bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clinical and anatomical findings of acute iliofemoral deep venous thrombosis
Authors: Saarinen J , Anturaniemi M , Heikkinen M , Suominen V , Salenius J-P 
Published: March 2004

Objective: To observe the clinical and anatomical features of acute iliofemoral deep venous thrombosis (DVT). Methods: A consecutive sample of phlebographically confirmed DVT cases during a 25-month period were retrospectively assessed. There were 390 DVT cases, including 73 patients with iliofemoral DVT. The phlebograms of iliofemoral DVTs were reviewed and the location of the thrombus mapped. The patients' files were completely reviewed in all patients with DVT, including concomitant diseases and mortality after the diagnosis of DVT. Results: The average age of the patients with iliofemoral DVT was 63 years compared with 57 years in the cases of infrainguinal DVT ( P<0.005). Left : right-ratio was 2.43 in iliofemoral DVTs, and 1.42 in infrainguinal cases ( P<0.005). Iliofemoral DVT cases were multisegmental (from calf into iliac veins) in 92% of the legs. The aetiology of iliofemoral DVT was idiopathic in 55%, surgery in 14%, malignancy in 14%, immobilization in 10%, trauma in 5%, coagulation disorder in 1% and pregnancy in 1% of the cases. No concomitant diseases were noted in 32% of the patients with iliofemoral DVT, and the corresponding finding in the subgroup of infrainguinal DVTs was 57%. The incidence of death within one-year was 18% and 8% in the subgroups of iliofemoral and infrainguinal DVT. In patients with a combination of iliofemoral DVT and malignancy,the incidence of death within one-year was 80%. Conclusions: According to anatomical findings iliofemoral DVT is typically left-sided and multisegmental. However, clinical findings show that patients with this condition are relatively aged, and the frequency of concomitant diseases is high. The prognosis among the patients with pre-existing malignant disease was very poor. Prevention of post-thrombotic syndrome by using invasive treatment should be considered only in selected cases.
Complete resection of leiomyosarcoma of the suprarenal inferior vena cava without caval replacement
Authors: Minakuchi H , Iwai T , Inoue Y , Sugano N , Takiguchi N 
Published: March 2004

Objective: To successfully treat leiomyosarcoma of the suprarenal segment of the inferior vena cava (IVC) by section without caval replacement. Methods: Multiple occlusive clamps were used to maintain haemodynamic stability. Measurement of the stump pressure of the distal IVC and both renal veins was employed to evaluate venous congestion. Results: Use of these techniques allowed avoidance of suprarenal IVC reconstruction in our patient, who had well-developed collateral veins. Conclusions: Our experience indicates that reconstruction is not always mandatory.
Doppler tomography of Algols
Authors: Richards M. T. 
Published: March 2004

AbstractThe technique of Doppler tomography has been influential in the study of mass transfer in Algol‐type interacting binaries. The Algols contain a hot blue dwarf star with a magnetically‐active late‐type companion. In the close Algols, the gas stream flows directly into the photosphere of the blue mass‐gaining star because it does not have enough room to avoid impact with that star. Doppler tomograms of the Algols have been produced from over 2500 time‐resolved spectra at wavelengths corresponding to Hα, Hβ, He I (6678 Å), Si II (6371 Å) and Si IV (1394 ° A). These tomograms display images of accretion structures that include a gas stream, accretion annulus, accretion disk, stream‐star impact region, and occasionally a source of chromospheric emission associated with the cool, mass‐losing companion. Some Algol systems alternate between streamlike and disk‐like states, and provide direct evidence of active mass transfer within the Algols. This work produced the very first images of the gas stream for the entire class of interacting binaries, and demonstrated that the Algols are far more active than formerly believed, with variability on time scales of weeks to months. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Echo mapping of active galactic nuclei
Authors: Peterson B. M. , Horne K. 
Published: March 2004

AbstractEcho mapping makes use of the intrinsic variaibility of the continuum source in active galactic nuclei to map out the distribution and kinematics of line‐emitting gas from its light travel time‐delayed response to continuum changes. Echo mapping experiments have yielded sizes for the broad line‐emitting region in about three dozen AGNs. The dynamics of the line‐emitting gas seem to be dominated by the gravity of the central black hole, enabling measurement of the black‐hole masses in AGNs. We discuss requirements for future echo‐mapping experiments that will yield the high‐quality velocity–delay maps of the broad‐line region that are needed to determine its physical nature. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mapping the shape of the accretion disk of Hercules X‐1
Authors: Leahy D.A. 
Published: March 2004

AbstractHercules X‐1 is an x‐ray binary with a 1.7 day orbit and which exhibits a regular 35‐day intensity cycle, which comes in two types: 0.2 orbital phase turn‐on and 0.7 phase turn‐on. The cycle is well measured by the RXTE/ASM and is caused by a sequence of occultations by the inner and outer edges of the accretion disk. In addition to the 35‐day x‐ray cycle, the accretion disk shadows the companion star HZ Her to give the regular and well known optical modulation, and gives a modulation of the EUV emission from the system. The x‐ray modulation is most precisely measured and best for determination of the disk shape. Here disk and emission region models are used to derived the disk shape from the 0.2 turn‐on cycles and compared to a previous derivation based on 0.7 turn‐on cycles. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Surface images of the short period contact binary AE Phe
Authors: Barnes J. R. , Lister T. A. , Hilditch R. W. , Collier Cameron A. 
Published: March 2004

AbstractWe present high resolution Doppler images of the short period (P = 0.362 d) contact binary AE Phe. Using least squares deconvolution, we make use of the information content of the several thousand lines in each échelle spectrum to obtain the necessary S/N and time resolution required to resolve individual starspot features. A single pair of rotationally broadened profiles (free of sidelobes due to blending) with a typical S/N of 3000 ‐ 4000 per spectrum is thus obtained. With 300 sec exposures we achieve a cadence of 350 sec which is equivalent to sampling the rotation phase every 4°. We derive images for four nights of data which reveal starspots at most latitudes on both components of the common envelope system. Individual starspots evolve significantly on very short timescales, of order one day; significantly faster than the week timescales found on active single stars and the Sun. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Indirect imaging of polars
Authors: Schwope A.D. , Staude A. , Vogel J. , Schwarz R. 
Published: March 2004

AbstractTomographic techniques of different flavour offer enormous diagnostic power for the analysis of magnetic cataclysmic binaries, particularly those of AM Herculis type, the so‐called polars. The three main ingredients of such systems, the donor star, the accretor and the accretion stream between the two stars, are investigated by Doppler tomography, Roche tomography and eclipse mapping methods. The indirect imaging methods reveal the structure, extent and ionization conditions in the accretion stream, they reveal the extent of the irradiation zone on the secondary star and constrain the mass ratio and the orbital inclination of the binary. We describe a new code for Roche tomography, the achievements and limitations of straight Doppler tomography and a new mapping technique tentatively called curtain tomography. This new technique will map emission line profiles to an accretion curtain making full use of the velocity and the photometric information. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stellar surface imaging: mapping brightness and magnetic fields
Authors: Hussain G. A. J. 
Published: March 2004

AbstractRapidly rotating late‐type stars typically display signs of magnetic activity that exceed those seen on the Sun by over two orders of magnitude. The techniques of Doppler imaging and Zeeman Doppler imaging have been instrumental in unveiling magnetic activity patterns at the photospheres of these active stars. Essentially, these techniques work by inverting time‐series of high resolution spectra to produce temperature, brightness and/or magnetic field maps at the surfaces of stars. I will describe how these techniques work and review what they have taught us about the nature of magnetic activity in rapid rotators over the last 20 years. Finally, I will conclude by outlining the capabilities of these techniques in light of new instrumentation that is now becoming available. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Roche tomography of the secondary stars in CVs
Authors: Watson C. A. , Dhillon V. S. 
Published: March 2004

AbstractThe secondary stars in cataclysmic variables (CVs) are key to our understanding of the origin, evolution and behaviour of this class of interacting binary. In seeking a fuller understanding of these objects, the challenge for observers is to obtain images of the secondary star. This goal can be achieved through Roche tomography, an indirect imaging technique that can be used to map the Roche‐lobe‐filling secondary. The review begins with a description of the basic principles that underpin Roche tomography, including methods for determining the system parameters. Finally, we conclude with a look at the main scientific highlights to date, including the first unambiguous detection of starspots on AE Aqr B, and consider the future prospects of this technique. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Eclipse mapping of the hot circumstellar plasma in Algol binaries
Authors: Peters G.J. , Polidan R. S. 
Published: March 2004

AbstractPhase‐resolved FUV observations of three Algol‐type interacting binaries (V356 Sgr, TT Hya, and RY Per) have been made during totality with the Far Ultraviolet Spectroscopic Explorer to map the location of the hot circumstellar plasma that produces emission lines of O VI, Si III,IV, S IV, C III, and N II. Since OVI shows very little variation in profile, strength, and velocity as the disk of the secondary occults the line formation region, we conclude that the emission originates in material that has a substantial flow perpendicular to the orbital plane (perhaps a bipolar jet). The behavior of the emission lines from the moderate‐ionization species suggests that the plasma producing these emission features has a large equatorial component. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Few projections astrotomography: 2‐CLEAN DSA reconstruction
Authors: Agafonov M. I. 
Published: March 2004

Abstract2‐CLEAN DSA method of Determination of permissible Solutions Area created on the basis of the Radioastronomical approach to image reconstruction from few projections is presented as a component of astrotomography and also as a method of reconstruction, as it has good prospects for a wide range of remote sensing. Its basis was described and published before 1990 in the application to the reconstruction of 2D‐images. Later the method received its name and was thoroughly developed, in particular for 3‐D reconstruction from 2D and 1D‐projections. 2‐CLEAN DSA method allows to carry out 2D‐recognition in a wide space frequency band {0, ωb} constrained only by the upper frequency ωb when the number of 1D‐projections contains only ∼ 0.1 of the number needed for the usual tomographical approach. It easily adapts to the wide range of additional constraints. Some of the important points connected with 2D‐reconstruction of the images and sections of optically thin emissive objects are described. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Tomography of stellar non‐radial pulsations
Authors: Berdyugina S. V. 
Published: March 2004

AbstractThe stellar surface imaging technique is used for studying stellar non‐radial pulsations on the basis of inversions of time series of variable line profiles without making assumptions on the specific shape of the pulsations. The inversion results in an image of the stellar surface in which sectoral and tesseral modes can be distinguished in many cases and the pulsational degree and the azimuthal order can be determined. The capability of the technique is studied with simulated data. Then, the surface imaging technique is applied to high‐resolution spectra of the rapidly rotating Beta Cep‐type star ω1 Sco, which shows strong line‐profile variations. Stellar surface imaging is concluded to be a useful technique for pulsation‐mode identification. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Differential rotation of cool active stars
Authors: Petit P. , Donati J.‐F. , Collier Cameron A. 
Published: March 2004

AbstractThe surface differential rotation of active solar‐type stars can be investigated by means of Doppler and Zeeman‐Doppler Imaging, both techniques enabling one to estimate the short‐term temporal evolution of photospheric structures (cools spots or magnetic regions). After describing the main modeling tools recently developed to guarantee a precise analysis of differential rotation in this framework, we detail the main results obtained for a small number of active G and K fast rotating stars. We evoke in particular some preliminary trends that can be derived from this sample, bearing the promise that major advances in this field will be achieved with the new generation of spectropolarimeters (ESPaDOnS/CFHT, NARVAL/TBL). (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Tomographic studies of exoplanet atmospheres
Authors: Collier Cameron A. , Leigh Ch. 
Published: March 2004

AbstractWe review the current state of models for the optical and near‐infrared reflection spectra of exoplanetary atmospheres, with particular reference to the close‐orbiting giant planets that offer the best prospects for high‐resolution spectroscopic detection.We describe the main steps in the tomographic procedures that have been used in recent attempts to separate these faint signals from the direct spectra of the parent stars.We compare recent, deep upper limits on planetary albedos with model predictions, and discuss prospects for future attempts to detect and characterise the reflection, transmission and thermal emission spectra of these planets at optical and infrared wavelengths. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Doppler Tomography of X‐ray binaries
Authors: VrtíLek S.D. , Quaintrell H. , Boroson B. , Shields M. 
Published: March 2004

AbstractThe Space Telescope Imaging Spectrograph (STIS) on HST provides the first ultraviolet data that are of sufficient spectral and temporal resolution to generate Doppler tomograms of X‐ray binaries.We show both optical and ultraviolet maps constructed for the intermediate mass system Hercules X‐1/HZ Her and the massive wind‐fed system SMC X‐1/SK160. We have used the maps and corresponding lightcurves as diagnostics with which to test the validity of published models for Hercules X‐1. We find that although the models are mostly able to explain the light curves they are not consistent with the full phase maps. We present simulations of Doppler maps of X‐ray lines that will be possible with the spectral and temporal resolution and substantial effective area of the next major X‐ray mission, Con‐X. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Astrotomography
Authors: Cameron A.C. , Schwope A. , Vrielmann S. 
Published: March 2004

AbstractEven in the new millenium, many astronomical objects cannot be resolved spatially with any available telescope. Most stars are too small and galaxies are too far away to be imaged directly or in detail in the foreseeable future. However, advances in data‐analysis techniques allow us now to create detailed indirect images using tomographic methods. These images provide unprecedented insights into fundamental processes that drive the evolution of stars and galaxies, such as accretion and magnetic‐field generation, on length scales that are of great physical importance but which are otherwise inaccessible. Here we present a collection of papers on recent progress in astrotomography, all of which were presented at Joint Discussion 09 of the XXV General Assembly of the IAU in Sydney, during July 2003. The online edition of the journal contains several illustrative movies for free download. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Chemoenzymatic Synthesis of (2S)‐ and (2R)‐2‐(1,3‐Dithian‐2‐ylmethyl)oxirane
Authors: Sundby Eirik , Holt Jarle , Vik Anders , Anthonsen Thorleif 
Published: March 2004

AbstractLipase‐catalyzed transesterifications and biological reductions were used to obtain the (S)‐enantiomers of 3‐chloro‐1‐(1,3‐dithian‐2‐yl)‐2‐propanol and 1‐(1,3‐dithian‐2‐yl)‐3‐fluoro‐2‐propanol and their (R)‐acetates. (S)‐3‐Chloro‐1‐(1,3‐dithian‐2‐yl)‐2‐propanol and (R)‐3‐chloro‐1‐(1,3‐dithian‐2‐yl)‐2‐propyl acetate were converted into the respective enantiomers of 2‐(1,3‐dithian‐2‐ylmethyl)oxirane. During this work we also isolated a new gem‐disubstituted epoxide, 2‐(chloromethyl)‐2‐(1,3‐dithian‐2‐yl)oxirane. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Chemical and Structural Properties of the Inclusion Complex of Euplotin C with Heptakis(2,6‐di‐O‐methyl)‐β‐cyclodextrin through NMR Spectroscopy, Electrospray Mass Spectrometry and Molecular Mechanics Investigations
Authors: Guella Graziano , Callone Emanuela , Mancini Ines , Uccello‐Barretta Gloria , Balzano Federica , Dini Fernando 
Published: March 2004

AbstractThe inclusion complex of heptakis(2,6‐di‐O‐methyl)‐β‐cyclodextrin (DIMEB) with euplotin C (EC), a cytotoxic metabolite isolated from the protistan strains composing the marine ciliate Euplotes crassus, has been investigated by 1H NMR techniques, electrospray ionization mass spectrometry (ESI/MS) and molecular mechanics (MM) calculations. The results suggest that DIMEB preferentially includes the side chain of this sesquiterpenoid with the terminal methyl groups exposed at the narrower rim of the cyclodextrin (CD). The dihydropyranic ring of EC is also well enclosed in the host cavity, whereas the acetyl group and the ring protons at C‐4 and C‐5 lie outside the larger rim. A kinetic degradation study of EC and its inclusion complex (EC‐DIMEB) in aqueous solution has been performed by HPLC‐UV‐MS measurements obtaining structural data for the hydrolysis end‐products. A significant increase in the chemical stability of complexed EC compared with free EC has also been determined. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Oxidative Fragmentation of the Bridged β‐Triketone Core of Hyperforin
Authors: Verotta Luisella , Lovaglio Erminio , Sterner Olov , Appendino Giovanni , Bombardelli Ezio 
Published: March 2004

AbstractThe β‐triketone core of the antidepressant phloroglucinol hyperforin (1) undergoes a series of peroxide‐induced oxidative rearrangements leading to compound 5, which is formed by opening of ring A, and compound 6, which is formed by removal of the C‐1 carbonyl bridge. A mechanistic rationale for this process is proposed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
A Novel Synthesis of 2‐Alkoxy‐3‐hydroxytropones and 2,7‐Dihydroxytropones from Dialkoxy‐8‐oxabicyclo[3.2.1]oct‐6‐en‐3‐ones
Authors: Zinser Hartmut , Henkel Sonja , Föhlisch Baldur 
Published: March 2004

AbstractTrichloro‐substituted 8‐oxabicyclo[3.2.1]oct‐6‐en‐3‐ones 6 and 7 are solvolysed by methanolic sodium methoxide to form the bicyclo[3.2.1] α,α‐dimethoxy ketones 13 and 14, with preservation of one chloro substituent. In the case of 6a, prolonged reaction time with an excess of methanolic sodium methoxide provides a trimethoxy‐substituted oxanorbornene aldehyde 19 through ring contraction. Treatment of the mixture of 13 and 14 with zinc and aqueous acetic acid affords dechlorinated α‐oxo acetals 15 and 16. Starting with the [4+3] cycloadducts derived from 2‐methylfuran and tetrachloroacetones (6b and 7b), the same procedure, but with use of ethanol or trifluoroethanol, results in the corresponding ethoxy‐ and trifluoroethoxy acetals. These compounds can be converted into the oxabicyclic compounds 15, which undergo cleavage of the ether bridge on heating with KOH in methanol, thus providing 2‐alkoxy‐3‐hydroxytropones 20, which can be dealkylated to give the 2,7‐dihydroxytropones (7‐hydroxytropolones) 29. The lithium enolate generated from the α‐oxo acetal 15a can be exo‐alkylated with methyl iodide. Michael addition with 2‐nitro‐1‐butene followed by a Nef reaction furnishes the bicyclic dioxo acetal 5. Treatment of 5 with basic methanol results in an epoxyazulenone derivative 26, and a hydroxytropone 20f, which is in equilibrium with the cyclic hemiacetal form 28. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Reactions of Levulinic Acid with Norbornane/ene Amino Acids and Diamines
Authors: Stájer Géza , Szabó Angela E. , Csámpai Antal , Sohár Pál 
Published: March 2004

AbstractWhereas the cyclizations of di‐endo‐3‐aminobicyclo[2.2.1]heptane‐2‐carboxylic acid (2) and di‐endo‐3‐aminobicyclo[2.2.1]hept‐5‐ene‐2‐carboxylic acid (3) with 4‐oxopentanoic acid (1) yield methanodioxopyrrolo[1,2‐a][3,1]benzoxazines 6 and 7, the di‐exo analogues give either the pyrrolo[1,2‐a]pyridine 8 as sole product (in the case of 4), or 10 together with the methyl‐substituted derivative 9 (in the case of 5). Compound 1 reacts with di‐exo‐3‐aminobicyclo[2.2.1]heptane‐2‐methanamine (11) and di‐exo‐3‐aminobicyclo[2.2.1]hept‐5‐ene‐2‐methanamine (12) to give the methylene‐bridged pyrrolo[2,1‐b]quinazolinones 13 and 14 respectively; a pentacyclic product containing a dipyrrolodiazepine moiety 15 was also isolated. The structures and stereochemistry were elucidated by means of IR and NMR spectroscopy, including COSY, DIFFNOE, DEPT, HMQC and HMBC techniques.
Chemoselective Acylation of Amines in Aqueous Media
Authors: Naik Sarala , Bhattacharjya Gitalee , Talukdar Bandana , Patel Bhisma K. 
Published: March 2004

AbstractAmines are efficiently acylated by both cyclic and acyclic anhydrides by dissolving them in an aqueous medium with the help of a surfactant, sodium dodecyl sulfate (SDS). Cyclic and acyclic anhydrides react with equal ease with an amine, and amines with various stereo‐electronic factors react at the same rates with an anhydride. Chemoselective acylation of amines in the presence of phenols and thiols and of thiols in the presence of phenols has been achieved. No acidic or basic reagents are used during the reaction. No chromatographic separation is required for isolation of the acylated products. Reactions in a neutral aqueous medium, easy isolation of products, and innocuous by‐products make the present method a green chemical process. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)