showing 36 of ~574560 from 574555 documents
Charge transfer in high-Tc(Y/Pr)Ba2Cu3O7superlattices
1996
We comment on the charge-transfer model for the unique softening of the apex [O(4)] oxygen observed in Raman spectra of a- and c-oriented (${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7}$${)}_{\mathit{m}}$(${\mathrm{PrBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7}$${)}_{\mathit{n}}$ superlattices presented in a recent paper by Ham et al. [Phys. Rev. B 50, 16 598 (1994)]. We find the size of the charge transfer necessary for the observed shift too large to explain the observations. In addition, a conclusion about the unique behavior of both types of superlattices can only be drawn if the sample quality is properly considered. \textcopyright{} 1996 The American Physical Society.
The essential variation of a function and some convergence theorems
1996
ВВОДИтсь ОпРЕДЕлЕНИ Е ВАРИАцИИ ФУНкцИИ, пР И кОтОРОМ ФОРМУлА $$V(F,E) = \int_E {|\bar DF(x)} |dx$$ спРАВЕДлИВА Дль пРОИ жВОльНОИ ФУНкцИИF И пРОИжВОльНОгО ИжМЕР ИМОгО МНОжЕстВАE НА ОтРЕжкЕ пРьМОИ. В т ЕРМИНАх ЁтОИ ВАРИАцИ И пОлУЧЕНы тЕОРЕМы О пОЧлЕННОМ ДИФФЕРЕНцИРОВАНИИ п ОслЕДОВАтЕльНОстИ Ф УНкцИИ И тЕОРЕМы О пРЕДЕльНОМ пЕРЕхОДЕ пОД жНАкОМ И НтЕгРАлА ДАНжУА-пЕРР ОНА.
The Innervation of Taste Buds in the Soft Palate of the Rat as Revealed by Methylene Blue Staining.
1996
Light microscopic data on the innervation of taste buds in the soft palate of the rat obtained by methylene blue (MB) supravital staining are presented here for the first time. The taste pore including subpopulations of taste bud cells and nerve fibers were stained. Intragemmal nerve fibers were detected ascending up to the taste pore; this suggests the possibility of additional paracellular pathways in taste transduction directly via nerve fibers. Moreover, relatively large bulbous or laminar enlargements of the intragemmal nerve fibers were found. The branches of these nerve fibers, showing minute spiny protuberances, appeared to anastomose. Some perigemmal nerve fibers were also seen in …
Bilateral hairy polyp of the oropharynx.
1996
AbstractHairy polyp of the nasopharynx is an unusual but well-recognized entity, generally presenting as a single mass at birth or in the first year of life. We describe the clinico-pathological features of a previously unreported bilateral hairy polyp in an adult and briefly discuss the pathogenesis of this condition.
Models with clinically-relevant and life-threatening histamine-related cardiovascular disturbances: Evaluation of the clinical effectiveness of H1/H2…
1996
Criterios para gestionar una política de adquisiciones: estudio estadístico del catálogo colectivo de publicaciones seriadas de la Universitat de Val…
1996
One of the most important topics in libraries management, specially nowadays when library budgets have been blocked or shortened, is to set up a suitable acquisitions policy. This article aims, from a particular experience, to supply some information that allow to fix such an acquisitions policy. It analyses the Valencia University Serials Catalog, taking into account its growth throughout time, changes in titles distribution by the publishing country, in libraries and collections, always relating the whole collection to the current one, to conclude with a view of the collection distribution in knowledge areas, taking into account the number of students.<br><br>Uno de los temas …
Treatment of patients with duodenal ulcer positive for helicobacter pylori infection: ranitidine or omeprazole associated with colloidal bismuth subc…
1996
Abstract This study evaluated treatment of patients affected with duodenal ulcer positive for Helicobacter pylori . We compared patients treated with ranitidine plus amoxicillin plus colloidal bismuth subcitrate (n = 20) with patients treated with omeprazole plus amoxicillin plus colloidal bismuth subcitrate (n = 20) with regard to: (1) healing of duodenal ulcer; (2) eradication of H pylori ; and (3) recurrence of ulcer. Baseline and follow-up for 24 months were performed through clinical, laboratory, and endoscopic tests. The ulcer healing rate was 95% in the ranitidine group and 100% in the omeprazole group; the H pylori eradication rate was 90% and 95%, respectively. During follow-up, on…
Determination of organic fluorine in aqueous samples with neutron activation analysis in comparison with the DIN method
1996
Neutron activation analysis (NAA) has been used as detection technique for adsorbable organic fluorine in aqueous samples. The results have been compared with the standardized DIN method which uses a fluoride-ion-selective electrode (ISE).
Reduced stretch-reflex sensitivity after exhausting stretch-shortening cycle exercise.
1996
The stretch-shortening cycle (SSC) is an effective and natural form of muscle function but, when repeated with sufficient intensity or duration, it may lead to muscle damage and functional defects. A reduced tolerance to impact has been reported, which may be partly attributed to a reduced stretch-reflex potentiation. The aim of the present study was to examine the influence of SSC-induced metabolic fatigue and muscle damage on the efficacy of stretch reflexes, as judged by the electromyograph (EMG) response of two shank muscles (lateral gastrocnemius LG, soleus SOL) to controlled ramp stretches. These EMG responses were recorded before and immediately after exhausting SSC-type leg exercise…
On-Line Derivatization into Precolumns for the Determination of Drugs by Liquid Chromatography and Column Switching: Determination of Amphetamines i…
1996
A chromatographic system for the on-line derivatization of drugs using column switching is described. The system uses a 20 mm × 2.1 mm i.d. precolumn packed with a unmodified ODS stationary phase. This column is used for sample cleanup and enrichment of the analytes. Next, the trapped analytes are derivatized by injection of the derivatization reagent into the precolumn. Finally, the derivatives are transferred to the analytical column for their separation under reversed-phase conditions. The influence of several parameters such as the reaction time, the amount of derivatization reagent, or the system design has been studied using some amphetamines as model compounds and three derivatizatio…
Pedro Tedde y Carlos Marichal (coordinadores): La formación de los bancos centrales en España y América Latina, (2 vols.), Madrid, Banco de España, S…
1996
External laryngeal frame function in voice production revisited: A review
1996
Research indicates significant contribution of extrinsic laryngeal mechanisms to voice production. This article reviews the major theories of the role of the external laryngeal factors in voice production and relevant experimental data. The review suggests that partly neglected external factors and possibly even misinterpretation of some of the recently documented individual variation in physiological data may have unnecessarily complicated the issues pertaining to the interplay between the physiological mechanisms of the larynx. The implications of contemporary findings and documentation in the modeling of the extrinsic factors are discussed and a synthesis of empirical data into two simpl…
A Qualitative-Quantitative Approach to V-Belt Mechanics
1996
A simplified formulation is adopted for the theoretical problem of tension distribution and radial penetration of a V-belt along the pulley groove. The trajectory portrait of the second order differential system describing the belt behavior is carefully analyzed and asymptotic approximations for the tension solutions are derived which are well suited for design purposes.
Alteration in membrane fluidity and lipid composition, and modulation of H(+)-ATPase activity in Saccharomyces cerevisiae caused by decanoic acid.
1996
Decanoic acid, a lipophilic agent, inhibited in vitro the plasma membrane H+-ATPase of Saccharomyces cerevisiae grown in YPD medium. Conversely, when decanoic acid (35 μM) was present in the growth medium, the measured H+-ATPase activity was four times higher than that of control cells. K m, and pH and orthovanadate sensitivity were the same for the two growth conditions, which indicated that H+-ATPase activation was not due to conformational changes in the enzyme. The activation process was not entirely reversible which showed that plasma membrane H+-ATPase activation is due to several mechanisms. 1,6-diphenyl-1,3,5-hexatriene anisotropy performed on protoplasts from cells grown in YPD rev…
Coherent forward-scattering amplitude in transmission and grazing incidence Mössbauer spectroscopy
1996
The theory of both transmission and grazing incidence M\"ossbauer spectroscopy is re-analyzed. Starting with the nuclear susceptibility tensor a common concise first order perturbation formulation is given by introducing the forward scattering amplitude into an anisotropic optical scheme. Formulae of Blume and Kistner as well as those of Andreeva are re-derived for the forward scattering and grazing incidence geometries, respectively. Limitations of several previously intuitively introduced approximations are pointed out. The grazing incidence integral propagation matrices are written in a form built up from 2x2 matrix exponentials which is particularly suitable for numerical calculations a…
Studies of the binding of diolepoxide metabolites of polycyclic aromatic hydrocarbons to DNA using electrofluorescence polarization spectroscopy
1996
In the electrofluorescence method, a solution of DNA with covalently bound polycyclic hydrocarbons is placed in an electric field, and changes in the intensity of polarized fluorescence are observed. Under the correct conditions, these charges can be used to determine a value for the angle psi between the long axis of the hydrocarbon molecule and the axis of the DNA helix. For DNA or poly(dA-dT) treated with each stereoisomer of anti-benzo[c]phenanthrene diolepoxide, psi ranged from 55 degrees to 61 degrees, consistent with a mixture of quasi-intercalated adenine adducts and externally bound guanine adducts. Similar results were obtained with another set of 'fjord-region' diolepoxides, deri…
H-point standard additions method for resolution of overlapped chromatographic peaks with a conventional fluorescence detector. Determination of phen…
1996
The H-Point Standard Additions Method (HPSAM) is proposed in order to resolve overlapping peaks in liquid chromatography by using a conventional fluorescence detector. The method uses as analytical signals the heights or the areas obtained at two previously selected emission wavelengths, and good results are obtained for highly overlapping peaks with highly overlapping fluorescence spectra. The principal benefits of the method are the ease of finding the required wavelengths, its insensitivity to changes in the retention time of the peak from one injection to another, and the possibility of using it in highly or only partially overlapping peaks. We have applied the method to the determinati…
Cytokine expression profile in idiopathic inflammatory myopathies.
1996
Cytokines have been shown to be potent inducers of major histocompatibility complexes (MHC) class I and II as well as of cell adhesion molecules in muscle tissue cultures, indicating that cytokines may play a role in mediating muscle fiber damage in inflammatory myopathies. We found in 21 cases of autoimmune myositis various amounts of inflammatory cells expressing interleukin (IL)-1 alpha and -beta, IL-2, IL-4, tumor necrosis factor (TNF) -alpha and -beta, and interferon (IFN)-gamma and its receptor. Muscle fibers displayed enhanced expression of IL-1 alpha and -beta, IL-2, and TNF-alpha. Upregulation of cytokines was strongest at sites of cellular infiltration typical for the respective m…
Dermale Skelettelemente vonLissodus (Chondrichthyes: Hybodontoidea) aus dem Unterperm des Saar-Nahe-Beckens
1996
The appearance ofLissodus sp. NM in the Rotliegend of the NE Saar-Nahe basin extends the knowledge of this genus of the superfamily Hybodontoidea. Additional to some isolated teeth, which represent the most important diagnostic feature, many scales and a spine fragment could be described from the Niedermoschel locality. The functional morphology of the scales will be discussed on the basis of wellknown results from Recent sharks.
Almost Planar Homoclinic Loops in R3
1996
AbstractIn this paper we study homoclinic loops of vector fields in 3-dimensional space when the two principal eigenvalues are real of opposite sign, which we call almost planar. We are interested to have a theory for higher codimension bifurcations. Almost planar homoclinic loop bifurcations generically occur in two versions “non-twisted” and “twisted” loops. We consider high codimension homoclinic loop bifurcations under generic conditions. The generic condition forces the existence of a 2-dimensional topological invariant ring (non necessarily unique), which is a topological cylinder in the “non-twisted” case and a topological Möbius band in the “twisted” case. If the third eigenvalue is…
Aging-induced Up-regulation of Nuclear Binding Activities of Oxidative Stress Responsive NF-kB Transcription Factor in Mouse Cardiac Muscle
1996
The accumulation of lipofuscin to cardiomyocytes is a classical parameter of aging and is believed to reflect oxidative stress. NF-kB transcription factor complex is one of the cellular sensors which responds to oxidative stress and regulates gene expression. Our purpose was to study whether aging affects the level and distribution of DNA binding activities of NF-kB transcription factors both in cardiac sarcoplasm and nuclear extracts. We used electrophoretic mobility shift assays (EMSA) to characterize the DNA binding activities of NF-kB and two other transcription factors. AP-1 and Sp-1, in the myocardium of 4 months and 24 months old male and female NMRI-mice. The protein levels of p50, …
Meningiomas of the Space of the Cavernous Sinus
1996
During the years 1985 to 1992, we encountered 59 patients with meningiomas involving the space of the cavernous sinus. In 29 of these patients, meningiomas were primarily located within the space of the cavernous sinus and were operated on without mortality and with low morbidity. A small subtemporal surgical approach was favored, which allowed initial tumor resection from the posterior aspect, where the Parkinson's triangle is wide, thus avoiding the additional morbidity of large-scale approaches. According to the relationships of the all-important cranial nerves passing within the lateral wall of the cavernous sinus, we divided the primary intracavernous meningiomas into four types, which…
Serum and urine markers of type I collagen metabolism in elderly women with high and low bone mineral density.
1996
The serum markers of bone formation (carboxy-terminal propeptide of type I collagen, PICP) and resorption (pyridinoline cross-links containing telopeptide of type I collagen, ICTP), as well as urinary resorption markers, pyridinoline (Pyr) and deoxypyridinoline (Dpyr), were studied in 78-year-old women with high (n = 18) and low (n = 17) bone mineral density (BMD) measured from the calcaneus and tibia. The low-BMD group had higher values for PICP (P = 0 center dot 025), Pyr (P = 0 center dot 001) and Dpyr (P < 0 center dot 001) than the high-BMD group. No inverse relationship between these markers and BMD was, however, observed within the study groups. ICTP, Pyr and Dpyr correlated with eac…
An insect juvenile hormone-specific epoxide hydrolase is related to vertebrate microsomal epoxide hydrolases.
1996
Abstract We describe the first cDNA sequence encoding a juvenile hormone-specific epoxide hydrolase from an insect. A full-length cDNA clone revealed a 462-amino-acid open reading frame encoding an amino acid sequence with 44% identity and 64% similarity to human microsomal epoxide hydrolase. All residues in the catalytic triad (residues Asp 227 -His 428 -Asp 350 in the M. sexta protein) were present, as was the conserved Trp 154 corresponding to the oxyanion hole. The surprising similarity of insect juvenile hormone epoxide hydrolase to vertebrate microsomal epoxide hydrolases, coupled with the ancient lineage of the epoxide hydrolases and haloalkane dehalogenases, suggests that this catab…
Difference between Guinea Pig and Rat in the Liver Peroxisomal Response to Equivalent Plasmatic Level of Ciprofibrate
1996
Abstract Guinea pig was previously classified as a species nonresponsive to peroxisome proliferators. However, none of the previous reports was based on pharmacokinetic data. Here, after a comparative pharmacokinetic study between guinea pig and rat, we evaluate the guinea pig liver peroxisomal response to ciprofibrate, a hypolipemic agent and a potent peroxisome proliferator in rat. (1) Pharmacokinetic results show that plasmatic concentrations of ciprofibrate are equivalent in guinea pig and rat when guinea pigs are treated with ciprofibrate at 30 mg/kg twice a day and rats are treated at 3 mg/kg once a day. (2) The treatment of guinea pigs at 30 mg/kg twice a day for 2 weeks leads to a s…
Complete congenital heart block is associated with increased autoantibody titers against calreticulin.
1996
Complete congenital heart block (CCHB) is associated with anti-Ro/SS-A and anti-La/SS-B antibodies. Calreticulin, a calcium-binding, multi-functional protein of the endoplasmic reticulum with C-terminal KDEL-sequence, is not part of the Ro/SS-A ribonucleoprotein complex. In this study anti-calreticulin autoantibody responses in serum samples from 18 infants with CCHB, their mothers and in a control group of 11 anti-Ro/SS-A or anti-La/SS-B positive infants without heart block and their mothers were analysed. Specific enzyme-linked immunosorbent assays were performed. Nine out of 18 sera with CCHB contained IgG anti-calreticulin antibodies. Four sera of those with IgG antibodies also had IgM …
Residual Stresses and Reactivity of Solids. Determination and Part Plaid in the Reaction Mechanisms
1996
Postural balance and its sensory-motor correlates in 75-year-old men and women: a cross-national comparative study.
1996
Background. There are no earlier cross-national comparative studies analyzing the functioning of the posture control mechanisms and its sensory-motor correlates in elderly subjects. We investigated whether there are differences in balance between elderly subjects living in different geographical areas, and analyzed the sensory-motor associates of balance in men and women separately. Method. Using a force platform method, the functioning of the posture control system under three standardized conditions (normal standing, eyes open; normal standing, eyes closed; and tandem standing, eyes open) was studied among samples of 75-year-old residents in three Nordic localities, namely Glostrup in Den…
Coping variables as predictors of perioperative emotional states and adjustment
1996
Abstract Surgery, regardless of its kind and severity, can be regarded as a major stress situation for any patient. High preoperative emotional arousal may negatively influence adaptation during surgery and, consequently, rate of postoperative recovery. In a series of previous studies, our research group analyzed the influence of dispositional and actual coping on subjective and objective stress indicators before, during, and after surgery. The present study investigates the influence of the dispositional coping variables vigilance and cognitive avoidance on actual surgery-related coping, state anxiety, and indicators of intra- and postoperative adjustment. The sample consisted of 42 male a…
European concepts in teacher education
1996
Large-eddy simulations of turbulent flow with heat transfer in simple and complex geometries using Harwell-FLOW3D
1996
Abstract Large-eddy simulation (LES) results are presented and discussed for the turbulent flow with heat transfer in different geometrical configurations, including a plane channel, a channel bearing transverse square ribs on one of the walls, and a crossed-corrugated air heater. They were obtained using the computational fluid dynamics (CFD) code Harwell-FLOW3D (Release 2), finite-volume grids having up to 423 nodes, and the Smagorinsky subgrid model with several variants regarding near-wall damping and wall boundary conditions. The first problem (plane turbulent Poiseuille flow with heat transfer) was mainly used as a benchmark to investigate the influence of numerical methods (pressure-…
Congenital Müllerian anomalies: diagnostic accuracy of three-dimensional ultrasound
1996
Objective To determine whether it is possible to identify and diagnose accurately Mullerian anomalies with three-dimensional (3-D) ultrasound (US). Design Controlled blinded clinical study. Setting Normal human volunteers undergoing infertility evaluation in a university hospital. Patients Forty-two patients who underwent laparoscopy and hysterosalpingography as part of their work up for infertility and were found to have either a normal uterus (30 patients) or a Mullerian abnormality (12 patients) consented to be evaluated with 3-D US by sonographers who were unaware of their infertility history or of their laparoscopy and hysterosalpingography diagnoses. Interventions Transvaginal 3-D US …
Subchronic Antidepressant Treatment with Venlafaxine or Imipramine and Effects on Blood Pressure and Heart Rate: Assessment by Automatic 24-Hour Moni…
1996
Venlafaxine is a new nontricyclic antidepressant inhibiting the reuptake of serotonin, noradrenaline, and, to a lesser extent, dopamine without antagonizing cholinergic, histaminergic, or noradrenergic receptors. Significantly, in a first placebo-controlled safety and efficacy study, high doses of venlafaxine increased blood pressure in some study subjects. In order to investigate further the effect of subchronic antidepressant drug treatment on blood pressure and heart rate, the effects of a conventional tricyclic (imipramine) and a structurally different phenethylamine antidepressant (venlafaxine) were compared. Sixteen inpatients with major depression (melancholic type) were treated for …
Studies of inelastic cross-section in Rb(7S) + Rb(5S) collisions
1996
The cross section σ = (8 ± 4) × 10−15 cm2 was determined for the Rb(7S) + Rb(5S) → Rb(5D) + Rb(5S) excitation energy transfer process, and the quenching cross section σq = (2 ± 1) × 10−14 cm2 for the Rb(5D) state in collisions with ground state Rb atoms. Applying rubidium quasimolecular asymptotic potential curves at relatively large internuclear distances, a qualitative interpretation of the experimental results is presented. It is shown that the quenching of the Rb(5D) atoms in collisions may be explained by a reversed energy pooling process Rb(5D) + Rb(5S) → Rb(5P) + Rb(5P).
Predation on artificial ground nests in relation to forest fragmentation, agricultural land and habitat structure
1996
The impacts of forest fragmentation, agricultural land and habitat structure on depredation of artificial ground nests were studied in the cultivated area in central Finland and in the forest dominated area in Finnish Lapland. The overall predation rate did not differ between the regions. The overall predation rate was also independent of landscape characteristics forest patch size and the distance to patch edge. However, nest predation was clearly affected by the agricultural land since the robbing rate in forest edges was higher near farmlands than further away. This effect was caused by avian predators which proportional importance in predation was higher in the agricultural landscape th…
Consequences of food-attraction conditioning in Helix: a behavioral and electrophysiological study
1996
Food-attraction conditioning is a learning phenomenon by which adult Helix pomatia acquire the ability to locate food through exposure to that particular food. Food-conditioned snails can be distinguished from ‘naive’ snails during their approach to food. ‘Naive’ snails keep their tentacles upright — whereas ‘food-conditioned’ animals bend the tentacles down-ward, in a horizontal orientation, pointed in the direction of the food.