Search results for "microtomography"

Effects of obesity on periodontal tissue remodeling during orthodontic movement.

2021

Made available in DSpace on 2021-06-25T15:01:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-04-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) German Research Foundation (DFG) Introduction: Orthodontic movement triggers a sequence of cellular and molecular events that may be affected by different systemic conditions. This study evaluated the effect of obesity on rat periodontal tissue remodeling induced by mechanical orthodontic force. Methods: Thirty-two Holtzman rats were distributed into 4 groups: control, obesity induction (O), orthodontic movement (M), and obesity induction and orthodontic movement (OM). Obesity was induced by a high-fat diet for 90 days. Af…

Bond strength of cemented fiber posts to teeth with simulated internal root resorption

2020

Made available in DSpace on 2021-06-25T10:58:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-03-01 Background: Teeth with internal root resorption (IRR) have guarded prognosis, considering that IRR defect could influence on the post bond strength. The aim of this study was to evaluate the bond strength and the bond interface between different glass fiber-reinforced posts (FRP) after cementation in teeth with simulated internal root resorption (IRR). Material and Methods: Forty-five (45) human premolar roots with simulated IRR were embedded in acrylic resin blocks and cross-sectioned into two segments, enabling them to be re-approximated by screws. Intracanal medication was inserte…

Longitudinal imaging and evaluation of SAH-associated cerebral large artery vasospasm in mice using micro-CT and angiography

2019

Longitudinal in vivo imaging studies characterizing subarachnoid hemorrhage (SAH)-induced large artery vasospasm (LAV) in mice are lacking. We developed a SAH-scoring system to assess SAH severity in mice using micro CT and longitudinally analysed LAV by intravenous digital subtraction angiography (i.v. DSA). Thirty female C57Bl/6J-mice (7 sham, 23 SAH) were implanted with central venous ports for repetitive contrast agent administration. SAH was induced by filament perforation. LAV was assessed up to 14 days after induction of SAH by i.v. DSA. SAH-score and neuroscore showed a highly significant positive correlation (rsp = 0.803, p < 0.001). SAH-score and survival showed a negative sig…

Orthogonal switching of AMS axes during type-2 fold interference : Insights from integrated X-ray computed tomography, AMS and 3D petrography

2017

We applied X-ray computed microtomography (μ-CT) in combination with anisotropy of magnetic susceptibility (AMS) analysis to study metamorphic rock fabrics in an oriented drill core sample of pyrite-pyrrhotite-quartz-mica schist. The sample is extracted from the Paleoproterozoic Martimo metasedimentary belt of northern Finland. The μ-CT resolves the spatial distribution, shape and orientation of 25,920 pyrrhotite and 153 pyrite grains localized in mm-thick metapelitic laminae. Together with microstructural analysis, the μ-CT allows us to interpret the prolate symmetry of the AMS ellipsoid and its relationship to the deformation history. AMS of the sample is controlled by pyrrhotite porphyro…

Predicting stiffness and strength of birch pulp:Polylactic acid composites

2016

This paper studies failure of birch pulp–polylactic acid composites. Stiffness and strength are calculated using the theory of short fibre composites and the results are compared to experimental data. The results differed from the experimental values by 0–6%. With less aligned fibres the short fibre theory is not feasible. The performance of the 40 wt% birch pulp – polylactic acid composite is predicted with X-ray microtomography based finite element modelling, and the results are compared with experiments. Stiffness results differed from experiments by 1–17% . By adding into the models a third material phase representing the interface between the fibres and the matrix, the stress–strain c…

Calibration of the bone mineral density scale on X-ray microtomography

2016

Modelling the effect of porosity on the mechanical properties of unidirectional composites. The case of thick-walled pressure vessels

2018

International audience; The present article highlights morphological features present in composite pressure vessels. The use of X-ray microtomography provides three-dimensional information about the voids in a large thick-walled type 3 pressure vessel at the mesoscopic scale. The observations show that the porosity structure depends strongly on composite thickness and orientation. A numerical approach is proposed to model realistically the damage phenomena in pressure vessels.

Microstructural evaluation and recommendations for face masks in community use to reduce the transmission of respiratory infectious diseases

2022

Funding Information: A.K., H.Y. and R.J. also acknowledges the funding through Academy of Finland BESIMAL (Decision No. 334197) and Aalto University, Department of Communications and Networking. This work has also received funding in part from the EPSRC UK (grant number EP/R012091/1). A.K. would also like to thank Mr. Volkan Kaplan for the fruitful discussions in the early concept generation. Publisher Copyright: © 2022 The Author(s) Background and Objective: Recommendations for the use of face masks to prevent and protect against the aerosols (≤5µm) and respiratory droplet particles (≥5µm), which can carry and transmit respiratory infections including severe acute respiratory syndrome coro…