Effect of Gibberellin on Mature Euonymus europaeus L. Seeds

1992

The release from dormancy of Euonymus europaeus L. embryos by a brief treatment with GA 3 has been studied. During 48 h incubation of dormant embryos in GA-free medium, phospholipid levels increased at first, then declined sharply over the last 6 h. When the embryos were placed in GA, medium during this 6 h period levels of total phospholipids as well as of phosphatidylethanolamine increased whilst phosphatidylinositol and phosphatidylcholine declined slightly

Dihydrogen complexes of metalloporphyrins: characterization and catalytic hydrogen oxidation activity

1992

A series of monometallic dihydrogen complexes of the type M(OEP)(L)(H{sub 2}) (M = Ru, Os; L = THF, *Im) was synthesized and characterized by {sup 1}H NMR. The H-H bond length was found to increase when Os was replaced by Ru or when *Im was replaced by THF. The bond distances (as determined by T{sub 1}) range from 0.92 to 1.18 {angstrom}. The first example of a bimetallic bridging dihydrogen complex, Ru{sub 2}(DPB)(*IM){sub 2}(H{sub 2}), was also prepared. The H{sub 2} ligand is simultaneously bound to both Ru-metal centers. High-field {sup 1}H NMR experiments (620 MHz) revealed a -7.37 Hz dipolar splitting of the H{sub 2} ligand for this complex. Analysis of this splitting suggests that th…

The role of association/complexation equilibria in the anionic polymerization of (meth)acrylates

1992

The kinetics of the anionic polymerization of methacrylates and acrylates in THF as well as the MWD of the polymers formed depend on the concentration of active centres and of additives, such as lithium halides and lithium alkoxides. These results are discussed on basis of multiple equilibria between non-associated, associated, and complexed ion pairs which are supported by viscosity measurements. The position of these equilibria determines the rate of polymerization, whereas the dynamics of interconversion determine the polydispersity. In the absence of additives the rate of monomer addition to non-associated ion pairs competes with the rate of association. Addition of lithium chloride mai…

Resolution of the photon scanning tunneling microscope: influence of physical parameters

1992

Abstract The photon scanning tunneling microscope (PSTM) is the photon analogue of the electron scanning tunneling microscope (ESTM). It uses the evanescent field due to total internal reflection (TIR) of a light beam in a prism modulated by a sample placed on the base of the prism. Our experimental results shown details which present a lateral size as small as 200 A. The PSTM axial resolution is more difficult to evaluate. It is a function of the roughness of the sample. For very smooth samples, images shown an axial resolution of about 10 A. At last we discuss how both lateral and axial resolution can be affected by several parameters such as the tip surface distance and the roughness of …

Laser Doppler flux and tissue oxygenation of experimental tumours upon local hyperthermia and/or hyperglycaemia

1992

Laser Doppler fluxmetry and oxygen partial pressure (pO2) histography have been applied to investigate the acute effects of hyperthermia (HT) and/or hyperglycaemia (HG) on microcirculatory function and tissue oxygenation of subcutaneous rat tumours growing on the dorsum of the hind foot. The experiments were performed to test whether, and to what extent, the two adjunct treatment modalities applied alone or in combination can modify these therapeutically relevant parameters. Local HT was performed in a saline bath (44 degrees C) for 2 h; HG was induced by i.v. infusion of 40% glucose solution for 2.5 h (blood glucose levels: 35-40 mM during heating). Laser Doppler flux (LDF) in superficial …

Occlusion of the pig superior sagittal sinus, bridging and cortical veins: multistep evolution of sinus-vein thrombosis

1992

✓ Cerebral sinus-vein thrombosis may lead to severe hemodynamic changes, elevated intracranial pressure (ICP), and brain edema. It is supposed that progression of the thrombus from the sinus into bridging and cortical veins plays a key role in the development of these pathophysiological changes, but this hypothesis lacks experimental proof. The aim of this study, using a novel animal model of sinus-vein thrombosis, was to evaluate the effects of a standardized occlusion of the superior sagittal sinus and its bridging and cortical veins on hemodynamic alterations, on brain water content, and on ICP in domestic pigs. In 10 animals, the middle third of the superior sagittal sinus was occluded …

Effects of the axial isoscalar neutral current for solar neutrino detection

1992

Abstract An essential assumption in the analysis of all the large solar neutrino experiments sensitive to neutral currents has been that the axial transitions are purely isovector. The recent results on the spin structure of the proton suggest the presence of an axial isoscalar neutral-current interaction. This would modify the assumed transition strengths for the neutral-current detection of solar neutrinos. We demonstrate that in the long wavelength limit a deuterium target is insensitive to such a mechanism. Our results for the situation of the planned BOREX experiment show that the suggested isoscalar strength would increase the observed rate by 30–40%, depending on the transition.

Electrophysiologic and inotropic effects of alpha-adrenoceptor stimulation in human isolated atrial heart muscle.

1992

The effects of α-adrenoceptor stimulation on force of contraction were investigated in human atrial heart muscle and compared with those of β-adrenoceptor stimulation. The maximal positive inotropic effect produced by stimulation of α-adrenoceptors with phenylephrine (in the presence of atenolol 10 μmol/l) was significantly smaller than that seen in response to β-adrenoceptor stimulation with isoprenaline. The maximal effect of phenylephrine (25% of the maximal effect of isoprenaline) required far higher concentrations (1 mmol/l) than isoprenaline (100 nmol/l); the EC50 values amounted to 33.1 μmol/l and 3.3 nmol/l, respectively. In the presence of the α-adrenoceptor blocking agent phentola…

Dynamics of multilayer adsorption: a Monte Carlo simulation

1992

Abstract The growth of an adsorbed film at an initially empty surface which is exposed at time t = 0 to a gas is studied within the framework of a kinetic lattice gas model by Monte Carlo simulation. The model includes an attractive potential V ( z ) between adsorbed particles at distance z from the surface, V(z) = −A z 3 and a nearest-neighbor attractive interaction between the gas atoms. Several choices of the surface potential depth A , corresponding to different sequence of layering transitions, are considered. The Monte Carlo process assumes random evaporation/condensation events of gas atoms in adsorbed layers close to the surface, while surface diffusion is disregarded. For temperatu…

Acute toxicity and oxygen consumption in the gills of Procambarus clarkii in relation to chlorpyrifos exposure.

1992

Solvability of nonlinear equations in spectral gaps of the linearization

1992

Keywords: strongle indefinite ; nonlinear Hill's equation Reference ANA-ARTICLE-1992-002doi:10.1016/0362-546X(92)90116-VView record in Web of Science Record created on 2008-12-10, modified on 2016-08-08

Prognostisch relevante Faktoren bei der intraabdominalen infektion

1992

From 1.1.1982-30.9.1989 280 patients were treated for intraabdominal infection at the clinic for general and abdominal surgery. With regard to their prognostic significance, the extent and localization of the peritonitis, abscess formation, the number of failed organ system, patients' age, total protein, thrombocytes and leucocytes were examined in these patients. The most unfavorable prognosis showed diffuse peritonitis with a mortality rate of 47.2%. Subsequent abscessing worsened the prognosis of the illness. There was a close correlation between the number of failed organ systems at the time of hospitalization and mortality. Low total protein content or more so a necessary substitution …

Book Review: An Introduction to Ultrathin Organic Films from Langmuir-Blodgett to Self-Assembly. By A. Ulman

1992

In-vitro-Studie der Interferenz von kieferorthopädischer Bebänderung und Füllungswerkstoffen

1992

Discoloring and layers on bands and restorations during fixed orthodontic therapy are well known clinical phenomenon. Because of the complexity of etiological factors an in-vitro model was used in this study. Aim of the study was to examine the amounts and sort of metals which are dissolved. Therefore, respectively 25 normed MOD-cavities in Frasaco-teeth were filled with a non-gamma-2-amalgam (Amalcap plus, Vivadent) and condensed manually or mechanically. In addition, ten crowns of a high golden (Maingold SG, Heraeus) as well as a palladium basis alloy (Albabond A, Heraeus) were casted. Then they were banded with stainless steel bands (Dentaurum) and cemented with a glass ionomer cement (K…

Pseudomastus deltaicus , gen. et sp.n. (Polychaeta: Capitellidae) from a shallow- water bay in the North- Western Mediterranean Sea

1992

4 Páginas ; 2 Figuras

Analysis of Polychlorinated Biphenyls in Aqueous Samples Using C18 Glass Column Extraction

1992

Abstract A method for polychlorinated biphenyl (PCB) trace extraction from contaminated water at the part-pertrillion levels is described. This procedure involves quantitative adsorption of PCBs on Cis glass microcolumns. PCBs are retained on the surface and subsequently eluted with n-hexane (5 mL) before gas chromatography. Recovery of water fortified with PCBs was 83.6-108.5%. Compared to liquid-liquid extraction methods, the Cis glass microcolumns give comparable results, lessen solvent costs, and are less time-consuming.

Caryophyllene derivatives from Pulicaria dysenterica

1992

Abstract A reinvestigation of the aerial parts of Pulicaria dysenterica has allowed the isolation of six new caryophyllene derivatives and 12 known ones. 13 C NMR data of all these derivatives are reported.

Ureteropelvic junction obstruction in childhood.

1992

Biostatistical basis of individualization and segregation analysis using the multilocus DNA probe MZ 1.3: results of a collaborative study.

1992

A collaborative study using the multilocus minisatellite DNA probe MZ 1.3 was carried out to investigate segregation information, mutation rate, DNA fragment frequencies as well as band sharing characteristics. The fingerprint patterns of 393 children as well as 694 unrelated individuals were analysed after digestion of DNA with the restriction enzyme HinfI. A mutation rate of 1% per meiosis or 0.04% per band was found with a mean number of 26 bands/individual. It was shown that maternal and paternal fragments are inherited in equal proportions. Population frequencies of restriction fragments demonstrated a distribution with increasing frequencies in the small fragment size range below 10 k…

Current‐voltage curves of bipolar membranes

1992

Bipolar membranes consist of a layered ion‐exchange structure composed of a cation selective membrane joined to an anion selective membrane. They are analogous to semiconductor p‐n devices as both of them present current‐voltage curves exhibiting similar rectification properties. In this article, we present some current‐voltage curves obtained for different bipolar membranes at several temperatures. The results can be interpreted in terms of a simple model for ion transport and field‐enhanced water dissociation previously developed. The mechanism responsible for water splitting is assumed to be a catalytic proton transfer reaction between the charged groups and the water at the membrane int…

Dissipation of vibronic energy in a dimer

1992

Abstract The density matrix theory is used for the study of the dissipative quantum dynamics of electron transfer in a dimer. The vibrational modes of the dimer are divided into a single interaction coordinate coupling to the transfered electron and the remaining modes which form a dissipative environment. To correlate the dissipative dynamics with the exact eigenlevels computed for the model system without dissipative environment we analyse the time dependence of the expectation value of the number of vibrational quanta. We analyse the renormalisation of the eigenvalues due to the damping and the relaxation of an excitation into these states.

Phenolics of Reichardia and their taxonomic implications

1992

Abstract Fifteen compounds have been detected in Reichardia tingitana and R. picroides (nine flavonoids, four cinnamic derivatives and two unidentified non-phenolic compounds). The present study examines the taxonomic implications of these compounds in relation to the morphological and karyological characteristics.

Clinical verification of a unilateral otolith test.

1992

Abstract In a previous study13 we reported promising results for a new test to differentiate in vivo unilateral otolith functions. That study pointed to a need for further validation on known pathological cases. In this presentation we will detail the results gathered on a group of clinically verified vestibular defectives (verum) and a normal (control) group. The subjects in the verum group were former patients of the ENT clinic of the university hospital. These subjects had usually suffered from neurinoma of the VIIth cranial nerve or inner ear infections. All had required surgical intervention including removal of the vestibular system. The patients were contacted usually two or more yea…

Epiphysäre Dysplasie des Hüftgelenks, Diagnostik und Differentialdiagnostik mit der MRT

1992

Sixteen hip joints of eight patients with multiple epiphyseal dysplasia were examined by clinical investigation, plain films and by magnetic resonance imaging (MRI), using T1- and T2-weighted images and gradient echoes. MRI is useful in demonstrating the congruity of the joint, in the changes of the epiphyseal signal intensities and the epiphyseal line. Individual changes of the signal intensity patterns on T1- and T2-weighted scans are described. Although MRI exhibits a variety of patterns in different patients, a clearcut differentiation from Legg-Calve-Perthes' disease is possible.

On the role of procrastination for machine learning

1992

Kritische Bewertung unkonventioneller diagnostischer und therapeutischer Methoden in der Zahnheilkunde

1992

Unkonventionelle medizinische Methoden werden vielen Kranken angeboten, obwohl deren Wirksamkeit nicht belegt bzw. in kontrollieren Studien bestatigt werden konnte. Bei nicht nachweisbarer Effektivitat sind aber weder Risiken bei der Anwendung noch die Behandlungskosten solcher Methoden gerechtfertigt. Im Zuge einer Vereinheitlichung der Gesundheitsgesetzgebung innerhalb der EG ist zu erwarten, das Methoden der “alternativen” Medizin, die in andern EG Landern kritischer als in der Bundesrepublik bewertet werden, nur bei entsprechender Effektivitat als Mittel der Diagnostik und Therapie anerkannt werden. Der vorliegende Beitrag setzt sich kritisch mit lolgenden Methoden auseinander: Regulati…

Effects of insulin-like growth factor I on the rates of glucose transport and utilization in rat skeletal muscle in vitro.

1992

1. The effects of insulin-like growth factor I (IGF-I) on the rates of glucose transport and utilization and its interaction with insulin were investigated in rat soleus muscle in vitro. IGF-I increased the rates of glucose transport, lactate formation, glycogen synthesis and the flux of glucose to hexose monophosphate, but it had no effect on the rate of glucose oxidation or glycogenolysis. 2. In the absence of insulin, low levels of IGF-I (0-30 ng/ml) increased the rate of glycolysis and the content of fructose 2,6-bisphosphate, but the content of glucose 6-phosphate remained unaltered; at higher levels of IGF-I (300-3000 ng/ml) the rate of glycolysis and the content of fructose 2,6-bisph…

Multifractal electronic wave functions in disordered systems

1992

Abstract To investigate the electronic states in disordered samples we diagonalize very large secular matrices corresponding to the Anderson Hamiltonian. The resulting probability density of single electronic eigenstates in 1-, 2-, and 3-dimensional samples is analysed by means of a box-counting procedure. By linear regression we obtain the Lipschitz-Holder exponents and the corresponding singularity spectrum, typical for a multifractal set in each case. By means of a Legendre transformation the mass exponents and the generalized dimensions are derived. Consequences for spectroscopic intensities and transport properties are discussed.

The combined operative and radiotherapeutic treatment (CORT) of recurrent tumors infiltrating the pelvic wall: First experience with 18 patients

1992

CORT is a new radiosurgical treatment concept for patients with recurrent gynecologic malignancies infiltrating the pelvic wall. The operative part consists of (i) staging laparotomy; (ii) maximum debulking of the tumor from the pelvic wall and exenteration of infiltrated central pelvic organs; (iii) implantation of brachytherapy guiding tubes on the residual tumor/tumor bed at the pelvic wall; (iv) pelvic wall plasty with muscle and omentum flaps to create a protective distance between the tubes and the pelvic hollow organs and to induce therapeutic angiogenesis; and (v) surgical reconstruction of bowel, bladder, and vulvoperineovaginal functions. Radiation is given postoperatively as frac…

On natural convection in a single and two zone rectangular enclosure

1992

Abstract Convective heat transfer was investigated numerically for rectangular enclosures both undivided and divided in two zones by a vertical partition, and having opposite isothermal walls at different temperatures. The aspect ratio was varied from 0.1 to 16 and the Rayleigh number from 3.5 ∗ 10 3 to ∗ 10 7 (non-partitioned enclosures) and from 1.0 ∗ 10 5 to 1.6 ∗ 10 8 (partitioned enclosures). The thickness and conductivity of the partition were varied. The end wall thermal boundary conditions were adiabatic or LTP (Linear Temperature Profile). The continuity, momentum and energy equations for a 2-D laminar steady flow were solved under the Boussinesq approximation by using a finite-dif…

Gas phase chromatography of halides of elements 104 and 105

1992

On-line isothermal gas phase chromatography was used to study halides of261104 (T1/2=65 s) and262,263105 (T1/2=34 s and 27 s) produced an atom-at-a time via the reactions248Cm(18O, 5n) and249Bk(18O, 5n, 4n), respectively. Using HBr and HCl gas as halogenating agents, we were able to produce volatile bromides and chlorides of the above mentioned elements and study their behavior compared to their lighter homologs in Groups 4 or 5 of the periodic table. Element 104 formed more volatile bromide than its homolog Hf. In contrast, element 105 bromides were found to be less volatile than the bromides of the group 5 elements Nb and Ta. Both 104 and Hf chlorides were observed to be more volatile tha…

A semi-empirical approach for the simulation of circular dichroism spectra of gramicidin A in a model membrane

1992

In an extension of our previous work (Bañó, M. C., Braco, L., and Abad, C. 1991. Biochemistry. 30:886-94), the kinetics of dissociation of gramicidin A double-stranded dimers into beta 6.3-helical monomers in small unilamellar vesicles prepared following different protocols, were investigated using in combination circular dichroism (CD) and high-performance liquid chromatography (HPLC). The analysis of the data from both techniques according to a two-component model strongly supports that any given CD pattern of gramicidin incorporated in the phospholipid bilayer can be deconvoluted essentially as a linear combination of the reference subspectra calculated for the double-stranded dimer and …

Flow cytometric assay for estimating fungicidal activity of Amphotericin B in human serum

1992

We describe a simple and rapid bioassay for estimating fungicidal activity of Amphotericin B in human serum using flow cytometry. The method exploits the fact that Candida albicans damaged by Amphotericin B show a decrease in size and take up propidium iodide to exhibit a red fluorescence after deoxycholate treatment. These phenomena display characteristic dose dependencies, and their assessment permits serum fungicidal activity to be broadly grouped into three categories: (1) subfungicidal; (2) fungicidal; and (3) strongly fungicidal. In normal human serum, these three categories correspond to Amphotericin B concentrations of 0 less than or equal to 0.5 micrograms/ml, 0.75-1.5 micrograms/m…

A sesquiterpene ester from Lactuca serriola

1992

Abstract The aerial parts of Lactuca serriola yielded a new guaiane ester together with five known guaianolides.

Non-linear optical spectra of excitons in polydiacetylene

1992

Abstract Adding long-range Coulomb interactions to the Su-Schrieffer-Heeger model makes it possible to investigate excitonic states in conjugated polymers. Various characteristic features due to these states as well as due to the electron-hole continuum can be found in the calculated non-linear optical susceptibilities. In particular the electroabsorption spectrum and the third harmonic generation intensity and its dependence on the system size are examined. Using only moderate interaction strength, various experiments in polydiacetylene can be interpreted in a consistent way.

Mitochondrial and chromosomal DNA alterations in human chromophobe renal cell carcinomas

1992

Renal cell tumours are characterized by the loss of chromosome 3p and trisomy of 5q segments (common, non-papillary renal cell carcinoma), or by trisomy of chromosomes 7 and 17 and loss of the Y chromosome (papillary renal cell carcinoma), or by random karyotype changes and mitochondrial DNA alterations (renal oncocytoma). We have studied by means of RFLP analysis the genomic and mitochondrial DNA in 11 chromophobe renal cell carcinomas, which have a unique morphology among kidney cancers. We found a loss of the constitutional heterozygosity at chromosomal regions 3p, 5q, 17p, and 17q, a combination of allelic losses that has not been found in other types of renal cell tumours. Three of the…