Synthesis, structure and conductivity of Ag2ZnSiO4, Ag2ZnGeO4 and Ag2BeSiO4

1995

Abstract The compounds Ag2MM′O4 with MM′ = ZnSi, ZnGe and BeSi have been synthesised by reacting the corresponding Na compounds with molten AgNO3. The crystal structures of Ag2ZnSiO4 and Ag2ZnGeO4 have been refined from Cu K α1 powder diffractometer data by the Rietveld technique to RF = 3.3 and 7.1%, respectively. They are isostructural with monoclinic Na2ZnSiO4. The powder pattern of Ag2BeSiO4 indicates that it is isostructural with orthorhombic Na2BeSiO4. The conductivity of the compounds has been determined using ac impedance measurements. Ag2ZnSiO4 and Ag2BeSiO4 are ionic conductors, with conductivities that are very similar to those of their corresponding isostructural Na compounds. A…

A SIMPLE PREPARATION OF MONO-tert-BUTYL BENZYLOXYCARBONYL-L-GLUTAMATES

1995

(1995). A SIMPLE PREPARATION OF MONO-tert-BUTYL BENZYLOXYCARBONYL-L-GLUTAMATES. Organic Preparations and Procedures International: Vol. 27, No. 3, pp. 378-380.

Carol Myers-Scotton, Duelling languages: Grammatical structure in Code-swithing. Oxford: Clarendon, 1993. Pp. xiv, 263. Hb £30.00, $45.00.

1995

Calorimetric investigation of the interaction between a macromolecular prodrug of diflunisal and human platelets

1995

The thermal effect due to the interaction between human platelets and α,β poly(N-hydroxy-ethyl)-DL-aspartamide (PHEA) or the PHEA-Diflunisal conjugate was measured by the calorimetric technique at 25°C. The experimental data confirm that PHEA is a biocompatible macromolecule and that its conjugate influences the physiological activity of human platelets.

Voice intelligibility in patients who have undergone laryngectomies.

1995

In this paper, we evaluate the speech intelligibility of two groups of Spanish-speaking people who have undergone laryngectomies: a group who used esophageal speech and a group who used tracheoesophageal (TES) prostheses. Audio recordings of 24 Spanish words produced by each talker were presented to a group of normal-hearing naive listeners who phonetically transcribed their responses. Listeners’ responses were registered in confusion matrices. Results indicate that differences between these two groups of patients appear when we consider phoneme types. The difficulty in producing the voicing distinction appeared in both TES and esophageal talkers. This finding is consistent with studies of …

Dye-containing S∗cside-on/end-on copolymers

1995

Abstract Mesomorphic copolysiloxanes, which combine ‘normal’ end-on linked chiral mesogenic units inducing S∗c phases and side-on fixed chromophores were prepared. The interplay of the different orientational tendencies of these moieties, which are perpendicular (end-on linked mesogenic groups) or parallel (side-on fixed chromophores) to the polymer chain, lead to a strong destabilization of the S∗c phase. However, copolymers with up to about 10 mol % of chromophores still show a smectic C∗ phase. FTIR measurements show that both moieties orient parallel to each other and perpendicular to the polymer chains. These copolymers are interesting to consider as coloured guest-host S∗c materials f…

A method for rapid generation of competitive standard molecules for RT-PCR avoiding the problem of competitor/probe cross-reactions.

1995

The analysis of gene expression is a widespread issue in a growing number of fields such as molecular genetics, immunology, and medical diagnostics. The ideal method for mRNA detection should be fast, inexpensive, sensitive, and reliable. Well-elaborated standard methods such as Northern hybridization, Sl-mapping, and RNAse protection are useful and recommended, but only reverse transcription PCR (RT-PCR) gives the highest possible sensitivity required. For many issues it is necessary not only to detect a distinct mRNA but to compare changes in mRNA levels. The use of RT-PCR for such semiquantitative and quantitative approaches resolves problems attributable to the intrinsic property of PCR…

Magnetresonanztomographische Befunde nach Resektionsarthroplastik des Humeruskopfes

1995

PURPOSE The resection of the humeral head is normally carried out only with respect to four-part and dislocation fractures in elderly patients. The purpose of this study was to examine whether there is a correlation between the clinical results and the MRI findings. MATERIAL AND METHODS 8 patients underwent clinical and MR examination two to 6 years after resection. RESULTS A cartilage-like tissue formation between the remaining humeral head and the glenoid fossa, with signal intensities comparable to hyalin cartilage was found in all patients. CONCLUSION The good functional results following resectional surgery of the humeral head can partially be related to new substitute cartilage result…

Sensory and Chemical Analysis of Fractions Obtained by Gel Permeation of Water-Soluble Comte Cheese Extracts

1995

The pure water extraction of Comte cheese solubles and their chromatographic separation facilitate sensory analysis experiments with the fractions directly collected from the column. Two extracts, one obtained after ultrafiltration, the other after chromatography on Sephadex G25, have been separated on Toyopearl HW-40S. The sensory evaluation of the obtained fractions shows in the two cases that some fractions have interesting flavors. However, physicochemical analysis shows that organoleptic characteristics are linked more to the presence of amino acids and salts than to the presence of peptides. Apart from monosodium glutamate, most of the amino acids are present in the fractions at conce…

Structural similarities and differences among attractors and their intensity maps in the laser-Lorenz model

1995

Abstract Numerical studies of the laser-Lorenz model using parameters reasonably accessible for recent experiments with a single mode homogeneously broadened laser demonstrate that the form of the return map of successive peak values of the intensity changes from a sharply cusped map in resonance to a map with a smoothly rounded maximum as the laser is detuned into the period doubling regime. This transformation appears to be related to the disappearance (with detuning) of the heteroclinic structural basis for the stable manifold which exists in resonance. This is in contrast to the evidence reported by Tang and Weiss (Phys. Rev. A 49 (1994) 1296) of a cusped map for both the period doublin…

Chronic toxicity of diazinon todaphnia magna:Effects on survival, reproduction and growth

1995

The sublethal effect of 0.15, 0.18, 0.22, 0.25 and 0.30 μg/L diazinon on the survival, reproduction and growth of D. magna was monitored for 21 days. Neonates (≤ 24 h) were obtained from the stock cultures and raised individually in 50 mL glass beakers. All daphnids were transfered every other day to a new beaker containing fresh medium, food and the appropriate pesticide concentration. The animals were maintained in an environmental chamber at 22±1°C on a 12L: 12D photoperiod and were fed daily on 5 x 105 cell/mL of the green algae Nannochloris oculata. The parameters used to determine the effect of the pesticide on reproduction were: mean total young per female, mean brood size, mean numb…

High spin band structures in104Cd

1995

High spin states in Cd-104 have been investigated by means of heavy ion induced reactions using the Nordball detector array. The level scheme constructed from yy-coincidences is dominated by three ...

Theory of birefringence and spontaneous polarization in the tetragonal phase of PbTiO3 due to lattice deformation caused by the change of temperature

1995

The microscopic mechanism of birefringence in the tetragonal phase of PbTiO3 is discussed taking account of the dipole-dipole interaction (dipole-dipole effect) due to the ionic and electronic polarizations of the crystal and the spontaneous Kerr effect as a cause of the strong local field acting on the constituent ions, where the lattice deformation due to the change of temperature is also considered. For the spontaneous polarization we use only the first effect. It is found that the birefringence and the spontaneous polarization are in good agreement with the experimental data.

Nonlinear finite element analysis of no-tension masonry structures

1995

A numerical approach for structural analysis of masonry walls in plane stress conditions is presented. The assumption of a perfectly no-tension material (NTM) constitutive model, whose relevant equations are in the form of classical rate-independent associated flow laws of elastoplastic material, allows one to adopt numerical procedures commonly used in computational plasticity. An accuracy analysis on the integration algorithm employed in the solution of constitutive relations has been carried out. The results obtained for some relevant case-studies and their comparison with data, available in the literature show the effectiveness of the proposed method.

Studies on coordination compounds—VIII. Syntheses, structural, magnetic, spectral and thermal properties of some cobalt(II), nickel(II) and copper(II…

1995

Abstract The complexes bis[triaqua(2-aminopyrimidine)-μ-sulphato-O,O′-cobalt(II)] dihydrate (1), catena-[diaqua(2(2-aminopyrimidine))-μ-sulphato-O,O′nickel(II)]2-amino-pyrimidine (2), [pentaaqua(2-aminopyrimidine)nickel(II)]sulphate 2-aminopyrimidine (3) and catena-[aqua(2(2-aminopyrimidine))-μ-sulphato-O,O′-copper(II)] dihydrate (4) were prepared, structure determined by X-ray methods and physical properties studied by magnetic, IR, NMR, EPR and reflectance methods. The thermal behaviour was studied by TG and mass spectrometric methods. The results are discussed on a structural basis.

Polybutadiene model networks —synthesis, mechanical characterization and comparison with rubber elasticity models

1995

Model networks of defined crosslink density are prepared via nonradical statistical crosslinking of polybutadiene in bulk and concentrated solution using a masked bistriazolinedione as crosslinker. The kinetics of crosslinking is monitored by FT-IR-spectroscopy. The reaction follows pseudo-1st-order reaction kinetics. The activation parameter of the crosslinking reaction is estimated from crosslinking at various temperatures. Networks of deuterated polybutadiene are prepared by this reaction in a wide range of crosslink densities. The stress strain behavior is analyzed according to the Junction Constraint-Theory of rubber elasticity (JCT) and to the approach introduced by Graessley accounti…

Perturbations of the classical Lotka-Volterra system by behavioral sequences

1995

The complexity and the variability of parameters occurring in ecological dynamical systems imply a large number of equations.

Synthesis and characterization of water-swellable?,?-polyasparthydrazide derivatives

1995

α, β-polyasparthydrazide (PAHy) was crosslinked by glutaraldehyde to form water-swellable materials possessing a three-dimensional molecular network. Different crosslinking degrees were prepared varying glutaraldehyde/PAHy ratio and samples containing 5-fluorouracil were obtained by incorporating the drug into the polymer networks during the crosslinking reaction. All samples were characterized by swelling tests, thermal, x-ray and SEM analysis. Their microstructure was observed through scanning electron microscopy. Furthermore, for samples containing the anticancer drug,in vitro release studies were performed in pH 7.4 buffer solution.

Synthesis and spectroscopic investigations (IR, NMR and Mössbauer) of tin(IV) and organotin(IV) derivatives of bis(pyrazol-1-yl) alkanes: X-ray cryst…

1995

A series of 1:1 adducts of the type [(L)R(n)SnX(4-n)] . zH(2)O (L = bis(4-methylpyrazol-1-yl)methane (L(4)), bis(3,4,5-trimethylpyrazol-1-yl)methane (L(T)), 1,2-bis(pyrazol-1-yl)ethane (L(A)) or 1,2-bis(3,5-dimethylpyrazol-1-yl)ethane (L(B)); R = Me, Et, Bu or Ph; X = I, Br or Cl; n = 0, 1 or 2; z = 1, 1.5 or 2), and the likely polynuclear [(L(A))(5)(SnCl4)(4)] . (H2O)(5) and [(L(B))(2)(SnCl4)(3)] . 1/2[Et(2)O] have been characterized in the solid state and in solution by analyses, spectral (IR, Mossbauer, and H-1, C-13 and Sn-119 NMR) data and conductivity measurements. When L(T) reacts with SnCl4, cleavage of a carbon (sp(3))-nitrogen bond was observed and the adduct [(3,4,5-trimethylpyra…

Comparison of Foot and Hand Reaction Times among Men: A Methodologic Study Using Simple and Multiple-Choice Repeated Measurements

1995

The primary study goal was to compare visual simple and choice reaction times of the hand and foot to assess validity of measurements for evaluating subjects' ability to perform rapid, controlled movements. First, we examined the repeatability ( N = 34) for four different data-sampling methods from a series of 12 trials within sessions and between two test sessions. Simple and choice reaction times with the preferred hand and both feet were then compared among 153 healthy male volunteers aged 35 to 67 years. Pearson correlations for hand and ipsilateral and contralateral foot reaction times on simple and choice tasks (.53 to .80, p<.001) showed that psychomotor foot reaction time is a v…

Mechanism of anionic polymerization of (meth)acrylates in the presence of aluminium alkyls, 2. Kinetic investigations with methyl methacrylate in tol…

1995

The kinetics of the polymerization of methyl methacrylate initiated by lithium alkyls (tert-butyllithium or ethyl α-lithiobutyrate) was investigated in the presence of aluminium alkyls (triethylaluminium or triisobutylaluminium) in toluene at −78°C. The rate of polymerization decreases considerably once the living dimer is formed. This suggests that the aluminate end-group coordinates with the penultimate ester group of the polymer chain, thus decreasing reactivity. The results are at variance with an activated monomer mechanism.

Two discourses: researchers and policy-making in higher education

1995

The theme of this article focuses on how policy discourse and research discourse meet in contract research in higher education. The interplay of these discourses has consequences for researchers who have to balance conflicting demands, which we view as links between research and policy cycles. Two evaluation studies on the introduction and effects of new policy instruments are discussed, focusing on the interaction between policy needs, and research design. The examples are taken from policies in the development towards increasing self-regulation in higher education, of which Finland and the Netherlands are interesting examples in the European context.

Lack of requirement for CD8+ cells in recovery from and resistance to experimental autoimmune encephalomyelitis.

1995

Abstract Experimental autoimmune encephalomyelitis (EAE) is a model of T-cell mediated autoimmune disease. Active disease is mediated by myelin basic protein specific CD4+T-cells, whose adoptive transfer can also induce passive disease. In the Lewis rat EAE is a transient disease inducing lasting resistance to rechallenge. The mechanisms of recovery and resistance are poorly understood. CD8+suppressor T-cells have mostly been thought to be central, especially in resistance to reinduction of the disease. In this study we showed by complete depletion of CD8+cells that this subset does not influence either recovery or resistance to EAE in the Lewis rat. This was further confirmed by depleting …

Parathyroid hormone-related peptide and 8701-BC breast cancer cell growth and invasion in vitro: evidence for growth-inhibiting and invasion-promotin…

1995

It has been previously reported that 8701-BC cells, derived from a primary carcinoma of the breast, constitutively express parathyroid hormone-related peptide (PTHrP) gene and that N-terminal PTHrP immunoreactivity can be found in cell medium. Here we have firstly measured immunoreactive PTHrP in 8701-BC cell medium using antibodies raised against midregion and C-terminal fragments, and also demonstrated the expression of PTH/PTHrP receptor by 8701-BC cells. Secondly, we have examined the role, if any, elicited by diverse PTHrP domains on 8701-BC cell proliferation, and invasive behaviour in vitro related to production of extracellular proteolytic enzymes. Our data show that PTHrP [1-34], a…

Continuous-flow spectrophotometric determination of sulfadiazine by diazotisation with in situ preparation of nitrite

1995

Abstract Nitrite is prepared in situ for the determination of sulfadiazine. The method is based on solid-phase reduction of copperized cadmium of nitrate; the nitrite reagent merges with the sample stream in hydrochloric acid medium and the resulting mixture is injected into the water carrier, pure distilled water, and then merges with the N-(1-naphthyl)ethylendiamine reagent and is measured spectrophotometrically at 542.0 nm. The calibration graph is linear over the range 0.5–50 μg ml−1 sulfadiazine, mid-range R.S.D. = 0.3% (n = 5) and sample throughput 72 h−1. The procedure is applied to sulfadiazine determination in a pharmaceutical formulation and to in vitro dissolution studies of two …

Relationships between time of day, day of the week, and positive mood: Exploring the role of the mood measure

1995

This study examined the relationship between time of day, day of the week, and two measures of positive affect (PA). According to previous research and the circumplex model of affect, one scale was designed to assess the activation component of PA, and the other one measured the pleasantness aspect. Subjects rated their mood three times a day for 7 consecutive days. Consistent with our hypotheses, PA-Pleasantness showed a peak on the weekend, whereas PA-Activation remained stable throughout the week. Regarding time of day, maximum PA-Activation was reached in the afternoon. In contrast, the Pleasantness component of PA increased from morning to evening. Implications of these results as well…

Nucleation of quasicrystals by rapid cooling of a binary melt: A molecular-dynamics study.

1995

A binary Lennard-Jones fluid was cooled in an NPT ensemble by molecular-dynamics simulations. Depending on the cooling rate, we find a sharp transition from the melt either into a disordered structure or into a phase of icosahedral long-range order. We also observed a decagonal phase.

Central obesity and hypertension: Pathophysiologic role of renal haemodynamics and function

1995

OBJECTIVE: To investigate the role of alterations in renal haemodynamics and function and in plasma renin activity on obesity-induced hypertension. DESIGN: Renal haemodynamics and function, salt-regulating hormones and structural cardiac parameters were evaluated in 20 lean normotensives and in 64 obese subjects with central or peripheral fat distribution, 43 of them were normotensives and 21 of them were hypertensives. Obesity and central fat distribution were defined according to sex-specific 85th percentile respectively of Body Mass Index (BMI) and Waist to Hip Ratio (WHR). MEASUREMENTS: Serum immunoreactive insulin (IRI), plasma renin activity (PRA), plasma aldosterone (PA), microalbumi…

gamma-Aminobutyric acid type A/benzodiazepine receptors regulate rat retina neurosteroidogenesis.

1995

Abstract It has been previously shown that retinal ganglion cells have the ability to synthesize steroids including neuroactive steroids such as pregnenolone sulfate. Since ganglion cells possess GABAA/benzodiazepine (BZ) receptors and neurosteroids modulate retinal GABAA receptor function, we investigated the role of these receptors in isolated rat retina neurosteroidogenesis. Ligands for central-type BZ receptors stimulated retinal pregnenolone synthesis. Clonazepam was the most potent ligand examined acting at nanomolar concentrations. Moreover, the effective steroidogenesis stimulatory dose (ED50) for these ligands and theKi to inhibit [3-H]flunitrazepam binding showed a coefficient of …

Potential health hazards of assisted human reproduction: Effects of manipulations in vitro of human oocytes and embryos on the birthweight of the res…

1995

Reassessment of adrenal androgen secretion in women with polycystic ovary syndrome

1995

Objective To reevaluate the clinical significance of elevations of adrenal androgens in polycystic ovary syndrome (PCOS). Methods Thirty women with PCOS and ten ovulatory controls were evaluated. Serum dehydroepiandrosterone (DHEA) sulfate and 11β-hydroxyandrostenedione were measured before and after 3 and 6 months of GnRH agonist (GnRH-A) therapy. All controls and 15 women with PCOS received intravenous ACTH before and after GnRH-A therapy. Results Twenty-one (70%) of the women with PCOS had elevations of DHEA sulfate, and 16 (53%) had elevations in 11/3-hydroxyandrostenedione. Only two women with PCOS had normal values of both adrenal androgens. After GnRH-A therapy, only 11 subjects (37%…

Orthogneisses in the Spessart Crystalline Complex, north-west Bavaria: Silurian granitoid magmatism at an active continental margin

1995

The Spessart Crystalline Complex, north-west Bavaria contains two orthogneiss units of granitic to granodioritic composition, known as the Rotgneiss and Haibach gneiss, respectively, which are structurally conformable with associated metasediments. The igneous origin of the Rotgneiss is apparent from field and textural evidence, whereas strong deformation and recrystallization in the Haibach gneiss has obscured most primary textures. New geochemical data as well as zircon morphology prove the Haibach gneiss to be derived from a granitoid precursor, which was chemically similar to the Rotgneiss protolith, thus suggesting a genetic link between those two rock units. Both gneiss types have che…

Einfluß der Proliferationsrate auf den Krankheitsverlauf von nodalnegativen Mammakarzinomen

1995

In 250 patients with node-negative breast cancer and no systemic adjuvant therapy the impact on the prognosis of the variables age, histological tumour type, tumour size, histological grade, receptor status and localisation of the tumour within the breast, was studied. Patients were followed over a mean period of 60 (range 7-164) months. In a subset of 124 cases additional examination of the growth fraction rate, detected by immunohistochemical determination of antibody Ki-67 and semiquantitative measurement of the stained tumour cell nuclei was performed. In 43 cases, measurement of S-phase fraction by flow cytometry was also performed. By univariate analysis, the histological tumour type …

Genes of the sea urchin embryo: An annotated list as of December 1994

1995

The main literature regarding gene structure and expression in sea urchin embryos is schematically reported and briefly commented upon. Although the subject has expanded particularly over the last 10 years, to which the review mostly refers, some historical reference is also given. More space is reserved to the regulation of the synthesis of histones and cytoskeletal actins, where the attention of various authors has been especially present; the regulation of such a synthesis is described both at a territorial level and a temporal level during the sea urchin development.

Morphology of cardiac muscle in septic shock. Observations with a porcine septic shock model.

1995

The morphology of cardiac muscle was investigated in a porcine model of septic shock, created by intermitted application of Escherichia coli-endotoxin. The earliest lesions, found after 18 h of septic shock, were endothelial cell swelling, marked leucostasis and slight ischaemic alterations of the muscle fibres. At the end point of the experiments, after 48 h, some fibrin thrombi were found associated with more pronounced ischaemic alterations of cardiac muscle cells and some necrotic fibres. Comparing these findings with the severe endothelial and muscle fibre lesions found in skeletal muscle, the endothelial cells of the heart microvasculature, are clearly more resistant to the attack of …

A finite number of regular rotational bands in the superdeformed well of 143Eu

1995

Abstract The number of excited superdeformed bands in 143 Eu is measured by use of the Fluctuation Analysis Method. Between 10 and 40 rotational bands, displaying typical rotational energy correlations over two consecutive transitions, are populated within a rather narrow range in transition energy, E γ ≈ 1300–1500 keV. These numbers are close to the values found for normally deformed nuclei and agree with microscopic cranking + band mixing calculations for the specific superdeformed nucleus, which predict the onset of rotational damping to occur at the excitation energy U 0 = 1.3–1.6 MeV above the yrast line.