Micromechanical Approach of the High Temperature Oxidation of Zirconium

1996

Effects of various hygiene procedures on the surface characteristics of titanium abutments.

1996

The use of cleaning instruments on titanium implants may cause undesired surface alterations. In a qualitative and quantitative assessment of these alterations, 5 titanium implant abutments were treated with a steel curet, a prototype pure titanium curet, an air abrasive polishing system, and an ultrasonic system. Custom-made polymer templates, used to secure the curet to a vertical guide bar and a spring scale to maintain a constant instrument pressure, guaranteed a standardized procedure and reproducible results. The ultrasonic and the air abrasive polishing method were also standardized. Evaluation by scanning electron microscopy (SEM) revealed surface alterations for all instruments and…

ANALGESIC EFFECT OF EXTRACORPOREAL SHOCK-WAVE THERAPY ON CHRONIC TENNIS ELBOW

1996

We report a controlled, prospective study to investigate the effect of treatment by low-energy extracorporeal shock waves on pain in tennis elbow. We assigned at random 100 patients who had had symptoms for more than 12 months to two groups to receive low-energy shock-wave therapy. Group I received a total of 3000 impulses of 0.08 mJ/mm2 and group II, the control group, 30 impulses. The patients were reviewed after 3, 6 and 24 weeks. There was significant alleviation of pain and improvement of function after treatment in group I in which there was a good or excellent outcome in 48% and an acceptable result in 42% at the final review, compared with 6% and 24%, respectively, in group II.

Nuevas obras de Antonio Mohedano y Francisco Varela

1996

Not availableNo disponible

Primary DNA damage in peripheral mononuclear blood cells of workers exposed to bitumen-based products.

1996

The genotoxic effect of occupational exposure to bitumen-based products was determined by the extent of DNA strand breaks and alkali-labile sites of the DNA of peripheral mononuclear blood cells from seven roofers, 18 road paving workers, and nine bitumen painters. In order to evaluate short-term genotoxic effect the workers were investigated on Fridays and on Mondays after a weekend free of occupational exposure. The roofers (all cigarette smokers) showed a significantly (P < 0.002) 43% higher mean level of alkaline DNA strand breaks on Friday than did the ten smoking controls included in this study. Also, comparison of the individual levels of alkaline strand breaks on Mondays and on Frid…

Majority and minority influence, task representation and inductive reasoning

1996

One hundred and fifty-five participants had to solve a set of 2–4–6 like reasoning problems (Wason, 1960), in which they were told which hypothesis a majority (or a minority) proposed, as well as which example was used for the test. In a 2 × 2 design, participants were also told that the problems allowed either one single correct answer or several possible answers. Results show that, when the source is a majority and the problem allows one single answer, most participants adopt the source's hypothesis and use confirmatory testing. On the contrary, it is when the source is a minority and the problem allows several answers that most participants give alternative hypotheses and use disconfirma…

Incidence and case-fatality rates of stroke in Burgundy (France). Comparison between a rural (Avallon) and an urban (Dijon) population, between 1989 …

1996

The decline of mortality from stroke observed in some countries may result from a fall in incidence or a decrease in case-fatality rates from stroke. The present study was conducted to evaluate the role of geographical parameters, comparing an urban and a rural population in Burgundy, France to look for differences in risk factor distribution. The study was a prospective, and complete case-ascertainment in a population-based survey. It was conducted on a well-defined population-based survey in a rural town (Avallon 8900 subjects) and an urban town (Dijon 140,000 subjects) in the area of Burgundy (France), from 1989 through 1993. All first-ever stroke events occurring in these two population…

Face-selective adhesion of calcium oxalate dihydrate crystals to renal epithelial cells

1996

The interaction between the most common urinary crystal, calcium oxalate dihydrate (COD) and the surface of monkey renal epithelial cells of the BSC-1 line was investigated. The [100] face of exogenous COD crystals bound selectively and rapidly to the kidney cell surface. Cellular processes extended preferentially over the [100] face initially, and then progressively covered the crystal so that by 24 hours some crystals were observed beneath the plasma membrane. When nucleated from solution onto the surface of the cell monolayer, COD crystals oriented preferentially so that their [100] faces were in direct contact with the cell surface. In contrast, when siliconized glass was used as a subs…

[Bis(phosphonio)isophosphindolide]silver complexes

1996

The outcome of reactions of bis(phosphonio)isophosphindolide salts 1[X] and 6[X] (X- Cl-, Br-, CF3SO3-) with silver salts AgY (Y- = CF3SO3-, CF3CO2-, CH3CO2-, 1/2 SO4-) depends strongly on the available anions X, Y. If X-, Y- CF3SO3-, both mononuclear and dinuclear silver complexes are formed which exhibit either μ1,μ1(P) or μ2,η1(P) coordination of the cations 1, 6 to one or to both metals. In solution, dynamic equilibria between both types of products and free 1, 6 were detected by 31P-NMR spectroscopy. Mononuclear (4a, 7) and dinuclear (5a, 8) complexes were isolated as solvates with CHCl3 or THF. If X-, Y- = CF3CO2, only equilibrium mixtures between the free ligands and silver complexes…

A high angular-resolution and time-of-flight detector system for recoil protons from the reactions p(γ, γ)p and p(γ, π0)p

1996

Using the Mainz NaI(Tl)BaF2 photon spectrometer CATS (Compton And Two photon Spectrometer) together with the prototype of a universal spectrometer for recoil protons TRAJAN (TRAjectory ANalyser) we have studied different methods to disentangle Compton scattering by the proton from the large π0 background through the energy range of the Δ resonance. CATS is a modular 48 cm ⊘ × 64 cm NaI(Tl) detector with an energy resolution of 1.5% combined with a 2π array of 61 BaF2 detectors. TRAJAN consists of a hodoscope with two planes, a wire chamber with horizontal and vertical wires and a grid of horizontal and vertical plastic scintillator strips, followed by a wall of nine NaI(Tl) detectors. By t…

Polymer solutions confined in slit-like pores with attractive walls: An off-lattice Monte Carlo study of static properties and chain dynamics

1996

Using a bead spring model of flexible polymer chains, the density profiles and chain configurational properties of polymer solutions confined between parallel plates were studied. A wide range of density ϕ, chain length N, and strength e of a short-range attractive wall potential was investigated. Both a temperature T in the good solvent regime (T > θ, θ being the Theta temperature where a chain in unconfined bulk three-dimensional solution would behave ideally) and a temperature in the bad solvent regime (T θ) show a crossover from two-dimensional excluded volume behavior (Rg ∝ N2ν with ν = 3/4) to ideal random walk behavior (ν = 1/2), the relaxation times show effective exponents Zeff (τ …

Pressure broadening, shift, and interference effect for a multiplet line in the rovibrational anisotropic stimulated raman spectrum of molecular oxyg…

1996

0022-2852; High-resolution stimulated inverse Raman spectroscopy has been applied to the study of collisional broadening, shifting, and line mixing for the O-o(J, N = 5) triplet line of the fundamental vibrational band of molecular oxygen. Accurate line broadening coefficients for the individual J components within the triplet have been measured for the first time and show a significant J dependence. The line broadening coefficients are larger than those previously obtained for unresolved pure rotational Raman lines. The additional broadening is expected to result from electronic spin relaxation. The pressure-induced line shift has been obtained for this Line and compared to the value obtai…

Characterization of Streptomyces venezuelae ATCC 10595 rRNA gene clusters and cloning of rrnA

1996

Streptomyces venezuelae ATCC 10595 harbors seven rRNA gene clusters which can be distinguished by BglII digestion. The three rRNA genes present in each set are closely linked with the general structure 16S-23S-5S. We cloned rrnA and sequenced the 16S-23S spacer region and the region downstream of the 5S rRNA gene. No tRNA gene was found in these regions.

Improved measurement of theB 0 andB + meson lifetimes

1996

The lifetimes of the B 0 and B + mesons have been measured with the Aleph detector at LEP, using approximately 3 million hadronic Z decays collected in the period 1991 1994. In the first of three methods, semileptonic decays of B 0 and B + mesons were partially reconstructed by identifying events containing a lepton with an associated D*- orbar D^0 meson. The second method used fully reconstructed B 0 and B + mesons. The third method, used to measure the B 0 lifetime, employed a partial reconstruction technique to identify B 0→ D*- π + X decays. The combined results are begin{gathered} tau _0 = 1.55 ± 0.06 ± 0.03 ps, \ tau _ + = 1.58 ± 0.09 ± 0.03 ps, \ tfrac{{tau _ + }}{{tau _0 }} = 1.03 ±…

Organische und kalkige Dinoflagellaten-Zysten aus den Böhlen-Schichten (Rupelium/Oligozän) der Leipziger Bucht (NW-Sachsen/Deutschland)

1996

Rupelian organic-walled and calcareous dinoflagellate cysts from two profiles (brown coal open cast minings Cospuden and Zwenkau) in the Bohlen-Schichten of the Leipzig Bay (E-Germany) are discussed. The sediments of these profiles were deposited in literal to sublitoral areas. The dinoflagellate cysts of Cospuden characterize a nearshore environment, while the associations of Zwenkau are more typical for offshore conditions.

Treatment of pituitary resistance to thyroid hormone (PRTH) in an 8-year-old boy.

1996

We report on an 8-year-old boy with pituitary resistance to thyroid hormone (PRTH) having a cysteine for arginine substitution at codon 320 in the TR-beta gene who was presented because of thyrotoxicosis. Due to its suppressive effect on the pituitary thyrotropin secretion, treatment with D-thyroxine (D-T4) was started. After a few days, clinical euthyroidism was achieved but thyroid stimulating hormone secretion was not suppressed. Symptoms of thyrotoxicosis relapsed when therapy was interrupted so that therapy with D-T4 was reinstituted and continued to date. Symptoms did not recur, and the psychomotor development proceeded normally. D-T4 should therefore be considered in the treatment of…

Bi2Sr2Ca2Cu3O10+δ based Josephson junctions and SQUIDs

1996

Josephson junctions and SQUIDs on SrTiO3 bicrystal substrates were prepared from epitaxial Bi2Sr2Ca2Cu3O10+δ thin films with critical temperatures around 95K. The current-voltage characteristics are well described by the resistively and capacitively shunted junction model.I c R n products of 50μV at 77K and 0.7m V at 4.2K have been reached. TheI c (B) dependence is symmetric toB=0 with anI c suppression of 90% in the first minimum. Nevertheless it turns out, that the junctions are inhomogeneous on a μm scale. The flux-voltage transfer function of a SQUID reached 2.7μV/Ф0 at 78K.

The collagen-like component of the complement system, C1q, is recognized by 7 S autoantibodies and is functionally impaired in synovial fluids of pat…

1996

Cross-reactivity between type II collagen (CII) and C1q, the collagen-like subunit of the first component of complement, has been demonstrated in synovial fluid (SF) from rheumatoid arthritis (RA) patients. Many authors have studied autoimmunity to CII in RA, but little work has been done on autoimmunity to C1q in RA. In the data presented here, we have been able to show that in addition to native C1q, an altered form of C1q is present in SF from RA patients. Furthermore, a low molecular weight form of C1q is present in RA SF, although its role, if any, in the pathogenesis of RA is unclear. The presence in these RA SF of C1q-specific antibodies (IgG and IgM) has been studied and we have par…

Urinary leukotriene E4 in the assessment of nocturnal asthma

1996

Urinary leukotriene E4 (LTE4) is a marker of the body's production of cysteinyl LTs, important mediators of airway inflammation. The role of the latter in nocturnal asthma is a topic of increasing interest.This investigation was aimed at determining whether nighttime attacks are associated with increased release of LTs, expressed by urinary LTE4, and the relationship between the two phenomena.Three groups were studied: group A, seven control subjects; group B, nine asthmatic patients without nocturnal attacks; and group C, nine asthmatic patients with a comparable daytime FEV1 but who were experiencing nocturnal exacerbations (morning dips in peak expiratory flow greater than 20%). Urine wa…

Effect of sulfur dioxide on cytokine production of human alveolar macrophages in vitro.

1996

Tumor necrosis factor-alpha, interleukin-1beta, interleukin-6, and transforming growth factor-beta are cytokines synthesized by alveolar macrophages. We investigated the effect of sulfur dioxide, a major air pollutant, on the production of these cytokines by alveolar macrophages. The cells were layered on a polycarbonate membrane and exposed for 30 min to 0.0, 1.0, 2.5, and 5.0 ppm sulfur dioxide at 37 degrees C and 100% air humidity. The cells were incubated for 24 h after exposure, thus allowing cytokine release. Cytotoxic effects of sulfur dioxide were evaluated by trypan blue exclusion. Cytokines were measured with enzyme-linked immunosorbent assays (i.e., tumor necrosis factor-alpha, i…

Instability of plasmid-encoded citrate permease in Leuconostoc

1996

M. KIHAL, H. PREVOST, M.E. LHOTTE, D.Q. HUANG AND C. DIVIES. 1996. The conversion from citrate positive (Cit+) to citrate negative (Cit-) phenotype of six strains of Leuconostoc mesetiteroides was followed during growth in milk and buffered or unbuffered MRS medium at 30 or 37°C. High rate of loss of Cit+ phenotype was observed. The Cit- phenotype was found to be linked to the loss of 22 to 23 kb plasmids. All Cit- mutants isolated from Leuc. mesenteroides subsp. cremoris 195 reverted spontaneously to the Cit+ phenotype. Hybridization experiments using a 0.8 kb fragment of the citP gene of Leuc. mesenteroides showed that all the plasmids which were lost in Cit- mutants encoded for a citrate…

Quality of School Life in the Finnish Comprehensive School: a comparative view

1996

Abstract The article attempts to answer the questions of how Finnish students experience the quality of school life as a whole and how students’ well‐being and social interaction in the Finnish comprehensive school compare with some other countries on the basis of extensive international comparative data. First, the concept ‘quality of school life’ and the self‐assessment instrument are described. Second, the validity of the instrument is explored. Next, the results of the assessment are first discussed from the national and then from the international perspective, comparing the data collected as a sub‐survey of the IEA Study of Reading Literacy in March 1991. The Finnish school is contrast…

Pheromonal emission during the mating behavior ofEurycotis floridana (Walker) (Dictyoptera: Blattidae)

1996

The sexual behavior of males and females ofEurycotis floridana was investigated and the various associated behavioral sequences are described. Olfactometer data proved that the male produces a volatile sex pheromone attractive at a distance to conspecific females. The male initiates courtship behavior by exposing the glandular areas on the anterior parts of abdominal tergites 2, 7, and 8. This male calling behavior was observed throughout the day. The males can mate when 8 days old, whereas virgin females are sexually receptive 18 days after becoming adults. Once attracted near the male, the female opens her genital atrium and climbs on the back of the male, where she feeds on the glandular…

Rapid DNA elution procedure from agarose gels.

1996

Sero-epidemiological analysis of the risk of virus infections for childhood leukaemia.

1996

Virus infections have been thought to be involved in the development of childhood leukaemia. In order to address this issue we determined, in a case-control study, the prevalence of antibodies to viruses infecting blood or bone-marrow cells [Epstein-Barr virsus (EBV), human herpes virus type 6 (HHV-6), parvovirus B19] as well as to the human virus known for its tumour-suppressive properties, the adeno-associated virus type 2 (AAV-2), in the sera of 121 children with leukaemia in Germany, and in 197 control individuals, hospitalized for other reasons, and matched for age and gender to the cases. In addition, we developed a questionnaire to be answered by the children's parents, in order to g…

Occupation, education, and Parkinson's disease: A case-control study in an Italian population

1996

Current epidemiologic data on the association between occupational exposures and Parkinson's disease (PD) are inconsistent. In a case-control study, we investigated the associations between occupation and PD and between education and PD. The cases (n = 62) were those identified in a prevalence survey (door-to-door, two-phase) of three Sicilian municipalities, as a November 1, 1987. We then randomly selected from the general population two controls for each case, matched for age ( +/- year), sex, and municipality (n = 124). Information on current and past occupations and education for cases and controls was obtained during the survey. Subjects who worked for most of their lives as farmers we…

Do macrophage centres in freshwater fishes reflect the differences in water quality?

1996

Abstract Macrophage centres have been considered as a potentially useful indicator of fish health. In this histological work we tested this hypothesis with macrophage centres (MCs) in the spleen, the liver and the hematopoietic part of the kidney of two common freshwater fish species in Finland, perch ( Perca fluviatilis ) and roach ( Rutilus rutilus ). Samples were collected over 5 seasons from a system of 4 lakes providing a gradation in water quality. The mean number of MCs/mm 2 and the area covered (μm 2 /mm 2 ) by them differed between individual fish, species, organs, and lakes, with interactions amongst these factors. Hemosiderosis was recorded from the spleen and liver of both fish …

Determination of Platinum-Group Elements (PGE) from catalytic converters in soil by means of docimasy and INAA.

1996

The nickelsulfide fire assay (docimasy) for the enrichment of platinum-group elements (PGEs) has been modified for the use with small samples and combined with instrumental neutron-activation analysis (INAA). This procedure has been applied to the determination of PGEs exhausted from catalytic converters and deposited in soil near the Wiesbadener Kreuz (highway A3, Frankfurt-Koln). Our results show a considerable enhancement of the Pt (up to 330 ng/g), Pd (6.6 ng/g) and Rh (7.5 ng/g) contents close to the highway.

Synthesis of SBC, SC and BC block copolymers based on polystyrene (S), polybutadiene (B) and a crystallizable poly(ɛ-caprolactone) (C) block

1996

The sequential anionic polymerization of polystyrene-block-polybutadiene-block-poly(e-caprolactone) (SBC) triblock copolymers as well as polystyrene-block-poly(e-caprolactone) (SC) and polybutadiene-block-poly(e-caprolactone) (BC) diblock copolymers was achieved in benzene. To initiate the polymerization of the highly reactive e-caprolactone, the nucleophilicity of the carbanion has to be reduced. For this purpose 1,1-diphenylethylene (DPE) was used. To avoid inter- and intramolecular transesterification reactions of the growing caprolactone block, the reaction time of this monomer in the block copolymers was strictly controlled. The reaction between polybutadienyl anions and DPE is too slo…

Selective Adhesion of Cells from Different Telencephalic Regions

1996

AbstractWe asked whether specification of different regions of the rodent and avian telencephalon during development involved the acquisition of differential adhesive properties. Cells from different regions were aggregated in a short-term aggregation assay, and their segregation was analyzed. Both neurons and precursor cells from cortex segregate from striatal cells at early, but not later, stages, whereas cells from rodent neocortex and hippocampus segregated only during later stages. Segregation was abolished when Ca2+-dependent but not Ca2+-independent adhesion molecules were selectively removed. Thus, selective adhesion appears to be a conserved mechanism that restricts cellular mixing…

Supravital Uptake of Methylene Blue by Dendritic Cells within Stratified Squamous Epithelia: a Light and Electron Microscope Study

1996

Electron microscopic data on methylene blue staining of dendritic cells in the epithelia of the soft palate and skin of the mouse after supravital dye injection are presented. The ultra-structural details were compared with corresponding light microscopic findings. Methylene blue stained tissue was fixed by immersion in a paraformaldehyde-glutaraldehyde solution containing phosphomolybdic acid. The ensuing dye precipitate was stabilized by ammonium heptamolybdate. The light microscopic investigation revealed that selective staining of dendritic cells depended on the presence of ambient oxygen. In addition, delicate morphological characteristics, like spinous structures of the dendrites, wer…

A review of the biological and pharmacological activities of saponins.

1996

Summary This paper reviews the important biological and pharmacological activities of saponins reported over the last few years. These include cancer-related activity, as well as antiphlogistic and antiallergic, immunomodulating, antihepatotoxic, antiviral, hypoglycemic, antifungal and molluscicidal activities. The action of saponins on the cardiovascular, central nervous, and endocrine systems and other miscellaneous effects are also discussed.

Die methematische Moderne und die Herrschaft der Zeichen

1996

Compte-rendu de l'ouvrage de H. Mehrtens intitule «Moderne - Sprache - Mathematik» (1990) qui inaugure le debat historique concernant la definition d'une modernite mathematique, fondee sur le langage des signes. Au-dela d'une analyse du pouvoir du discours mathematique, l'A. ouvre la voie a de nouvelles reflexions sur la dimension culturelle et sociale du debat

Sperm morphological abnormalities appearing in the male rabbit reproductive tract

1996

The role of the excurrent duct system in producing and/or eliminating morphologically abnormal spermatozoa may modify the semen parameters and interfere with sperm fertilizing capacity. To study this process, changes in the morphology of spermatozoa during their transit through the reproductive tract in sexually mature rabbits were investigated. The incidence of head, midpiece and tail abnormalities as well as of multiple defects in a single spermatozoon, and the position of the cytoplasmic droplet along the sperm midpiece were evaluated in samples from the testis, 6 regions of the epididymis and the vas deferens. Spermatozoa were characterized by rapid migration of the cytoplasmic droplet …

Pleomorphic adenoma and adenoid-cystic carcinoma of salivary glands: immunohistochemical assessment of proliferative activity in comparison with flow…

1996

In this study, 32 pleomorphic adenomas (PAs) and seven adenoid cystic carcinomas (ACCs) were analysed for the evaluation of proliferating cell nuclear antigen (PCNA) indices and flow cytometric variables. Our aim was to assess any possible relationship between these parameters and the clinico-pathological variables and to clarify their histogenesis and reasons for their biological differences. The tumours were divided into three groups, mainly epithelial (E), myxoid (M) and chondroid (C); PCNA labelling index (LI) and weighted mean index (WI) and the WI/LI ratio were analysed in the predominant components; a single PCNA index, weighted by the percentage of each component, was also calculate…

Characteristics of Escherichia coli strains belonging to enteropathogenic E. coli serogroups isolated in Italy from children with diarrhea.

1996

Fifty-five Escherichia coli strains belonging to enteropathogenic E. coli (EPEC) serogroups were examined for phenotypic and genetic factors associated with virulence. The strains were isolated in Italy from children with diarrhea and identified as EPEC by clinical laboratories using commercially available antisera. O:H serotyping showed that 35 strains (27 of O26, O111, and O128 serogroups) belonged to 11 serotypes considered to be classical EPEC O:H serotypes. The other 20 isolates were classified as 15 nonclassical EPEC O:H serotypes. All the potential EPEC virulence factors associated with bacterial adhesion (localized adherence, fluorescentactin staining test positivity, presence of th…