When the PDD (percentage depth dose) in the megavoltage beams is measured in the water phantom using the dosimetry system, the polarity and ion recombination effects of ionization chambers with depth in water are not usually taken into consideration. The polarity and ion recombination effects may vary depending on the radiation type and spectrum, which vary with depth in water [1-4]. If those e...

OBJECTIVES To evaluate the diagnostic value of a new photodynamic diagnosis (PDD) system using 5-aminolevulinic acid (ALA) for the diagnosis of bladder tumors. To validate whether false-positive findings caused by tangent effects in PDD can be resolved, we compared diagnostic accuracies between the new PDD system and a conventional PDD system. PATIENTS AND METHODS Among 30 transurethral bladd...

Electron beam radiotherapy is the most widespread treatment modality todeal with superficial cancers. In electron radiotherapy, energy spectrum isimportant for modelling and accurate dose calculation. Since thepercentage depth-dose (PDD) a function of beam’s energy, reconstruction from curve represents an inverse problem.Thus, can be related to by means anappropriate mathematical model as Fredh...

To clarify the relationship between attention deficit/hyperactivity disorder (AD/HD) and pervasive developmental disorders (PDD), we investigated the common features and differences of these disorders in neuropsychological profiles. The subjects were 4 groups of Japanese boys aged 6 to 15 years, categorized by diagnosis:AD/HD (n＝20), PDD with comorbid AD/HD (PDD＋:n＝16), PDD without comorbid AD/...

The Percentage Depth Dose (PDD) and dose profile of X-Ray output from a LINAC therapy device have been modeled analyzed. research was conducted by simulation method through the use Particle Heavy Ion Transport code System (PHITS) program. in this work refers to Siemens Primus device, which is operated at 6 MV, 10 MV 18 voltages. Determination PDD carried depth 0-30 cm 0-20 water phantom, placed...

The parallel diagonal dominant (PDD) algorithm is an efficient tridiagonal solver. This paper presents for study a variation of the PDD algorithm, the reduced PDD algorithm. The new algorithm maintains the minimum communication provided by the PDD algorithm, but has a reduced operation count. The PDD algorithm also has a smaller operation count than the conventional sequential algorithm for man...

The concept of pervasive developmental disorders (PDD) and autism spectrum disorders (ASD) closely resemble each other. Both ICD-10 and DSM-IV use the term PDD. The authors surveyed the perception of PDD/ASD and attitudes toward terminology. The subjects of this study were 205 medical/social-welfare professionals working in fields relating to developmental disorders. Questionnaires were mailed ...

BACKGROUND Previously, investigators suggested that diagnostic substitution from other diagnoses, e.g., mental retardation (MR) and/or cerebral palsy (CP) to pervasive developmental disorder (PDD) is a driving factor behind increases in autism. This study evaluated potential diagnostic substitution among subjects diagnosed with PDD vs. MR or CP by examining birth characteristic overlap. METHO...