 5–50 mm; mean, 16.8 mm) in 10 patients newly appeared after partial hepatectomy. The EN lesions were diagnosed as pseudolesions by the second postoperative follow‐up MRI in 17 patients or contrast‐enhanced computed tomography (CT) in two. A total of 13 EN lesions (33%) were located along the liver edge and 20 (51%) were adjacent to the resected area. The shape was circular in 11 (28%), oval in three (8%), irregular in 11 (28%), wedge shaped in five (13%), and serpiginous in nine (23%). No EN lesion showed hypointensity on gadolinium‐enhanced portal venous‐phase or equilibrium‐phase images. A total of 14 EN lesions (36%) showed slight hyperintensity on T2‐weighted images. The confidence levels for malignancy probability assigned by blinded radiologists were lower with EN lesions than with recurrent tumors (P < 0.001).ConclusionEN lesions are frequently seen in MRI following partial hepatectomy, and occasionally are slightly hyperintense on T2‐weighted images, mimicking malignant tumors. However, most EN lesions can be correctly diagnosed with MRI findings. J. Magn. Reson. Imaging 2004;20:66–74. © 2004 Wiley‐Liss, Inc.
In vivo colon wall imaging using endoluminal coils: Feasibility study on rabbits
Authors: Beuf O. , Pilleul F. , Armenean M. , Hadour G. , Saint‐Jalmes H. 
Published: June 2004

AbstractPurposeTo assess in vivo distal colon wall magnetic resonance imaging (MRI) feasibility on rabbits using an endoluminal radio frequency (RF) coil on a 1.5‐T clinical scanner.Materials and MethodsThe endoluminal coil signal‐to‐noise ratio (SNR) was compared to a clinical four‐element phased‐array body coil. High‐resolution (HR) MRI of rabbit colon walls was performed on six rabbits. The imaging protocol combined T1‐weighted fast low‐angle‐shot (FLASH) sequences with and without fat saturation (FS), T2‐weighted True‐Fast imaging with steady state precession (Fisp), turbo spin‐echo (TSE), and T1‐weighted FLASH FS after contrast media injection. Images were compared to histological sections. Catheter tracking using an endoluminal coil in addition to external coils was also evaluated on two rabbits.ResultsHR images allow visualization and identification of rabbit colon wall layers. Real‐time tracking allows a clear visualization and a good positioning of the endoluminal coil within the rabbit.ConclusionCompared to a clinical multielement array coil, a dedicated endoluminal RF coil provides an important SNR increase at the region of interest (ROI). Very HR images of in vivo rabbit colon walls were achieved providing detailed information on the different wall layers. This technique could be considered on humans for accurate tumoral and inflammatory bowel disease diagnosis. J. Magn. Reson. Imaging 2004;20:90–96. © 2004 Wiley‐Liss, Inc.
Differentiation between completely hyalinized uterine leiomyomas and ordinary leiomyomas: Three‐phase dynamic magnetic resonance imaging (MRI) vs. diffusion‐weighted MRI with very small b‐factors
Authors: Shimada Ken , Ohashi Isamu , Kasahara Ichiro , Watanabe Hiroshige , Ohta Sayako , Miyasaka Naoyuki , Itoh Eisaku , Shibuya Hitoshi 
Published: June 2004

AbstractPurposeTo assess the possibility of differentiating between completely hyalinized leiomyomas and ordinary leiomyomas by using diffusion‐weighted (DW) magnetic resonance imaging (MRI) (DWI) employing very small b‐factors (b = 1.51 and 55.3 seconds/mm2) in comparison with three‐phase dynamic MRI.Materials and MethodsThe subjects were 25 patients with 52 histopathologically confirmed uterine leiomyomas. All leiomyomas were divided into two histopathologic subtypes (5 completely hyalinized leiomyomas and 47 ordinary leiomyomas). For each leiomyoma, the enhancement index (EI) at three‐phase dynamic MRI and apparent diffusion coefficient (ADC) were obtained and then compared.ResultsThe EIs at second and third dynamic phases clearly differentiated the two types of leiomyomas without overlap of values. ADCs also clearly differentiated the two types of leiomyomas without overlap of values. Moreover, there were significant positive correlations between ADCs and EIs at all dynamic phases (r = 0.41–0.50, P < 0.01).ConclusionNot only three‐phase dynamic MRI but also DWI with very small b‐factors could be useful for differentiating completely hyalinized leiomyomas from ordinary leiomyomas. J. Magn. Reson. Imaging 2004;20:97–104. © 2004 Wiley‐Liss, Inc.
Directional correlation in white matter tracks of the human brain
Authors: Klose U. , Mader I. , Unrath A. , Erb M. , Grodd W. 
Published: June 2004

AbstractPurposeTo describe a technique for the detection of distinct brain fibers in sets of magnetic resonance (MR) diffusion tensor imaging (DTI) data.Materials and MethodsMR‐DTI can be used for a tractography of brain fibers presuming a data set of high spatial resolution and high signal to noise. A less demanding technique for the visualization of discrete brain fiber bundles involves segmentation. By using a region‐growing algorithm, those voxels that have a direction similar to that of the major eigenvector in neighboring voxels of a data set can be marked. It has been shown recently by Mori et al (1) that this technique can be successfully applied to data from a single slice of a mouse brain. In this study, the segmentation technique was applied with modifications to multislice DTI data from the human brain.ResultsA distinct segmentation of various brain fiber bundles could be achieved by the use of a two‐step algorithm. In the first step, voxels within large fiber tracts‐such as corticofugal tracts (e.g., corticospinal tract) and the optic radiation‐were segmented by starting the region‐growing algorithm in the corpus callosum (CC) and erasing this major structure from the data set. In the second step, remaining voxels were segmented by the same algorithm; this revealed a good assignment of the similarly oriented fibers derived by segmentation to the anatomically given brain lobes. This two‐step procedure was successfully applied to DTI data of six healthy volunteers.ConclusionThe segmentation technique for DTI data proposed by Mori et al (1) for data from mouse brains can be applied to multislice data from the human brain by using a two‐step algorithm including a masking of the major fiber tracts. J. Magn. Reson. Imaging 2004;20:25–30. © 2004 Wiley‐Liss, Inc.
Malignant hepatic tumor detection with ferumoxide‐enhanced magnetic resonance imaging: Is chemical‐shift‐selective fat suppression necessary for fast spin‐echo sequence?
Authors: Goshima Satoshi , Kanematsu Masayuki , Matsuo Masayuki , Kondo Hiroshi , Kako Nobuo , Yokoyama Ryujiro , Hoshi Hiroaki , Moriyama Noriyuki 
Published: June 2004

AbstractPurposeTo determine whether chemical‐shift‐selective (CSS) fat suppression is necessary for ferumoxide‐enhanced T2‐weighted fast spin‐echo (FSE) imaging in the detection of malignant hepatic tumors.Materials and MethodsFerumoxide‐enhanced magnetic resonance (MR) images obtained in 38 patients with surgically confirmed 61 malignant hepatic tumors (36 hepatocellular carcinomas (HCCs), 25 metastases) were retrospectively reviewed by three independent readers. Three sequences of MR images with CSS fat‐suppressed T2‐weighted FSE, non‐fat‐suppressed T2‐weighted FSE, and T2*‐weighted gradient‐recalled‐echo (GRE) sequences were randomly reviewed on a segment‐by‐segment basis in a blind fashion. Observer performance was tested using the McNemar's test and receiver‐operating‐characteristic (ROC) analysis for the clustered data. Lesion‐to‐liver contrast‐to‐noise ratio (C/N) was also assessed.ResultsThe mean C/N with the CSS fat‐suppressed FSE sequence was highest in HCCs, metastases, and tumors overall. Sensitivity was highest with the CSS fat‐suppressed FSE sequence in HCC, was highest with the non‐fat‐suppressed FSE sequence in metastases, and was comparable in tumors overall. Specificity was comparable between the sequences. The area under ROC curve (Az) value was greatest with the CSS fat‐suppressed FSE sequence in HCCs, was greatest with the non‐fat‐ suppressed FSE sequence in metastases, and was comparable in tumors overall. The sensitivities and Az values were lower with the GRE sequence than the FSE sequence.ConclusionThe CSS fat‐suppressed FSE sequence was superior to the GRE sequence in the detection of HCCs, but the non‐fat‐suppressed FSE sequence was comparable to the GRE sequence. The non‐fat‐suppressed FSE sequence was superior to the CSS fat‐suppressed FSE and GRE sequences in the detection of metastases. Optimal FSE imaging with CSS fat suppression or without aiming for the detection of HCCs or metastases, respectively, outperforms GRE imaging in ferumoxide‐enhanced MRI. J. Magn. Reson. Imaging 2004;20:75–82. © 2004 Wiley‐Liss, Inc.
Assessment of skeletal muscle perfusion by contrast medium first‐pass magnetic resonance imaging: Technical feasibility and preliminary experience in healthy volunteers
Authors: Lutz Amelie M. , Weishaupt Dominik , Amann‐Vesti Beatrice R. , Pfammatter Thomas , Goepfert Kerstin , Marincek Borut , Nanz Daniel 
Published: June 2004

AbstractPurposeTo probe the potential and pitfalls of contrast medium first‐pass skeletal muscle perfusion imaging under reproducible stress conditions.Materials and MethodsMagnetic resonance (MR) signal dynamics in calf muscle and lower‐leg arteries of 20 healthy volunteers were analyzed under postarterial occlusion reactive hyperemia and concurrent contrast medium first pass, using a saturation recovery spoiled gradient‐echo type sequence without heartbeat synchronization. The signal vs. time curves were analyzed descriptively and by two‐compartment deconvolution analysis.ResultsHighly significant changes in calf muscle signal dynamics in the hyperemic leg vs. those in the contralateral leg at rest were found in phenomenological and deconvolution analysis. Although a distortion of the arterial signal derived input function by inflow effects was found to cause large variations of the deconvolution results, the magnitude of the observed effects suggested a potential for immediate visual detection of areas with reduced tissue perfusion.ConclusionThe first‐pass approach appeared promising for visual evaluation. However, a disentanglement of inflow and contrast medium‐induced effects on arterial signal intensity was deemed a prerequisite for input function‐based numerical assessment. J. Magn. Reson. Imaging 2004;20:111–121. © 2004 Wiley‐Liss, Inc.