showing 36 of ~574560 from 574555 documents
Effects of repeated treatments with an extract ofGinkgo biloba (EGb 761) and bilobalide on glucose uptake and glycogen synthesis in rat erythrocytes:…
1994
The metabolic action of an extract of Ginkgo biloba (EGb 761) has been examined in an ex vivo study of rat erythrocytes. Oral administration of EGb 761 (100 mg/kg/day) for 5 days to Wistar rats caused an increase in the in vitro uptake of glucose by erythrocytes, especially in high-glucose (13.32 mM) medium, an effect that was associated with an increase in intracellular energy metabolism and reflected as a significant reduction in free glucose concentration. In contrast, the lactate concentration of the erythrocytes and lactate release to the bathing medium were not modified. Conversion of glucose into glycogen was significantly increased in the erythrocytes of EGb 761-treated animals. Tak…
Determination of catecholamines as aminochromes by micellar liquid chromatography with thermal lens spectrophotometric detection
1994
The determination of catecholamines (CAs) using micellar liquid chromatography with thermal lens spectrophotometric detection has been studied. CAs are oxidized with hexacyanoferrate(III) to aminochromes which are separated with a mobile phase of 0.05 M sodium dodecyl sulphate, 7% propanol and 0.03 M citrate buffer, pH 4.8, on a partially endcapped C18 column. The aminochrome-micelles and aminochrome-stationary phase association constants are evaluated. Using the 488 nm line of an Ar+ laser with 250 mW pump power the limits of detection are about 4 ng mL−1. The technique is applied to the determination of unconjugated CAs in urine using isoproterenol as internal standard.
false
1994
Polymer blends can undergo, during processing, degradation phenomena because of the presence of both temperature and mechanical stresses. With respect to pure homogeneous polymers, the degradation of polymer blends shows distinct features because of the possible interaction between the different chemical species. These interaction can give rise to both a faster degradation or to the formation of copolymers which act as stabilizing agents. This latter phenomena is particularly important in the processing of condensation polymers
How to Improve the Uterotomy Healing
1994
Abstract Suboptimal uterotomy healing following cesarean delivery or metroplastic operations may lead to considerable complications. New insights in the biology of wound healing and the availability of a variety of biologic response modifiers open the possibility to modulate the process of wound healing in order to gain clinical benefits. Can uterotomy healing be improved by local application of biosubstances? We developed an uterotomy model in the rat and measured the bursting pressure at defined times postwounding as a functional parameter of wound healing. In addition, the healing process was assessed by serial light microscopic histology. Uterotomy healing was investigated in the presen…
Unilateral medial forebrain bundle activation selectively enhances conditioned orienting head turns and ipsilateral cingulate cortex evoked field res…
1994
Effects of a unilateral medial forebrain bundle (MFB) stimulation unconditioned stimulus (US) on conditioned head turn and bilateral cingulate cortex field potentials were studied in cats. Conditioned stimuli (CSs) of different frequences were given randomly to either ear. The CS+ was followed by the US, and the CS— was presented alone. Before conditioning most cats predominantly turned toward the ear to which the CSs were presented, whereas after conditioning the head turns were in one direction, most prominently contralateral to the US. Negative field potentials were greater in the cingulate cortex ipsilateral to the US than in the cingulate cortex contralateral to the US. Cross correlati…
Traumatic lesion of the extracranial vertebral artery--a note-worthy potentially lethal injury.
1994
The autopsy findings from routine neuropathological investigations of the cervical spine after any history of trauma emphasized the vulnerability of the extracranial vertebral arteries. In 21 cases with trauma to the head and neck, normal autopsy procedures did not succeed in revealing an obvious cause of death. Traumatic lesions of the spinal cord such as contusion or neurorrhexis were seen in 10 cases. In 15 cases we observed different degrees and stages of traumatic lesions of the extracranial vertebral arteries. Sudden death due to acute brain stem ischemia might be considered as an explanation in some of these cases. Six case reports with traumatic vertebral artery (VA) lesions after s…
Evolution of deformation in the neutron-rich Zr region from excited intruder state to the ground state.
1994
Strong evidence for the existence of previously postulated deformed excited states in $^{98}\mathrm{Zr}_{58}$ has been obtained by an accurate measurement of the ${\mathrm{\ensuremath{\rho}}}^{2}$(${0}_{3}^{+}$\ensuremath{\rightarrow}${0}_{2}^{+}$) value for the decay of the second excited ${0}^{+}$ state at 1436 keV. In the neighboring isotope $^{99}\mathrm{Zr}_{59}$, at the edge of the region of strong ground-state deformation, evidence is found for a rotational band built on the state at 614 keV. Systematics of the excitation energies of the deformed states in Zr nuclei and their Sr neighbors show that the apparent sudden onset of deformation is explained by the steady lowering of a stro…
Stochastic resonance in a tunnel diode.
1994
We study stochastic resonance in a fast bistable electronic system: a tunnel diode. We investigate the phenomenon in a higher frequency regime than that studied in previous experiments. Detailed measurements of the output signal are reported for two values of the frequency of the periodic signal: ${\mathit{f}}_{\mathit{s}}$=1 kHz and ${\mathit{f}}_{\mathit{s}}$=10 kHz. We observe, in one case (${\mathit{f}}_{\mathit{s}}$=1 kHz), a nonmonotonic behavior characterized by a sharp dip in the output noise level measured at the frequency of the driving signal.
Dimensions of the laryngeal framework in adults
1994
The increasing application of sophisticated electrophysiological, radiological and surgical methods to the diagnosis and treatment of laryngeal disorders requires a profound knowledge of the size and proportions of the human larynx and it's cartilaginous components. Only inadequate data regarding this subject have so far been accessible. The larynges of 53 patients (28 male and 25 female, age 25-88 years, in the means 59 years) were removed during routine autopsy 12-48 h post mortem and immediately submitted to morphometric investigation. None of the patients had histories or visible signs of laryngeal disease. Anatomical preparations were performed with customary surgical tools and morphom…
The lift computation for an oscillating flat plate in incompressible potential flow
1994
The initial aim of this work was the estimation of the lift acting on a flat plate performing small oscillations in a plane uniform stream by means of a simplified model based on one or at the most two lumped vortices, and the assessment of its results by comparison to those that were exact. The model was found to work well up to a reduced frequency of about 1 or 2, above which the results diverged from those that were correct. In order to improve the model, its behaviour at very high frequencies was then investigated, discovering: (i) that if the number of lumped vortices is greater than one the possibility to impose all boundary conditions is subject to certain geometrical constraints; (i…
Absence of hyperscaling violations for phase transitions with positive specific heat exponent
1994
Finite size scaling theory and hyperscaling are analyzed in the ensemble limit which differs from the finite size scaling limit. Different scaling limits are discussed. Hyperscaling relations are related to the identification of thermodynamics as the infinite volume limit of statistical mechanics. This identification combined with finite ensemble scaling leads to the conclusion that hyperscaling relations cannot be violated for phase transitions with strictly positive specific heat exponent. The ensemble limit allows to derive analytical expressions for the universal part of the finite size scaling functions at the critical point. The analytical expressions are given in terms of generalH-fu…
Mother-Child Teaching Strategies and Learning Disabilities
1994
The teaching strategies used by mothers of sons with learning disabilities (LD) (n = 30) and normally achieving sons (NLD) (n = 30) were examined. The children were matched for age (8- to 11-year-olds) and for parents' socioeconomic status. The behavior of mother-child pairs was videotaped in a teaching task that was constructed to resemble a homework assignment. The results showed that the mothers of children with LD used fewer high-level strategies, and their total time used in teaching was less than that of the mothers of NLD children. The mothers of children with LD exhibited more dominance and less emotionality and cooperation than did the mothers of NLD children; however, the mothers…
Developmental expression of human cartilage matrix protein.
1994
Cartilage matrix protein (CMP) is a non-collagenous component of cartilage with a yet unknown function. In this study we used in situ hybridization to investigate the temporal and sptial distribution of CMP transcripts during human embryonic and early fetal development, and compared it to the pattern of expression observed for collagen types I, II, X, and decorin. The distribution of CMP and collagen type II transcripts followed a similar pattern in the embryonic bone anlage, the fetal growth plate, and the developing vertebral column. Expression was highest in the upper hypertrophic and lower proliferative zone, whereas calcified cartilage was negative throughout the different stages of bo…
MUSCLE BIOENERGETICS IN OBESE ZUCKER RATS
1994
International audience; Abstract: The purpose of this study was to investigate the energetic metabolism in obese Zucker rats, using phosphorus nuclear magnetic resonance spectroscopy at rest and during a 2-Hz muscle stimulation and subsequent recovery. Animals were anesthetized with ketamine (150 mg/kg ip). Fed obese rats and 2-day-fasted obese rats were compared with their normally fed and 2-day-fasted lean litter mates. No differences were found between the two groups for ATP, total creatine, phosphocreatine (PCr), and intracellular pH. Starvation in lean rats resulted in a significant fall in inorganic phosphate (Pi), increased resting ADP level, and decreased PCr and ADP recovery after …
Parasite community diversity in two Mediterranean labrid fishes Symphodus tinea and Labrus merula
1994
Examination of 111 peacock wrasse [Symphodus tinea (L.)] and 97 brown wrasse (Labrus merula L.) from the Valencian coast (Spain) yielded 24 metazoan parasite species (11 Digenea, three Cestoda, four Nematoda. one Acanlhocephala, five Crustacea). Eighteen species were from 5. tinea and 17 from L. merula; 11 of the 24 species were common to both hosts. Brillouin's diversity index, was applied to fully censused parasite infracommunities. This is the first time that all the metazoan parasites (internal and external) in any position in the host have been analysed for diversity. High values of prevalence, intensity, and diversity parameters indicate that these labrid fishes support diverse parasi…
Changes in fatty acid compositions of total serum and lipoprotein particles, in growing rats given protein-deficient diets with either hydrogenated c…
1994
The present study examines the effects of dietary saturated (hydrogenated coconut oil) and polyunsaturated (salmon oil) fats on the composition and metabolism of lipoproteins in growing rats fed on protein-deficient diets. Four groups of rats were fed on the following diets for 28 d: 200 g casein+50 g coconut oil (COC)/kg, 20 g casein+50 g coconut oil (COd)/kg, 200 g casein + 50 g salmon oil (SAC)/kg, 20 g casein+50 g salmon oil (SAd)/kg. Both protein-deficient groups exhibited low concentrations of protein and triacylglycerol (in serum, very-low-density lipoprotein (VLDL), low-density lipoprotein-high-density lipoprotein, (LDL-HDL1) and HDL2-3), of cholesterol (in LDL-HDL1) and of phosphol…
Ergebnisse nach Implantation von zementfreien metallspongiösen Hüftprothesen
1994
72 Huftgelenke mit zementfreier metallspongioser Huftprothese wurden zwei bis sieben Jahre (mittlere Nachuntersuchungszeit 43 Monate) nach der Implantation klinisch und rontgenologisch kontrolliert. Bei funf Patienten muste die zementfreie Prothese wegen Lockerung (ausbleibende knocherne Einheilung n=2, Pfannenlockerung infolge operationstechnischer Fehler n=3) gewechselt werden. Aufgrund der klinischen Befunde konnten 88% von 67 Huften mit sehr gut bzw. gut, 9% mit befriedigend und 3% mit unbefriedigend bewertet werden. 10% der Patienten klagten noch uber Oberschenkelschmerzen. Die typischen, rontgenologisch erkennbaren, knochernen Reaktionen des Implantatlagers werden beschrieben, eine In…
Identification and spectroscopy of the108Te nucleus
1994
Excited states of 108 Te were populated in the 54 Fe + 58 Ni (270 MeV) reaction using the NORDBALL detector array equipped with charged-particle and neutron detector systems for reaction channel separation. Gamma rays belonging to the neutron deficient nucleus 108 Te were identified for the first time. On the basis of γγ-coincidence and angular correlation relations a level scheme was constructed with tentative spin and parity assignments. The structure of the nucleus is discussed in the framework of systematics of heavier Te nuclei.
The 35-d modulation of the X-ray emission of Her X-1 in the framework of the SOD model: results of a three-dimensional SPH simulation
1994
Several models have been proposed to explain the 35-d X-ray periodicity observed in Her X-1. We present the results of six three-dimensional quasi-polytropic smoothed particle hydrodynamics (SPH) simulations of the tilted, twisted accretion disc of Her X-1 carried out in the light of Roberts' slaved orienting disc model (SOD) with the intention of finding some limits to the inclination of the rotation axis of the secondary and to the value of the polytropic index γ. These results show that a γ value between 1.05 and 1.1 and an inclination angle φ of the order of 45° are the most suitable for enabling the SOD model to work in three-dimensional space. The simulated disc is rather small and th…
QCD corrections to inclusive ΔS = 1, 2 transitions at the next-to-leading order
1994
24 páginas, 3 figuras, 2 tablas.-- arXiv:hep-ph/9402363v1
Insulin-like growth factors counteract the effect of interleukin 1 beta on type II phospholipase A2 expression and arachidonic acid release by rabbit…
1994
International audience; Interleukin 1 beta was found to stimulate arachidonic acid release, and the synthesis and secretion of type II phospholipase A2 by rabbit articular chondrocytes in vitro. Interleukin 1 beta had no effect on the level of cytosolic phospholipase A2 mRNA. Insulin-like growth factors, which help stabilize the cartilage matrix, reduced the effect of interleukin 1 beta on type II phospholipase A2 activity and mRNA level, and decreased the Interleukin 1 beta-stimulated arachidonic acid release to the basal values. This suggests that type II phospholipase A2 plays a key role in arachidonic acid release from rabbit articular chondrocytes and that insulin-like growth factors c…
Relation between Energy Level Statistics and Phase Transition and its Application to the Anderson Model
1994
A general method to describe a second-order phase transition is discussed. It starts from the energy level statistics and uses of finite-size scaling. It is applied to the metal-insulator transition (MIT) in the Anderson model of localization, evaluating the cumulative level-spacing distribution as well as the Dyson-Metha statistics. The critical disorder $W_{c}=16.5$ and the critical exponent $\nu=1.34$ are computed.
Bioanalysis of digoxin and its metabolites using direct serum injection combined with liquid chromatography and on-line immunochemical detection.
1994
Abstract An automated dual-column liquid chromatographic assay for digoxin is described. Serum samples are directly injected onto a restricted-access solid-phase extraction support. After liquid chromatographic (LC) separation on a C18 analytical column, antigenic analytes are detected by means of post-column immunochemical detection (ICD) using fluorescein-labelled antibodies against digoxigenin. The detection limit of this assay is 160 pg/ml (preconcentration of 1.0 ml serum). With the present method digoxin and three of its cross-reactive metabolites were determined in serum taken from patients which were orally administered a 1-mg dose of digoxin. The results obtained with LC—ICD were c…
Simultaneous determination of levodopa methyl ester, levodopa, 3-O-methyldopa and dopamine in plasma by high-performance liquid chromatography with e…
1994
A new procedure is described for the simultaneous determination of levodopa methyl ester (LDME) and its biotransformation products levodopa (L-DOPA), 3-O-methyldopa (3-OMD) and dopamine (DA) in stabilized plasma samples, using reversed-phase high-performance liquid chromatography. A coulometric detector equipped with a dual-electrode system operating in the redox mode was used to simultaneously quantitate all compounds. This system generated a double signal monitored by a dual-channel acquisition data system and allowed quantitation of compounds at the nanogram level. The intra- and inter-assay precision varied in the 2.4-6.9% and 3.2-9.1% ranges respectively, whereas the recoveries were cl…
In vitro differentiation of E-N-CAM expressing rat neural precursor cells isolated by FACS during prenatal development
1994
Most fetal rat brain cells expressing the embryonal, highly sialylated form of the cell adhesion molecule N-CAM (E-N-CAM) are precursor cells, as judged from the absence of marker molecules specific for mature neural cell types. However, the detection of E-N-CAM+ cells in frozen sections does not provide information on the lineage-specific differentiation of these cells during development. To investigate their differentiation behaviour in vitro, E-N-CAM+ cells were isolated at different times of brain development by fluorescence-activated cell sorting (FACS), using a monoclonal antibody (Mab RB21-7) which specifically recognizes polysialic acid (PSA) residues on E-N-CAM. Double-immunofluore…
Monte Carlo Calculations for Liquid $^4$He at Negative Pressure
1994
A Quadratic Diffusion Monte Carlo method has been used to obtain the equation of state of liquid $^4$He including the negative pressure region down to the spinodal point. The atomic interaction used is a renewed version (HFD-B(HE)) of the Aziz potential, which reproduces quite accurately the features of the experimental equation of state. The spinodal pressure has been calculated and the behavior of the sound velociy around the spinodal density has been analyzed.
Sequence similarity of mammalian epoxide hydrolases to the bacterial haloalkane dehalogenase and other related proteins Implication for the potential…
1994
Direct comparison of the amino acid sequences of microsomal and soluble epoxide hydrolase superficially indicates that these enzymes are unrelated. Both proteins, however, share significant sequence similarity to a bacterial haloalkane dehalogenase that has earlier been shown to belong to the alpha/beta hydrolase fold family of enzymes. The catalytic mechanism for the dehalogenase has been elucidated in detail [Verschueren et al. (1993) Nature 363, 693-698] and proceeds via an ester intermediate where the substrate is covalently bound to the enzyme. From these observations we conclude (i) that microsomal and soluble epoxide hydrolase are distantly related enzymes that have evolved from a co…
Influence of culture conditions on embryo formation and maturation in auxin-induced embryogenic cultures of Digitalis obscura.
1994
Somatic embryogenesis was induced in hypocotyls of Digitalis obscura using indoleacetic acid or 2,4-dichlorophenoxyacetic acid with different culture and subculture conditions. Indoleacetic acid-induced embryogenic cultures were used to investigate the effects of amino acids, polyamines and growth regulators on embryo differentiation and maturation. Supplementation of the media with amino acids, polyamines or abscisic acid did not influence or had an adverse effect on embryogenic response. Gibberellic acid at 1.4 μM in either culture (30 days) or subculture medium was effective in promoting both differentiation and normal embryo development. The efficiency of somatic embryogenesis was great…
Studies on the importance of microsomal epoxide hydrolase in the detoxification of arene oxides using the heterologous expression of the enzyme in ma…
1994
In order to investigate the role of the microsomal epoxide hydrolase (mEH) in the detoxification of arene oxides in the presence of a high endogenous glutathione S-transferase (GST) activity-a situation found in several organs--we expressed the rat mEH cDNA in BHK21 Syrian hamster cells. These cells have high GST activities but contain an extremely low endogenous mEH enzyme activity. We obtained several cell clones which expressed the mEH heterologously, as determined by immunoblotting. The cell clone BHK21-mEH/Mz1 had the highest level of mEH protein. Immunofluorescence showed that the level of expression was almost homogeneous throughout the cell population. Total protein isolated from th…
Dienediolates of unsaturated carboxylic acids in synthesis. Synthesis of cyclohexenones and polycyclic ketones by tandem Michael-Dieckmann decarboxyl…
1994
Abstract Substituted 2-cyclohexenones 4 to 7 and hexaxydronaphthalenones and hexahydroindenones 13 to 18 are prepared by tandem Michael-Dieckmann addition of lithium dienediolates of acyclic and alicyclic unsaturated carboxylic acids to the lithium salts of the same or other unsaturated carboxylic acids.
Infrastructure and Regional Economic Growth: The Spanish Case
1994
CUTANDA A. and PARICIO J. (1994) Infrastructure and regional economic growth: the Spanish case, Reg. Studies 28, 69-77. This paper considers the measurement of infrastructure capital in the Spanish regions and examines the regional disparities found. The relationship between income and infrastructure is studied in order to determine the impact of public capital in accounting for regional disparities in incomes. The empirical evidence shows that infrastructure has a significant positive effect on the income disparities at regional level. CUTANDA A. et PARICIO J. (1994) L'equipement et la croissance economique regionale, Reg. Studies 28, 69-77. Cet article considere la mesure du capital affec…
Products of groups and group classes
1994
Letχ be a Schunck class, and let the finite groupG=AB=BC=AC be the product of two nilpotent subgroupsA andB andχ-subgroupC. If for every common prime divisorp of the orders ofA andB the cyclic group of orderp is anχ-group, thenG is anχ-group. This generalizes earlier results of O. Kegel and F. Peterson. Some related results for groups of the formG=AB=AK=BK, whereK is a nilpotent normal subgroup ofG andA andB areχ-groups for some saturated formationχ, are also proved.
Expression of properdin in human monocytes
1994
Properdin is the only known positive regulator of the alternative pathway of complement activation. Northern blot analysis of cell lines derived from fibroblasts, B-cells, hepatoma cells, and cells of the monocyte-macrophage lineage revealed properdin expression only in the myelomonocytic cell line HL-60, in the monoblastic cell line U-937 and in the monocytic line Mono Mac 6. Culture of Mono Mac 6 cells for 24 h with phorbol 12-myristate 13-acetate, bacterial lipopolysaccharide and the cytokines interleukin-1 beta and tumour necrosis factor-alpha enhanced mRNA abundance, with the strongest effect (tenfold) being observed with the lipopolysaccharide. In contrast, recombinant interferon-gamm…
Ferrochirality: A simple theoretical model of interacting dynamically invertible helical polymers, 1. The basic effects
1994
The effect of interaction between reversible helical polymers of the poly(hexyl isocyanate) type is investigated by using a molecular field model. It is shown that for interacting helices a critical temperature exists below which they must adopt a common helix-sense spontaneously, even in the absence of any external or intrinsic chiral force
Synthesis and spectroscopic studies (Mo¨ssbauer, IR and NMR) of [R2SnCl2bipym] (R = butyl or phenyl) and the crystal and molecular structure of [Ph2S…
1994
Abstract The complexes [R 2 SnCl 2 bipym] (R = phenyl or butyl, bipym = 2,2′,6,6′-bipyrimidine) were synthesized and studied in solution by 1 H- and 13 C-NMR spectroscopy and in the solid state by IR and Mo¨ssbauer spectroscopy. The latter was also performed in frozen ethanolic solution. The structure of the phenyl complex was determined by single crystal diffraction methods. The value obtained for the angle C-SN-C in the phenyl compound is 169.3(2)° (X-ray) and 151° (Mo¨ssbauer), but the assignment of an octahedral configuration by Mo¨ssbauer spectroscopy is consistent with the structure determined by diffraction. The butyl complex is also octahedral and the two techniques show better agre…
Cellular ultrastructure of the ruptured anterior cruciate ligament. A transmission electron microscopic and immunohistochemical study in 55 cases.
1994
To evaluate the cellular ultrastructure following injury, we examined the anterior cruciate ligaments in 55 patients with complete tears in different phases after the injury and compared them to a control group of 39 cadaver knees. Samples were analyzed by electron microscopy, immunofluorescence, and ultramorphometry. After an invasion of inflammatory cells into the stumps of the ruptured ligaments, a marked proliferation of fibroblasts was found at the end of Phase 1 (2-3 days after the ligament injury), that was even more pronounced at the beginning of Phase II (4-17 days). These cells were initially highly metabolically active and secreted Type III collagen precursors. In Phase III (4-45…