Investigation of the Alkaloid Content of Rauwolfia serpentina Roots from Regenerated Plants.

1991

The indole alkaloid content of RAUWOLFIA SERPENTINA roots from regenerated plants (from stem-and root-callus) was compared with the parental stock. Although the total alkaloid content seems to be slightly higher in the roots from regenerated plants, HPLC-analysis of individual alkaloids indicated that the contents of the alkaloids ajmaline ( 1), serpentine ( 2), and reserpine ( 3) are lower than in the roots of the parental stock. The glucoalkaloid raucaffricine ( 4) was identified as a constituent of all samples, thus providing the first evidence for its occurrence in roots of RAUWOLFIA SERPENTINA.

High-Performance Liquid Chromatographic Study on Oxidation Products of Lignin and Humic Substances

1991

We describe a convenient method of preparing samples and characterizing the mixture of degradation products obtained from alkaline cupric oxide oxidation of water samples containing lignin and humic substances. The method was applied to one unpolluted humic water sample and a total mill effluent of a kraft pulp mill. The fractions (Mr > 1000) obtained by ultrafi1tration were oxidized and the products (mixtures of degradation products) were analyzed by reversed-phase high-performance liquid chromatography (Spherisorb 5 ODS column). Acetonitrile-0.01 M phosphate buffer (pH 2) was used as the eluent in a gradient system and UV (set at 280 nm) as the detection system. Differences in the …

Delta 5-desaturation of dihomogammalinolenic acid (20:3(n-6)) into arachidonic acid (20:4(n-6)) by rat liver microsomes and incorporation of fatty ac…

1991

Abstract Liver microsomes of rats fed an essential fatty acid (EFA)-deficient diet or a commercial balanced diet were used to study the effect of incubation time on the Δ 5 -desaturation of [ 14 C] dihomogammalinolenic acid (20:3( n −6)) into arachidonic acid (20:4( n −6)) and incorporation of the two acids into microsomal phospholipids. The EFA-deficient diet highly increased the desaturation rate of 20:3( n −6). Incorporation of the formed 20:4( n −6) into microsomal phospholipids was also increased but at saturating concentration of substrate only. At early times of incubation, the precursor 20:3( n −6) was rapidly incorporated into phospholipids. Formation and incorporation of 20:4( n −…

Multifractal wave functions at the Anderson transition.

1991

Electronic wave functions in disordered systems are studied within the Anderson model of localization. At the critical disorder in 3D we diagonalize very large (103 823\ifmmode\times\else\texttimes\fi{}103 823) secular matrices by means of the Lanczos algorithm. On all length scales the obtained strong spatial fluctuations of the amplitude of the eigenstates display a multifractal character, reflected in the set of generalized fractal dimensions and the singularity spectrum of the fractal measure. An analysis of 1D systems shows multifractality too, in contrast to previous claims.

History of lysimeter design and effects of environmental disturbances

1991

International audience

Precision lysimetry in France

1991

International audience

Bulk-plasmon dispersion relations in metals

1991

En utilisant une technique de la regle de somme dans l'approximation de la phase aleatoire etendue, on examine la relation de dispersion des plasmons en volume, en introduisant les effets de la correlation et de l'echange dans le modele du jellium. Les resultats obtenus sont compares aux resultats experimentaux. On souligne le role cle que jouent les effets de la correlation et de l'echange dans l'amelioration de l'accord entre la theorie et l'experience. On calcule egalement la polarisabilite statique en fonction de 9. Les formules peuvent etre facilement modifiees pour incorporer les effets de la structure de bandes (a travers une masse effective electronique intrabande) et les effets de …

Termination of transcription in an ‘in vitro’ system is dependent on a polyadenylation sequence

1991

Using HeLa cell nuclear extract as a source of the different transcription and polyadenylation factors and reverse transcription to analyze the levels of RNA 5' and 3' to the cleavage-polyadenylation site, an in vitro assay has been established to study polyadenylation coupled to transcription directed by different adenovirus promoters. The levels of transcription 5' and 3' to the cleavage site in the L3 polyadenylation region are practically the same as described previously, however, the level of transcription 3' to the cleavage site in the SV40 early polyadenylation region decreases immediately after the cleavage site indicating a termination of the transcription.

Simpson's neutrino and the singular seesaw

1991

We derive explicit forms for the neutrino and lepton "mixing-matrices" which describe the generic singular see-saw model. The dependence on the hierarchy parameter is contrasted with the non-singular case. Application is made to Simpson's 17 keV neutrino.

Photoperiod effects on bombesin- and cholecystokinin-like immunoreactivity in the suprachiasmatic nuclei of the Djungarian hamster (Phodopus sungorus)

1991

The immunocytochemical distribution of the putative satiety peptides bombesin (BBS) and cholecystokinin (CCK) were studied in the hypothalamic suprachiasmatic nuclei (SCN) of male and female Djungarian hamsters (Phodopus sungorus) held under either long (light/dark, LD 16:8 h) or short (LD 8:16) photoperiod. The animals were killed by perfusion with a fixative at the middle of the light period and the tissue was processed by routine immunohistochemical methods. Perikarya exhibiting BBS- or CCK-like immunoreactivity (LI) were found in the SCN of animals of all groups. Sex-related differences were not observed. In contrast, long-term exposure to short days decreased the number of neurons exhi…

Aetiology of community acquired pneumonia in Valencia, Spain: a multicentre prospective study.

1991

A year long multicentre prospective study was carried out in the Valencia region of Spain, to determine the cause of community acquired pneumonia. The study was based on 510 of 833 patients with pneumonia. Of these, 462 were admitted to hospital, where 31 patients died. A cause was established in only 281 cases--208 of bacterial, 60 of viral, and 13 of mixed infection. The most common microorganisms were Streptococcus pneumoniae (14.5%), Legionella sp (14%), Influenza virus (8%), and Mycoplasma pneumoniae (4%). There was a higher incidence of Legionella sp than in other studies.

Identification of minor affective disorders and implications for psychopharmacotherapy.

1991

Five hundred general practice patients with functional complaints were studied with the Polydiagnostic Interview (PODI) to see whether DSM-IIIR criteria were able to specify affective disorders satisfactorily. Almost one third of the patients received the diagnosis of depression not otherwise specified (NOS). When Research Diagnostic Criteria were applied to these patients more than 70% received specific diagnoses. A modification of DSM-IIIR algorithms enabled us to further specify diagnoses in subjects with depression NOS. On the 17-item Hamilton Depression Scale many of these patients reached scores of 13 or more which is severe enough to justify a therapy trial with antidepressants.

The polytron as a cw electron accelerator in the 10 GeV range

1991

Abstract This article is concerned with a generalized microtron, characterized essentially by the number of magnet pairs in its bending system. It is shown that the most serious physical energy limit of the microtron, emittance growth due to synchrotron radiation, may be overcome if this number is raised essentially above what has been considered in the past. The main properties of such “polytrons” are investigated and several design examples for 15 GeV output energy are discussed.

Locust flight metabolism studied in vivo by 31P NMR spectroscopy

1991

Flight metabolism of locusts has been extensively studied, but biochemical and physiological methods have led to conflicting results. For this reason the non-invasive and non-destructive method of 31P NMR spectroscopy was used to study migratory locusts, Locusta migratoria, at rest and during flight. 1. In the flight muscle of resting locusts the ratio of phosphoarginine to ATP was the same whether determined by NMR (1.76) or biochemically, but the NMR-visible content of inorganic phosphate (Pi) was only 40% of ATP, i.e., much lower than total Pi as determined biochemically. This suggests that most of the Pi in flight muscle is not free, and hence not available as substrate or effector for …

Threshold pion photoproduction in a light-cone quark model

1991

Abstract The instantaneous and seagull graphs are calculated for pion photoproduction in a relativistic light-cone model of the nucleon. In both pseudoscalar and pseudovector coupling we find the ratios A (−) : A (0) : A (+) = 1: ( −1 2 μ):( −9 5 μ) in the nonrelativistic limit. These results correspond to the sum of seagull and Z -graph in the nonrelativistic quark model. In pseudovector coupling also the numerical results for realistic-model parameters are close to those values.

false

1991

The thermal degradation mechanisms of amphiphilic acrylic copolymers containing mesogenic pyrimidine side chains and hydrophilic 2-hydroxyethyl acrylate (HEA) main-chain spacer units were investigated by thermogravimetry (TG) and pyrolysis-field ionization mass spectrometry (Py-FIMS). The degradation behaviour of these polymers depends on the amount of HEA incorporated. Thermogravimetry revealed that the main decomposition occurs in a single step for the pyrimidine homopolymer, whereas with increasing HEA content a two-step process evolves. The major products identified by Py-FIMS are two alcohols and one olefin split from the aromatic side chains. Depolymerization is only a minor degradati…

Results of the DEKORP 1 (BELCORP-DEKORP) deep seismic reflection studies in the western part of the Rhenish Massif

1991

Summary Within the DEKORP project (DEKORP: Deutsches Kontinentales Reflexionsseismisches Programm) a joint deep seismic reflection venture with the BELCORP (Belgian Continental Reflection Seismic Programme) group of the Belgian Geological Survey was carried out in 1987 across the Rhenish Massif, a part of the mid-European Variscides. This orogenic belt developed in the Upper Devonian/Carboniferous. Mostly Devonian rocks crop out at the surface. The Rhenish Massif is bordered by two sedimentary troughs: the sub-Variscan Foredeep in the north and the Permo-Carboniferous Saar-Nahe Basin in the south. In the east-west direction it is subdivided by the axial depression of the Eifel Nord-Sud Zone…

Effect of silver deposits on the photocatalytic activity of titanium dioxide samples for the dehydrogenation or oxidation of 2-propanol

1991

Abstract Until now, the effect of the deposition of metal particles onto a powdered semiconductor oxide on its photocatalytic activity has been determined for group VIII transition metals only. In this study, AGTiO2 samples were prepared by photodeposition, characterized by transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) and tested, under band-gap illumination, using the oxidation of 2-propanol (neat liquid phase or mixed with water) in the absence or presence of molecular oxygen. The silver deposits were found to be metallic both before and after use, but the size of the particles and their distribution on the support were markedly influenced by the type …

Acute effects of antidepressant drugs on long-term potentiation (LTP) in rat hippocampal slices.

1991

The actions of three clinically effective antidepressant drugs with different pharmacological profiles were investigated in the CA1 area of rat hippocampal slices. Imipramine and (+) or (-)-oxaprotiline had negligible effects on population spikes evoked by stratum radiatum stimulation, but reduced postsynaptic excitability in low Ca high Mg medium after an exposure of more than 15 min. Imipramine and (+)-oxaprotiline at 10 mumol/l enhanced long-term potentiation (LTP) when a lower stimulation strength was applied while (+)-oxaprotiline reduced LTP when a higher stimulus amplitude was used to evoke population spikes. (-)-oxaprotiline (levoprotiline) had a similar effect which was, however, n…

Ion implantation effects in BaTiO3 single crystals

1991

Abstract Thermally controlled helium implantation has been used to produce planar waveguides in BaTiO3 without noticeable depoling effects in the samples. Profiles for the ordinary and extraordinary refractive index are deduced from optical mode measurements. No annealing procedure is required. We report the effects of different ion fluences and energies in the MeV range on the waveguide properties.

Acanthocyturia—A characteristic marker for glomerular bleeding

1991

Acanthocyturia—A characteristic marker for glomerular bleeding. Erythrocyte morphology by phase contrast microscopic examination (PCM) of the urine is widely employed in distinguishing glomerular from nonglomerular bleeding. The proposed percentages of dysmorphic red cells are significant for glomerular bleeding in the range of 10 to 80% in the literature, because there is no clear cut definition of “dysmor-phism.” In the present study midstream urine samples of 351 patients with hematuria (> 8 erythrocytes/μl) and of 33 healthy controls were examined. The various dysmorphic red cells were analyzed by PCM according to a detailed hematological classification. Most of the dysmorphic red cells…

Interaction of oxygen with Mo(100), Mo(110), and Mo(111) surfaces. RHEED and AES analyses of the molybdenum oxide nucleation and growth

1991

Abstract A study of the nucleation and growth of MoO 3 generated by interaction of oxygen with Mo(100), Mo(110), and Mo(111) single crystalline surfaces is investigated at high oxygen pressure (10 4 Pa) and low temperature (620 to 820 K). The results of RHEED and AES analyses prove that under these oxidation conditions, MoO 3 nucleates directly from the metal without intermediate formation of MoO 2 or nonstoichiometric molybdenum oxide such as Mo 4 O 11 . The structure and orientation of MoO 3 nuclei are characterized in relation with the parent molybdenum surface. On the Mo(110) and Mo(111) surfaces, which are faceting, the nucleation and growth of MoO 3 takes place by successive structura…

Spectrophotometric Determination of Hydralazine with 2-Hydroxy-1-naphthaldehyde in Pharmaceuticals

1991

Abstract A new extraction-spectrophotometric method for the determination of hydralazine, based on its reaction with 2-hydroxy-1-naphthaldehyde at 25 °C, is described. The calibration curve was linear between 0.4 and 6 mg/mL of hydralazine. The molar absorbtivity of the product at 408 nm is 40 900 L · mol − 1 · cm − 1 . The method described was applied to the analysis of hydralazine in pharmaceutical preparations containing reserpine, hydrochlorothiazide, bendrofluorthiazine, propranolol, and other substances. The agreement with the U.S.P. XXI method was satisfactory for tablets and injections, but not for pellets.

Comparative cytokeratin analysis of sweat gland ducts and eccrine poromas.

1991

Human eccrine sweat gland ducts and benign and malignant eccrine poromas were studied for the expression of various cytokeratins (CK) and vimentin by applying immunoperoxidase and immunofluorescence microscopy to frozen or paraffin-embedded sections, and using two-dimensional gel electrophoresis and immunoblotting. In acrosyringia and dermal eccrine ducts, the luminal cells exhibited intense staining for CKs 1/10/11 and 19. The periluminal cell layers of acrosyringia contained CKs 1/10/11, while CK 5 was absent. In contrast, the basal cell layer of dermal ducts was only positive with the antibody against CK 5, i. e. a pattern resembling that seen in epidermal basal cells. CK 9 was detected …

Subtyping panic disorder by major depression and avoidance behaviour and the response to active treatment

1991

In order to establish the clinical validity of currently used ways of subtyping panic disorder the predictive power of associated current avoidance behaviour and (secondary) major depression for the response to active treatment (alprazolam, imipramine) was tested. The analysis was based on the data from the Cross-National-Collaborative-Panic-Study. Limited support for validity evidenced by predicting drug response was found for grading panic disorder by the severity of avoidance behaviour; patients with panic attacks and agoraphobia are more responsive to imipramine (compared with alprazolam) when using the reduction of the total number of panic attacks (or of spontaneous panic attacks) as …

Random walks with short memory in a disordered environment

1991

Etude du modele du saut en arriere pour le cas d'un reseau desordonne. Le modele du saut en arriere est un modele de la marche aleatoire de proches voisins correlee dans lequel le marcheur possede une probabilite de transition differente pour les sauts vers le site qu'il a visite anterieurement, par rapport aux sauts vers tous les autres sites proches voisins. La formulation standard de ce modele doit etre modifiee si le desordre est introduit au niveau de l'equation directrice habituelle. On discute des difficultes rencontrees avec la formulation standard. L'equation maitresse du premier ordre pour le modele du saut en arriere desordonne est etablie, et a partir d'elle, on derive une equat…

false

1991

The polysoaps [CH 2 C(Me)(CO 2 R)] n (R=(CH 2 ) 11 N + Me 2 (CH 2 ) 3 SO 3 − , (CH 2 ) 11 N + Me 2 CH 2 CH 2 OH) are studied. Their aqueous solution properties are strongly influenced by added salts; the surface activity can be modified efficiently by an appropriate choice of ions. The interactions of salts and polyzwitterions observed in solution can be extended to the behaviour in bulk. It enables the preparation of uniform, non crystalline blends containing up to equivalent amounts of inorganic salt and polyzwitterions

Low-temperature methyl group dynamics of hexamethylbenzene in crystalline and glassy matrices as studied by 2H NMR

1991

Abstract 2 H NMR spectra of hexamethylbenzene (HMB) in protonated crystalline and amorphous matrices at low temperatures are presented. All spectra reveal lineshape changes which can be attributed to methyl group tunnelling. Compared to neat HMB, a drastic increase of the tunnelling frequency is found for all systems. This indicates that the hindering potential originates predominantly from intermolecular forces. We studied the temperature dependence of these spectra and the spin-lattice relaxation in order to exclude a distribution of motional correlation times describing a thermally activated process. In addition, we find a distortion of the methyl tetrahedron.

Spermatocyte chromosome analysis of Helicella virgata (Pulmonata: Helicidae): silver-stained and C-banded chromosomes.

1991

Chromosome numbers of the snail Helicella virgata from the fields of Castellammare del Golfo (Sicily) are n = 26 and 2n = 52. Silver-staining analyses of testicular cells suggest that both mitotic and meiotic chromosomes are involved in nucleolus organization. A within-individual variability in NOR-banding pattern is present in each of the 20 specimens analyzed.

Superficial oxidation of molybdenum at high pressure and low temperature: RHEED and AES analyses of the molybdenum oxide formation

1991

Abstract Numerous studies relate to the interaction of the molybdenum surface with oxygen at low pressure and high temperature. They give results about oxygen chemisorption, surface facetting and the epitaxial formation of MoO 2 crystallites. This work deals with the interaction of Mo(100), Mo(110) and Mo(111) surfaces with oxygen at high pressure (10 4 Pa) and low temperature (620–820 K). RHEED and AES analyses results prove that, in these oxidation conditions: MoO 2 and non-stoichiometric molybdenum oxide such as Mo 4 O 11 are not evidenced in any of the molybdenum oxidation steps. The MoO 3 phase nucleates directly from any Mo surface. The structure and orientation of MoO 3 nuclei are ch…

Characterization of cell wall proteins of yeast and hydrophobic mycelial cells of Candida albicans

1991

Cell surface hydrophobicity (CSH) of blastoconidia and blastoconidia bearing germ tubes of Candida albicans ATCC 26555 was monitored by assessing attachment of polystyrene microspheres to the cell surface, and we found that mature hyphae were significantly hydrophobic. Treatment of intact cells with low concentrations of beta-glucanase (Zymolyase 20T) or proteases abolished or significantly reduced attachment of latex beads to hyphae. This effect paralleled an obvious reduction in CSH of the entire cell population, as measured by an aqueous-hydrocarbon biphasic partitioning assay. Analysis of the cell wall material released by Zymolyase and adsorbed on polystyrene microspheres indicated tha…

Solution properties of polyelectrolytes

1991

Abstract Chromatographic data for sodium polystyrene sulphonate were obtained on both silica- and polymer-based size-exclusion supports using mobile phases of various pH and ionic strength. Deviations of the elution volume were observed towards both lower and higher values relative to the reference calibration graph obtained with uncharged standards. An empirical correlation is proposed in order to account for all the secondary effects observed. The general applicability of this correlation was further tested for chromatographic data obtained for a series of peptides and proteins on a silica-based support under very different eluent conditions. Deviations from ideal elution behaviour such a…

Rank formulae for factorized groups

1991

The following inequalities for the torsion-free rank r0(G) of the group G=AB and for the p∞-rank rp(G) of the soluble-by-finite group G=AB are stated: $$\begin{gathered} r_0 (G) \leqslant r_0 (A) + r_0 (B) - r_0 (A \cap B), \hfill \\ r_p (G) \leqslant r_p (A) + r_p (B) - r_p (A \cap B). \hfill \\ \end{gathered} $$

Vitamin K, and Anaphylactic Shock

1991

Aussagefähigkeit der Abdomenübersichtsaufnahme in der Differenzierung der Rotavirus-negativen und Rotavirus-positiven nekrotisierenden Enterokolitis

1991

Clinical data and radiographic findings of 32 newborn suffering from necrotising enterocolitis were analysed [12 patients with rotavirus-positive necrotising enterocolitis (RV + NEC), 20 patients with rotavirus-negative necrotising enterocolitis (RV-NEC)]. The presence and degree of pneumatosis intestinalis, portal venous gas and pneumoperitoneum on abdominal radiographs were graded after Kosloske et al. according to "mild, moderate, and severe". Pneumatosis intestinalis occurred twice as often in the ascending colon in RV-NEC compared to RV + NEC, whereas the transverse colon was involved nearly as frequently as the descending colon in both groups. Portal venous gas was present in 10% of t…

A multicentre trial to evaluate the efficacy and tolerability of alpha-glycerylphosphorylcholine versus cytosine diphosphocholine in patients with va…

1991

An open clinical trial was carried out to compare the efficacy and the tolerability of 1 g/day α-glycerylphosphorylcholine (α-GPC) with 1 g/day cytosine diphosphocholine (CDP) both given intramuscularly for 90 days in 120 patients with mild to moderate vascular dementia. The clinical evaluation, carried out at the start as well as halfway through (45 days) and at the end of treatment (90 days), was expressed by psychometric tests (modified Parkside behaviour rating scale, Sandoz clinical assessment geriatric scale, word fluency test, Hamilton's rating scale of depression, narration subtest of Wechsler memory scale). Both treatments produced a definite symptomatic improvement and showed a v…