Influence Of Section Thickness Research Articles

Influence of Section Thickness on the Accuracy and Specificity of Histometric Parameters Using Confocal Laser Scanning Microscopy in a Canine Model of Experimental Peri-Implantitis—A Proof of Concept

Tissue breakdown was assessed by confocal laser scanning microscopy (CLSM) using autofluorescence around implants with ligatures, on a dog hemimandible. Influence of section thickness on the accuracy of histometrical observations was also evaluated, in comparison with thin sections in light microscopy. Three months after tooth extraction, implants were placed. Two months after abutment placement, ligatures were placed with no plaque control. 11 months post-implantation, the animal was sacrificed. Undecalcified thin (30 µm) sections were cut, stained and evaluated by light microscopy to be used as a reference. Additional sections were performed, so that another pair of unstained thick sections resulted (250-300 µm). Tissue loss was assessed using histomorphometric parameters under CLSM and was compared to the light microscopy reference ones. Morphometry confirmed tissue loss more pronounced on the "thick" and quick sections, when compared to the time-consuming and technique-sensitive "thin" ones. Within the limits of the present study, the adequacy of histometrical observations under CLSM reveal commensurable information about soft-tissue-bone-implant details, when compared to traditional light microscopy histological protocols. The CLSM investigation may seem demanding, yet the richness of data acquired may justify this approach, provided seatbacks caused by improper manipulation of "thick" sections are avoided.

Experimental study on influence of section thickness on mechanical behavior of die-cast AM60 magnesium alloy

Influence of section thickness on mechanical behavior of die-cast AM60 magnesium alloy has been experimentally studied. Tension, compression and shear tests with this material were performed on a universal test machine at strain rates from 5×10−4s−1 to 5×10−2s−1. Specimens were cut from plates with five as-cast section thicknesses of 6.5mm, 5.2mm, 3.9mm, 2.6mm and 1.3mm. According to the test results, flow stress becomes less sensitive to section thickness with larger section thickness, and the influence of strain rate on flow stress is also decreasing with larger section thickness. At different stress states, the tested material follows the von-Mises yield criterion. And stress state is found to be the main factor influencing the fracture behavior.

Study on the fluidity of AZ91+xRE magnesium alloy

Influence of section thickness, pouring temperature, mould temperature and content of rare earth (RE) element on the fluidity of AZ91 magnesium alloy has been studied through fluidity specimens with different section thickness cast in metal mould. The results show that the relation curve of filling length versus section thickness can be divided into two parts: (i) the filling length in the thin section increases slowly with increasing section thickness, after a critical thickness; and (ii) the filling length in the thick section increases rapidly with increasing section thickness. Elevating the pouring temperature has little influence on the fluidity in the thin section, but increases the filling length in the thick section remarkably. As mould temperature increases, the fluidity in the thin section increases a little, but the fluidity in the thick section rapidly increases. As RE content increases, the fluidity in the thin section changes from increasing to decreasing, and the fluidity in the thick section changes from increasing to decreasing, and to increasing again. Moreover, the critical thickness separating region of thin and thickness section behavior moves to higher values.

Influence of Section Thickness on Fatigue Crack Growth in Type 304 Stainless Steel

AbstractFatigue crack propagation rates at 24, 427, and 593°C were not affected by specimen thickness within the range 7.6 to 25.4 mm. Also, singleedge-notch cantilever and compact tension specimens gave comparable crack growth rates for a given stress intensity factor range. Crack growth behavior was analyzed with respect to fracture mechanics criteria.

QUANTITATIVE TESTS OF HISTOCHEMICAL METHODS FOR PHOSPHOMONOESTERASES IN BRAIN TISSUE.

Reliability of quantitative simultaneous coupling azo dye-based histochemical methods for acid and alkaline phosphatase activity was tested by comparing them with biochemical assays of tissue homogenates for the same activity using a modification of Gomori's phenol method. Gradations of histochemical staining observed with those methods, under carefully standardized conditions, reflected accurately enzyme levels obtained by assays of homogenized tissue. Stability of dyes formed by the histochemical reaction and the optimal method of extraction were investigated. Both nonspecific absorption and lipid solubility of reaction product could be excluded as possible sources of artefacts. The influence of section thickness, number, and storage, volume of medium, incubation time, and formalin fixation on activity measurements was studied.