INTRODUCTION Whitening toothpastes which have been accepted in populations may affect properties of enamel and restorative materials. The aim of this study was to compare the microhardness of human enamel and Z250 microhybrid composite resin after brushing with two whitening toothpastes. MATERIALS AND METHODS In this experimental study of enamel specimens, forty five freshly extracted human i...

The proper assembly of craniofacial structures and the peripheral nervous system requires neural crest cells to emerge from the neural tube and navigate over long distances to the branchial arches. Cell and molecular studies have shed light on potential intrinsic and extrinsic cues, which, in combination, are thought to ensure the induction and specification of cranial neural crest cells. Howev...

The neural crest is a multipotent, migratory cell population arising from the border of the neural and surface ectoderm. In mouse, the initial migratory neural crest cells occur at the five-somite stage. Bone morphogenetic proteins (BMPs), particularly BMP2 and BMP4, have been implicated as regulators of neural crest cell induction, maintenance, migration, differentiation and survival. Mouse ha...

the wepp physically model is able to dynamically simulate runoff and soil erosion using physical concepts of erosion and hydraulic of overland flow science considering plant growth, residue decomposition, winter process. determination of the capability of this model in runoff and erosion estimation in different range type with investigation the effects of management were the main objectives of ...

We have determined the pathways taken by the trunk neural crest of quail and examined the parameters that control these patterns of dispersion. Using antibodies that recognize migratory neural crest cells (HNK-1), we have found that the crest cells take three primary pathways: (1) between the ectoderm and somites, (2) within the intersomitic space and (3) through the anterior somite along the b...

Given a knot K in a 3-manifold M , we use N(K) to denote a regular neighborhood of K. Suppose γ is a slope (i.e an isotopy class of essential simple closed curves) on ∂N(K). The surgered manifold along γ is denoted by (H,K; γ), which by definition is the manifold obtained by gluing a solid torus to H − IntN(K) so that γ bounds a meridianal disk. We say that M is ∂-reducible if ∂M is compressibl...

Quantitative research on and the prediction of a landslide deformation area is an important point to accurately comprehensively understand failure mechanism landslides degree slope failure. This study uses image processing techniques quantitatively identify volume regions during rainfall-type destabilization under multifactor conditions. The findings revealed that (1) increase in rainfall inten...

Under the impact of earthquake, even if slopes do not fail, integrity rock slope structure would be damaged subjected to seismic motion. The process damage, destruction and failure for is characterized by dynamic evolution stability. In areas with active tectonic activities, frequent earthquakes have a significant effect on attenuation To investigate under earthquake motions, series shaking tab...

During an 11 days mission in February 2000 the Shuttle Radar Topography Mission (SRTM) collected data over 80% of the Earth's land surface, for all areas between 60 degrees N and 56 degrees S latitude. Since SRTM data became available, many studies utilized them for application in topography and morphometric landscape analysis. Exploiting SRTM data for recognition and extraction of topographic ...