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Showing papers by "Istanbul University published in 1984"


Journal ArticleDOI
TL;DR: In this paper, the authors derived distributions of discontinuity spacings along finite length scanlines on the basis of negative exponential and log-normal probability density functions, and the error percentages were presented for mean discontinuity spacing estimates from short scanlines.

110 citations


Journal ArticleDOI
M. Gürgöze1
TL;DR: In this article, the fundamental frequency and first mode shape of a beam or rod to which springs and point masses are attached are estimated. But the analysis is restricted to three examples and it is shown that the results are quite satisfactory.

83 citations


Journal ArticleDOI
S. Bahar1, J. Chiras, J. P. Carpena, J. F. Meder, J. Bories 
TL;DR: The authors discuss the relation-ship between arteriovenous fistulae and fibro-muscular dysplasia, and the specific problems of treatment in these two cases of spontaneous vertebro-vertebral arterIOvenous Fistulae associated with fibromuscular Dysplasia.
Abstract: Extracranial vertebral arteriovenous fistulae of non traumatic origin are extremly rare. The authors report two cases of spontaneous vertebro-vertebral arteriovenous fistulae associated with fibromuscular dysplasia. They discuss the relation-ship between arteriovenous fistulae and fibro-muscular dysplasia, and the specific problems of treatment in these two cases.

46 citations


Journal ArticleDOI
TL;DR: Although activity levels in fluid are normally low the enzyme may be released from coelomocytes as part of an internal defence mechanism against particular bacterial species encountered in the environment.

32 citations


Journal ArticleDOI
TL;DR: While a normal complement of coelomocytes appeared essential in preventing growth of bacteria, cell-free fluid inhibited some of the strains isolated, but most were not affected.

30 citations


Journal ArticleDOI
TL;DR: Data indicate that the degree of bone-marrow cellularity is not always related to functional capacity, and numerous agents may have etiologic roles in the development of aplastic anemia.
Abstract: To illustrate the etiologic role of drugs and chemicals in the development of aplastic anemia, we analyzed 108 cases of aplastic anemia among 3,715 hematologic patients during a ten-year period at the hematology section of Istanbul Medical School. Among these 3,715 patients, 695 had leukemia, a result indicating the relative rarity of aplastic anemia as compared with leukemia. Of the 108 patients, 58.3% were male and 41.7% were female. Their ages ranged from six months to 82 years. Pancytopenia was severe in 42.6% of the patients, and moderate or mild in 57.4%. Bone marrow was hypocellular in 84 patients, normocellular in 16, and hypercellular in eight. In 52 (48.1%) of the patients with aplastic anemia, the following etiologic factors were implicated: benzene (25 patients), antirheumatic drugs (ten), chloramphenicol (four), chloramphenicol plus hepatitis or chromosome anomalies (two), thiamphenicol plus sulfonamide (one), antituberculous drugs (three), daraprim (three), insecticides (two), hepatitis (one), and sulfonamide (one). Data indicate that the degree of bone-marrow cellularity is not always related to functional capacity, and numerous agents may have etiologic roles in the development of aplastic anemia.

25 citations


Journal ArticleDOI
TL;DR: In this paper, the reaction pathway of the thermolysis of 4 leading to the compounds 3 and 5 is additionally elucidated, by an X-ray structure determination of 4e and by the results of 14C-labeling.
Abstract: 4-Benzoyl-5-phenyl-2,3-furandion (1) reagiert mit Arylisocyanaten zu den Pyrrolo[2,3-d]pyrimidinen 4 und den 2,3-Pyrroldionen 2. Bei Verwendung von Alkylisocyanaten entstehen ausschlieslich die entsprechenden 2,3-Pyrroldione 2e – g. Die Bildung von 4 bzw. 2 umfast [4+2]-Cycloadditions- sowie Decarboxylierungsschritte und sollte uber (α-Iminobenzyl)furandion- (6) und (α-Iminobenzyl)pyrroldion- (5) Zwischenstufen verlaufen. Dies konnte durch chemische Umsetzungen, eine Rontgenstrukturanalyse von 4e sowie mittels 14C-Markierung gezeigt werden. Das Entstehen der Thermolyseprodukte 3 und 5 aus 4 wird erklart. Mechanistic Investigations with the Aid of Isotopic Labeling, VIII. Investigations of the Reaction Pathway to Pyrrolo[2,3-d]pyrimidines from 4-Benzoyl-5-phenyl-2,3-furandione and Aryl Isocyanates 4-Benzoyl-5-phenyl-2,3-furandione (1) reacts with aryl isocyanates to yield the pyrrolo[2,3-d]-pyrimidines 4 and the 2,3-pyrrolediones 2; using alkyl isocyanates the corresponding 2,3-pyrrolediones 2e – g are formed exclusively. The formation of 4 and 2 includes [4+2]cycloaddition steps and decarboxylation processes and should proceed via the (α-iminobenzyl)furandiones 6 and the (α-iminobenzyl)pyrrolediones 5 as probable intermediates. This is shown by chemical reactions, by an X-ray structure determination of 4e, and by the results of 14C-labeling. The reaction pathway of the thermolysis of 4 leading to the compounds 3 and 5 is additionally elucidated.

25 citations


Journal ArticleDOI
TL;DR: In this article, Spectral methods were used to determine the structures of the alkaloids of the Haplophyllum suaveolens, including flindersine, γ-fagarine, kokusaginine and one new alkaloid.

24 citations


Journal ArticleDOI
TL;DR: In this paper, an explicit expression for the surface current induced by sources on a perfectly conducting cylindrical reflector is obtained by taking into account the locality of the high-frequency diffraction phenomenon.
Abstract: An explicit expression for the surface current induced by sources on a perfectly conducting cylindrical reflector is obtained by taking into account the locality of the high-frequency diffraction phenomenon. The results show that the component previously conjectured by Ufimtsev involves several components having different propagation behaviors that can be separated into three main groups. When the reflector becomes infinitely large, the currents excited by edge diffraction are shown to reduce to those for the classical half-plane problem. The results are independent of the actual source configuration and may thus be useful in more complicated situations.

23 citations


Journal ArticleDOI
TL;DR: 7 cases of multiple myeloma with a history of exposure to benzene, radioactive iodine, chemotherapy for Hodgkin's disease and of repeated injections of autovaccine to Staphylococcus albus hemolyticus are described.
Abstract: 7 cases of multiple myeloma with a history of exposure to benzene, radioactive iodine, chemotherapy for Hodgkin's disease and of repeated injections of autovaccine to Staphylococcus albus hemolyticus are described. The relationship between the development of multiple myeloma and possible etiologic factors is discussed.

22 citations


Journal ArticleDOI
TL;DR: Helichrysum athrixiifolium afforded in addition to known ones three new prenylated flavanoids, one chalcone and two flavanones as discussed by the authors.

Journal ArticleDOI
TL;DR: In this paper, a one-step synthesis of 2 (1H)-quinoxalinone oxime from (1,2-benzenediamine) and s-trans-chloroethanedial dioxime is described.
Abstract: A new one-step synthesis of 2 (1H)-quinoxalinone oxime (3) from (1,2-benzenediamine (1) and s-trans-chloroethanedial dioxime (2) is described. This oxime is converted into a new heterocyclic compound, 1,2,4,5,-tetrazino)[1,6-a: 4,3-a′]diquinoxaline (4), by the template effect of Co(II) and Ni(II) ions.

Journal ArticleDOI
TL;DR: A sesquiterpene ester, tingitanol, isolated from Ferula tingitana L, was assigned as 1β,3β-dihydroxy-4α,8α-diangeloyloxydauc-5-ene on the basis of spectral, analytical, and X-ray data.

Journal ArticleDOI
TL;DR: In this article, the threshold for blood-brain barrier (B-BB) opening was approximately 160 mm Hg and for blood--CSF barrier opening 150mm Hg. The barrier permeability was increased when systemic blood pressure was elevated rapidly rather than gradually to the threshold level.

Journal ArticleDOI
TL;DR: Haplophyllum pedicellatum, H. robustum and H. glabrinum all yielded the known compound gossypetin 8,3′-dimethyl ether 3-rutinoside, and the first two species afforded isorhamnetin and its 3- RUTinoside.

Journal ArticleDOI
TL;DR: Six cultivars of barley Hordeum vulgare were exposed to 0·18 ppm of ozone (O3) for 6h, with or without the addition of sulphur dioxide (SO2) at a concentration (0·065 ppm) which, when applied alone had nor adverse effects on the plants.

Journal ArticleDOI
TL;DR: In this article, a triterpenoid was identified from the leaves of Salvia pinnata and the structures of these compounds were established by spectral data and by some chemical reactions.

Journal ArticleDOI
TL;DR: It is concluded that BBB dysfunction may remain even 60 min after an acute hypertensive episode of short duration, and Evans blue, the barrier tracer, was administered intravenously either prior to or at intervals of 3, 10, 20, 30, and 60 minutes after the angiotensin injection.

Journal ArticleDOI
TL;DR: In this article, the optimal design of Nyquist type signals of M < ∞ baud time duration, which maximizes spectral energy inside a given bandqidth ω and generates no inter-symbol interference is presented.

Journal ArticleDOI
TL;DR: In addition to known compounds an investigation of the fruits of Smyrnium rotundifolium afforded four new germacrane derivatives, all closely related to glechomanolide, one being a secogermacrane anhydride.

Journal ArticleDOI
V. Karadaǧ1
TL;DR: In this article, an 18 degrees of freedom beam finite element was developed for rotational and non-rotating aerofoil cross-sectioned blades, where bending and shear force displacements and slopes, and torsional displacements were taken as degrees offreedom at both ends of the element.

Journal ArticleDOI
TL;DR: In this paper, the structures of the benzene-1,2-bis(aminoglyoxime)(LH4) have been postulated on the basis of elemental analyses, magnetic measurements, and u.v.-visible spectra.
Abstract: Benzene-1,2-bis(aminoglyoxime)(LH4) has been prepared from o-phenylenediamine and anti-chloroglyoxime at -5[ddot]C. The Ni(II) and Cu(II) complexes of LH4 have a polymeric structure in which the ligand coordinates through the N atoms of the oximes. The Co(II) complex [(LH2) Cl2 (H2O)2Co2] is binuclear and coordinates through N and O atoms. The ligand with tetraoxime donor sites forms mononuclear complexes with Cd(II) and Zn(II) [(LH2)M, where M = Cd(II) or Zn(II)]. In the UO2(VI) complex, the metal/ligand ratio is 2:1 and a hydroxo-bridged polymeric structure is proposed. The structures of the complexes have been postulated on the basis of elemental analyses, magnetic measurements, i.r., and u.v.-visible spectra.

Journal ArticleDOI
TL;DR: In this paper, the authors provide a basis for design of cemented aggregate fill mixes based on data obtained from experimental investigations conducted for Uludaĝ Tungsten Mine in Turkey.

Journal ArticleDOI
D Yeker1, Cenk Büyükünal1, M Benli1, E Büyükünal1, I Urgancioğlu1 
TL;DR: This experimental model suggests that the use of cimetidine seemed to have some advantages: (a) nontarget (intestinal) radioactivity was diminished by cimetamines, and (b) the target to nontarget ratio increased withcimetidine pretreatment, which resulted in an enhanced accumulation of pertechnetate in the ectopic gastric mucosa, and reduced excretion of the radionuclide into the lumen.
Abstract: The aim of this study was to investigate the effects of prior administration of cimetidine in radionuclide imaging of Meckel's diverticulum. In three groups of seven rats with artificial Meckel's diverticulum, containing ectopic gastric mucosa, the effects of pentagastrin + glucagon plus 99mTc-pertechnetate, as well as cimetidine premedication plus 99mTc-pertechnetate, and 99mTc-pertechnetate alone were compared to attain improved radionuclide imaging of Meckel's diverticulum. This experimental model suggests that the use of cimetidine seemed to have some advantages: (a) nontarget (intestinal) radioactivity was diminished by cimetidine, (b) the target to nontarget (Meckel's diverticulum to intestinal activity) ratio increased with cimetidine pretreatment. This resulted in an enhanced accumulation of pertechnetate in the ectopic gastric mucosa, and reduced excretion of the radionuclide into the lumen. Consequently, better scintiphotograms and a low rate of false results added to the validity of this method.

Journal ArticleDOI
TL;DR: In this paper, the hydrodynamic behavior of two laterally interconnected channels with blockages in one of them has been studied experimentally, and two types of blockages have been considered: plate and smooth.
Abstract: In this research, the hydrodynamic behavior of two laterally interconnected channels with blockages in one of them has been studied experimentally. For blockages of different shapes and severities, the mass flow rates as well as the pressures in the channels upstream and downstream of the blockage were determined. The experiments were conducted on a test sections which consists of two-square channels separated by an intermediate plate with slots of different geometric parameters. Two types of blockages have been considered: plate and smooth. The shape of the smooth blockage was a cosine. In the region upstream of the blockage, the diversion cross-flow takes place over a relatively short distance. Downstream of the blockage, the recovery of the diverted flow by the blocked channel is a slow process and the rate of this recovery worsens with increasing blockage severity. For a given blockage rate, the diversion crossflow caused by a smooth blockage is smaller than that of a plate blockage.

Journal ArticleDOI
TL;DR: The endogenous-neurotic dimension emerged as a bipolar factor and the bimodal distribution of patients' scores on this factor indicated two distinct groups, which was compared with other factor-analytic studies and cross-cultural differences were discussed.

Journal ArticleDOI
TL;DR: In addition, a new furanogermacrane and a highly unstable furanoeremophilane were obtained from the fruits of Smyrnium cordifolium as discussed by the authors.

Journal ArticleDOI
TL;DR: In this paper, holographic records of diesel sprays are produced for a range of conditions, with the object of finding the variation of droplet size with time, injection pressure, and fuel properties.
Abstract: Holographic records of diesel sprays are produced for a range of conditions, with the object of finding the variation of droplet size with time, injection pressure, and fuel properties Analysis of the holograms is by means of measurement in the Fraunhofer plane using a droplet sizing instrument This rapid readout procedure has enabled the investigation of a large number of conditions Factors influencing the measurement are discussed, and size results are presented as a function of time for high- and low-load conditions, as well as a function of viscosity for a range of heavy fuel/diesel fuel mixtures

Journal ArticleDOI
Z. Celep1
01 Sep 1984
TL;DR: In this article, a stability and vibration analysis of a pre-twisted cantilever column subjected to vertical and follower loads at its free end was carried out using finite element modelling where the effects of transverse shear deformation and rotatory inertia were taken into account in deriving the element matrices.
Abstract: This paper presents a stability and vibration analysis of a pre-twisted cantilever column subjected to vertical and follower loads at its free end. The investigation is carried out using finite element modelling where the effects of transverse shear deformation and rotatory inertia are taken into account in deriving the element matrices. By using the assembly procedure and imposing the boundary conditions, a relationship between the load and vibration frequency is obtained. The critical, divergence and flutter, loads are calculated by evaluating the relationship and shown in figures for various values of non-conservativeness parameter, of twist angle, and those of rigidity ratio.