showing 36 of ~574560 from 574555 documents
Microregional distributions of glucose, lactate, ATP and tissue pH in experimental tumours upon local hyperthermia and/or hyperglycaemia
1993
Microregional distributions of glucose, lactate and ATP concentrations as well as tissue pH values were determined in subcutaneous rat tumours during normothermia and normoglycaemia, and upon local hyperthermia (HT) and/or hyperglycaemia (HG). Experiments were performed in order to investigate whether, and to what extent, these adjuvant therapeutic measures applied alone or in combination can modify the bioenergetic and metabolic status, parameters that are known to markedly influence the therapeutic response of tumours to heat. Local HT was performed in a saline bath (44 degrees C/2 h) and HG was induced by i.v. infusion of glucose for 2.5 h (blood glucose levels during heating: 35-40 mM).…
Changes in yield ofin-vivo fluorescence of chlorophyll a as a tool for selective herbicide monitoring
1993
Triazines and derivatives of phenylurea, which are often found in outdoor water samples, induce specific changes in the yield of thein-vivo chlorophyll α-fluorescence of PSII. These changes are correlated quantitatively with the concentration of the herbicides and can therefore be used to set-up a low-price monitor system. In order to detect selectively the herbicide-sensitive part of the fluorescence emission a pulse amplitude modulated fluorimeter was used. The bioassay system was optimised with respect to test organism, growing and measuring conditions. The relationship between fluorescence yield and herbicide concentrations were experimentally determined for the triazines atrazine and s…
Seasonal studies of the biology ofAchtheres percarumin perch,Perca fluviatilis, from four Finnish lakes over a 3-year period
1993
Achtheres percarum infection on the gills of perch Perca fluviatilis was studied from four lakes in central Finland in monthly or bimonthly samples of fish during a 3-year period. The highest prevalence and intensity of infection (30%, 0.7 copepods/fish) were found in the oligotrophic, unpolluted Lake Peurunka and the lowest (6%, 0.1 copepods/fish) in the eutrophic and polluted Lake Vatia. According to hierarchical loglinear models the prevalence of A. percarum infection was related to the lake, but not to the year. However, when logit models were constructed such that two ‘seasons’ (‘cold’ and ‘warm’ periods) were included, it was apparent that the year also influenced the prevalence of A.…
Optimal selection of the four best of a sequence
1993
We consider the situation in which the decision-maker is allowed to have four choices with purpose to choose exactly the four absolute best candidates fromN applicants. The optimal stopping rule and the maximum probability of making the right choice are given for largeN∈N, the maximum asymptotic value of the best choice being limN→∞P(win)≈0.12706.
Surface phenotype and functions of tumor-infiltrating dendritic cells: CD8 expression by a cell subpopulation.
1993
Although the function and significance of tumor-infiltrating dendritic cells (TIDC) in the immune response to tumor have never been clearly demonstrated, their location suggests that they play a critical role in the presentation of tumor antigen to specific T cells. We studied the morphological and functional characteristics of interstitial dendritic cells (DC) located inside tumors obtained by injection of cancer cells into syngeneic rats. Single and double immunostaining of tumor sections revealed a dense network of cells which expressed class II major histocompatibility complex (MHC II) molecules. Cell morphology and surface markers were characteristic of DC populations in other tissues.…
Social service professionals in Finland under the pressures of a depressed economy and European integration
1993
The Nordic welfare states are known as women-friendly. However, during the last years their policies have been to turn the back on women. At least in Finland there seem to exist two powerful forces that have advanced the non-egalitarian development: the economic recession of the 1990s and the integration of Europe. The decline of the Nordic welfare states is going to have considerable consequences for social service professionals, the great majority of whom are women. Therefore, they should create new strategies and find new allies in order to defend their own as well their clients rights.
Calculation of allowed and first-forbidden beta-decay transitions of odd-odd nuclei
1993
Abstract A method for calculating the β − and β + EC transitions from an odd-odd nucleus to the excited states of the adjacent even-even nucleus is presented. The beta transitions are treated combining the charge-conserving and the charge-changing mode of the quasi-particle random- phase approximation assuming a common vacuum. The beta-decay transitions are treated in their allowed and first-forbidden approximations, including also the ground-state transition. As a test case of the present formalism, detailed beta-decay properties of the following odd-odd-to-even-even transitions have been calculated and compared with experiment: the β − decay transitions 136 I (2 − )→ 136 Xe (J π ) and 136…
Glutamate Activates Phospholipase D in Hippocampal Slices of Newborn and Adult Rats
1993
Phospholipase D (PLD) is activated by many neurotransmitters in a novel signal transduction pathway. In the present work, PLD activity was studied comparatively in hippocampal slices of newborn and adult rats. Basal PLD activity in adult rats was almost three times higher than in newborn rats. In newborn rats, L-glutamate and 1S,3R-1-aminocyclopentane-1,3-dicarboxylic acid (1S,3R-ACPD) time- and concentration-dependently enhanced the formation of [3H]phosphatidylpropanol ([3H]PP) and of [3H]phosphatidic acid in the presence of 2% propanol. N-Methyl-D-aspartate and kainate (both 1 mM) caused small, but significant increases (approximately 50%), whereas alpha-amino-3-hydroxy-5-methylisoxazole…
Metacognition, Metalanguage and Metapragmatics
1993
Abstract In this article, the author briefly reports John Flavell's analysis of metacognition. By attempting to integrate metalinguistic activities into this analysis, the author brings to light several interesting characteristics of the field of meta-linguistics and its current state of research. Firstly, it appears that, unlike other meta-abilities, the metalinguistic abilities are defined in terms of their objects. On this basis, metalinguistic activities are at least partially independent of other metacognitive activities. Secondly, it appears that the position of metapragmatics in relation to meta-linguistics is in need of greater clarification. In particular, it seems necessary to dra…
Serial measurements of transient evoked otoacoustic emissions (TEOAEs) in healthy newborns and in newborns with perinatal infection.
1993
Detection of hearing impairment in early childhood is difficult. We serially recorded transient evoked otoacoustic emissions (TEOAEs) to search for signs of ototoxicity in term, healthy newborns and compared the results to a second group of term babies treated for perinatally acquired bacterial infection with ampicillin plus either cefotaxime or plus aminoglycoside. At initial evaluation, in the group of 45 healthy children born at term, well reproducible emissions were observed in all but two children. In each of these two, initially well reproducible TEOAEs were detected in one ear only. At the time of the second recording (mean at day 8.5) excellent emissions were seen in all ears of all…
L-type calcium channel activity in human atrial myocytes as influenced by 5-HT.
1993
5-Hydroxytryptamine (10 mumol/l; 5-HT) exerted a positive inotropic effect associated with an increase in the Ca2+ current (ICa) in the human right atrium. For detailed analysis, L-type Ca2+ channel currents were recorded from cell-attached patches using 100 mmol/l Ba2+ as charge carrier. Ca2+ channel activity was identified, first, by burst-like inwardly directed currents and, second, by the appearance of long channel openings promoted by Bay K 8644 (1 mumol/l) upon repetitive depolarizations from -80 to 0 mV. The unitary conductance of the Ca2+ channel amounted to 25.8 pS. During superfusion with 5-HT, ensemble averaged (mean) current was enhanced by about 60%. The increase in mean curren…
Characterization of a multimeric polypeptide complex on the surface of thymus-derived cells in the Mexican axolotl.
1993
We previously raised a rabbit antiserum (L12) against a 38 kD polypeptide which is expressed on the surface of thymocytes and peripheral T cells of an Urodele Amphibian, the Mexican axolotl (Ambystoma mexicanum). Here we show that L12 antibodies immunoprecipitate several labelled molecules from surface iodinated axolotl spleen cells, including the 38 kD molecule, but also two polypeptides of 43 and 22 kD which are covalently linked to other elements. Another rabbit antiserum (L10) was raised against detergent-solubilized axolotl thymocyte membranes and shown to recognize the majority of thymocytes and about half of the splenocytes in immunofluorescence. In Western blotting, L10 antibodies r…
Nuclear Shadowing in a Parton Recombination Model
1993
Deep inelastic structure functions $F_2^A(x)$ are investigated in a $Q^2$ rescaling model with parton recombination effects. We find that the model can explain experimentally measured $F_2^A(x)$ structure functions reasonably well in the wide Bjorken$-x$ range ($0.005<x<0.8$). In the very small $x$ region ($x<0.02$), recombination results are very sensitive to input sea-quark and gluon distributions.
New trends in photobiology
1993
Abstract At the beginning of our century few scientists paid attention to the phenomenon of inactivation of photosynthesis by high light intensities which was later called photoinhibition. In the period 1925–1950, the idea was established that photoinhibition is a reversible inactivation, determined by light intensity and exposure time, followed by irreversible damage of the photosynthetic apparatus. However, the absence of a uniform terminology demonstrates that photoinhibition was not completely perceived and understood. In 1956, B. Kok gave the first definition of photoinhibition as a photochemical inactivation of pigment complexes.
Critical evaluation of two commonly used techniques for the treatment of data from extract dilution sniffing analysis
1993
The data from the extract dilution sniffing analysis of beer samples have been treated by two methods of analysis to give either «charm» or «FD» values. The results obtained from these two methods were compared and demonstrated that the rank order of intensity of the odor-active regions was different for most panelists when the data were presented as charm rather than FD values. Points of uncertainty observed while using this method such as between- and within-individual reproducibility and gaps in the coincident response five also been discussed
Refractive index of water-AOT-n-heptane microemulsions
1993
Refractive index measurements on water/AOT/n-heptane microemulsions as a function of the volume fraction ϕ of the dispersed phase (water plus AOT) and of the water/AOT molar ratio R have been performed at 25°C. The refractive index was found to vary monotonically with ϕ without any change in rate during the crossover of the percolation threshold. Such a behavior suggested that, well above the percolation threshold, the water-AOT-n-heptane microemulsions are still formed by water-containing AOT reversed micelles dispersed in the oil phase. The analysis of the experimental data allowed an evaluation the fraction of the water molecules bonded to the AOT head group as a function of R.
Comparing the relative volume with a revolution manifold as a model
1993
Given a pair (P, M), whereM is ann-dimensional connected compact Riemannian manifold andP is a connected compact hypersurface ofM, the relative volume of (P, M) is the quotient volume(P)/volume(M). In this paper we give a comparison theorem for the relative volume of such a pair, with some bounds on the Ricci curvature ofM and the mean curvature ofP, with respect to that of a model pair\(\left( {\mathcal{P},\mathcal{M}} \right)\) where ℳ is a revolution manifold and\(\mathcal{P}\) a “parallel” of ℳ.
Specialty and advanced polymers by carbocationic macromolecular engineering
1993
This study briefly surveys a variety of new advanced polymeric materials and controlled synthetic processes available by carbocationic macromolecular engineering techniques and having potential commercial interest. These recent developments, mainly by living carbocationic polymerization, have led to new opportunities in polymerization process control, and in designing microstructure, functionality, molecular weight and molecular weight distribution (MWD) and thus properties of a wide variety of unique polymer systems. The fundamentals of these new emerging technologies and the novel materials offered by them, such as macromonomers, telechelics, polymers with pendant functional groups (liqui…
Influence of Senna, Fibre, and Fibre + Senna on Colonic Transit in Loperamide-induced Constipation
1993
Retarded colonic transit and disturbed defecation are the most prominent pathophysiological mechanisms in constipation. Both may be influenced by bulking agents and by laxatives such as senna. Direct measurements of the influence of such substances on colonic transit are rare mainly because of technical problems. We measured gastric emptying, small and large intestinal transit in 24 healthy volunteers by a newly developed method employing a metal detector. Twelve persons taking a normal diet received loperamide in a dose sufficient to double the individual transit time. All subjects measured gastrointestinal transit time under normal conditions and with Sennatin containing purified sennosid…
Diorganotin(IV) dipeptide complexes with potential antitumour activity
1993
A series of complexes of the dimethylltin(IV) moiety with dipeptides has been synthesized. The dipeptides are L-alanyl-L-histidine (H2AlaHis), L-methionyl-L-methionine (H2MetMet), L-glycyl-L-histidine (H2GlyHis) and L-histidyl-L-glycine (H2HisGly). The complexes have been characterized by IR and 119Sn Mossbauer spectroscopy in the solid state and by 1H NMR in CD3OD and D2O solutions. They consist of monomeric entities, with the tin atom arranged in a pentacoordinated trigonal bipyramidal structure. The dipeptides are coordinated via the amino group, deprotonated peptide nitrogen and carboxylate group. Neither imidazole in histidine-containing dipetides, nor the thioether group in MetMet, is…
Human complement C81 (C8 A) polymorphism: detection and segregation of new variants
1993
In addition to the earlier detected C81(A) rare variants A1, A2 (now A3) and B1 (now B2), six new rare variants (C81 A2 new, A4, A5, A6, M1 and B1new) are described within the polymorphism of the eighth component of human complement (alpha-gamma chain subunit). Except for A3, all rare C81 A variants are only detected by isoelectric focusing, and not by SDS polyacrylamide gel electrophoresis (PAGE), in the alpha-gamma subunit. In one individual out of approximately 700 individuals studied, a reversed position of the common allele (B vs A) was observed by SDS PAGE and the isofocusing technique. The segregation of A1, A3 and A4 could be followed in putative father/child combinations.
Sequence analysis of the rDNA spacer of Paracentrotus lividus and observations about pre-rRNA processing. NTS sequence of Paracentrotus lividus rDNA.
1993
We have isolated and sequenced one intergenic region and a small part of the flanking regions (18S and 26S rRNA coding regions) of the rRNA-encoding genes (rDNA) from the sea urchin Paracentrotus lividus. This region is about 3.8 Kb long. Northern blot hybridizations and S1 mapping experiments demonstrated the presence of a partially processed 21S rRNA precursor while has the same 5' terminus as the 32S primary precursor, also in developmental stages characterized by a low rate of rRNA synthesis.
Anti-vimentin staining in muscle pathology
1993
The intermediate filaments of immature muscle fibres contain desmin and vimentin; vimentin is lacking in mature fibres. Regenerating fibres react with anti-vimentin antibodies and more intensely for desmin than mature fibres. The aim of the present study was to evaluate anti-vimentin staining for muscle pathology. Anti-vimentin-reactive fibres were found in 40 of 89 biopsies assessed. Fifteen patients with progressive destructive myopathy, infantile spinal muscular atrophy, clinically suspected Leigh's disease or unclassifiable congenital myopathy had between 1% and 95% vimentin-positive fibres. Less than 1% positive fibres were found in 25 patients with neuropathy with secondary myopathy o…
La financiacion de la ensenanza superior en Andalucia : 1987-1993
1993
International audience
Secretin—cerulein test and fecal chymotrypsin concentration in children with intestinal giardiasis
1993
We studied six patients with giardiasis (five males, one female), median age 3.5 yr (range 1-11) and 12 healthy control subjects (10 males, 2 females), median age 3.5 yr (range 1-10). Intestinal biopsy and a contemporaneous secretin-cerulein test were performed in all patients, and fecal chymotrypsin was also assayed. Intestinal biopsy was normal in five of the six patients with giardiasis, whereas one of the six presented a partial atrophy of the intestinal villi. The secretin-cerulein test (1 CU/kg of secretin + 75 ng/kg of cerulein) did not show any significant difference between values in the outputs of chymotrypsin, lipase, phospholipase, and bicarbonate obtained in patients and in con…
Insulin-like growth factor 1 and sodium-lithium countertransport in essential hypertension and in hypertensive left ventricular hypertrophy
1993
The aim of this work was to study the insulin-like growth factor 1 (IGF1), a substance able to promote cell proliferation in vascular smooth muscle, in patients with mild-to-moderate hypertension and to analyse its relationship to sodium-lithium countertransport, a genetic marker of hypertension that is related to cardiovascular complications.We studied 32 hypertensive subjects, some with left ventricular hypertrophy, and 14 healthy subjects. Fasting plasma IGF1 was measured by means of a radioimmunoassay after octadecylsilica chromatography and Na(+)-Li+ countertransport was determined by the method of Canessa.Hypertensive patients had higher values of both IGF1 and Na(+)-Li+ countertransp…
Removability theorems for solutions of degenerate elliptic partial differential equations
1993
Influence of Structural Isomerism on the Electronic Properties of Extended Phthalocyanines
1993
Abstract The electronic structure of isomeric naphthalocyanines (H2Nc) is investigated using the nonempirical valence effective Hamiltonian (VEH) technique. The way the outer benzene rings are annelated (linearly as in 2,3-H2Nc or angularly as in 1,2-H2Nc) is shown to determine very important changes in the electronic properties. While similar properties to those of phthalocyanine are calculated for 1,2-H2Nc, lower oxidation potentials and red-shifted optical absorptions are predicted for 2,3-H2Nc in agreement with experimental data. The isomerism resulting from the different relative positions of the angularly annelated benzene rings in 1,2-H2Nc is shown to have almost no effect on the ele…
Isolation and characterization of a photosystem I-associated antenna (LHC I) and a photosystem I—core complex from the chlorophyll c-containing alga …
1993
Abstract A photosystem (PS) I holocomplex was isolated from Pleurochloris meiringensis Vischer (Xanthophyceae) using sucrose density centrifugation. This complex exhibited a fluorescence emission maximum at 715 nm, which is in accordance with the long wavelength emission of whole cells. The complex was further dissociated into a core complex and a light-harvesting protein (LHC I). The core protein contains mainly Chl a and β-carotene, is 8.25 times enriched in P700 and has its main emission maximum at 715 nm. Therefore, the longest wavelength emission of P. meiringensis is due to the PS I core, which is in contrast to higher plants. The LHC I differs from LHC II with regard to its polypepti…
Analysis of the in vitro cytokine production by liver-infiltrating T cells of patients with autoimmune hepatitis.
1993
SUMMARY The pathogenic mechanisms underlying the development of autoimmune hepatitis (AIH) are still unclear. Since AIH is associated with the presence of various autoantibodics and certain HLA subtypes, it is likely that T and B cells play a major role in this disease. In this study we have determined the functional capacities of in vivo preactivated liver-infiltrating T cells (LTC) from patients with AIH. As controls we used LTC from patients with non-autoimmune hepatitis (non-AIH). Our results show that preactivated LTC from patients with AIH predominantly (190/255 clones) reside in the CD4+ population, whereas LTC in non-AIH are dominated by the CD8+ phenotype (148/254 clones). In view …
Discotic Liquid Crystals - A New Class of Fast Photoconductors
1993
We showed for the first time that discotic liquid crystals are well suited for a new class of fast photoconducting materials. Due to their spontaneous orientation and their dynamical fluctuations in the mesophase, they show exceptionally high mobilities of 1·10−3 cm2/Vs, about two to three orders of magnitude higher than those obtained for conventional amorphous polymers. Further on, the Gaussian transport (for holes in the mesophase) is remarkable, which is characterized by the existence of a conduction band and the absence of trapping states. In contrast, the charge carrier transport in amorphous photoconductors is generally trap-dominated which limits technical properties, leading to low…
Type II narrow double barrier quantum well structures : Γ-X coupling and interface effects
1993
Photoluminescence (PL), PL excitation and time resolved PL experiments have been performed on Al0.42Ga0.58As/AlAs/GaAs symmetric double barrier quantum wells (DBQW) with only one or two AlAs monolayers constituting the intermediate barriers. In agreement with the envelope function predictions we show that such DBQW's undergo a type I - type II transition when the GaAs thickness is reduced below 7 and 5 monolayers for 2 and 1 AlAs molecular planes respectively. In type II configuration the PL decay time is found to be strongly dependent on the energy difference between AlAs Xz - and GaAs Γ - electron confined states and the coupling parameter of the Γ and Xz valleys can be deduced (4.2 meV o…
Does prehospital care by physicians result in a better outcome than resuscitation by other EMS personnel?
1993
In-Plane Anisotropy and Phase Change in Langmuir-Blodgett Films of a Triphenylene Derivative
1993
Abstract The “in-plane anisotropy” of a triphenylene derivative in Langmuir-Blodgett (L.B.) films has been investigated. Upon heating, L.B. films exhibit a reversible phase transition appearing as an abrupt increase from a low to a high “in-plane anisotropy” corresponding to the formation of the same hexagonal liquid crystal phase observed in the bulk material at almost the same temperature, with the columnar axis aligned along the dipping direction.
A precise measurement of the real part of the elastic scattering amplitude at the Sp̄pS
1993
Abstract A precise measurement of pp elastic scattering in the Coulomb-strong interaction interference region was performed at the CERN SppS Collider at a centre-of-mass energy of 541 GeV. The ratio of the real to the imaginary part of the forward elastic scattering amplitude was found to be ρ = 0.135 ± 0.015. The slope of the exponential fall off of the strong interaction part was also measured to be b = 15.5 ± 0.1 GeV −2 .
Remission of experimental autoimmune hepatitis is associated with antigen-specific and non-specific immunosuppression.
1993
SUMMARY Experimental autoimmune hepatitis (EAH) is an animal model for autoimmune hepatitis. The disease is T cell-mediated and runs a subacute course, with maximal disease activity around week four after disease induction and a slow ensuing recovery. The aim of the present study was to investigate the immunoregulatory mechanisms that may account for recovery in EAH. It was found that T cell reactivity to liver antigens preceded histological disease, but at the peak of disease activity this T cell response was already suppressed. Active and antigen-specific suppression could be demonstrated, as irradiated splenocytes from animals at the beginning of recovery from EAH were able to suppress i…