Showing papers by "Istanbul University published in 1987"

Boundary conditions of the electromagnetic field

Abstract: The classical boundary conditions describing the discontinuities of the electromagnetic field across a surface supporting ordinary surface charges and currents are discussed in the case where nontangential currents and polarisations of higher orders are possible.

Xanthogranulomatous pyelonephritis in children and adults.

Abstract: Summary— Sixteen patients with xanthogranulomatous pyelonephritis (XGP) are reported. The preoperative diagnosis of XGP may be difficult because of its clinical and radiological similarities to various other renal lesions, but in four patients XGP was suspected pre-operatively. Nephrectomy is necessary in most patients, although medical treatment may help a few.

Distribution of mitochondrial introns in the species Schizosaccharomyces pombe and the origin of the group II intron in the gene encoding apocytochrome b

Abstract: The mitochondrial genome size of 26 different Schizosaccharomyces pombe strains varies between 17.6 and 24.6 kilobase pairs due to the presence or absence of introns. One of these is the group II intron in the gene encoding apocytochrome b (cob: intron cobI1). Partial DNA sequences of continuous cob genes from six strains (including strain EF1: Trinkl et al. 1985) revealed identical nucleotide sequence in the region where the group II intron is inserted in the mosaic form of the gene. In contrast, analysis of the mosaic cob gene in strain UCD-FstI revealed several base pair changes in the exon regions flanking the splice point, compared with the continuous genes and with the mosaic cob gene in strain 50 (Lang et al. 1985). The base pair differences between the exons of the two mosaic cob genes and the identity of exons in all continuous cob genes argue in favour of the two cob introns in strains 50 and UCD-FstI as independent later acquisitions of the genes, rather than loss of the intron from a common mosaic ancestor of all strains. Other introns present in some but not all strain include two group I introns without open reading frame in the gene encoding subunit 1 of cytochrome c oxidase (cox1: introns cox1I2a and cox1I3), and two group I introns with open reading frames in the same gene (introns cox1I1 and cox1I2b).

HLA antigens in recurrent oral ulceration: evidence against a common disease spectrum with Behçet's syndrome.

Abstract: Among 50 patients with recurrent oral ulceration (ROU) the prevalence of HLA B5 was not increased as was the case among 50 patients with Behcet's Syndrome (BS) compared to 52 healthy controls. On the other hand, HLA DR4 was present in 16 of 30 (53%) patients with ROU whereas the same allele was present in 16% of BS patients and 22% of the healthy controls. These findings suggest that ROU and BS are not in the same disease spectrum.

Preparation of a novel polymeric copper phthalocyanine containing crown ether moieties and its alkali metal binding property

Abstract: Preparation par polymerisation dans la pyridine du systeme tetrabromodibenzo-18 crown-6/CuCN dans un tube scelle

Antidepressant action of lithium in behavioral despair test.

Abstract: The effects of long term (30 days) lithium treatment of various doses on behavioral despair test and on serotonin metabolism in the hypothalamus, midbrain and striatum of rats were examined. Lithium at doses of 0.5, 2 and 5 mEq/kg significantly decreased the duration of immobility. In other words, lithium behaved as an antidepressant drug. Serotonin turnover increased only in the hypothalamus in response to 0.5 and 2 mEq/kg doses of lithium.

Oral rehydration therapy in neonates and young infants with infectious diarrhoea.

Abstract: The clinical response and changes in water and salt homeostasis during ORT was studied in 15 infants less than 2 months old (range 2-50 days) with acute diarrhoea. Eight patients were neonates and 7 were 1-2 months old. The oral rehydration solution contained 60 mmol sodium per litre. All patients except one were successfully rehydrated. The fluid retention was significantly higher in neonates and young infants than in infants above 3 months of age treated in the same way. One patient in the group of neonates who had a normal sodium level on admission developed hypernatremia with a sodium level of 162 mmol/l 36 hours after the start of ORT. The urinary sodium excretion was lower in the neonates than in the young infants. The results show that neonates and young infants have a lower capacity than older infants to excrete water and salt and therefore run a great risk of developing fluid and salt retention during ORT. The risk is most pronounced in neonates who, due to immaturity of the renal function, are unable to excrete excess fluid and salt.

Fully integrated active-RC filters using MOS and non-balanced structure

Abstract: A technique for implementing fully integrated continuous time non-switched capacitor filter has been recently reported in the literature. the technique uses a balanced structure using op-amps, capacitors and MOS transistors operated in the non-saturated region as voltage-controlled resistors. In order to eliminate the non-linearity of the MOS transistors over an extended voltage range the current techniques use fully balanced circuits. This paper provides a simple technique for cancellation of non-linearities, thereby reducing the number of elements, and proposes several simple circuits. the technique is then used in the design of high-order filters.

Sebum production is increased in Behçet's syndrome and even more so in rheumatoid arthritis.

Abstract: Sebum production is under hormonal control. We had shown that male sex is associated with more severe disease in Behcet's syndrome and the acneiform skin lesion of this disorder is not different from ordinary acne, an androgen-dependent lesion. Sebum excretion rate was higher in patients with Behcet's syndrome than in healthy controls, children and patients with ankylosing spondylitis. On the other hand, patients with rheumatoid arthritis had high levels of sebum excretion rate comparable to those found in patients with acne vulgaris. These suggest the presence of a sebotrophic hormone and/or other hormonal effects in Behcet's syndrome and rheumatoid arthritis.

Storage Coefficient Determination from Quasi-Steady State Flow

Abstract: A method has been proposed for determining a unique storage coefficient value for confined and unconfined aquifers tapped by a large diameter well. The prerequisites for the application of this method are estimation of the transmissivity value and the field measurements of well radius, pumping discharge and time-drawdown measurements at large times, or preferably at the steady or quasi-steady state flow conditions. The application of the method does not require any complicated mathematical procedure of the classical type curve matching procedures. It is recommended especially as a supplementary method to the existing techniques in determining the storage coefficient.

An Assessment of the International Conference on Marketing and Development

Abstract: The Journal of Macromarketing was one of the academic sponsors of the first comprehensive international conference on marketing and development. This successful conference, which was hosted and locally sponsored by Istanbul University in Istanbul, September 1-4, 1986, brought together about 130 participants from 15 countries and various backgrounds: academicians, government representatives, international agency officials, and practitioners. Another conference is scheduled in two years and plans were also made for the formation of an association.