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Showing papers by "Radboud University Nijmegen published in 1977"


Journal ArticleDOI
08 Jul 1977-Science

438 citations



Journal ArticleDOI
TL;DR: In this article, the truncated diagonalization method with hydrogenic basis functions was used to classify the doubly excited states in isoelectronic helium (Z = 1, 2, 3, 4, 5) into series and outer quantum number.

162 citations


Journal ArticleDOI
TL;DR: A series of 1,420 Dutch patients with facial fractures was compared with series from three other European countries and found the need for treatment of facial fractures in well-equipped centers is important and cooperation with other specialiies is very often necessary.

147 citations


Journal ArticleDOI
TL;DR: It seems probable that the same mechanism can be held responsible for the lesions of the olfactory, optic, vestibular and cochlear nerves, the hypophyseal form of diabetes insipidus, retarded sexual maturation, abnormal pupillary reaction, myelopathy and the electro-encephalographic, electroneurological and electromyographic changes in the Wolfram syndrome.
Abstract: A review of 88 cases from the literature with personal observations on 3 new patients is given of the syndrome featured by juvenile diabetes mellitus, optic atrophy, hearing loss, diabetes insipidus, atonia of the urinary tract and bladder and other abnormalities The postmortem in one of our cases is mentioned The pattern of inheritance is autosomal recessive The interpretation of the data on diabetes insipidus from the literature and in our three patients is also discussed It can only be stated that neurohypophyseal diabetes insipidus can be a component of the syndrome and that in many cases--particularly in the presence of lesions of the efferent urinary tract--the possibility of nephrogenous diabetes insipidus can not be excluded with certainty It seems probable that the same mechanism can be held responsible for the lesions of the olfactory, optic, vestibular and cochlear nerves, the hypophyseal form of diabetes insipidus, retarded sexual maturation, abnormal pupillary reaction, myelopathy and the electro-encephalographic, electroneurological and electromyographic changes in the Wolfram syndrome The process underlying this affection of neural structures remains obscure

130 citations


Journal ArticleDOI
TL;DR: The structural organization of the brain and spinal cord of the lamprey is surveyed and it is felt justified in using in the present treatise the term “lamprey” without any further specification.
Abstract: From the dawn of comparative neuroanatomy the central nervous system of the lamprey has attracted the attention of a great number of workers. Owing t o its alleged primitiveness and simplicity’ it was expected that analysis of the brain and spinal cord of these forms would yield the “prototype”2 i.e., the natural starting point for the study of the development and differentation of the vertebrate neuraxis. Hence, many so-called evolutionary trends, like for example the progressive migration, differentiation, segregation, and specialization of neurons and neuron groups, were considered as having their point of departure in the brain of the lamprey or in lamprey-like brains. Unfortunately, many of these trends have been described in a straightforwardly phylogenetic setting without any clear justification for doing so. In fact, all of these trends are naturally based on the study of a single or a few related features and should be considered on that account as typologic rather than phylogenetic. Lampreys have a long, independent phylogenetic history behind them and n o recent group of vertebrates, let alone the entire vertebrate kingdom, can be said t o have arisen from them. However, it cannot be denied that the lampreys retain more features of the presumed ancestral craniates than d o any other members of the group,3 and therefore deserve especial attention. The first part of the present paper will survey the structural organization of the brain and spinal cord of the lamprey. This survey is based on a study of the literature and o n our own Nisslstained and silver-impregnated material of Lampetra fluviatilis. In the second part of this paper the central nervous system of the lamprey will be placed in a comparative perspective. Some of the “trends” referred to above will be review ed. It should be noted that our present-day knowledge of the central nervous system of the lamprey is based on the study of many different species. It stands t o reason that these species differ sufficiently t o be distinguished by the taxonomist. However, neuroanatomically there are no appreciable differences among them; hence, I feel justified in using in the present treatise the term “lamprey” without any further specification.*

122 citations



Journal ArticleDOI
TL;DR: A 1 g interior sample of the Murchison CII meteorite was examined for the presence of purines and pyrimidines by dual-column, ion-exclusion chromatography and ultraviolet spectroscopy as mentioned in this paper.

108 citations


Journal ArticleDOI
TL;DR: Yeast strains belonging to at least 9 genera were isolated from natural habitats and screened for killer-sensitive relationships and killer and sensitive characteristics were exhibited by 17 and 11 percent of the isolates, respectively.
Abstract: Yeast strains (157) belonging to at least 9 genera were isolated from natural habitats and screened for killer-sensitive relationships. Killer and sensitive characteristics were exhibited by 17 and 11% of the isolates, respectively. The strains belong to either one of two mutually exclusive killer-sensitive groups.

93 citations


Journal ArticleDOI
TL;DR: Evidence for a major adrenal origin of the elevated testosterone values in the women with Cushing's disease was derived from the parallel suppression of cortisol and testosterone during dexamethasone administration, the testosterone responsiveness to ACTH and its dramatic fall after adrenalectomy.
Abstract: Elevated plasma testosterone levels were found in 8 women with Cushing's disease and oligo-or amenorrhea and/or hirsutism. In 4 men with Cushing's syndrome either due to adrenal hyperplasia or adenoma, plasma testosterone levels were lowered. Three of these 4 men complained of impotence or loss of libodo. Evidence for a major adrenal origin of the elevated testosterone values in the women with Cushing's disease was derived from the parallel suppression of cortisol and testosterone during dexamethasone administration, the testosterone responsiveness to ACTH and its dramatic fall after adrenalectomy. In the men with Cushing's syndrome the lowered plasma testosterone values were further suppressed by high doses of dexamethasone irrespective of concomitant cortisol suppression. Adrenalectomy or adenotomy restored the decreased plasma testosterone levels to normal. In women with Cushing's syndrome adrenal hyperandrogenism may account for the sexual and gonadal disturbances, in men glucocorticoid induced suppression of Leydig cell function may be responsible.

92 citations



Journal ArticleDOI
TL;DR: L-Ornithine-ketoacid-transaminase deficiency was established in cultured fibroblasts obtained from a patient with hyperornithinaemia and gyrate atrophy of the choroid and retina, indicating that the enzymic defect was not due to a decreased affinity for this substrate.


Journal ArticleDOI
TL;DR: It was shown that the pedometer does not reflect the differences in energy expenditure levels at different speed very well, and the actometer might be a valid indicator of the daily physical activity in terms of energy expenditure.
Abstract: The purpose of this study was a critical evaluation of pedometer and actometer for estimating daily physical activity.

Journal ArticleDOI
TL;DR: In this article, the first prelude of J.S. Bach's Wohltemperiertes Clavier was performed by three professional musicians and a number of temporal characteristics were derived that possibly play a role in the perception and appreciation of musical performances.

Journal ArticleDOI
TL;DR: In this article, a relatively simple ab initio method to calculate full van der Walls interaction potentials between molecules is presented, and closed expressions for the long range interaction energy are derived in which the orientational dependence is simplified to the utmost.
Abstract: Presenting a relatively simple ab initio method to calculate full van der Walls interaction potentials between molecules, rules are given for the optimization of basis functions which permit the reliable evaluation of second order long range interactions. Closed expressions for the long range interaction energy are derived in which the orientational dependence is simplified to the utmost. Calculations show that even for molecules which have no dipole moment, such as ethylene, the strongly anisotropic electrostatic interactions are of the same magnitude as the dispersion interactions, but also that the anisotropic (''cross'') terms in the dispersion energy are about equal in size to the corresponding ''quadratic'' terms. Even though these anisotropic forces cancel to a large extent in the cohesion energy of the ethylene crystal, they can have important effects on some of the other crystal properties.

Journal ArticleDOI
TL;DR: N-ethylmaleimide lowers the number of sites which are phosphorylated by inorganic phosphate, without affecting the dissociation constant of the enzyme-phosphate complex, and does not affect the relative stimulation by ATP of the K+-stimulated 4-nitrophenylphosphatase activity.

Journal ArticleDOI
TL;DR: In this article, a new technique of forming tiny point contacts between normal metals is described, based on measuring the voltage derivative of the resistance of such contacts at 1.2 K, structure is found which is consistent with bulk-phonon densities of states.
Abstract: A new technique of forming tiny point contacts between normal metals is described. By measuring the voltage derivative of the resistance of such contacts at 1.2 K, structure is found which is consistent with bulk-phonon densities of states. Similar results were reported recently by Yanson using a shorted-film technique. When interpreted, the observed structures yield electron-phonon coupling parameters in close agreement with literature values.

Journal ArticleDOI
TL;DR: The pedometer results point out that when the percentage of intense activity is high the pedometer tends to underestimate the level of activity and the actometer results indicate that such a motion recorder gives a reliable estimation of activity in children.
Abstract: The validity of the pedometer and actometer for estimating the daily physical activity was evaluated by means of an observation study. The physical activity in a classroom of 11 pupils of a kindergarten was assessed by means of a pedometer, actometer and by observation. Besides this an activity questionnaire was completed by the infant-quide. On basis of the individual observation it is clear that the infant-guide can give valuable information about the activity of the children at school. The results of the pedometer attached to the waist and the actometers attached to the ankle were significantly correlated with the results of the observation method. The wrist actometer showed a smaller but still significant correlation with the other variables. Implications of this findings are discussed in regard toward the physical activity. The pedometer results point out that when the percentage of intense activity is high the pedometer tends to underestimate the level of activity. The actometer results indicate that such a motion recorder gives a reliable estimation of activity in children. The findings are discussed in terms of the practical applications of the actometer in the research of daily physical activity and the physical rehabilitation treatment of certain diseases.

Journal ArticleDOI
TL;DR: In this paper, three mechanisms were found suitable to describe the hydrogenation of benzene on a nickel-silica catalyst: a mechanism with a rate determining step, the following hydrogen addition steps being faster; a mechanism based on the assumption that all hydrogen addition step have the same rate constant; and a set of slow steps after an adjustable number of fast addition steps.

Journal ArticleDOI
TL;DR: In this paper, the mean square vibrational amplitude and isomer shift of gold atoms in small particles of gold metal embedded in gelatin were investigated by the M\"ossbauer effect.
Abstract: The mean-square vibrational amplitude and isomer shift of gold atoms in small particles of gold metal embedded in gelatin were investigated by the M\"ossbauer effect. Nine samples with average particle diameters of 30-170 \AA{} were examined, three of which (31, 52, and 168 \AA{}) as function of temperature. All samples showed different, but positive, isomer shifts with respect to bulk gold without an apparent correlation with the particle size. At 4.2\ifmmode^\circ\else\textdegree\fi{}K the M\"ossbauer fraction shows no significant difference with bulk gold, whereas at higher temperatures the M\"ossbauer fraction decreases more rapidly when the particle size becomes smaller. This temperature dependence is analyzed within the framework of the Debye continuum theory of lattice vibrations, which is a good approximation in case of bulk gold. It is shown that neither the application of a low-frequency cutoff on the phonon spectrum, nor the contribution of surface and edge modes or an independent treatment of bulk and surface atoms gives a satisfactory explanation of the observations, but, that the vibration of the particle as a whole has to be taken into account, which overshadows possible size effects.

Journal ArticleDOI
TL;DR: In a group of 13 healthy male adults in the Netherlands, a seasonal variation in circulating serum thyroxine and triiodothyronine levels was found, inversely correlating with the seasonally altering environmental temperature.
Abstract: In a group of 13 healthy male adults in the Netherlands, a seasonal variation in circulating serum thyroxine (T4) and triiodothyronine (T3) levels was found, inversely correlating with the seasonally altering environmental temperature. Lowest serum T4 and T3 levels were found in the summer.

Journal ArticleDOI
TL;DR: The results suggest that an arginine residue is present in the nucleotide binding centre of the enzyme and protects partially against the inactivating effect of butanedione.

Journal ArticleDOI
TL;DR: Mercapturic acid derivatives or other thioethers can be considered as the endproducts of the metabolic detoxification of possibly alkylating agents and their appearance in the urine can be used as an indicator of exposure of the organism to such toxic compounds.
Abstract: Mercapturic acid derivatives or other thioethers can be considered as the endproducts of the metabolic detoxification of possibly alkylating agents. It is proposed that the appearance of these metabolites in the urine can be used as an indicator of exposure of the organism to such toxic compounds. A simple, practical procedure for determination of thioethers in urine samples is described. Employees of chemical and metal industries have been compared with respect to their urinary thioether concentrations. It was found that chemical workers excreted more thioether compounds than persons engaged in metal industry.

Journal ArticleDOI
TL;DR: The properties of the cation binding sites of the phosphate uptake mechanism and those of theosphate-dependent cation transport mechanism have been compared and the existence of a separate sodium-phosphate cotransport system is proposed.


Journal ArticleDOI
TL;DR: In this article, the response of a step train on a jump in supersaturation has been investigated by means of computer simulations, and the results are in good agreement with the experiments.

Journal ArticleDOI
10 Nov 1977-Nature
TL;DR: Evidence is presented here that the poly A segments of non-polysomal mRNA of Ehrlich ascites tumour cells and of rabbit reticulocytes—in contrast to the polysomalpoly A segments10–13—do not contain the 76,000 MW protein.
Abstract: CYTOPLASM of animal cells contains mRNA associated with ribosomes (in polysomes) and mRNA free of ribosome attachment. Both classes of mRNA occur as ribonucleoprotein (mRNP) complexes1–3. The role of the untranslated pool of free mRNA (referred to as informosomes3) is uncertain. They represent the form in which mRNA exists in transit from the nucleus to the cytoplasm awaiting association with ribosomes3, and in addition the pool of free cytoplasmic mRNA contains inactive (or inactivated) and storage forms of mRNA4. It has been established that most of the polysomal mRNP complexes contain predominantly two proteins with approximate molecular weights (MW) of 49,000–52,000 and 73,000–78,000 respectively5–9. It is generally accepted that the larger of these proteins is attached to the 3′ poly A tail of mRNA10–12. We present evidence here that the poly A segments of non-polysomal mRNA of Ehrlich ascites tumour cells and of rabbit reticulocytes—in contrast to the polysomal poly A segments10–13—do not contain the 76,000 MW protein.

Journal ArticleDOI
TL;DR: The striatum of the lizard Tupinambis nigropunctatus lies in the lateral wall of the telencephalon and consists of two major subdivisions: the dorsal striatum and the ventral striatum.
Abstract: The striatum of the lizard Tupinambis nigropunctatus lies in the lateral wall of the telencephalon and consists of two major subdivisions: the dorsal striatum and the ventral striatum. Electrolytic lesions were placed in all parts of the striatal complex and in adjacent areas and the subsequent anterograde degeneration was studied using the Nauta-Gygax and Fink-Heimer techniques. Lesions in the dorsal striatum cause terminal degeneration in the ventral striatum both ipsi- and contralaterally. In addition, projections have been found to the lateral amygdaloid nucleus and to parts of the dorsal striatum not affected by the lesion. Following lesions in the ventral striatum fiber degeneration could always be observed in the ventral peduncle of the lateral forebrain bundle. Corresponding terminal degeneration was found in the anterior and posterior entopeduncular nuclei, the tegmentum mesencephali, the substantia nigra, the prerubral area, the mesencephalic central grey and the lateral cerebellar nucleus. When the large celled part of the ventral striatum was involved in the lesion additional degeneration could be traced to the nucleus rotundus via the dorsal peduncle of the lateral forebrain bundle.

Journal ArticleDOI
TL;DR: Study of the intracellular localization of HCO-3-stimulated, SCN--inhibited magnesium-dependent ATPase in gill tissue of the rainbow trout, rabbit kidney and rabbit gastric mucosa showed that this ATPase also appears to be of mitochondrial origin and probably represents mitochondrial inner membranes.