bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamics of Adsorbed Star‐Branched Polymer Chains: A Computer Simulation Study
Authors: Sikorski Andrzej 
Published: June 2003

AbstractThe simple cubic‐lattice model of polymer chains was used to study the dynamic properties of adsorbed, branched polymers. The model star‐branched chains consisted of f = 3 arms of equal lengths. The chain was modeled with excluded volume, that is, in good solvent conditions. The only interaction assumed was a contact potential between polymer segments and an impenetrable surface. This potential was varied to cover both weak and strong adsorption regimes. The classical Metropolis sampling algorithm was used for models of star‐branched polymers in order to calculate the dynamic properties of adsorbed chains. It was shown that long‐time dynamics (diffusion constant) and short‐time dynamics (the longest relaxation time) were different for weak and strong adsorption. The diffusion of weakly adsorbed chains was found to be qualitatively the same as for free nonadsorbed chains, whereas strongly adsorbed chains behaved like two‐dimensional polymers. The time‐dependent properties of structural elements such as tails, loops, and trains were also determined.The mean lifetimes of tails, loops, and trains versus the bead number for the chain with N = 799 beads for the case of the weak adsorption εa = −0.3.imageThe mean lifetimes of tails, loops, and trains versus the bead number for the chain with N = 799 beads for the case of the weak adsorption εa = −0.3.
1H and 13C chemical shifts for acridines: Part XVIII. 9‐Chloroacridine and 9‐(N‐allyl)‐ and 9‐(N‐propargyl)acridinamine derivatives
Authors: Roubaud G. , Faure R. , Galy J.‐P. 
Published: June 2003

AbstractThe1H and 13C NMR resonances for acridine derivatives 9‐substituted with chloro, allylamino and propargylamino groups were completely assigned using a concerted application of gs‐COSY, gs‐HMQC and gs‐HMBC experiments. 9‐(N‐Allyl)‐ and 9‐(N‐propargyl)acridinamine derivatives present amino–imino tautomerism including a large broadening of 1H and 13C NMR signals at room temperature. To obtain suitable resolution, therefore, these latter compounds were studied at 370 K in DMSO‐d6 solutions and showed a complete shift towards the imino tautomers. Copyright © 2003 John Wiley & Sons, Ltd.
Computation and analysis of 19F substituent chemical shifts of some bridgehead‐substituted polycyclic alkyl fluorides
Authors: Adcock William , Peralta Juan E. , Contreras Ruben H. 
Published: June 2003

AbstractThe 19F NMR shieldings for several remotely substituted rigid polycyclic alkyl fluorides with common sets of substituents covering a wide range of electronic effects were calculated using the DFT‐GIAO theoretical model. The level of theory, B3LYP/6–311+G(2d,p), was chosen based on trial calculations which gave good agreement with experimental values where known. The optimized geometries were used to obtain various molecular parameters (fluorine natural charges, electron occupancies on fluorine of lone pairs and of the CF bond, and hybridization states) by means of natural bond orbital (NBO) analysis which could help in understanding electronic transmission mechanisms underlying 19F substituent chemical shifts (SCS) in these systems. Linear regression analysis was employed to explore the relationship between the calculated 19F SCS and polar substituent constants and also the NBO derived molecular parameters. The 19F SCS are best described by an electronegativity parameter. The most pertinent molecular parameters appear to be the occupation number of the NBO p‐type fluorine lone pair and the occupation number of the CF antibonding orbital. This trend suggests that in these types of rigid saturated systems hyperconjugative interactions play a key role in determining the 19F SCS. Electrostatic field effects appear to be relatively unimportant. Copyright © 2003 John Wiley & Sons, Ltd.
Complete 1H and 13C NMR spectral assignment of hydrogenated oxoisoaporphine derivatives
Authors: Sobarzo‐Sánchez Eduardo , Cassels Bruce K. , Castedo Luis 
Published: June 2003

Abstract2,3,8,9,10,11‐Hexahydro‐7H‐dibenzo[de,h]quinolin‐7‐one, 5‐methoxy‐2,3,8,9,10,11‐hexahydro‐7H‐dibenzo[de,h]quinolin‐7‐one, 5‐methoxy‐6‐hydroxy‐1,2,3,7a,8,9,10,11,11a,11b‐decahydro‐7H‐dibenzo[de,h]quinolin‐7‐one, 5‐methoxy‐5,6,8,9,10,11‐hexahydro‐4H‐dibenzo[de,h]quinolin‐7‐ol, 5,6,8,9,10,11‐hexahydro‐4H‐dibenzo[de,h]quinolin‐7‐ol and 5,6‐dihydro‐4H‐dibenzo[de,h]quinolin‐7‐ol were prepared by catalytic hydrogenation of oxoisoaporphines or their 2,3‐dihydro derivatives over PtO2 in acetic acid under mild conditions. Their structures were confirmed and 1H and 13C NMR spectra were completely assigned using a combination of one‐ and two‐dimensional NMR techniques. Copyright © 2003 John Wiley & Sons, Ltd.
14N NMR of amminecobalt(III) compounds
Authors: Kofod Pauli 
Published: June 2003

AbstractDirectly detected ammine 14N NMR chemical shifts of 20 amminecobalt(III) compounds are reported. The coordination shifts, δCS = δcoord − δfree, are in all cases negative and range from −4.4 ppm for the trans ammine ligand in [Co(NH3)5(CH3)]2+ to −73.6 ppm for the trans ammine ligand in [Co(NH3)5(F)]2+. Among the ligands studied, the NO2− ligand is unique in that it exerts a significant cis influence. The regularity in trans or cis influences upon the ammine nitrogen chemical shifts provides a basis for assignments in cases where this cannot be deduced from intensity ratios. Copyright © 2003 John Wiley & Sons, Ltd.
A two‐step Taylor–Galerkin algorithm applied to shock wave propagation in soils
Authors: Mabssout M. , Pastor M. 
Published: June 2003

AbstractThis paper presents a two‐step Taylor–Galerkin algorithm formulated in terms of velocities and stresses which can be applied to solid dynamics problems requiring good resolution of small wavelengths, such as propagation of shocks. The proposed model is both fast, as it uses simple linear elements (triangles in 2D and tetrahedra in 3D), and accurate. It avoids locking and mesh alignment problems, and therefore can be applied to localized failure computations without the limitations exhibited by the classical displacement formulations. Copyright © 2003 John Wiley & Sons, Ltd.
Motor evoked potentials from the striated urethral sphincter and puborectal muscle: Normative values
Authors: Brostrom Soren , Jennum Poul , Lose Gunnar 
Published: June 2003

AbstractAimsTranscranial magnetic stimulation enables the study of corticospinal motor pathways through evoked potential testing. By separate stimulation of cortical centers and spinal roots, it is possible to test motor conduction times segmentally. This method enables the localization of central or peripheral demyelinating neuropathies. As lower urinary tract dysfunction often accompanies these diseases, we wanted to present normative data for the motor innervation of the external urethral sphincter (EUS) and the puborectal muscle (PR).MethodsThirty healthy women without evidence of neurologic or lower urinary diseases were studied. They had a mean age of 52 years. Transcutaneous magnetic stimulations were applied to the vertex, the upper lumbar spine, and the sacrum. Evoked potentials were recorded with concentric needle electrodes placed in the EUS and the PR by a transvaginal route. Stimulations were performed with relaxed pelvic floor and with tonic contraction (facilitated responses). At least three responses were recorded for each modality. Stepwise multiple regression analysis was performed to test for the effect of age, height, body mass index, vaginal parity, and menopause.ResultsIn some subjects, it was only possible to record cortical latencies with facilitation. Technical difficulties were encountered with spinal stimulations. Reference values are presented as means with 95% confidence intervals. Regression analysis revealed height as a dependent factor for sacral latencies.ConclusionsOur data can serve as reference values for future studies of the fast conducting fibers in patients with sphincter dysfunction. The height of the patient should be taken into account. The clinical applicability of the method is questionable. Neurourol. Urodynam. 22:306–313, 2003. © 2003 Wiley‐Liss, Inc.
Compliance of the bladder neck supporting structures: Importance of activity pattern of levator ani muscle and content of elastic fibers of endopelvic fascia
Authors: Barbič Matija , Kralj Božo , Cör Andrej 
Published: June 2003

AbstractAimsFirm bladder neck support during cough, suggested to be needed for effective abdominal pressure transmission to the urethra, might depend on activity of the levator ani muscle and elasticity of endopelvic fascia.MethodsThe study group of 32 patients with stress urinary incontinence and hypermobile bladder neck, but without genitourinary prolapse, were compared with the control group of 28 continent women with stable bladder neck. The height of the bladder neck (HBN) and compliance of the bladder neck support (C) were assessed, the latter by the quotient of the bladder neck mobility during cough and the change in abdominal pressure. By using wire electrodes, the integrated full‐wave rectified electromyographic (EMGave) signal of the levator ani muscle was recorded simultaneously with urethral and bladder pressures. The pressure transmission ratio (PTR), time interval between the onset of muscle activation and bladder pressure increment (ΔT), and area under the EMGave curve during cough (EMGcough) were calculated. From bioptic samples of endopelvic fascia connecting the vaginal wall and levator ani muscle, elastic fiber content was assessed by point counting method. Mann‐Whitney test was used to compare all the variables. Correlations between the parameters were evaluated by using the Spearman correlation coefficient.ResultsIn the study group, HBN was significantly lower (P < 0.001), C was significantly greater (P < 0.001), and PTR was significantly lower (P < 0.001). In the study group, the muscular activation started later (median, ΔTl, −0.147 second; ΔTr, −0.150 second), and in the control group, it preceded (ΔTl, 0.025 second; P < 0.001; ΔTr, 0.050 second; P < 0.001) the bladder pressure increment. EMGcough on the left side was significantly greater in the study group (P < 0.046). Elastic fiber content showed no difference between the groups. The analysis of all patients revealed negative correlations between C and PTR (r = −0.546; P < 0.001) and between C and ΔTl (r = −0.316; P < 0.018).ConclusionsFirm bladder neck support enables effective pressure transmission. Timely activation of the levator ani seems to be an important feature. Neurourol. Urodynam. 22:269–276, 2003. © 2003 Wiley‐Liss, Inc.
Clinical diagnosis of bladder outlet obstruction in men with lower urinary tract symptoms: Reliability of commonly measured parameters and the role of idiopathic detrusor overactivity
Authors: Vesely Stepan , Knutson Tomas , Fall Magnus , Damber Jan‐Erik , Dahlstrand Christer 
Published: June 2003

AbstractAimsThere is no generally accepted consensus how to evaluate patients with lower urinary tract symptoms (LUTS) suggestive of bladder outlet obstruction (BOO). We have tried to determine whether the most frequently used objective variables as prostate volume, IPS‐score, maximum flow rate, residual urine volume, functional bladder capacity, and pressure‐flow study are reliable for diagnosis of BOO and we investigated the influence of idiopathic detrusor overactivity (IDO) on this condition.MethodsA total of 153 men with LUTS and suspected BOO were systematically examined with routine investigation including digital rectal examination, transrectal ultrasound (TRUS), post‐void residual urine volume measurement, uroflowmetry, and pressure‐flow study. All patients completed IPS‐score. Patients were divided into groups based on Schäfer's grade of obstruction and incidence of IDO and clinical and urodynamical variables were compared.ResultsAt baseline, 45.8% of the patients were urodynamically moderately obstructed and 37.9% were found to be severely obstructed. The grade of obstruction did not correlate with age. Prostate volume, post‐void residual volume (PVR), and maximum flow rate correlated significantly with the degree of obstruction. The mean IPS‐score remained almost unchanged throughout all obstruction groups. The incidence of IDO was 40.5% and increased from 16% in the minor obstruction group to 38.6% and 53.4% in the moderate and severe obstruction group, respectively. The patients with IDO were older, had larger prostates and were more obstructed. There was no impact of IDO on symptomatology of BOO.ConclusionsThese data indicate that IPS‐score does not achieve sufficient diagnostic accuracy and its role in the assessment of BOO is limited. The grade of obstruction is more related to prostate volume, PVR, and maximum flow rate. BOO and IDO seem to be related and have numerous mutual interactions. Neurourol. Urodynam. 22:301–305, 2003. © 2003 Wiley‐Liss, Inc.
Loss of urinary voiding sensation due to herpes zoster
Authors: Hiraga Akiyuki , Nagumo Kiyomi , Sakakibara Ryuji , Kojima Shigeyuki , Fujinawa Naoto , Hashimoto Tasuku 
Published: June 2003

AbstractA case of sacral herpes zoster infection in a 56‐year‐old man with the complication of loss of urinary voiding sensation is presented. He had typical herpes zoster eruption on the left S2 dermatome, hypalgesia of the S1–S4 dermatomes, and absence of urinary voiding sensation. There was no other urinary symptom at the first medical examination. Urinary complications associated with herpes zoster are uncommon, but two types, acute cystitis and acute retention, have been recognized. No cases of loss of urinary voiding sensation due to herpes zoster have been reported. In this case, hypalgesia of the sacral dermatomes was mild compared to the marked loss of urethral sensation. This inconsistency is explained by the hypothesis that the number of urethral fibers is very small as compared to that of cutaneous fibers, therefore, urethral sensation would be more severely disturbed than cutaneous sensation. Neurourol. Urodynam. 22:335–337, 2003. © 2003 Wiley‐Liss, Inc.
Role of β‐adrenoceptor subtypes in mediating relaxation of the pig bladder trigonal muscle in vitro
Authors: Yamanishi Tomonori , Chapple Christopher R. , Yasuda Kosaku , Yoshida Ken‐Ichiro , Chess‐Williams Russell 
Published: June 2003

AbstractAimsTo investigate the role of β‐adrenoceptor subtypes in mediating relaxation of the pig bladder trigonal muscle in vitro.Materials and MethodsLongitudinal strips of trigonal muscle were isolated, and the mucosa and serosa removed. Tissues were precontracted with KCl, and β‐adrenoceptor agonists (isoprenaline or salbutamol) were added cumulatively, and concentration–relaxation curves (CRCs) were obtained. CRCs to agonists were obtained in the absence and presence of antagonists and antagonist affinity values were calculated.ResultsIsoprenaline (non‐selective β‐agonist) relaxed with high potency (pEC50 = 7.2). Propranolol antagonized CRCs to isoprenaline with a high affinity (apparent pKB = 8.8), but the Schild plot had a slope significantly (P < 0.01) less than unity (0.61), suggesting that responses were mediated by more than one β‐adrenoceptor subtype. CGP20712A (β1‐antagonist) antagonized responses to isoprenaline with a low affinity (apparent pKB = 5.13), indicating β1‐adrenoceptors did not participate in the response. The affinity of ICI118551 (β2‐antagonist) for antagonism of responses to isoprenaline was also relatively low (apparent pKB = 6.9), and the Schild slopes were significantly (P < 0.01) less than unity (0.58). SR59230A (β3‐antagonist) antagonized CRCs to isoprenaline with a relatively low affinity (apparent pKB = 7.5), and with a Schild slope significantly (P < 0.01) less than unity (0.86), indicating that responses may be mediated by more than one β‐adrenoceptor subtype. In contrast to that observed with isoprenaline, the β2‐adrenoceptor selective agonist salbutamol induced relaxation with a relatively low potency (pEC50 = 6.6) and with maximum responses of 80% of that to isoprenaline. ICI118551 competitively antagonized (Schild plot of unity) responses to salbutamol with a high affinity (pA2 = 8.3).ConclusionsThese data suggest that β‐adrenoceptor mediated responses to isoprenaline of the bladder trigone are mediated via both the β2‐ and β3‐adrenoceptor subtypes whilst responses to salbutamol appear to be mediated only via the β2‐adrenoceptor. Neurourol. Urodynam. 22:338–342, 2003. © 2003 Wiley‐Liss, Inc.
Uroneurological assessment of spina bifida cystica and occulta
Authors: Sakakibara Ryuji , Hattori Takamichi , Uchiyama Tomoyuki , Kamura Koichi , Yamanishi Tomonori 
Published: June 2003

AbstractAimsSpina bifida is a rare but well‐documented congenital spinal anomaly comprising a cystic form, which appears in infancy, and an occult form, which appears in late childhood and in adulthood. Herein, we report the results of uroneurological assessment in patients with spina bifida cystica and occulta, with respect to diagnosis and management of the disorders.MethodsWe performed a neurological examination, urinary questionnaire, and urodynamic studies in 28 consecutive patients with urinary symptoms, including 16 with the cystic form (nine male and seven female patients, ages 2 to 25 years), all of whom underwent neonatal surgical management, and 12 with occult form (six men and six women, ages 7 to 32 years) diagnosed by myelography and spinal magnetic resonance imaging who did not undergo surgery.ResultsNeurological examination revealed a combination of flaccid and spastic paresis, with dominant lower motoneuron signs in the cystic form, whereas there were dominant upper motoneuron signs in the occult form. Four patients with occult spina bifida presented with urinary symptoms as the sole initial complaint. There was no correlation between neurological findings and urodynamic abnormalities. Urinary incontinence and enuresis were common at all ages, and large post‐micturition residuals and vesicoureteral reflux were not uncommon, particularly in the cystic form. Bladder abnormalities in the cystic and occult forms included detrusor hyperreflexia during filling in 38% and 42%, low compliance detrusor in 81% and 67%, supersensitivity to bethanechol in two (100%) patients with the cystic form and in three of four (75%) with the occult form, and impaired bladder sensation in 25% and 8% in each form, respectively. Urethral abnormalities in cystic and occult forms included detrusor/sphincter dyssynergia in 50% and 27%, low Pure max in 56% and 17%, silent sphincter electromyographic activity in 25% and 0%, absent bulbocavernosus reflex in 87% and 56%, absent anal reflex in 100% and 57%, neurogenic motor unit potentials in one patient with cystic form studied and in two of three patients with occult form, respectively.ConclusionsSpina bifida cystica and occulta present with a wide spectrum of urodynamic abnormalities including upper and lower motoneuron types of bladder and urethral dysfunction. Careful uroneurological assessment and spinal magnetic resonance imaging are important for diagnosing young adult patients with spina bifida occulta because they may present with urinary symptoms as the sole initial complaint and have no other obvious neurological abnormalities. Neurourol. Urodynam. 22:328–334, 2003. © 2003 Wiley‐Liss, Inc.
A co‐rotational grid‐based model for fabric drapes
Authors: Sze K. Y. , Liu X. H. 
Published: June 2003

AbstractFabric drapes are typical large displacement, large rotation and small strain problems. Compared to conventional geometric non‐linear shell analyses, computational fabric drape analysis is particularly challenging due to the extremely weak bending rigidities of fabrics. Compared to continuum shell finite element methods, grid‐ or particle‐based methods appear to be more successful in high drapeability problems. The latter methods often resort to simple particle mechanics and formulate the elastic energy in terms of the inter‐particle distances and trigonometrical functions of the angles between the straight lines joining adjacent particles. In this paper, the co‐rotational approach and commonly employed assumptions for small strain problems in finite element analysis will be adopted to formulate the elastic energy. It will be seen that the internal force vector and the stiffness matrix are considerably simpler than other grid‐based models, yet the sparsity of the tangential stiffness matrix remains unchanged. A number of examples are considered and the predicted results are promising. Copyright © 2003 John Wiley & Sons, Ltd.
A modified element‐free Galerkin method with essential boundary conditions enforced by an extended partition of unity finite element weight function
Authors: Alves Marcelo Krajnc , Rossi Rodrigo 
Published: June 2003

AbstractIn this work we propose a method which combines the element‐free Galerkin (EFG) with an extended partition of unity finite element method (PUFEM), that is able to enforce, in some limiting sense, the essential boundary conditions as done in the finite element method (FEM). The proposed extended PUFEM is based on the moving least square approximation (MLSA) and is capable of overcoming singularity problems, in the global shape functions, resulting from the consideration of linear and higher order base functions. With the objective of avoiding the presence of singular points, the extended PUFEM considers an extension of the support of the classical PUFE weight function. Since the extended PUFEM is closely related to the EFG method there is no need for special approximation functions with complex implementation procedures, and no use of the penalty and/or multiplier method is required in order to approximately impose the essential boundary condition. Thus, a relatively simple procedure is needed to combine both methods. In order to attest the performance of the method we consider the solution of an analytical elastic problem and also some coupled elastoplastic‐damage problems. Copyright © 2003 John Wiley & Sons, Ltd.
3D modelling of strong discontinuities in elastoplastic solids: fixed and rotating localization formulations
Authors: Mosler J. , Meschke G. 
Published: June 2003

AbstractThis paper is concerned with the incorporation of displacement discontinuities into a continuum theory of elastoplasticity for the modelling of localization processes such as cracking in brittle materials. Based on the strong discontinuity approach (SDA) (Computational Mechanics 1993; 12:277–296) mesh objective 2D and 3D finite element formulations are developed using linear and quadratic 2D elements as well as 8‐noded 3D elements. In the formulation of the finite‐element model proposed in the paper, the analogy with standard formulations is emphasized. The parameter defining the amplitude of the displacement jump within the finite element is condensed out at the material level without employing the standard static condensation technique. This approach results in linearized constitutive equations formally identical to continuum models. Therefore, the standard return mapping algorithm is used to solve the non‐linear equations. In analogy to concepts used in continuum smeared crack models, a rotating formulation of the SDA is proposed in addition to the standard concept of fixed discontinuities. It is shown that the rotating localization approach reduces locking effects observed in analyses based on fixed localization directions. The applicability of the proposed SDA finite‐element model as well as its numerical performance is investigated by means of a three‐dimensional ultimate load analysis of a steel anchor embedded in a concrete block subjected to a shear force. Copyright © 2003 John Wiley & Sons, Ltd.