Showing papers by "Ghent University published in 1975"
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TL;DR: In this article, it was shown that the modes of a dielectric resonator are of two types: confined and non-confined, and their radiation pattern and quality factor were investigated.
Abstract: It is shown that the modes of a dielectric resonator are of two types: confined and nonconfined. Orthogonality properties and variational principles are derived for these modes, and their radiation pattern and quality factor are investigated. The material of the resonator is assumed lossless and of very high permittivity.
140 citations
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TL;DR: Evidence is presented indicating a rapid in vivo evolutionary change in this strain of Staphylococcus aureus, which is probably of human origin.
140 citations
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TL;DR: The nucleotide sequence of the A-protein gene of bacteriophage MS2 has been determined and a model for its secondary structure is proposed and the amino acid sequence has been almost completely elucidated.
Abstract: The nucleotide sequence of the A-protein gene of bacteriophage MS2 has been determined and a model for its secondary structure is proposed. Also the amino acid sequence of the A-protein has been almost completely elucidated.
136 citations
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01 Dec 1975TL;DR: In this paper, a mathematical model accounting for frequency laws is presented, in which a distribution of time constants is assumed, associated with dielectric relaxation phenomena in the double layer at the semiconductor/electrolyte interface.
Abstract: The impedance of several nearly ideally polarizable semiconductor electrodes (CdSe, CdS, TiO2) has been studied as a function of applied voltage and of frequency. The differential capacitance and resistance appear to obey to simple frequency laws. A mathematical model accounting for these laws is presented, in which a distribution of time constants is assumed, associated with dielectric relaxation phenomena in the double layer at the semiconductor/electrolyte interface. The experimental results indicate, that the source of the frequency-dependence has to be sought in structural irregularities of the surface region of the electrode. The proposed model appears to be also applicable to results, mentioned in the literature, concerning other semiconductor/electrolyte systems. The possibility of determining the flat-band potential from frequency-dependent capacitance data is discussed.
Die Impedanz verschiedener fast ideal polarisierbaren Halbleiterelektroden (CdSe, CdS, TiO2) wurde in Abhangigkeit von der angelegten Spannung und der Frequenz untersucht. Die Differentialkapazitat und der Differentialwiderstand zeigen einfache Frequenzabhangigkeiten. Diese Gesetze werden aufgrund eines mathematischen Modells gedeutet, in dem eine Verteilung von Zeitkonstanten angenommen wird, die mit dielektrischen Relaxationserscheinungen in der Doppelschicht an der Halbleiter/Elektrolyt-Phasengrenze in Zusammenhang stehen. Die Ergebnisse deuten darauf hin, Strukturdefekte im Oberflachengebiet der Elektrode seien fur die Frequenzabhangigkeit verantwortlich. Es zeigt sich, das das vorgeschlagene Modell auch auf Literaturergebnisse betreffs anderer Halbleiter/Elektrolyt-Systeme anwendbar ist. Die Moglichkeit, das Flachbandpotential aus frequenzabhangigen Kapazitatsergebnissen zu bestimmen, wird besprochen.
120 citations
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TL;DR: The purpose of this study was to investigate the influence of an occlusal bite plane splint on jaw position and relief of functional temporomandibular joint (TMJ) and muscle symptoms.
Abstract: E v e n though the effect of the therapy is only partially understood and is sometimes equivocal, occlusal splints have been used extensively in the treatment of patients with functional disturbances of the temporomandibular joints. ~-; The effectivehess of splints has been related to tim avoidance of the disturbing input of oeclusal interferences o n the neuromuscular mechanism of the masticatory system."" ~ The purpose of this study was to investigate the influence of an occlusal bite plane splint on jaw position and relief of functional temporomandibular joint (TMJ) and muscle symptoms.
110 citations
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TL;DR: In this paper, a classification of the mutual spatial distributions of the coarse and fine fabric elements of lowest order: the c/f-related distributions is made of five orthotypes: monic, only one size fraction is present; gefuric, bridges of finer material exist between coarser grains; chitonic,finer material coats the coarser seeds; enaulic, the finer material occurs as small aggregates in the spaces between the coarse seeds.
92 citations
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TL;DR: In contrast to the use of coupling constants, chemical shift criteria may lead to unambiguous structural elucidations in pseudorotational frameworks (pentacycles, heptacycles etc.).
Abstract: It is shown that in contrast to the use of coupling constants, chemical shift criteria may lead to unambiguous structural elucidations in pseudorotational frameworks (pentacycles, heptacycles, etc.).
85 citations
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TL;DR: It is shown that a necessary condition for the existence of a maximal arc (as a proper subset of a given plane 7r(q) is that n should be a factor of q, and it is proved that this condition does suffice in the case of any desarguesian plane of order 2 h.
84 citations
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TL;DR: In three patients treated for macular degeneration with argon laser photocoagulation choroidal neovascularization occurred four to six weeks later at the photocogulation site, the patients were treated for angioid streaks of the macular region.
83 citations
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TL;DR: Controlled mass culture of brine shrimp larvae to the adult stage has been extremely difficult until now; the literature on the subject is reviewed and a new tech-nique of high density culturing at the pilot-stage is described.
62 citations
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TL;DR: In this article, the response of a dielectric resonator excited by either interior volume sources or incident exterior waves is investigated, and special attention is devoted to phenomena at resonace, and in particular to the induced electric and magnetic dipoles.
Abstract: The response of a dielectric resonator excited by either interior volume sources or incident exterior waves is investigated. Special attention is devoted to phenomena at resonace, and in particular to the induced electric and magnetic dipoles. Simple formulas are obtained for the scattering cross section. The material of the resonator is assumed lossless and of very high permittivity.
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TL;DR: Strains isolated from the skin and the upper respiratory tract of chickens and from bovine udders showed characteristics typical for Staphylococcus epidermidis biotype 2, but produced a heat-resistant nuclease (DNase) and reacted in the tube coagulase test.
Abstract: Strains isolated from the skin and the upper respiratory tract of chickens and from bovine udders showed characteristics typical for Staphylococcus epidermidis biotype 2, but produced a heat-resistant nuclease (DNase) and reacted in the tube coagulase test. The strains were physiologically, biochemically and serologically indistinguishable from Staphylococcus hyicus strains isolated from swine. However, in contrast to S. hyicus, they appeared to be devoid of pathogenicity when tested in colostrum deprived piglets. The poultry strains occur frequently as skin inhabitants.
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TL;DR: In this article, the frequency dependences of the real and imaginary parts of an electrical impedance are correlated by the Kramers-Kronig relations, and the importance of these relations in electrochemistry is illustrated by the examples of certain electrochemical impedance types.
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TL;DR: Testes from rats of different ages were incubated with or without tritiated testosterone and metabolites were mainly metabolized to 7α-hydroxylated testosterone in adult animals, and to Set-reduced metabolites in immature animals.
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TL;DR: The synthesis of DNA and RNA and the increase in dry matter were followed in the elongating cells of the epicotyl of peas (Pisum sativum L.) germinating in total darkness or in continuous light.
Abstract: The synthesis of DNA and RNA and the increase in dry matter were followed in the elongating cells of the epicotyl of peas (Pisum sativum L.) germinating in total darkness or in continuous light. The amounts of DNA and RNA per epicotyl were estimated by chemical methods, the amount of DNA per cell was measured by histophotometric techniques. The increase in DNA, RNA and dry matter in the epicotyl cells is much higher during germination in darkness than in light. During elongation in the dark most cortical epicotyl cells reach the 8C polyploidy level, in the light only the 4C polyploidy level is reached. A decrease in RNA synthesis is in agreement with a reduction in nuclear volume.
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TL;DR: The data of the study suggest that the specific training of paddlers do result in a effect on the haemodynamic adaptations to arm work, and oxygen consumption and ventilation during work with the arms was lower in the group of paddler.
Abstract: Maximal oxygen uptake and circulatory adaptation to work with legs and arms were studied in a group of 5 paddlers members of the Belgian national squad and a control-group of 9 trained subjects. The results showed that the specific armtraining of paddlers induced changes in the arm-to-leg ratio of physiological parameters at submaximal and maximal work. In the group of paddlers maximal oxygen intake and workload during arm-exercise averaged respectively 88.6% and 80.3% of the scores obtained with leg-exercise. In the control group the arm to leg ratio varied between 81.2% and 65.2%. At a submaximal load of 100 W the difference in heartfrequency was 21 beats/min in the canoe group and 35 beats/min in the control group. Oxygen consumption and ventilation during work with the arms was lower in the group of paddlers. The data of our study suggest that the specific training of paddlers do result in a effect on the haemodynamic adaptations to arm work
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TL;DR: In this article, the cation distribution and the oxygen parameter for the system Mg1+y Fe2(1−y) Ti 2 y O4 have been determined using the intensities of X-ray reflections.
Abstract: The cation distribution and the oxygen parameter for the system Mg1+y
Fe2(1−y) Ti
y
O4 have been determined using the intensities of X-ray reflections. Results are given for slowly cooled and quanched samples. An explanation is proposed to account for the behaviour of the lattice parameter and the oxygen parameter.
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TL;DR: A simple method is described for the routine detection of antithyroid residues in thyroid, liver, kidney and meat contaminated at levels as low as 10 ppb (10 parts per 10(9).
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TL;DR: Important populations of Staphylococcus aureus were found to be present on the body surfaces of live poultry originating from flocks without history of staphylitis and their sized increased considerably until approximately the seventh week of life after which time they were maintained at equally high levels.
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TL;DR: In einem Fall von akuter Parathion-Intoxikation, welcher 9 Tage uberlebte, wurden bei der Autopsie segmentale Nekrosen in der Nahe der motorischen Endplatten in den Zwerchfellmuskelfasern gefunden as discussed by the authors.
Abstract: In einem Fall von akuter Parathion-Intoxikation, welcher 9 Tage uberlebte, wurden bei der Autopsie segmentale Nekrosen in der Nahe der motorischen Endplatten in den Zwerchfellmuskelfasern gefunden. Obwohl die nekrotischen Veranderungen nur am Zwerchfell gefunden wurden, fehlte die Cholinesteraseaktivitat auch in allen ubrigen untersuchten Muskelendplatten. Die Nekrose im Endplattenbereich des immer noch beweglichen Zwerchfelles war wahrscheinlich eine Folge der langdauernden Depolarisation mit Veranderungen der postsynaptischen Membran als Ergebnis der hohen Acetylcholinkonzentration.
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TL;DR: Two unknown steroids were isolated from the urine of patients with hypertension and/or adrenal disorders and the behaviour of compound x in solution is very similar to that of 18-OH-DOC (predominance of the 18–20 hemi-ketal, formation of dimer and of other derivatives).
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TL;DR: The urinary and biliary excretion of radioactive products in a 6 hr period after intravenous administration of [3H]papaverine was studied in rat, guinea-pig, rabbit, cat and dog.
Abstract: 1. The urinary and biliary excretion of radioactive products in a 6 h period after intravenous administration of [3H]papaverine was studied in rat, guinea-pig, rabbit, cat and dog. All species excreted metabolites extensively in the bile; only in rabbit and guinea-pig is urinary excretion important.2. Metabolites in urine and bile of all species studied are mainly monophenolic compounds conjugated to glucuronic or sulphuric acid. Differences in the excretion patterns of the metabolites between different species are only quantitative.3. Blood or plasma levels of papaverine after intravenous injection decreased with half-lives of approximately 12, 15, 22, 60 and 60 min for rabbit, rat, guineapig, cat and dog, respectively. The metabolites disappeared much more slowly than papaverine from the plasma.4. Binding of papaverine to plasma proteins, as studied by equilibrium dialysis, was more than 90% in all species.
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TL;DR: In this article, the separation and quantitative analysis of piperine and its isomers by HPLC on aluminum oxide is described and the influence of light (photoisomerization) on ground pepper and pepper extracts is illustrated.
Abstract: The separation and quantitative analysis of piperine and its isomers by HPLC on aluminum oxide is described. Only piperine has a strong pungent taste. The isomers of piperine occur in pepper and in pepper extracts. The influence of light (photoisomerization) on ground pepper and pepper extracts is illustrated.
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TL;DR: In this article, a special case of a Denisyuk set-up is used for double-exposure holographic interferometry, namely, with the photographic plate fixed to one point of the object under study and plane illumination through the plate, some interesting advantages can be obtained.
Abstract: When a special case of a Denisyuk set-up [1] is used for double-exposure holographic interferometry, namely, with the photographic plate fixed to one point of the object under study and plane illumination through the plate, some interesting advantages can be obtained. The stability requirements are drastically reduced (a general translation and a rotation around an axis parallel to the illumination direction can be allowed); the optical set-up is very simple; white-light reconstruction can be used. For the determination of in-plane displacement patterns, one can either use fringe-order subtraction between two symmetrical off-axis views (eventually Moire subtraction), or use speckle correlation techniques. The most important advantage is that Cartesian components of displacements can be determined with complete object motion compensation by combining holographic and speckling techniques. Some practical applications of the method and its drawbacks are presented.
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TL;DR: The alkaloids have been shown to originate from a spontaneous condensation of the corresponding amines with formaldehyde, this latter being formed in the first stage of the reaction by enzymatic conversion from 5-methyltetrahydrofolic acid.
Abstract: The use of thin-layer chromatography has demonstrated that incubations of indoleamines with 5-methyl[14-C]tetrahydrofolic acid and an enzyme previously described as an N-methyltransferase, do not yield Nw, N1, or O-methylated products. Further elucidation by thin-layer chromatography, gas chromatography, mass spectrometry and selected ion monitoring enabled us to identify the reaction products as tetrahydroisoquinolines and tetrahydro-beta-carbolines in mixtures incubated respectively with catecholamines and indoleamines in the presence of 5-methyl[14-C]tetrahydrofolic acid and enzyme. The alkaloids have been shown to originate from a spontaneous condensation of the corresponding amines with formaldehyde, this latter being formed in the first stage of the reaction by enzymatic conversion from 5-methyltetrahydrofolic acid.
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TL;DR: In this article, a reaction of α,α-dihalogenated aldimines with lithium aluminium hydride provided a facile synthesis of 1,1-disubstituted aziridines (a three step synthesis starting from ordinary aliphatic aldehydes).
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TL;DR: A syndrome of combined right lateral gaze palsy and right internuclear ophthalmoplegia, followed by a left exotropia in a case of subarachnoid hemorrhage, and the mechanism of these characteristic ocular motor disturbances in relation to the post mortem findings and the topopathogenesis of the pontine infarction are discussed.
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TL;DR: Une pénicilline V-acylase intracellulaire, produite par une soucheErwinia aroideae a été purifiée et caractérisée, présente des propriétés différentes des penicilline-acyLases classiques.
Abstract: Une penicilline V-acylase intracellulaire, produite par une soucheErwinia aroideae a ete purifiee et caracterisee. Cette enzyme presente des proprietes differentes des penicilline-acylases classiques.
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TL;DR: After hydrolysis with glusulase of bile from rats treated with papaverine, four metabolites (A, B, C and D) were separated and the structures A, B and C were established as monodemethylated compounds, 4'-desmethyl, 7-des methyl-, and 6-desmethylpapaverine.
Abstract: 1. After hydrolysis with glusulase of bile from rats treated with papaverine, four metabolites (A, B, C and D) were separated.2. The structures of A, B and C were established as the monodemethylated compounds, 4′-desmethyl-, 7-desmethyl-, and 6-desmethylpapaverine, respectively.3. D was formed from papaverine by bis-demethylation. Since it was found in cat bile after administering either A or C, but not B, it was identified as 4′,6-desmethylpapaverine.