I. Glass Transition. Theoretical concepts on the glass transition of polymers and their test by computer simulation

1996

Various organic molecules, in particular polymers, are extremely good glass formers and allow the study of supercooled melts near the glass transition in metastable equilibrium. Theories of the glass transition imply such an equilibrium (e.g. mode-coupling theory, or Gibbs-di Marzio theory) and can hence be tested in these systems. Simplified lattice models for polymer melts (e.g. the bond fluctuation model) have been developed that can very efficiently be studied by Monte-Carlo simulation, and although they fail to accurately describe the local structure, they describe many features of the experiments very well. In this model, the mechanism of the glass transition is a competition between …

The parameterized local deduction theorem for quasivarieties of algebras and its application

1996

Let τ be an algebraic type. To each classK of τ-algebras a consequence relation ⊧ K defined on the set of τ-equations is assigned. Some weak forms of the deduction theorem for ⊧ K and their algebraic counterparts are investigated. The (relative) congruence extension property (CEP) and its variants are discussed.CEP is shown to be equivalent to a parameter-free form of the deduction theorem for the consequence ⊧ K .CEP has a strong impact on the structure ofK: for many quasivarietiesK,CEP implies thatK is actually a variety. This phenomenon is thoroughly discussed in Section 5. We also discuss first-order definability of relative principal congruences. This property is equivalent to the fact…

Fatal cerebellar haemorrhage due to phenprocoumon poisoning.

1996

A 32-year-old patient died of a cerebellar haemorrhage and the blood coagulation analysis before death suggested defective synthesis of vitamin K-dependent clotting factors due to vitamin K deficiency. The post-mortem toxicological examination of different tissues revealed phenprocoumon poisoning as the cause of death. The differential diagnosis of vitamin K deficiency and the toxicology of hydroxycoumarins are discussed.

Social Inequalities in French Secondary Schools : From Figures to Theories

1996

In spite of the unified type of junior secondary school (the "college") implemented in France since 1975, significant social inequalities of school careers can be observed today. A specific longitudinal study sheds some light on the variety of mechanisms which generate these social inequalities. Difference in academic progress is one mechanism, but parents' strategies are also important. Finally, another aspect of social inequality arises from the school attended, some schools being more selective at the streaming points, these "school effects' being related to the social characteristics of the pupils of the catchment area. All these facts and figures have some relevance with regard to diff…

Changes associated with aging and replicative senescence in the regulation of transcription factor nuclear factor-kappa B.

1996

Both the aging of animals and the senescence of cultured cells involve an altered pattern of gene expression, suggesting changes in transcription factor regulation. We studied age-related changes in transcription factors nuclear factor (NF)-kappa B, activator protein factor-1 (AP-1) and Sp-1 by using electrophoretic mobility shift binding assays; we also analysed changes in the protein components of NF-kappa B complex with Western blot assays. Nuclear and cytoplasmic extracts were prepared from heart, liver, kidney and brain of young adult and old NMRI mice and Wistar rats as well as from presenescent, senescent and simian virus 40-immortalized human WI-38 fibroblasts. Aging of both mice an…

Strassmann in the shadow

1996

Surface properties of valine-gramicidin A at the air-water interface

1996

Abstract Fluorescence microscopy, X-ray reflectivity and ellipsometry have been applied to the study of a monolayer of valine-gramicidin A (VGA) at the air-water interface to obtain insight into the conformation and orientation of VGA, and to clarify the shoulder observed in its π - A curve (12.5–16 mN m −1 , 240 – 175 A 2 molecule −1 ). At low molecular areas, the X-ray reflectivities are consistent with formation of a single layer of tubular-shaped dimers. Fluorescence microscopy yielded homogeneous pictures suggesting that on the macroscopic scale the shoulder cannot be attributed to domain formation. Thicknesses calculated from the ellipsometric isotherm are consistent with the X-ray da…

Zirkadiane Serotonin- und Melatonin-Serumspiegel bei Anorexia-nervosa-Patientinnen im Vergleich zu normal-menstruierenden Frauen

1996

Day and night rhythms of melatonin and serotonin were measured in four female anorexia nervosa patients and for comparison in a control group with normal 28-day menstrual cycle. In the anorexia nervosa group the levels of gonadotropins and sexual steroids were distinctly lowered. In the LHRH test the hormonal profile showed pubertal to prepubertal patterns of secretion with an only moderate increase of LH and distinct shifting of the LH/FSH ratio in direction of FSH. For both groups the 24-hour profiles of melatonin and serotonin showed a normal cycle, i.e. melatonin had its maximum by night, whereas serotonin in contrast displayed its highest values by day. However, in the group of patient…

Local administration of antisense phosphorothioate oligonucleotides to the p65 subunit of NF-kappa B abrogates established experimental colitis in mi…

1996

Chronic intestinal inflammation induced by 2,4,6,-trinitrobenzene sulfonic acid (TNBS) is characterized by a transmural granulomatous colitis that mimics some characteristics of human Crohn's disease. Here, we show that the transcription factor NF-kappa B p65 was strongly activated in TNBS-induced colitis and in colitis of interleukin-10-deficient mice. Local administration of p65 antisense phosphorothioate oligonucleotides abrogated clinical and histological signs of colitis and was more effective in treating TNBS-induced colitis than single or daily administration of glucocorticoids. The data provide direct evidence for the central importance of p65 in chronic intestinal inflammation and …

Polynuclear copper(II) complexes with μ2-1,1-azide bridges. Structural and magnetic properties

1996

Abstract Two novel, weakly antiferromagnetically coupled, tetranuclear copper(II) complexes [Cu4(PAP)2(μ2-1,1-N3)2(μ2-1,3-N3)2(μ2-CH3OH)2(N3)4 (1) (PAP = 1,4-bis-(2′-pyridylamino)phthalazine) and [Cu4(PAP3Me)2 (μ2-1,1-N3)2(μ2-1,3-N3)2(H2O)2(NO2)2]- (NO3)2 (2) (PAP3Me = 1,4-bis-(3′-methyl-2′-pyridyl)aminophthalazine) contain a unique structural with two μ2-1,1-azide intramolecular bridges, and two μ2-1,3-azide intermolecular bridges linking pairs of copper(II) centers. Four terminal azide groups complete the five-coordinate structures in 1, while two terminal waters and two nitrates complete the coordination spheres in 2. The dinuclear complexes [Cu2(PPD)(μ2-1,1-N3)(N3)2(CF3SO3)]CH3OH) (3) a…

The hospital anxiety and depression scale questionnaire in physical danger and evaluation situations

1996

In this article we analyze the variables of anxiety and depression in two different situations: a combat situation and taking an exam. We used the Hospital Anxiety and Depression Scale questionnaire with a sample of 621 subjects, divided in four groups, two groups of soldiers, one of them in situation of combat (SBH) and the other one on the military service (CMS). The other two groups were composed of male students (MS) and female students (FS) that were going to take an exam. Results could be organized in two ways: quantitative results, where the more stable subjects are the soldiers in situation of combat (SBH), both in anxiety and in the depression variables. The female students (FS) ob…

Pyrgomorphid grasshoppers of the genus Phymateus contain species-specific decapeptides of the AKH/RPCH family regulating lipid-mobilization during fl…

1996

. Using heterologous and conspecific bioassays, two peptides have been isolated from methanolic extracts of corpora cardiaca from the pyrgomorphid grasshopper Phymateus morbillosus L.The structures of both peptides were elucidated by a combination of Edman degradation, after deblocking the N-terminal pyroglutamic acid residue, and mass spectrometric techniques.One peptide is an octapeptide (pGlu-Leu-Asn-Phe-Ser-Thr-Gly-TrpNH2) which also occurs in other insects and is code-named Scg-AKH-II.The second peptide is a novel decapeptide member of the AKH/RPCH family (pGlu-Leu-Asn-Phe-Thr-Pro-Asn-Trp-Gly-SerNH2 code-named here Phm-AKH.It is the first example of a different peptide in the same genu…

Transmission of electronic effects in 4-aryl-2,6-diphenylpyrylium perchlorates and related compounds

1996

Mapping land surface emissivity from NDVI: Application to European, African, and South American areas

1996

Thermal infrared emissivity is an important parameter both for surface characterization and for atmospheric correction methods. Mapping the emissivity from satellite data is therefore a very important question to solve. The main problem is the coupling of the temperature and emissivity effects in the thermal radiances. Several methods have been developed to obtain surface emissivity from satellite data. In this way we propose a theoretical model that relates the emissivity to the NDVI (normalized difference vegetation index) of a given surface and explains the experimental behavior observed by van de Griend and Owe. We can use it to obtain the emissivity in any thermal channel, but in this …

Ligase Chain Reaction (LCR®) assay for semi-quantitative detection of HBV DNA in mononuclear leukocytes of patients with chronic hepatitis B

1996

Summary. A ligase chain reaction (LCR®)-based approach to detect hepatitis B virus (HBV) DNA in peripheral blood mononuclear cells (PBMC) is described. Using this new amplification technique, we determined semi-quantitatively the amount of a short HBV S-gene fragment in PBMC lysates of 25 patients with different forms of chronic hepatitis (group A (n= 8), hepatitis B s antigen (HBsAg)+/hepatitis B e antigen (HBeAg)+; group B (n= 9), HBsAg+/HBeAg-; group C (n= 8), HBsAg-/HBeAg-). The LCR results were compared with the findings obtained with polymerase chain reaction (PCR) amplification of three distinct HBV gene regions (preS1/2, S and C) and related to the serological profiles of the patien…

Groupe de monodromie g�om�trique des singularit�s simples

1996

Cette Note tente de repondre a une question de Sullivan: le groupe fondamental du complementaire du discriminant d'un deploiement universel d'une singularite isolee en deux variables complexes s'injecte-t-il dans le groupe de diffeomorphismes de la fibre modulo son bord, par l'application de monodromie? La reponse est affirmative pour les singularites simples A n et D n

Contaminantes bacterianos en inoculantes comerciales para Soja (Glycine max L.) Merrill

1996

Experimental studies on the suitability of human mesothelial cells for seeding vascular prostheses: shear stress resistance in vitro

1996

This investigation forms part of a study on the suitability of human omentum mesothelial cells (HOMES) as an alternative to endothelial cells (EC) for seeding vascular grafts. Isolated HOMES were grown in primary culture and characterized by their morphology (light microscopy and scanning electron microscopy (SEM)), as well as by fluorescence-activated cell sorting (FACS) and immunocytochemistry. The latter two methods showed cells which were positive for smooth muscle-type actin and cytokeratin, but negative for factor VIII-related antigen. HOMES were grown to confluence on glass with or without a fibronectin coating. Controlled shear stress was applied for up to 30 min using a plate and c…

A series expansion of the extended Debye-H�ckel equation and application to linear prediction of stability constants

1996

The Debye-Hückel semiempirical extended equation is frequently used to calculate activity coefficients of chemical species and equilibrium constants at ionic strengths different from those used in their experimental evaluation. A series expansion of the extended Debye-Hückel equation is proposed here and checked with experimental data taken from the literature. The expansion is linear in the ionic parameters and yields a geometrical series which converges rapidly and that enables the accurate calculation of interpolated and extrapolated activity coefficients and equilibrium constants by simple and multiple linear regression without previous knowledge of the ionic parameters.

The quantitative humoral immune response to the hepatitis C virus is correlated with disease activity and response to interferon-alpha.

1996

Virus-host interactions may have pathogenetic significance in chronic hepatitis. Thus the humoral immune response was evaluated during the clinical course of HCV-infected patients.Eighteen selected chronic HCV patients received three doses of 3 or 6 MU interferon-alpha 2a weekly for 6 to 12 months and were followed up for 6 to 60 months. Anti-HCV antibody levels were serially measured either in end-point diluted sera with the Matrix-Assay or with quantitative anti-HC34-IgG and -IgM ELISA. Circulating immune complexes were assessed by flow cytometry and the results were correlated with histology, quantitative HCV-RNA levels and genotypes.Nine complete responders (CR; genotypes 1a n = 4; 1b n…

Detection of phase transitions in thin films with a quartz crystal microbalance

1996

Abstract The quartz crystal microbalance (QCM) is used to determine the phase transition point of thin films by measuring the change in frequency as a function of temperature. To elucidate this relationship, two types of polymers were studied where the bulk phase transitions were known. We investigated a casted thin film of an amphiphilic polyoxazoline and a Langmuir-Blodgett film comprised of fifteen double layers of an amphotropic polyacrylate. The phase transition points of the thin films could be detected by the QCM which were in the same range as for the bulk materials.

Decays of theY97isomers to the single neutron nucleusZr97

1996

The decays of the 9/2(+) and of the three-quasiparticle high spin isomer in Y-97 have been investigated following on-line mass separation with the ion-guide technique. Spins and parities for several of the lowest-lying levels in the daughter nucleus Zr-97 are revised and configurations are proposed. In particular, the 2264 keV level is identified as the h(11/2) single-neutron level. The population of a cascade on top of the h(11/2) level provides evidence for Gamow-Teller beta decay of the high-spin Y-97 isomer. Levels and transition rates are qualitatively well reproduced by regarding Zr-97 as a single-neutron nucleus with respect to the doubly closed Zr-96 core.

Minimum effective dose for antidepressants - an obligatory requirement for antidepressant drug evaluation?

1996

Extensive clinical trials are required for registration and approval of new antidepressants in most countries including the requirement that a minimal effective dose should be determined. The rationale for this requirement is to avoid the use of unnecessarily high doses. The implication is that for every antidepressant, a dose exists that serves as a threshold, below which all doses are not effective or are clearly less effective in treating a major depressive episode. Dose titration and fixed dose studies are used to determine the minimal effective dose, but both strategies have limitations and often do not allow definite establishment of a clear-cut minimal effective dose. The effort of e…

Modelling nanoscale fluid dynamics and transport in physiological flows

1996

The concept of nanotechnology is discussed, and its connection with biomedical engineering is elucidated. For the specific field of nanoscale flow and transport problems of physiological relevance, some typical examples are presented, and their interaction is discussed for some classic biomechanical problems like the flow in arteries with blood-wall coupling. Then, existing computational models are presented and classified according to the length scale of interest, with emphasis on particle-fluid problems. Final remarks address the essential unity of biomedical and engineering behaviour and the possible relevance to small-scale industrial research.

Rifles, Blankets, and Beads: Identity, History, and the Northern Athapaskan Potlatch . William E. Simeone

1996

Cell cycle studies on the mode of action of yeast K28 killer toxin.

1996

The virally encoded K28 killer toxin of Saccharomyces cerevisiae kills sensitive cells by a receptor-mediated process. DNA synthesis is rapidly inhibited, cell viability is lost more slowly and cells eventually arrest, apparently in the S phase of the cell cycle with a medium-sized bud, a single nucleus in the mother cell and a pre-replicated (1n) DNA content. Cytoplasmic microtubules appear normal, and no spindle is detectable. Arrest of a sensitive haploid yeast strain by alpha-factor at START gave complete protection for at least 4 h against a toxin concentration that killed non-arrested cells at the rate of one log each 2.5 h. Cells released from alpha-factor arrest were killed by toxin…

Synthesis of New Functionalized Discotic Liquid Crystals for Photoconducting Aplications

1996

Abstract The columnar structure of discotic liquid crystals has been shown to be well suited for electronic transport parallel to the columnar axis. To tailor the processibility and mesophase behavior of such materials, several hydroxytriphenylene derivatives were synthesized. These hydroxytriphenylenes can be converted into oligomers, networks or polymers. Further, they can be reduced to arenes which posses reactive sites for classical aromatic substitutions. A number of mixed tail triphenylene derivatives and fluorescent, low symmetry triphenylene discotic liquid crystals were synthesized and characterized.

Intravascular ultrasound detected classification of coronary lesions as a predictor of dissections after balloon angioplasty.

1996

Dissection after balloon angioplasty of coronary arteries may give rise to an unfavourable early outcome. Compared with coronary angiography, intravascular ultrasound (IVUS) allows more detailed characterisation of dissections. We investigated the incidence and type of dissections after balloon angioplasty in calcified coronary lesions. IVUS was performed in 43 patients with 48 lesions before and after percutaneous balloon angioplasty. Significant calcification was defined as an arc of more than 90 degrees with typical acoustic shadowing. Dissections were classified as type A when the media was not involved by the dissection and as type B when media involvement had occurred. In the group wi…

Communication complexity in a 3-computer model

1996

It is proved that the probabilistic communication complexity of the identity function in a 3-computer model isO(√n).

Quasi-elastic light scattering in polymer-containing microemulsion

1996

Abstract Quasi-elastic light scattering (QELS) was performed in dilute water in oil microemulsion stabilized by AOT surfactant. The water-soluble polyethylene oxide (PEO) with low molecular weight (8000) added to the microemulsion seems to be confined within the aqueous microphase, since PEO is insoluble in oil (n-heptane). The measurements by QELS of diffusion coefficient, at dilute concentrations, allow determination of the size of the droplets. The phase diagram of the microemulsion undergoes remarkable changes on addition of the polymer. The results show that at fixed R ( water surfactant ratio) the droplets decrease their size as the concentration of polymer increases. This occurrence …

Octreotide prevents the pathological alterations of bowel obstruction in cancer patients

1996

Determination of Sulfur in Fertilizers by Inductively Coupled Plasma-Atomic Emission Spectrometry: Spectral and Interelement Effects at Various Wavel…

1996

Abstract Three analytical wavelengths (180.731,182.037, and 182.625 nm) were tested for determination of sulfur in 2 fertilizers by inductively coupled plasmaatomic emission spectrometry (ICP-AES). Variable S results at 182.037 nm were caused by a downward sloping background shift (Fe line at 181.851 nm) during measurement of the sample solutions. At 182.625 nm an emission peak doublet, 182.619/182.635 nm, was observed from which the instrument selected the measurement peak. A shift from calibrated peak 182.619 nm to noncalibrated peak 182.635 nm occurred when the S/B ratios were ≤22-31 in the fertilizer samples examined. For the 3 wavelengths of S investigated, the pattern of spectral and …

Heavy Baryon Specroscopy from the Lattice

1996

The results of an exploratory lattice study of heavy baryon spectroscopy are presented. We have computed the full spectrum of the eight baryons containing a single heavy quark, on a $24^3\times 48$ lattice at $\beta=6.2$, using an $O(a)$-improved fermion action. We discuss the lattice baryon operators and give a method for isolating the contributions of the spin doublets $(\Sigma,\Sigma^*)$, $(\Xi',\Xi^*)$ and $(\Omega,\Omega^*)$ to the correlation function of the relevant operator. We compare our results with the available experimental data and find good agreement in both the charm and the beauty sectors, despite the long extrapolation in the heavy quark mass needed in the latter case. We …

Apparent vs real effects of scopolamine on the learning of an active avoidance task.

1996

The effects of scopolamine hydrobromide (0.5 and 2 mg/ kg) administered intraperitoneally to Balb/c male mice before or after training in active avoidance were explored in four training sessions and in a subsequent test session, free of drug. Animals given scopolamine prior to training performed better than controls, an effect that was reversed in the session free of drug. However, a deeper analysis of the data permits us to interpret this increment in the number of avoidance responses as a consequence of the increase in activity produced by the drug and not as learning. In the animals injected with scopolamine after sessions no effects were observed. In conclusion, the results of the prese…

Recognition of human renal cell carcinoma and melanoma by HLA-A2-restricted cytotoxic T lymphocytes is mediated by shared peptide epitopes and up-reg…

1996

Cytotoxic T lymphocytes (CTL) have previously been isolated from peripheral blood of patients with renal cell carcinoma (RCC). The CD8-positive CTL line MZ1257-CTL-5 (CTL-5) has been shown to lyse autologous cultured RCC cells in an HLA-A2 restricted fashion. Allogeneic, HLA-A2-matched RCC and melanoma cell lines were also lysed by CTL-5, suggesting that melanoma and renal cancer share antigenic determinants. The aim of the study was to determine whether RCC and melanoma share peptide epitopes that are recognized by CTL-5 in the context of HLA-A2 molecules. Peptides were acideulated from various cell lines, separated by reversed phase high performance liquid chromatography (RP-HPLC), and as…

Influence of interferon-alpha on cytokine expression by the bone marrow microenvironment--impact on treatment of myeloproliferative disorders.

1996

Myeloproliferative disorders (MPD) are characterized by several common clinical and biological features, although at the molecular level, each disease entity exhibits distinct abnormalities. IFN-alpha exerts beneficial therapeutic effects in chronic myelogenous leukemia, polycythemia vera and essential thrombocythemia, resulting in control of hematopoietic hyperplasia and, in a minority of patients, in induction of cytogenetic remission. The mechanism of action of IFN-alpha in MPD is poorly defined. Recently published in vitro findings suggest that IFN-alpha interacts with the regulation of hematopoiesis by multiple ways. Its antiproliferative activity is well known for more than a decade, …