VALID REPRESENTATION of the lifespan and destruction of a specific cell type is provided by studies of labeled cells if a number of requirements are met. These include that the label should not be injurious to the cell, that there is no elution of the label, that there is no reutilization of label at time of cell death, that the age distribution of the labeled cell population should be known, a...

PURPOSE We aimed to evaluate ultrasonography (US) findings for Breast Imaging Reporting and Data System (BI-RADS) category 4 lesions using BI-RADS US lexicon and determine the positive and negative predictive values (PPV and NPV) of US with respect to biopsy results. METHODS Sonograms of 186 BI-RADS 4 nonpalpable breast lesions with a known diagnosis were reviewed retrospectively. The morphol...

Three-dimensional (3-D) genome organization in the nuclear space affects various genomic functions. Circular chromosome conformation capture (4C-seq) is a powerful technique that allows researchers to measure long-range chromosomal interactions with a locus of interest across the entire genome. This method relies on enzymatic cleavage of cross-linked chromatin and consecutive ligation to create...

UNLABELLED To evaluate the performance of three digital devices regarding the noise added to digital radiographic images containing different optical densities. METHODS A radiographic image was digitized repeatedly ten times using two scanners (HP 4c/T and HP 5370C) and a digital camera (Nikon 990). A histogram tool measured a mean pixel value and the standard deviation of the region of inter...

OBJECTIVES The purpose of this study is to provide a theoretical rationale for the implementation of the four-component instructional design model for complex learning (4C/ID-model) at the University of Pretoria with the aim of systematically developing the clinical reasoning of undergraduate dental students in a classroom setting. METHODS Recent literature provides a rationale for the use of...

Background: The presence of a wedge filter in the beam trajectory can modify the beam quality and cause some changes in the dosimetry parameters which are usually difficult to be measured directly and accurately. Material and Methods: In this study the MCNP-4C Monte Carlo code was used to simulate the 9 MV photon beam generated by a linear accelerator. Upon getting a good agreement bet...

Background: Obtaining high quality images in Single Photon Emission Tomography (SPECT) device  is the most important goal in nuclear medicine. Because if image quality is low, the possibility of making a mistake in diagnosing and treating the patient will rise. Studying effective factors in spatial resolution of imaging systems is thus deemed to be vital. One of the most important factors in S...

The glutamate receptor gene GluR-4 is proposed to generate two spliced isoforms (Sommer et al., 1990). Screening a rat cerebellar cDNA library, we have now identified a third type of transcript derived from GluR-4 gene by differential RNA processing. This transcript encodes a protein with a "flop" module between transmembrane regions 3 and 4, but with a C-terminus segment of 36 amino acids diff...