false

1988

The unperturbed dimensions parameter KΘ is one of the most important characteristics of a polymer chain. For binary systems (polymer/solvent) and mostly for ternary systems (polymer/solvent(1)/solvent(2)) the KΘ values show large discrepancies with respect to those under thetaconditions in a single solvent. These discrepancies can be explained by considering that the interaction parameter χ (and consequently the coil dimensions or the number of intramolecular contacts between polymer segments) changes with molecular weight M. Assuming this dependency, a modified Stockmayer-Fixman equation is proposed from which a unique value of KΘ for a given polymer, independent of M, is obtained. The use…

On trifactorized soluble minimax groups

1988

false

1988

Transmural distribution of biochemical markers of total protein and collagen synthesis, myocardial contraction speed and capillary density in the rat…

1988

The effect of angiotensin II-induced hypertension on selected biochemical parameters was studied in Sprague-Dawley rats. Angiotensin II infusion at rates of 41.7 micrograms h-1 kg-1 and 12.5 micrograms h-1 kg-1 for 2, 5, 10 and 15 days elevated the systolic blood pressure from 143 +/- 7 mmHg to 215-230 mmHg (P less than 0.001) and 185-195 mmHg (P less than 0.001), respectively. The left ventricular weight/body weight ratio increased 10-14% (P less than 0.05) and 23-32% (P less than 0.001) after 2-15 days in rats treated at the lower and higher infusion rates, respectively. Prolyl 4-hydroxylase (PH) activity, a marker of collagen synthesis, was evenly distributed in the left ventricle. PH ac…

Tissue characterization of benign brain tumors: Use of NMR-tissue parameters

1988

Abstract To evaluate the potentials of NMR tissue parameters for tissue characterization we investigated 68 patients with benign brain tumors. Tissue parameters were accurately measured by a recently developed interlaced triple sequence. Each individual tumor was characterized by a set of three numbers (relaxation times T 1 and T 2 and proton density Rho). Different tumors exhibited significant overlaps of the three tissue parameters. Therefore a reliable prediction of the histological diagnosis based on the quantitative analysis of tissue parameters alone was not possible. T 2 -prolongation correlated well with water content and “regressive changes” in meningiomas and neuromas.

Study of the molecular origin of the mechanical and dielectric β relaxation of methyl methacrylate/isopropenyl methyl ketone copolymers

1988

Resultats de l'etude dielectrique, mecanique et par TSC en faveur d'une combinaison d'une barriere intra- et intermoleculaire dans la relaxation beta

Prinzipien für die Gestaltung des kieferorthopädischen Arbeitsplatzes

1988

Ausgehend von einer Untersuchung uber die Arbeitshaltung von Kieferorthopaden wurden systematische Uberlegungen zur Gestaltung des kieferorthopadischen Arbeitsplatzes angestellt. Dabei wurden ergonomische, hygienische und psychologische Aspekte berucksichtigt. Als Ergebnis dieser Uberlegungen wurde ein konkretes Arbeitsplatzkonzept verwirklicht.

The Einstein field equation in a multidimensional universe

1988

String theory [4] predicts that the universe has 10 or 26 dimensions. A salient problem is how the Einstein field equation should be written in terms of these revivified Kaluza-Klein cosmologies. The answer is by now well-known, yet nobody seems to have rewritten the seminal computation in [6] where an unnecessarily involved Euler-Lagrange variational method is employed and, curiously enough, no allusion to the Gauss-Bonnet-Chern theorem is made. We provide a more straightforward argument, which has been inspired by Hilbert's original derivation of the Einstein field equation [5].

Perkutan transhepatische Feinkaliber-Cholangioskopie

1988

Percutaneous transhepatic fine calibre cholangioscopy is described. A specially developed transparent instrument is used, which makes it unnecessary to have a steerable endoscope; visualisation of the biliary tree is of diagnostic value for assessing biliary stenoses due to tumours (choice of biopsy site, extent of intraductal radiation therapy) and for the assessment of anastomoses between the biliary system and the gut (condition of the mucosa, stenoses). In the presence of percutaneous biliary drainage, the method has little utility. Extension of the method for treating intraductal stones may be possible if in future a useful lumen can be added to the fine endoscope.

Experimental Testicular Torsion: Effect on Endocrine and Exocrine Function and Contralateral Testicular Histology

1988

In order to investigate whether unilateral testicular torsion exerts a negative influence on the previously undisturbed contralateral side, exocrine and endocrine testicular function were evaluated before and two months after torsion. A rat model with 6 hours', 12 hours' or permanent extravaginal 540 degrees torsion of the right testis was used; a sham operated group of animals served as controls. Ejaculates were collected by electrostimulation; LH, FSH and testosterone serum levels were determined by radioimmunoassays. Eight weeks after torsion sperm output had decreased by half in the experimental groups, and LH levels increased significantly, whereas the other hormone levels, as well as …

Beta-adrenoceptor stimulation enhances transmitter output from the rat phrenic nerve.

1988

Abstract 1. Neurally-evoked output of newly synthesized [3H]-acetylcholine from the rat phrenic nerve was measured in the absence of cholinesterase inhibitors. 2. Noradrenaline and isoprenaline enhanced neurally-evoked transmitter output markedly. Moreover, immediately after the application of noradrenaline the basal tritium efflux increased significantly. 3. Pretreatment with propranolol (0.1 mumol l-1) or atenolol (0.3 mumol l-1) completely prevented the stimulatory effect of noradrenaline and isoprenaline on evoked transmitter output. 4. The facilitatory effect of isoprenaline declined, when the exposure time was increased. This observation supports the assumption that beta-adrenoceptors…

Synthesis, antimony-121 mössbauer and infrared spectral characterization of antimony trifluoride and catecholatoantimony(III) fluoride adducts with t…

1988

Abstract The synthesis of the adducts SbF 3 (L) and (C 6 H 4 O 2 )SbF(L) [L = pyridine-2-carboxaldehyde- 2-pyridylhydrazone (paphyH); 2,2′:6′,2″-terpyridine (terpy) and 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tpta)] is reported. Infrared data are consistent with the occurred chelation from the terdentate ligand providing an overall pseudo-seven coordination at Sb. The stereoactivity of the antimony lone pair is inferred from the large value of the Mossbauer quadrupole coupling constant observed for all the compounds.

[Recurrent abdominal pain in childhood]

1988

Antibodies to cell surface ganglioside GD3 perturb inductive epithelial-mesenchymal interactions

1988

Abstract Most epithelial sheets emerge during embryogenesis by a branching and growth of the epithelium. The surrounding mesenchyme is crucial for this process. We report that branching morphogenesis and the formation of a new epithelium from the mesenchyme in the embryonic kidney can be blocked by a monoclonal antibody reacting with a surface glycolipid, disialoganglioside G D3 . In contrast, a more than 10-fold excess of antibodies to adhesive glycoproteins (N-CAM, L -CAM, fibronectin) fails to inhibit morphogenesis. Although the anti-G D3 antibody affected epithelial development, the disialoganglioside G D3 was expressed not in the epithelium, but in the mesenchyme surrounding the develo…

Aspects of the breeding ecology of Rufous Bush RobinsCercotrichas galactotesin southeast Spain

1988

The breeding ecology of Rufous Bush Robin Cercotrichas galactotes was studied over 4 years in southeast Spain. The vegetation of the study area was made up mainly of Olives, Almonds and small shrubs. The density of this species decreased from 0.36 pairs 10 ha-1 in 1980 to 0.7 pairs 10 ha-1 in 1984, a decrease similar to one observed in other parts of Spain. The breeding season lasted from late May or early June to late August. About two-thirds of the pairs laid 2 clutches. Mean clutch size was 3.6 eggs. The incubation period lasted about 13 days and nestlings left the nest after 10 days. Mortality was greater in first clutches, mainly because of predation, which did not occur in second clut…

A Theoretical Study of the Wet Removal of Atmospheric Pollutants. Part III: The Uptake, Redistribution, and Deposition of (NH4)2SO4Particles by a Con…

1988

Abstract Our model for the scavenging of aerosol particles has been coupled with the two-dimensional form of the convective cloud model of Clark and Collaborators. The combined model was then used to simulate a convective warm cloud for the meteorological situation which existed at 1100 LST 12 July 1985 over Hawaii; assuming an aerosol size distribution of maritime number concentration and of mixed composition with (NH4)2SO4 as the soluble compound. A shallow model cloud developed 26 min after the onset of convection leading to moderate rain which began after 45 min and ended after 60 min. Various parameters which characterize the dynamics and micophysics of the cloud, as well as the scaven…

Antibodies to hepatitis B core antigen in blood donors screened for alanine aminotransferase level and hepatitis non-A, non-B in recipients.

1988

Four-hundred and seventeen patients undergoing open-heart surgery were followed for more than 9 months after transfusion. All 2270 blood units transfused had alanine aminotransferase levels less than or equal to 30 U/l. Blood units positive for antibodies to hepatitis B core antigen (anti-HBc) were more frequently associated with recipient hepatitis non-A, non-B (HNANB) (13.7%) than anti-HBc-negative units (4.2%) (p less than 0.001). The frequency of HNANB among recipients of at least 1 anti-HBc-positive blood unit (8/79, 10.1%) was fivefold greater than among recipients of exclusively anti-HBc-negative blood units (7/338, 2.1%) (p less than 0.01). In this study the exclusion of donors posi…

Injection-Locked Flashlamp-Pumped Dye Lasers Of Very Narrow Linewidth

1988

Very high spectral quality flashlamp-pumped dye lasers are described, in which spectral narrowing is achieved by injection-locking of pulsed amplifying cavities to the wavelength of low power single-mode cw lasers. With the help of a fast electronic stabilization of the cavity length, we obtain a reliable complete injection. Peak powers up to 12 kW in 300 ns at a bandwith of 6 MHz are achieved over a 150 nm tuning range between 572 and 722 nm. The repetition rate is 10 Hz, limited mainly by the circulating pumps. Applications of these lasers are found in high resolution coherent Raman spectroscopy and nonlinear difference frequency mixing.

High Resolution Coherent Anti-Stokes Raman Spectroscopy (CARS) Of O 2 And CO 2

1988

With the help of high spectral quality (linewidth , 6 MHz) injection-locked flashlamp-pumped dye lasers, high resolution Coherent Anti-Stokes Raman Spectroscopy (CARS) has been applied to the study of the Q-branches of 0 2 and CO 2 . The Q-branch linewidths of 02 were obtained from the first nine transitions (J 2 = 1 to 17) recorded at pressures from 0.094 to 1 atm at room temperature. A least squares program was employed to fit calculated spectra to experimental spectra by adjusting different parameters. The collisional broadening coefficients we have obtained are consistent with available Raman data. We have also studied the Q-branch of the fundamental v1 band of CO 2 in the Fermi resonan…

The energy distribution between the photosystems and light-induced changes in the stoichiometry of system I and II reaction centers in the chlorophyl…

1988

The chlorophyll b-containing alga Mantoniella squamata was analyzed with respect to its capacity to balance the energy distribution from the light-harvesting antenna to photosystem I or photosystem II. It was shown, that this alga is unable to alter the absorption cross section of the two photosystems in terms of short-time regulations (state transitions). The energy absorbed by the LHC, which contains 60% of total photosynthetic pigments, is transferred to both photosystems without any preference. The stoichiometry of the two photosystems is found to be extremely unequal and variable during light adaptation. In high light, the molar ratio of P-680 per P-700 is found to be two, whereas unde…

Long-spined polymorphic neurons of the medial cortex of lizards: a Golgi, Timm, and electron-microscopic study.

1988

The morphology, ultrastructure, and principal synaptic input of longspined neurons located in the inner plexiform layer of the medial cortex in three related species of lizards is described. Golgi impregnations have been used to define the external morphology of these neurons and their axonal trajectories. Their most striking characteristic is the presence of very long spines or “microdendrites” especially abundant on the distal dendritic segments. Axons have ascendent trajectories, pass through the cell layer, and ramify in the outer plexiform layer. Combined Golgi-electron microscopy as well as standard electron microscopy permitted the definition of the ultrastructure of these neurons. T…

Follow-up of patients with colonic polyps containing severe atypia and invasive carcinoma. Compliance, recurrence, and survival

1988

Between January 1975 and December 1984 1769 polyps were endoscopically removed from 1219 patients. Eight percent of these patients had polyps containing severe atypia and 5.0% had polyps containing invasive cancer. A close postoperative surveillance program was followed by only a few patients, but compliance improved with longer follow-up intervals. Metachronous polyps were observed with similar frequency in patients with benign polyps (34.8%) and those with polyps containing severe atypia (23.8%) or cancer (41.7%). Patients in whom malignant polyps were endoscopically removed had a 5-year survival rate of 84.3% that did not differ from that of patients' whose polyps contained severe atypia…

Studies on protein kinases involved in regulation of nucleocytoplasmic mRNA transport

1988

The rate of energy-dependent nucleoside triphosphatase (NTPase)-mediated nucleocytoplasmic translocation of poly(A)-containing mRNA [poly(A)+mRNA] across the nuclear envelope is thought to be regulated by poly(A)-sensitive phosphorylation and dephosphorylation of nuclear-envelope protein. Studying the phosphorylation-related inhibition of the NTPase, we found that phosphorylation of one polypeptide of rat liver envelopes by endogenous NI- and NII-like protein kinase was particularly sensitive to poly(A). This polypeptide (106 kDa) was also phosphorylated by nuclear-envelope-bound Ca2+-activated and phospholipid-dependent protein kinase (protein kinase C). Activation of kinase C by tumour-pr…

Anthropological investigation of a Kurdish village population from south-eastern Turkey. II. Internal differentiation of morphological features

1988

A small scale village society from southern Turkey has been investigated by demographic, social and anthropological criteria. An internal differentiation of the population on the basis of demographic and social data could be verified for morphological features, too. This is shown clearly by a differentiation of the population into two family complexes. The consequences for the interpretation of metrical random sample surveys in typological investigations are discussed.

Anthropological investigation of a Kurdish village population from south-eastern Turkey. I. Regional comparison of morphological features

1988

The paper is dealing with an anthropological investigation of a Kurdish village population from southern Turkey. We especially attached importance on the complete registration of all inhabitants to get a reliable sample for regional comparison of morphological features. Anthropological data of other Kurdish population groups are used for univariate and multivariate analysis. The resulting clusters are discussed beside the question of representation under the standpoint of regional and cultural origin of the samples.

Optical Fibre Control-Measurement Systems Of Compound HV/HP Electrical Equipment

1988

Responsible electrical equipment should be controlled during the work in care of their high reliability. Traditional control measurement systems cannot fulfil the task because of the hard conditions in which the equipment may operate (various electrical potentials, electromagnetic interferences, changes of temperature, etc.). The development of fibre optic transmission media and fibre optic sensors allows the construction of new control measurement systems for cooperation with such electrical equipment as: converters, generators, treLnsforniens, switch bays, busbards, etc. Those optical fibre structures, composed of bu-ses and sensors are subject of this paper. The main attention is paid to…

La culture matérielle du peuple de Chartres au 18e siècle : méthodes de recherche et résultats

1988

National audience; Les inventaires après décès sont les documents de base pour l'étude de la culture matérielle populaire. A Chartres au XVIIIe siècle, une nette évolution apparaît dans le nombre des objets possédés, dans les matières qui les composent, dans les formes, dans les couleurs, etc. Elle ne s'effectue pas au même rythme selon les milieux et selon les sexes. Elle révèle un changement des mentalités devant la consommation des objets.

Macroscopic persistent currents in YBa2Cu3O7

1988

Persistent currents in polycrystalline YBa2Cu3O7 rings have been investigated by measuring the spatial distribution of the magnetic flux trapped in field-cooled samples. The results unambiguously show that macroscopic persistent ring currents exist. The critical current density depends very sensitively on the sample quality, reachingj c ≈250 A/cm2 at 77 K for our best samples.

Transmission of mechanical energy through polymeric liquid crystals and their blends

1988

Molecular composites, also called polymeric liquid crystals (PLC), are contrasted with the traditional composites; the name heterogeneous composites is proposed for the latter. Advantages of blending PLCs with ordinary engineering polymers are discussed. Results reported for blends of poly(ethylene terepthalate) (PET) with a PLC containing sequences of PET and p-hydroxybenzoic acid (PHB) include thermophysical properties, melt rheology, mechanical properties of solid blends, and scanning electron microscopy of fracture surfaces. A model called the island model was developed to explain the results: One assumes that the lines of force as well as propagating cracks tend to concentrate in the p…

false

1988

Structure et proprietes thermodynamiques de polyamides rigides portant ces groupes lateraux flexibles

Lawrencium chemistry: no evidence for oxidation states lower than 3+ in aqueous solution

1988

Lawrencium (3-min 260Lr) together with other actinides, was produced in the bombardment of a 249Bk target with 18O ions. There was no sign of a reduction of Lr3+ in dilute hydrochloric acid by V2+ or Cr2+, although in the same experiments, Md3+ was reduced to Md2+ (E°=−0.2 V). The resulting limit for the reduction potential of the Lr3+/Lr1(2)+ couple is E° < −0.44 V.

Karyological studies in Coris julis (Pisces, Labridae).

1988

In the present investigation the diploid number 2n = 48 (NF = 58) has been determined for females, primary males, and secondary males of Coris julis from the Gulf of Palermo. Differentiated sex chromosomes have not been observed in the population under study.

A sphenoorbital encephalocele — clinical, radiological, and morphological findings

1988

We report here on congenital sphenoorbital encephalocele which could not be disclosed by computed tomography including contrast medium application or by orbital sonography. Surgery and histological examination were necessary to establish correct the diagnosis.

Secretion of Protein-bound Hydroxyproline from Moss Callus Cells

1988

Abstract A glycoprotein rich in hydroxyproline was found in wall preparations of callus cells of the moss Physcomitrium pyriforme Brid. It is apparently attached to the non-cellulosic polysaccharides of the wall, and the majority is extractable by boiling the wall fraction or by using a chaotropic salt at room temperature. A pulse-chase technique was used to study the transport of this protein to the wall. Cytochalasin B seems to inhibit its secretion from the callus cells. Some of this wall-associated protein is probably secreted from the cells into the medium. Electron microscopic evidence shows vesicular activity in the cytoplasm and secretion and incorporation into the wall layers (not …

D-Galactose binding lectins from the tunicate Ascidiamalaca: Subunit characterization and hemocyte surface distribution

1988

Abstract D-galactose specific lectins purified from Ascidia malaca serum contain a major protein component with an apparent molecular weight of about 58,000 daltons, which moves more rapidly under non-reducing conditions. Intramolecular disulfide linkages can explain this behaviour, suggesting a compact protein structure. Membrane lectins have been demonstrated on the surface of about 34% hemocytes by immunofluorescent methods using a rabbit antiserum against the isolated serum lectins. Small, medium and large hemocytes can be positive, as also shown by binding on Sepharose spherules or by rosette formation with sheep and rabbit erythrocytes. Binding is inhibited by the same sugars specific…

Minimum-cost distances in spatial analysis

1988

An axiomatic approach to distance is developed which focuses on thosebehavioral concepts of distance related to movement in space. In particular,spatial movement by behaving units is postulated to involve a choice fromamong some set of abstract trips in space, and implicitly, to involve theminimization of some relevant notion of trip costs. In this context, therelevant behavioral notion of distance in space is taken to be theminimum-cost distance generated by this choice process. These trip-costconcepts extend the classical notions of paths, path lengths, and shortestpaths in metric spaces. Hence many of the analytical results of the paperinvolve extensions of classical shortest-path distan…