1Department of Ophthalmology, Valiaser Hospital; 2Nursing College, Birjand Medical University, Birjand, Islamic Republic of Iran. 3Department of Ophthalmology, Mashhad University of Medical Science, Mashhad, Islamic Republic of Iran. Received: 09/05/03; accepted: 20/10/03 ABSTRACT To investigate the possible relationship between hyperhomocysteinaemia and retinal vascular occlusion, we measured ...

New techniques for the prediction of tumour behaviour are needed since statistical analysis has low accuracy and is not applicable to the individual. Artificial intelligence (AI) may provide suitable methods. We have compared the predictive accuracies of neuro-fuzzy modelling (NFM), artificial neural networks (ANN) and traditional statistical methods for the prediction of bladder cancer. Experi...

Congenital Hepatic Fibrosis (CHF) is a rare disease that affects both the liver and kidneys.  Congenital hepatic fibrosis (CHF) is an autosomal recessive inherited malformation defined pathologically by a variable degree of periportal fibrosis and irregularly shaped proliferating bile ducts. Affected individuals also have impaired renal function, usually caused, in children and teenagers, by an...

Genotyping for 10 mutations in the CYP21 gene was performed in 88 families with congenital adrenal hyperplasia due to 21-hydroxylase deficiency. Southern blot analysis was used to detect CYP21 deletions or large gene conversions, and allele-specific hybridizations were performed with DNA amplified by the polymerase chain reaction to detect smaller mutations. Mutations were detected on 95% of ch...

This paper introduces a new class of oscillators that generate sinusoidal signals by formation of a circular standing wave on a ring (closed-loop) transmission line (t-line). A basic form of the circular standing wave oscillator (CSWO), schematically illustrated at the top left of Fig. 21.2.1, consists of a ring t-line and two pairs of cross-coupled inverters located at two opposite ports on th...

Demand for faster data rates in wireline and wireless markets has resulted in tighter jitter and phase noise requirements for oscillators. Although active device noise (and not the resonator noise) dominates the phase noise of most CMOS oscillators [1], in a properly designed oscillator, the quality factor, Q, of the resonant tank indirectly plays a central role in the phase noise. The best pha...