bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transcatheter creation of atrial septal perforation using a radiofrequency transseptal system: Novel approach as an alternative to transseptal needle puncture
Authors: Sakata Yoshihito , Feldman Ted 
Published: February 2005

AbstractIndications for the transseptal approach to the left side of the heart have recently broadened, as it provides a therapeutic access for both left‐sided catheter ablation and also percutaneous transvenous valvular intervention. Despite rising demand for transseptal procedures, the technique and device used for this purpose have remained essentially unchanged over the past 4 decades. The possibilities of failure of puncturing distorted and thickened atrial septal tissue or risks of complications related to cardiac perforation remain limitations of the technique. A new radiofrequency catheter provides an alternative approach to create a controlled transseptal perforation. We applied this technique to a series of patients and evaluated its feasibility as an alternative to conventional transseptal needle puncture. Catheter Cardiovasc Interv 2005;64:327–332. © 2005 Wiley‐Liss, Inc.
Bilateral carotid angioplasty and stenting
Authors: Henry Michel , Gopalakrishnan Lakshmi , Rajagopal Sriram , Rath P.C. , Henry Isabelle , Hugel Michele 
Published: February 2005

AbstractBilateral carotid stenosis is generally treated by staged stenting procedure and rarely simultaneously due to concerns about hemodynamic impairment from stimulation of the carotid sinus baroreflex (severe bradycardia, hypotension) and the risk of cerebral hyperperfusion syndrome. Most of the accounts of bilateral carotid stenting are of small series. The aim of this study was to evaluate the feasibility and safety of simultaneous bilateral carotid angioplasty and stenting (CAS) in comparison with staged procedure. We retrospectively analyzed the procedural outcome and complications of bilateral CAS done between February 1995 and June 2004 in a consecutive series of 57 high‐risk patients. Mean age was 64 ± 9 years (male, 43; female 14). One hundred fifteen arteries were treated (one patient had bilateral internal carotid artery stenosis associated to an ostial common carotid artery stenosis). Thirty‐nine patients were symptomatic (70%). Thirty‐six patients had severe coronary artery disease. Seventeen patients underwent a simultaneous bilateral CAS (group 1), 40 in a staged manner (group 2). Among these 40 patients 10 were treated with a time interval of 24 hr, while the 30 other ones were treated with a time interval of 2 days to 2 months. A neuroprotection device was used in the last 42 patients. There was technical success in all patients and transient bradycardia and/or hypotension in 25 patients (44%). There was no prolonged bradycardia or hypotension. At 30 days, we observed in group 1 (simultaneous bilateral CAS) no transient ischemic attack (TIA), no minor stroke, one (5.8%) major stroke (hyperperfusion syndrome with brain hemorrhage leading to death in a patient under IIb/IIIa inhibitors), one myocardial infarction leading to death, and two (11.7%) death/stroke/myocardial infarction; in group 2 (staged procedure), two (5%) TIAs, no minor stroke, no major stroke, and one (2.5%) hyperperfusion syndrome with rapid recovery. Among the 10 patients treated with a time interval of 24 hr, we observed one TIA. Among carefully selected patients, bilateral CAS is feasible simultaneously or the day after, with a safety and complication rate comparable to that of large published series of CAS or endarterectomies in high‐risk patients. Nevertheless, careful monitoring of the patient, blood pressure, and heart rate is mandatory to avoid complications related to hyperperfusion syndrome. Routine use of neuroprotection device and meticulous technique should improve the outcomes of bilateral CAS. Catheter Cardiovasc Interv 2005;64:275–282. © 2005 Wiley‐Liss, Inc.
Superiority of endovascular grafts compared to bare metal stents with transstent coil embolization for endovascular abdominal aortic aneurysm repair in patients at high risk for surgery
Authors: Boccalandro Fernando , Cohen Alan , Raval Barat , Chen Phoebe , Muench Andreas , Achour Hela , Carter Catherine , Underwood Carol , Smalling Richard W. 
Published: February 2005

AbstractWe sought to determine the effectiveness of uncovered stents with aneurysm transstent coil embolization compared with endografts for percutaneous abdominal aortic aneurysm (AAA) repair. Thirty‐six patients with AAA considered inoperable underwent endovascular repair using the Ancure bifurcated endograft or overlapping uncovered stents with transstent coil embolization. Procedural success, outcomes, serial aneurysm size, aneurysm blood flow, and growth ratios were compared between groups. One patient in each group died due to the procedure and two patients in the endograft cohort required acute surgical repair. After 2.0 ± 0.8 years of follow‐up, three patients required endograft placement, four surgical repair, three had AAA rupture, with two AAA‐related deaths in the uncovered stent group. No late deaths or surgical conversion occurred in the endograft group. The primary AAA flow exclusion and aneurysm expansion rate and growth were superior in the endograft group and during follow‐up. In high‐risk patients with AAA, the use of endografts was superior compared to uncovered stents with transstent coil embolization for endovascular repair. Catheter Cardiovasc Interv 2005;64:283–290. © 2005 Wiley‐Liss, Inc.
Retrograde percutaneous aortic valve implantation for critical aortic stenosis
Authors: Hanzel George S. , Harrity Philip J. , Schreiber Theodore L. , O'Neill William W. 
Published: February 2005

AbstractRecently, a prosthetic aortic valve has been implanted percutaneously in several patients using an antegrade transseptal approach. This has been shown to be feasible and associated with dramatic hemodynamic improvement. We report a retrograde implantation of a percutaneous heart valve (PHV) in an 84‐year‐old man with critical aortic stenosis and refractory congestive heart failure after difficulties encountered with an initial antegrade approach. While attempting antegrade transseptal implantation of a PHV, the anterior leaflet of the mitral valve was tethered by the guidewire resulting in severe mitral regurgitation and pulseless electrical activity. Cardiac resuscitation was successful. Utilizing a retrograde approach, the PHV was successfully implanted in a stable position below the coronary ostia and well above the mitral valve leaflets. The aortic valve area increased from 0.55 to 1.7 cm2 with only mild paravalvular aortic regurgitation. Despite marked improvement in aortic valve function, the patient died secondary to guidewire‐induced mitral valve anterior leaflet laceration, severe mitral regurgitation, and cardiogenic shock. Retrograde implantation of a PHV can be successfully performed with substantial increase in aortic valve area and an acceptable degree of aortic regurgitation. Although the retrograde approach may be associated with greater risk of vascular access site complications, it may be considerably safer by avoiding potential guidewire injury to the mitral valve. Further refinements in technique may establish the retrograde approach as the preferred means of PHV implantation in nonsurgical patients with critical aortic stenosis. Catheter Cardiovasc Interv 2005;64:322–326. © 2005 Wiley‐Liss, Inc.
Percutaneous balloon aortic valvuloplasty: Antegrade transseptal vs. conventional retrograde transarterial approach
Authors: Sakata Yoshihito , Syed Zubair , Salinger Michael H. , Feldman Ted 
Published: February 2005

AbstractPercutaneous balloon aortic valvuloplasty (BAV) has been limited predominantly to a palliative treatment for poor surgical candidates with critical aortic stenosis and multiple high‐risk or comorbid conditions. The most commonly used technique for BAV is the retrograde approach, in which the balloon is passed via the femoral artery using 12–14 Fr sheaths. We compared an antegrade transseptal approach using the Inoue balloon vs. the retrograde transarterial approach using conventional balloons. The antegrade group had an improved acute hemodynamic outcome, including 20% additional increase of aortic valve area and 20% greater reduction of transaortic valve gradient compared to the retrograde approach. Preclosure with the Perclose device was used for the 14 Fr venous access sites, resulting in immediate hemostasis, minimizing the need for transfusion, and diminishing the period of bed rest. The improved acute efficacy and relative ease of venous access for the antegrade approach facilitate BAV by eliminating the need for large‐caliber arterial access sheaths. The antegrade approach also incorporates technical elements necessary for percutaneous aortic valve replacement and may have expanded applications as an adjunct to this developing therapy. The impact of improved acute results on the long‐term clinical outcome for this patient group will require further study. Catheter Cardiovasc Interv 2005;64:314–321. © 2005 Wiley‐Liss, Inc.
Self‐Assembled Nanotapes of Oligo(p‐phenylene vinylene)s: Sol–Gel‐Controlled Optical Properties in Fluorescent π‐Electronic Gels
Authors: George Subi J. , Ajayaghosh Ayyappanpillai 
Published: February 2005

AbstractA rational approach to the design of supramolecular organogels of all‐trans oligo(p‐phenylene vinylene) (OPV) derivatives, a class of well‐known organic semiconductor precursors, is reported. Self‐assembly of these molecules induced gelation of hydrocarbon solvents at low concentrations (<1 mM), resulting in high aspect ratio nanostructures. Electron microscopy and atomic force microscopy (AFM) studies revealed twisted and entangled supramolecular tapes of an average of 50–200 nm in width, 12–20 nm in thickness, and several micrometers in length. The hierarchical growth of the entangled tapes and the consequent gelation is attributed to the lamellar‐type packing of the molecules, facilitated by cooperative hydrogen bonding, π stacking, and van der Waals interactions between the OPV units. Gelation of OPVs induced remarkable changes in the absorption and emission properties, which indicated strong electronic interaction in the aggregated chromophores. Comparison of the absorption and emission spectra in the gel form and in the solid film indicated a similar chromophore organization in both phases. The presence of self‐assembled aggregates of OPVs was confirmed by solvent‐ and temperature‐dependent changes in the absorption and emission properties, and by selective excitation experiments. This is the first detailed report of the gelation‐induced formation of OPV nanotapes, assisted by weak, nondirectional hydrogen‐bonding motifs and π–π stacking. These findings may provide opportunities for the design of a new class of functional soft materials and nanoarchitectures, based on π‐conjugated organic semiconductor‐type molecules, thereby enabling the manipulation of their optical properties.
Stereochemical Investigation of Palladium(II) Complexes with Phenanthroline Ligands: A Molecular Mechanics Approach
Authors: Calligaris Mario , Zangrando Ennio , Milani,Angelica Marson Barbara 
Published: February 2005

AbstractSpecific force field parameters have been derived through an optimisation procedure based on crystal structure data to describe the geometry of PdII‐phenanthroline complexes. The X‐ray structure of [Pd(CH3)(3‐sBu‐phen)2][OTf] is also reported. Molecular mechanics calculations show that intramolecular steric interactions yield severe distortions from a square‐planar geometry of the metal atom, both in bischelated [Pd(3‐R‐phen)2]2+ and monochelated [Pd(CH3)(3‐R‐phen)2]+ complexes. A complete stereochemical analysis of the possible diastereoisomers of this last complex (R = sBu) allows the rationalisation of its fluxional behaviour observed in solution. Complexes like [Pd(H)(3‐tmp‐phen)2]+ and [Pd{CH(C6H5)CH2C(O)OCH3}(3‐tmp‐phen)(CH3OH)]+ (tmp = 1,2,2‐trimethylpropyl) have also been investigated as species reasonably involved in the copolymerisation reactions. It is suggested that the remarkable increase of the copolymer molecular weight obtained with the 3‐tmp‐phen ligand derives from the steric destabilisation of an intermediate species postulated for the termination reaction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
New Complexes of Divalent Thulium with Substituted Phospholyl and Cyclopentadienyl Ligands (Eur. J. Inorg. Chem. 4/2005)
Authors: Nief François , Tayart de Borms Brice , Ricard Louis , Carmichael Duncan 
Published: February 2005

AbstractThe cover picture shows the X‐ray crystal structure of bis(1,3‐di‐tert‐butylcyclopentadienyl)thulium(tetrahydrofuran), a new organothulium(II) complex and the first one with all‐carbon κ‐ligands. Two new and particularly stable phospholylthulium(II) complexes are also described. The very existence and relative ease of formation of the so far described thulium(II) molecular compounds strongly suggest that many more such compounds can be prepared, provided that adequate steric and/or electronic protection of the thulium(II) ion can be archieved, thus paving the way to new and hopefully exciting studies in the field of thulium(II) chemistry. Details are discussed in the article by F. Nief et al. on p. 637 ff. The cover picture was rendered in POVRAY 3.5, and the initial input file was obtained with Louis J. Farrugia′s ORTEP‐III for Windows programme.
Aromatic plants of tropical Central Africa. XLVIII. Comparative study of the essential oils of four Hyptis species from Cameroon: H. lanceolata Poit., H. pectinata (L.) Poit., H. spicigera Lam. and H. suaveolens Poit.
Authors: Tchoumbougnang F. , Zollo P. H. Amvam , Boyom F. Fekam , Nyegue M. A. , Bessière J. M. , Menut C. 
Published: February 2005

AbstractThe chemical composition of the essential oils obtained by hydrodistillation of fresh leaves from Hyptis lanceolata, H. pectinata, H. spicigera and H. suaveolens growing in Cameroon were analysed by GC and GC–MS. The oil of H. suaveolens was rich in sabinene (20.6%), β‐caryophyllene (17.5%) and bergamotol (10.9%), while the oil of H. pectinata contained germacrene D (28.0%) and β‐caryophyllene (22.1%) as the major constituents. H. spicigera oil contained α‐pinene (28.3%), β‐caryophyllene (19.1%), limonene (13.4%) and ß‐pinene (10.3%) as the main components. The most abundant constituents identified in the oil of H. lanceolata were β‐pinene (40.7%) and germacrene D (19.9%). These chemical profiles were compared with literature results; relative similarities were found in chemical compositions of each species, but some quantitative and qualitative variations were noted. Copyright © 2005 John Wiley & Sons, Ltd.
Calcium uptake in glycerol‐extracted rabbit psoas muscle fibers II. Electron microscopic localization of uptake sites
Authors: Pease D. C. , Jenden D. J. , Howell J. N. 
Published: February 2005

AbstractAn effort has been made to ascertain the site of calcium uptake in rabbit psoas muscle by electron microscopy. Following a brief glycerol extraction, small groups of fibers were exposed in a suitable electrolyte environment to calcium and ATP. Conditions were such that calcium was accumulated as an insoluble oxalate salt. Conventional preparatory procedures for electron microscopy were modified so that the calcium oxalate deposits were retained in situ in ultrathin sections. These were found localized in the longitudinal component of the sarcoplasmic reticulum including the terminal dilatations which form the outer elements of the triads. The possible participation of the intermediate element of the triad in the uptake of calcium could not be determined. The results are regarded as direct evidence that the sarcoplasmic reticulum is intimately concerned with the uptake and release of calcium associated with the contraction‐relaxation cycle.
The involvement of pH, Adenosine triphosphate, calcium, and magnesium in the contraction of the glycerinated stalks of Vorticella
Authors: Townes Mary M. , Brown Dugald E. S. 
Published: February 2005

AbstractA glycerinated Vorticella stalk is prepared which remains relaxed at pH 6.8 or lower but contracts maximally when the pH is raised from 6.8 to 7.0. At pH 6.8, a maximum contraction is also produced when the Ca++ concentration is increased to 3 μ M.The degree of relaxation below pH 6.8 is fostered by ATP and Mg++ which, along with Ca++, determine the degree of contraction at pH 7.0. A major role of calcium on the pH‐induced contraction is to lower the pH‐threshold from pH 7.5, obtaining in its absence to a stable value of pH 6.8. The only condition in which ATP is shown to cause a maximum contraction is at pH 7.0 in a medium containing 6 × 10−3 M Mg++ and 3 × 10−9 Ca++.It is considered that Ca++, Mg++, and ATP react with the contractile proteins to form a contractile complex which is in the relaxed form at pH 6.8. At this pH an increase of 0.2 pH units or the addition of 3 μ M Ca++ converts the complex to the shortened form, a contraction ensuing.
Possible carriers in erythrocytes
Authors: Hunter F. R. , George Jaime , Ospina Bertha 
Published: February 2005

AbstractUsing a densimeter technique, the effect of tannic acid and n‐butanol on the permeability to non‐electrolytes of erythrocytes of various species was studied. If both tannic acid and butanol decrease the permeability it is suggested that a carrier mechanism is involved. If tannic acid has little or no effect and butanol increases the permeability it is suggested that the penetration of such a molecule depends only on diffusion. According to this theory carriers are involved in the following systems: Urea — mouse, sheep, pig, ox and man; Ethylene glycol — man and possibly mouse; Glycerol — man, mouse, rabbit; Erythritol — mouse and possibly man; Ribose — mouse, man; Mannose, glucose, sorbose — man. No carriors are involved in the following systems: Urea — chicken; Ethylene glycol — pig, chicken, ox, sheep; Thiourea — rabbit, chicken, sheep, man, pig, ox; Glycerol — chicken, pig, sheep, ox; Erythritol — rabbit; Ribose — rabbit.
The effect of potassium concentration on Ca45 uptake in frog sartorius muscle
Authors: Weiss George B. , Bianchi C. P. 
Published: February 2005

AbstractRadiocalcium uptake by frog sartorius muscle is increased as the potassium concentration of the bathing Ringer is increased from 1.6 mM to 32.0 mM; at higher concentrations of K+ no further increase in radiocalcium uptake occurs. Substitution of the chloride of Ringer solution by nitrate increases the amount of radiocalcium uptake at potassium concentrations between 1.6 and 32.0 mM but not at higher concentrations. The nitrate anion enhances both the maximum tension and the area of the contracture curves that occur between 16 and 80 mM K+. Comparison of paired muscle preparations in nitrate Ringer at 32 mM K+ and 80 mM K+ shows no difference in total radiocalcium uptake and no difference in the area under the contracture curves. When a three minute prequilibration period in Ca45 is omitted, the radiocalcium uptake by the sartorius muscle in 80 mM K+, Ca45 Ringer nitrate is reduced by 50% as compared to its mated muscle soaked in 32 mM K+, Ca45 Ringer nitrate. Within the limitations of the experimental techniques employed, it appears that calcium uptake is more prolonged at lower levels of potassium (32.0 mM) but the total amount taken up is the same as at higher levels of potassium (80 mM).
Growth, survival and biochemical alteration of Euglena gracilis in medium limited in sulfur
Authors: Buetow D. E. 
Published: February 2005

AbstractThe sulfur requirement for growth and survival of Euglena gracilis is satisfied by sulfate or by certain organic sources, especially methionine. When deprived of sulfur, cultures remain fully viable for about 1.5 days. By 15 days of sulfur deprivation, viability is reduced to 25%. Sulfur is found in significant quantity in all the major cellular fractions of Euglena including the hot‐TCA‐soluble fraction. During external sulfur deprivation, sulfur is redistributed within the cell in order to maintain “structural protein.” Cells which survive apparently are able to regulate the utilization and redistribution of their depleted sulfur reserves.
Modification of receptors for acetylcholine in the early embryonic heart
Authors: Roberts Carmel Montgomery , Gimeno Martha A. , Leyden Webb J. 
Published: February 2005

AbstractWhole chick embryo blastoderms at zero‐ to 7‐somites have been explanted onto a nutrient medium and incubated at 37°C for 20 hours, in order to develop to 18‐ to 19‐somites, when the heart rate is depressed by acetylcholine and even more strongly by a number of parasympathomimetic drugs and cholinesterase inhibitors. Hence we have concluded that receptors for acetylcholine are present in the early chick embryo heart before innervation by the vagus nerve is initiated, but that the receptors do not possess the specificity of adult acetylcholine cardiac receptors. Incubation of the zero‐ to 7‐somite blastoderms on media containing certain of the parasympathomimetic drugs and cholinesterase inhibitors greatly increased the sensitivity of the hearts to depression of rate by acetylcholine at 18‐ to 19‐somites, and we have concluded that development of acetylcholine receptors has been stimulated by the drugs. A possible stereochemical relationship between acetylcholine receptors and drugs that are able to stimulate the development of the receptors is postulated.
Factorizations and characterizations of induced‐hereditary and compositive properties
Authors: Farrugia Alastair , Mihók Peter , Richter R. Bruce , Semanivšin Gabriel 
Published: February 2005

AbstractAn Erratum has been published for this article in Journal of Graph Theory 50:261, 2005.A graph property (i.e., a set of graphs) is hereditary (respectively, induced‐hereditary) if it is closed under taking subgraphs (resp., induced‐subgraphs), while the property is additive if it is closed under disjoint unions. If ${\cal P}$ and ${\cal Q}$ are properties, the product ${\cal P}\circ {\cal Q}$ consists of all graphs G for which there is a partition of the vertex set of G into (possibly empty) subsets A and B with G[A] $\in {\cal P}$ and G[B] $\in {\cal Q}$. A property is reducible if it is the product of two other properties, and irreducible otherwise.We show that very few reducible induced‐hereditary properties have a unique factorization into irreducibles, and we describe them completely. On the other hand, we give a new and simpler proof that additive hereditary properties have a unique factorization into irreducible additive hereditary properties [J. Graph Theory 33 (2000), 44–53]. We also introduce analogs of additive induced‐hereditary properties, and characterize them in the style of Scheinerman [Discrete Math. 55 (1985), 185–193]. © 2005 Wiley Periodicals, Inc. J Graph Theory 49: 11–27, 2005