showing 36 of ~574560 from 574555 documents
Two-component density-functional theory: Application to positron states.
1985
A quantitative approach to calculating properties of inhomogeneous two-component Coulomb-Fermi systems is presented. As an application, the ground-state electronic structure of a jellium vacancy containing a trapped positron is calculated self-consistently. While the resulting density profiles and energetics are quite different from those obtained neglecting cross correlations, the conventional estimates for the annihilation rates are shown to remain valid, due to canceling effects of the increase in the mean electron density and the decrease in short-range screening.
Synthesis of peptides with α,β‐dehydroamino acids, III. Debenzyloxycarbonylation and detrifluoroacetylation of dehydroalanine and dehydrophenylalanin…
1985
The removal of amino protecting groups from a series of twelve model Z-3) or TFA-dipeptides of dehydroalanine and (Z)-dehydrophenylalanine was investigated. During this deprotection, peptides with Δ Ala are prone to side reactions to a higher extent than those with Δ Phe. Therefore it is interesting to note that from the Δ Ala peptides, the Z group can be split off in preparative manner with HCO2NH4 in the presence of Pd C (Table 4). Synthese von Peptiden mit α,β-Dehydroaminosauren, III.– Debenzyloxycarbonylierung und Detrifluoracetylierung von Dehydroalanin- und Dehydrophenylalanin-Peptiden An einer Serie von zwolf Z-3) oder TFA-Modellpeptiden mit Dehydroalanin und (Z)-Dehydrophenylalanin …
ChemInform Abstract: PHOTOLYSIS OF ENOL ACETATES AND α-BROMO DERIVATIVES OF O-(ACYLOXY)ACETOPHENONES
1985
UV irradiation of enol acetates 3a – g in benzene gives mainly o-(acetoxy)acetophenones 2 and 2-methylchromones 4. Under the same conditions, the dimethyl derivatives 3h and 3i remain unaffected. The α-bromo ketone 5a gives rise to mixtures of o-(acetoxy)acetophenone (2a), the diketone 6, and/or α-acetoxy-o-hydroxyacetophenone (7), depending on the irradiation conditions. The similarities and differences between the two series of experiments, as well as their possible mechanistic implications, are discussed. Photolyse von Enolacetaten und α-Bromderivaten von o-(Acyloxy)acetophenonen UV-Bestrahlung der Enolacetate 3a – g in Benzol liefert o-(Acetoxy)acetophenone 2 und 2-Methyl-chromone 4 als…
Characteristics and Prognostic Value of Morning Dipping of Peak Expiratory Flow Rate in Stable Asthmatic Subjects
1985
Characteristics and prognostic relevance of morning dip of peak expiratory flow rate (PEFR) were evaluated in stable asthmatic subjects. Among 246 outpatients monitored four times daily for two weeks, 38 (group A) showed a significant difference between morning reading of PEFR and each of the others; they were compared to 38 randomly selected patients (group B) not showing morning dip in PEFR. Less frequent seasonal course, extrinsic pathogenesis, and sensitization to mites characterized group A; starting airflow limitation was more severe in those with morning dip, but no significant difference between mean PEFR measured throughout two weeks was found. At 6 to 12 weeks, morning dip was not…
Evidence of Back Charge Transfer in DMBP-TCNQ3
1985
The single crystal conductivity of (N,N'-dimethyl-4,4'-bipyridinium)2+(7,7,8,8-tetracyanop- quinodimethanide)3 2-, DMBP-TCNQ3, exhibits an anomaly at 170 K which may be attributed to a phase transition and, also, a change in activation energy at 135 K which may be attributed to the onset of extrinsic behaviour. Above 135 K the conductivity varies as σ = σ0 exp(-E2/kT) where σ300K. = 1 S cm-1 and Ea = 0.18 eV. In the high temperature region the thermoelectric e.m.f. saturates to a temperature independent value of S = - 20 μVK-1 whereas for the related monoquaternised salt, [N-phenyl-4-(4'-pyridyl)-pyridinium]+(TCNQ)2 -, ØBP-TCNQ2, S = - 55 μVK-1. The thermoelectric data may be interpreted in…
Distribution of dopamine-beta-hydroxylase—like immunoreactivity in the rat pineal organ
1985
The aim of the present investigation was to study the distribution in the rat pineal gland of dopamine-beta-hydroxylase (DBH) which is essential for the formation of the melatonin synthesis-regulating substance noradrenaline (NA). In 5- and 8-month-old male Sprague-Dawley rats DBH-like immunoreactivity (DBH-LI) was studied using polyclonal antibodies against DBH and the indirect immunofluorescent technique. DBH-LI was mainly located in pineal nerve fibres coming from the superior cervical ganglia. The intensity of the staining reaction was considerably lower than in non-pineal noradrenergic nerve fibres and the impression was gained by comparison of DBH-LI specimens with glyoxylic acid-trea…
A rapid spectrofluorimetric method for the determination of the degree of synchronism inSaccharomyces cerevisiae
1985
A fluorescence technique that allows direct measurement of DNA and synchrony levels inSaccharomyces cerevisiae cell cultures is reported. The spectrofluorimetric estimation of DNA with 4,6-diamidino-2-phenylindole (AT-dye) does not require prior extraction, is highly stable, and requires small quantities of cells.
L'analyse des coûts et du financement de l'éducation au Sénégal
1985
référence interne : 85034
Postnatal development of functional T cell subsets in the mouse: a frequency analysis of mitogen reactive precursors of proliferating, of cytotoxic a…
1985
In order to study the postnatal development of functional T cell subsets in the mouse, a mitogen-driven limiting dilution culture system was used for a precursor frequency analysis of proliferating, of cytolytic and of IL 2-producing T cells, respectively, present in spleen and thymus of mice from neonatal to adult age. In adult mice, the majority (up to 100%) of splenic T cells was capable to respond to Concanavalin A. In contrast, an up to tenfold lower frequency of mitogen-reactive precursors was found within positively selected Thy-1+ spleen cells of neonatal mice. Within this fraction of Con A reactive neonatal T cells, there was an apparent imbalance in the CTLp/PTLp ratio within the …
ON THE ASYMPTOTIC DISTRIBUTION OF BARTLETT'S Up-STATISTIC
1985
Abstract. In this paper the asymptotic behaviour of Bartlett's Up-statistic for a goodness-of-fit test for stationary processes, is considered. The asymptotic distribution of the test process is given under the assumption that a central limit theorem for the empirical spectral distribution function holds. It is shown that the Up-statistic tends to the supremum of a tied down Brownian motion. By a counterexample we refute the conjecture that this distribution is in general of the Kolmogorov-Smirnov type. The validity of the central limit theorem for the spectral distribution function is then discussed. Finally a goodness-of-fit test for ARMA-processes based on the estimated innovation sequen…
Endliche Automorphismengruppen von direkten Produkten komplexer Raumkeime
1985
Economic analysis of vaccine production : choice between domestic production and import of vaccines in China
1985
référence interne : 85052
Comparison of131I-metaiodobenzylguanidine scintigraphy with urinary and plasma catecholamine determinations in the diagnosis of pheochromocytoma
1985
In a retrospective study of 31 patients with suspected pheochromocytoma we examined the preoperative results of 131I-metaiodobenzylguanidine (131-I-MIBG) scintigraphy and a fluorimetric urine catecholamine determination test. An additional radioenzymatic plasma catecholamine determination test was performed in 25 patients. In 14 of the 31 patients the diagnosis of pheochromocytoma was later histologically confirmed. In the remaining 17 patients the suspected diagnosis was finally rejected after a clinical decision had been made on the basis of clinical history, symptoms, laboratory and imaging tests. 131-I-MIBG scintigraphy apparently had a very high specificity (no false-positive results a…
Recent Advances in the Morphology of Myositis
1985
Summary Myositis in man may be divided into infectious and non-infectious forms. The myopathologist more often deals with the latter forms which comprise dermatomyositis/polymyositis, inclusion body myositis, mixed connective tissue disease/collagenoses, and granulomatous myopathies. Modern morphological techniques as enzyme-histochemistry, electron microscopy, immunohistology, and morphometry are of different value in various forms of myositis, but are often indispensable techniques in up-to-date diagnostic work up of a myositis.
Ergometrie — Empfehlungen zur Durchführung und Bewertung ergometrischer Untersuchungen
1985
Investigations on organotin, organolead, lead(IV), and lead(II) dithiolates
1985
Abstract Bis(triorganometal) 1,2-dithiolates (R3M)2S2R′ [(HS)2R′ = C7H8S2 for toluene-dithiol-3,4 (H2TDT); M = Sn, Pb; R = Ph; or (HS)2R′ = C10H14S2 for 1,2-dimethyl-4,5-bis(mercaptomethyl)benzene (H2DBB); M = Sn, R = CH3, C6H5; M = Pb, R = C6H5], diorganometal 1,2-dithiolates R2MS2R′ [(HS)2R′ = C6H6S2 for 1,2-dimercaptobenzene (H2DMB); M = Pb, R = CH3, C2H5, C6H5; or (HS)2R′ = H2TDT; M = Sn, R = CH3, C6H5; M = Pb, R = C6H5; or (HS)2R′ = H2DBB; M = Sn, R = CH3, C6H5; M = Pb, R = CH3, C2H2, C6H5; or (HS)2R′ = C8H6N2S2 for 2,3-dimercaptoquinoxaline (H2QDT); M = Pb, R = C6H5] and some lead(IV) and lead(II) dithiolates Pb(S2R′)n [(HS)2R′ = H2DMB, n = 2; (HS)2R′ = H2TDT, n = 2; (HS)2R′ = H2DBB, …
Use of quantitative ECG analysis for early detection and prediction of coronary heart disease
1985
(1985). Use of quantitative ECG analysis for early detection and prediction of coronary heart disease. Medical Informatics: Vol. 10, No. 3, pp. 207-214.
Prognostic significance of repetitive ventricular response in chronic coronary artery disease.
1985
A prospective study was conducted in 267 patients with angiographically defined coronary artery disease without documented ventricular tachycardia to determine the prognostic significance of repetitive ventricular response (RVR) after programmed electrical stimulation (PES). The patients were classified inducible if RVR with 3 or more echo beats (RVR greater than or equal to 3) could be induced. 89 patients without previous myocardial infarction (MI), 61 survivors of MI occurring between 6 weeks and 3 months before and 117 patients who had survived longer than 3 months after MI were studied. A standardized stimulation protocol with single (S1S2) and double (S1S2S3) extrastimuli during ventr…
Reliability of Parameter Estimation Methods Applied to the Identification of Biomedical Multicompartment Systems
1985
Abstract The reliability of parameter estimation in biomedical multicompartment models is influenced by the chosen mathematical representation of the model, by the sensitivity of the output on the relevant parameters to be identified and by the experimental conditions, e.g. choice of the data-set. this paper the reliability of different parameter estimation methods applied in a multi-compartment model of the circulatory system has been studied under the assumption that there exists a partially system output insensitivity against the compliance parameters. Suitable conditions for efficient parameter estimation have been found by simulation of sensitivity equations of the system, which is of …
Hochleistungsfl�ssigchromatographische Bestimmung von organischen S�uren, Zuckern, Glycerin und Alkohol im Wein an einer Kationenaustauschers�ule
1985
Mit der HPLC ist es moglich, die wichtigsten Bestandteile von Wein (Ethanol, Glycerin, Glucose, Fructose, Tartrat, Malat, Lactat, Succinat, Acetat und Citrat) in einem Lauf innerhalb von 25 min zu trennen und quantitativ zu bestimmen. Als stationare Phase dient der Kationenaustauscher HPX 87 H und als mobile Phase verdunnte Schwefelsaure. Die Untersuchungsergebnisse an einigen Weinen werden dargestellt. Es besteht eine gute Ubereinstimmung zwischen den Analysenergebnissen der HPLC und herkommlichen Methoden.[/p]
Über bismut-haltige heterocyclen
1985
Abstract Methyl and phenyl oxadithia and trithiabismocanes have been synthesized from methyl or phenyl diethoxybismutane and the respective dithiol. The light-sensitive compounds have been investigated by mass, vibrational and 13C NMR spectra: ν(BiMe) 470–460, ν(BiS2) 300–240 cm−1; δ(13Me) −12 ppm. The crystal structure of 5-phenyl-1,4,6,5-oxadithiabismocane has been determined (R = 0.056). The eight-membered ring has the chair-chair conformation. Besides three direct bonds (BiPh 225(2), BiS 256.0(2) and 260.2(3) pm) there are one transannular (Bi⋯O 297(1) and two intermolecular contacts (Bi ⋯S 344.0(3) and 350.9(3) pm) to bismuth in resulting a ψ-monocapped octahedral sphere of coordina…
INSERTION OF ISOCYANIDES INTO THE PALLADIUM CARBON BOND OF C-2-PALLADATED HETEROCYCLES - SYNTHESIS OF TRANS-[PDCL(C(RN)=NR) (PPH3)2] COMPLEXES (RN = …
1985
The titles complexes trans-[PdCl{C(RN)NR}(PPh3)2] (RN = 2-pyridyl (2-py), R = p-C6H4OMe, Me; RN = 2-pyrazyl (2-pyz), R = p-C6H4OMe) can be prepared by reaction of the N-protonated compounds, cis-[PdCl2(RNH)(PPh3] (RNH = 2-pyridylium (2-pyH) or 2-pyrazylium (2-pyzH) group), with PPh3, followed by addition of the isocyanide CNR and deprotonation with triethylamine, in a molar ratio Pd/PPh3/CNR/NEt3 of 1/1/1/1.1. The reaction sequence involves the successive formation of the cationic intermediates trans-[PdCl(RNH)(PPh3)2]+, trans-[Pd(RNH)(CNR)(PPh3)2]2+ and trans-[Pd(RN)(CNR)(PPh3)2]+, which were isolated and characterized as perchlorate salts for RN = 2-pyridyl. In the final step the coordin…
The role of the substantia nigra on the rage reaction elicited by hypothalamic stimulation, in the cat.
1985
The effects of substantia nigra stimulation on the rage reaction evoked by hypothalamic activation were studied. The reference value of the rage reaction was the latency of the hissing, which was constant in all animals when hypothalamic stimulation was performed with the same parameters. Simultaneous activation of substantia nigra and hypothalamus determined a significant decrease in hissing latency. The influence of the substantia nigra on the affective components of the aggressive behavior is underlined.
Role of elastic and electronic interactions in trapping of hydrogen by impurities in transition metals
1985
The interplay between the lattice distortion and the electronic contributions to the trapping of migrating hydrogen isotopes by substitutional impurities is investigated. We use a comprehensive calculational scheme incorporating (i) the effective-medium theory for the electronic interaction, (ii) the lattice Green’s function for elastic coupling, and (iii) the hydrogen quantum motion. The calculations for Ti and Cr impurities in V host show that lattice strain effects dominate. Cr, which otherwise provides an electronic trap site, does not induce trapping when elastic effects are incorporated. The situation in the case of Ti is just the reverse. We find no isotope dependence of the binding …
Molecular association and dynamics in n-pentanol and 2-methyl-2-butanol
1985
Static dielectric constant, viscosity, density, ultrasonic and dielectric relaxation measurements are reported for two pentanol isomers (n-pentanol and 2-methyl-2-butanol) in a wide range of temperatures. The results show a different extent of H-bonds self-association in relation to the molecular geometry of the alcohol. The activation energies obtained from dielectric and ultrasonic studies are compared with those obtained from viscous flow. Such a comparison, together with the analysis of all the dielectric and ultrasonic relaxation data, show that in n-pentanol a correlation between viscosity and ultrasonic relaxation exists, while dielectric relaxation is not correlated with the other t…
Insulin receptors and insulin sensitivity in normo and hyperinsulinemic obese patients
1985
The authors have studied insulin receptors on peripheral blood monocytes and insulin sensitivity, evaluated by simultaneous infusion of glucose, insulin and somatostatin in 10 control subjects and in 20 obese patients with normal glucose tolerance. The obese patients have been divided into two groups, normo (NO) and hyperinsulinemic (HO), according to the total insulin response during OGTT. We considered HO patients with insulin response higher than M + 2DS of controls. Obese patients showed, in comparison to the controls, a lower specific binding and higher degree of insulin resistance. The subdivision of obese patients allowed us to distinguish two groups. The first was characterized by b…
Generalization of a finite-difference numerical method for the steady-state and transient solutions of the nernst—planck flux equations
1985
Abstract A generalization of the numerical method of Brumleve and Buck for the solution of Nernst—Planck equations when convective flux and electric current are involved has been developed. The simulation procedure was applied to a specific case: transport of strong electrolytes in a wide-pore membrane with simultaneous diffusion, convection and electric current. Good agreement was found between experimental data and computed results.
L'aztreonam Nelle Infezioni Delle Vie Urinarie
1985
La tendance politique des grandes villes : conséquence ou cause de la répartition de la population dans les agglomérations ?
1985
Référence interne IREDU : 85030; Les élections municipales françaises de 1983 se sont traduites par un succès particulièrement marqué des partis de droite ou de centre-droit dans les grandes villes, et de façon particulièrement sensible à Paris1. A cette occasion, on a vu réapparaître dans les commentaires politiques l’idée que. en raison de la répartition de la population dans les agglomérations, les villes-centres sont plus ou moins vouées à voter "à droite". Préciser et vérifier empiriquement cette hypothèse est le premier objet de notre étude.Mais celle-ci a un deuxième objet. En admettant qu'elle ait effectivement uneincidence politique, la répartition de la population d'une agglomérat…
Circulating immune complexes in Fièvre boutonneuse.
1985
Circulating immune complexes (CIC) occurred in 36% of a group of 25 patients with Fièvre boutonneuse. CIC were present only in the first week of the disease and there was no evidence of other humoral immunological abnormalities or alterations of the coagulation factors studied. The presence of CIC was not associated with a more severe clinical manifestation or with symptoms or tissue injuries. It is considered that CIC do not play a major role in Fièvre boutonneuse.
Two types of receptors for 5-hydroxytryptamine on the cholinergic nerves of the guinea-pig myenteric plexus
1985
Abstract The effects of 5-hydroxytryptamine (5-HT) on spontaneous and electrically-evoked release of [3H]-acetylcholine (ACh) from guinea-pig myenteric plexus preparations preincubated with [3H]-choline have been investigated in the absence of cholinesterase inhibitors. 5-HT caused a transient increase in spontaneous release and an inhibition of the electrically-evoked release of [3H]-ACh. The 5-HT-induced contractions of the longitudinal muscle were clearly related to the increase in spontaneous release. The inhibitory effect was not due to activation of alpha-adrenoceptors since it was also observed in the presence of tolazoline and on strips from reserpine-pretreated guinea-pigs. After d…
Finite semiaffine linear spaces
1985
Shear induced deformation of polystyrene coils in dilute solution from small angle neutron scattering
1985
The deformation of the overall conformation of polystyrene,Mw=280000 g/ mole in dilute solution in a constant shear gradient has been investigated by small angle neutron scattering (SANS).
Infezioni Delle Vie Urinarie: Germi responsabili e chemioresistenza negli anni 1978–1983
1985
Generalized singly-implicit Runge-Kutta methods with arbitrary knots
1985
The aim of this paper is to derive Butcher's generalization of singly-implicit methods without restrictions on the knots. Our analysis yields explicit computable expressions for the similarity transformations involved which allow the efficient implementation of the first phase of the method, i.e. the solution of the nonlinear equations. Furthermore, simple formulas for the second phase of the method, i.e. computation of the approximations at the next nodal point, are established. Finally, the matrix which governs the stability of the method is studied.