Of all birth DEFECTS, Congenital Heart Disease (CHD) remains the most prevalent. These malformations are largely multifactorial with both environmental and genetic components, but known CHROMOSOMAL abnormalities and mutations of single genes account for less than 10% of all cardiac DEFECTS (1). They affect approximately 6 to 13 newborns per 1000 live births (2) and are made up of 5 major Atrial Septal DEFECTS (ASDs), including primum and secundum type DEFECTS, sinus venosus and coronary sinus DEFECTS, and Patent Foramen Ovale (PFO). However, there is debate within the medical community regarding inclusion of PFOs and coronary sinus DEFECTS within the realm of CHD. PFOs do not have absent septal tissue, and coronary sinus DEFECTS, or unroofed coronary sinus, represent an abnormal communication between the superior portion of the coronary sinus and the neighboring left atrium.

Time-of-Flight Diffraction (TOFD) technique is a well-known inspection method used in ultrasonic nondestructive evaluation. This inspection technique is based on the time of arrival of the diffracted echoes from the tips of planar discontinuity. This is in contrast with the conventional ultrasonics which rely on the amplitude of specular reflections received from discontinuities. Like any other technique, ToFD has its limitations. In this paper, the finite element method is employed to evaluate the planar DEFECTS using ultrasonic time-of-flight diffraction method. The commercially available software ABAQUS/Explicit is used to simulate the ultrasonic wave behavior in the wedge transducers, specimen and wave interaction with the embedded planar defect. The CPE4R plane strain element is employed for discretization of the steel specimen and wedge transducers. The CINPE4 infinite element is also used on the wedge side walls for reducing unwanted echoes and noise reduction inside the ultrasonic wedge.The wave attenuation of the Plexi-glass wedge is simulated as the mass and stiffness proportional damping model. Evaluation and sizing of various DEFECTS show that, the accuracy of the proposed method is within acceptable range compared to the conventional ToFD method.

Background & Aim: Until the last decades the chance of survival for patients suffered from different types of malignancies was less. In fact prior to 1950, patients with acute lymphoblastic leukemia had a hope to live less than 20 weeks, but with introducing the new methods of chemotherapy, radiotherapy and surgery, a vast improvement obtained in their prognosis with increase of children's life length suffering from cancer, different specialists concentrated on affects may result from the late treatment. Immediate effects of chemotherapy and radiotherapy on soft tissues had been identified well, but there is a less information from their long term effects on dental tissues during their developments.Material & Method: The purpose of this study which was performed in 1999 was to evaluate the relationship between chemotherapy and enamel DEFECTS in children suffered from malignant diseases who seek medical advise from Mofid children's hospital in Tehran.Results: In this study 42 patients containing, 15 girls and 27 boys -whom were under chemotherapy, were chosen and the same number of healthy control group were chosen assording to the following rules: For omitting the fluorosis factor, all cases were selected from the citizens of Tehran.- In all children with malignancies, chemotherapy should have been finished (In off therapy stage).- Non of children should have been under radiotherapy on dental and jaw area. - From 1471 teeth in 84 patients, 729 teeth (49.6%) were in case group and 742 teeth (50.4%) in control group. - From this number in first group 29 teeth (4%) and 13 teeth (2%) in control group had enamel involvement.- There was a significant relationship between involved teeth in control group (P<0.025).- The result of this study showed, although enamel DEFECTS were more in case group related to control, but this value was not considerable according to total number of children and the observed teeth need more investigation in the future for understanding the probable effects of chemotherapy on enamel genesis.

In all organisms, transfer RNA (tRNA) molecules are required to undergo post-transcriptional modifications at different levels in order to convert into mature tRNAs. These modifications are critical for many aspects of tRNA function and structure, such as translational efficiency, flexibility, codon– anticodon interaction, stability, and fidelity. Up to now, over 100 modified nucleosides have been identified in tRNAs from all domains of life. Post-transcriptional modifications include different chemical processes such as methylation, deamination, or acetylation, with methylation reactions as the most common. tRNA methyltransferases are a family of enzymes involved in the post-transcriptional methylation of tRNA bases. Recent studies have reported different human diseases resulting from DEFECTS in tRNA methyltransferase activity, including cancer, diabetes and neurological disorders such as intellectual disability (ID). In this article, we focused on biological function and characterization of tRNA methyltransferases associated with ID in order to explain how functional disruption of tRNA methyltransferases could lead to ID phenotype.

Background. Three-dimensional regeneration of periodontal tissues arises when Janctional Epithelial cells reach to the wound but epithelial cells and fibroblasts are excluded from wound. For prevention of this procedure membranes work as a barrier that protecting bone DEFECTS against fibroblasts and also promote osteoblasts adhesion and proliferation. we use barrier membranes for healing of fenestration and dehiscence around teeth and implants, fresh socket implants and also regeneration of alveolar bone and Soft tissues. Methods. This study is based on articles found in PubMed databases, published in 2015 and later. The keywords for this research were Barrier membranes, Periodontal tissue regeneration, Periimplant regeneration and Bone reconstruction. Results. The main properties of barrier membranes are, biocompatibility, cell occlusion, tissue integration, space making and good handling properties. Knowledge related to different type of membranes is critical for handeling of periodontal tissue regeneration. Membranes are classified into biologic source and non biologic source. Biologic source membranes are included natural membrane (like collagen and chitosan) and alloderm. Non biologic source membranes are consist of titanium and synthetic. Synthetic membranes are divided to resorbable type (polyester, PEG) and non resorbable type (D-PTFE, E-PTFE). Conclusions. Actually the techniques that base on barrier membranes (GTR, GBR) are the first generation of periodontal tissues reconstructive methods, it is hypothesized that next-generation of GTR and GBR membranes will be active biologically. Application of adhesion molecules should lead to tissue selection on the membrane surface. It is promising approach for periodontal tissue engineerin. Better understanding of factors influencing regenerative procedure will improve predictability of therapy of bone DEFECTS around natural teeth and implants.