Imaging the root–rhizosphere interface using micro computed tomography: quantifying void ratio and root volume ratio profiles

Root growth alters soil fabric and consequently its mechanical and physical properties. Recent studies show that roots induce compaction of soil in their immediate vicinity, a region that is central for plant health. However, high quality quantification of root influence on the soil fabric, able to inform computational models is lacking from the literature. This study quantifies the relationship between soil physical characteristics and root growth, giving special emphasis on how roots in early stage formation influence the physical architecture of the surrounding soil structure. High-resolution X-ray micro-Computed Tomography (µCT) is used to acquire three dimensional images of two homogeneously-packed samples. It is observed that the void ratio profile extending from the soil-root interface into the bulk soil is altered by root growth. The roots considerably modify the immediate soil physical characteristics by creating micro cracks at the soil-root interface and by increasing void ratio. This paper presents the mechanisms that led to the observed structure as well as some of the implications that it has in such a dynamic zone.

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Micro-Computed Tomography Analysis of Subchondral Bone Regeneration Using Osteochondral Scaffolds in an Ovine Condyle Model

Applied Sciences ◽

10.3390/app11030891 ◽

2021 ◽

Vol 11 (3) ◽

pp. 891

Author(s):

Taylor Flaherty ◽

Maryam Tamaddon ◽

Chaozong Liu

Keyword(s):

Computed Tomography ◽

Bone Regeneration ◽

Subchondral Bone ◽

Volume Ratio ◽

Bone Volume ◽

Osteochondral Defects ◽

Micro Ct ◽

Micro Computed Tomography ◽

Trabecular Thickness ◽

Osteochondral Scaffold

Osteochondral scaffold technology has emerged as a promising therapy for repairing osteochondral defects. Recent research suggests that seeding osteochondral scaffolds with bone marrow concentrate (BMC) may enhance tissue regeneration. To examine this hypothesis, this study examined subchondral bone regeneration in scaffolds with and without BMC. Ovine stifle condyle models were used for the in vivo study. Two scaffold systems (8 mm diameter and 10 mm thick) with and without BMC were implanted into the femoral condyle, and the tissues were retrieved after six months. The retrieved femoral condyles (with scaffold in) were examined using micro-computed tomography scans (micro-CT), and the micro-CT data were further analysed by ImageJ with respect to trabecular thickness, bone volume to total volume ratio (BV/TV) ratio, and degree of anisotropy of bone. Statistical analysis compared bone regeneration between scaffold groups and sub-set regions. These results were mostly insignificant (p < 0.05), with the exception of bone volume to total volume ratio when comparing scaffold composition and sub-set region. Additional trends in the data were observed. These results suggest that the scaffold composition and addition of BMC did not significantly affect bone regeneration in osteochondral defects after six months. However, this research provides data which may guide the development of future treatments.

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3D-printed Poly-Lactic Co-Glycolic Acid (PLGA) scaffolds in non-critical bone defects impede bone regeneration in rabbit tibia bone

Bio-Medical Materials and Engineering ◽

10.3233/bme-216017 ◽

2021 ◽

pp. 1-7

Author(s):

Jin Xi Lim ◽

Min He ◽

Alphonsus Khin Sze Chong

Keyword(s):

Computed Tomography ◽

Bone Regeneration ◽

Bone Defect ◽

Volume Ratio ◽

Bone Defects ◽

Control Group ◽

Micro Computed Tomography ◽

Rabbit Tibia ◽

3D Printed ◽

Critical Bone Defects

BACKGROUND: An increasing number of bone graft materials are commercially available and vary in their composition, mechanism of action, costs, and indications. OBJECTIVE: A commercially available PLGA scaffold produced using 3D printing technology has been used to promote the preservation of the alveolar socket after tooth extraction. We examined its influence on bone regeneration in long bones of New Zealand White rabbits. METHODS: 5.0-mm-diameter circular defects were created on the tibia bones of eight rabbits. Two groups were studied: (1) control group, in which the bone defects were left empty; (2) scaffold group, in which the PLGA scaffolds were implanted into the bone defect. Radiography was performed every two weeks postoperatively. After sacrifice, bone specimens were isolated and examined by micro-computed tomography and histology. RESULTS: Scaffolds were not degraded by eight weeks after surgery. Micro-computed tomography and histology showed that in the region of bone defects that was occupied by scaffolds, bone regeneration was compromised and the total bone volume/total volume ratio (BV/TV) was significantly lower. CONCLUSION: The implantation of this scaffold impedes bone regeneration in a non-critical bone defect. Implantation of bone scaffolds, if unnecessary, lead to a slower rate of fracture healing.

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Micro-computed tomography analysis of early stage bone healing using micro-porous titanium mesh for guided bone regeneration: preliminary experiment in a canine model

Odontology ◽

10.1007/s10266-017-0298-1 ◽

2017 ◽

Vol 105 (4) ◽

pp. 408-417 ◽

Cited By ~ 9

Author(s):

Yunia Dwi Rakhmatia ◽

Yasunori Ayukawa ◽

Yohei Jinno ◽

Akihiro Furuhashi ◽

Kiyoshi Koyano

Keyword(s):

Computed Tomography ◽

Bone Regeneration ◽

Bone Healing ◽

Early Stage ◽

Canine Model ◽

Porous Titanium ◽

Guided Bone Regeneration ◽

Titanium Mesh ◽

Micro Computed Tomography ◽

Tomography Analysis

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Imaging of the Mouse Lymphatic Sinus during Early Stage Lymph Node Metastasis Using Intranodal Lymphangiography with X-ray Micro-computed Tomography

Molecular Imaging and Biology ◽

10.1007/s11307-018-01303-4 ◽

2019 ◽

Vol 21 (5) ◽

pp. 825-834 ◽

Cited By ~ 1

Author(s):

Ryo Iwamura ◽

Maya Sakamoto ◽

Shiro Mori ◽

Tetsuya Kodama

Keyword(s):

Computed Tomography ◽

Lymph Node ◽

Lymph Node Metastasis ◽

Early Stage ◽

Micro Computed Tomography ◽

X Ray ◽

Node Metastasis ◽

Intranodal Lymphangiography

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Mapping cyclic stretch in the postpneumonectomy murine lung

Journal of Applied Physiology ◽

10.1152/japplphysiol.00635.2013 ◽

2013 ◽

Vol 115 (9) ◽

pp. 1370-1378 ◽

Cited By ~ 5

Author(s):

Nenad Filipovic ◽

Barry C. Gibney ◽

Milos Kojic ◽

Dalibor Nikolic ◽

Velibor Isailovic ◽

...

Keyword(s):

Computed Tomography ◽

Shear Strain ◽

Computational Models ◽

Mammalian Species ◽

Stretch Ratio ◽

Growth Patterns ◽

Cyclic Stretch ◽

Micro Computed Tomography ◽

Maximum Shear Strain ◽

Computed Tomography Scanning

In many mammalian species, the removal of one lung [pneumonectomy (PNX)] is associated with the compensatory growth of the remaining lung. To investigate the hypothesis that parenchymal deformation may trigger lung regeneration, we used respiratory-gated micro-computed tomography scanning to create three-dimensional finite-element geometric models of the murine cardiac lobe with cyclic breathing. Models were constructed of respiratory-gated micro-computed tomography scans pre-PNX and 24 h post-PNX. The computational models demonstrated that the maximum stretch ratio map was patchy and heterogeneous, particularly in subpleural, juxta-diaphragmatic, and cephalad regions of the lobe. In these parenchymal regions, the material line segments at peak inspiration were frequently two- to fourfold greater after PNX; some regions of the post-PNX cardiac lobe demonstrated parenchymal compression at peak inspiration. Similarly, analyses of parenchymal maximum shear strain demonstrated heterogeneous regions of mechanical stress with focal regions demonstrating a threefold increase in shear strain after PNX. Consistent with previously identified growth patterns, these subpleural regions of enhanced stretch and shear strain are compatible with a mechanical signal, likely involving cyclic parenchymal stretch, triggering lung growth.

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Three-Dimensional Radiological Methods for Age Estimation in Adults by Using the Pulp/Tooth Relation: an Integrative Review

Brazilian Journal of Forensic Science Medical Law and Bioethics ◽

10.17063/bjfs10(2)y202197-110 ◽

2021 ◽

Vol 10 (2) ◽

pp. 97-110

Author(s):

Vanessa Moreira Andrade ◽

Thais Uenoyama Dezem ◽

Andreia Cristina Breda de Souza ◽

Casimiro Abreu Possante de Almeida ◽

Luiz Francesquini Junior ◽

...

Keyword(s):

Computed Tomography ◽

Age Estimation ◽

Three Dimensional ◽

Volume Ratio ◽

Integrative Review ◽

Coefficient Of Determination ◽

Micro Computed Tomography ◽

Human Teeth ◽

Global Comparison ◽

Time Restriction

Assessment of secondary dentin apposition is an observable phenomenon widely used to estimate age. An integrative review was performed by searching the keywords "computed tomography AND age estimation AND pulp tooth volume ratio" and "microfocus x-ray AND age estimation AND pulp tooth volume ratio" in the electronic platforms Embase, PubMed, Scopus and Web of Science, in July 2020. Studies included: complete articles with age estimation from human teeth by use of computed tomography or micro-computed tomography, written in English, without time restriction. Excluded studies: not written in English or not in form of an article, clinical cases, literature reviews, if did not realize age estimations or if age estimation is done in animals teeth. The search resulted in 32 different articles. With application of the above criteria only 26 were reviewed. Data collected included: reference, year, country, tooth type, number of subjects, number of teeth, age group, image type, measuring instrument/software, type of analysis, coefficient of determination, correlation coefficient with age and accuracy. These data provided a quick global comparison of various methodologies that use the pulp/tooth relation, being practical for researchers and forensic team to which method they can use accordingly to a specific case and its expected accuracy.

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Effect of deep tillage on soil physical characteristics and corn (Zea mays L.) root growth and production

Soil and Tillage Research ◽

10.1016/s0167-1987(97)00041-x ◽

1997 ◽

Vol 43 (3-4) ◽

pp. 219-228 ◽

Cited By ~ 44

Author(s):

E.C. Varsa ◽

S.K. Chong ◽

J.O. Abolaji ◽

D.A. Farquhar ◽

F.J. Olsen

Keyword(s):

Zea Mays ◽

Root Growth ◽

Zea Mays L ◽

Physical Characteristics ◽

Deep Tillage ◽

Soil Physical Characteristics

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Analysis of tumor vascularization in a mouse model of metastatic lung cancer

Scientific Reports ◽

10.1038/s41598-019-52144-2 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Ariunbuyan Sukhbaatar ◽

Maya Sakamoto ◽

Shiro Mori ◽

Tetsuya Kodama

Keyword(s):

Computed Tomography ◽

Mouse Model ◽

Blood Vessel ◽

Tumor Cells ◽

Lung Metastasis ◽

Cell Activation ◽

Ex Vivo ◽

Early Stage ◽

Micro Computed Tomography ◽

Epr Effect

Abstract Therapies targeting tumor vasculature would improve the treatment of lung metastasis, although the early changes in vascular structure are incompletely understood. Here, we show that obstructive metastatic foci in lung arterioles decrease the pulmonary vascular network. To generate a mouse model of lung metastasis activation, luciferase-expressing tumor cells were inoculated into the subiliac lymph node (SiLN) of an MXH10/Mo-lpr/lpr mouse, and metastatic tumor cells in the lungs were activated by SiLN resection. Activation of metastases was monitored by in vivo bioluminescence imaging. Pulmonary blood vessel characteristics were analyzed using ex vivo micro-computed tomography. The enhanced permeability and retention (EPR) effect in neovasculature after tumor cell activation was evaluated from the accumulation of intravenously injected indocyanine green (ICG) liposomes. Metastatic foci in lung arterioles were investigated histologically. Micro-computed tomography revealed decreases in pulmonary blood vessel length, volume and number of branching nodes during the early stage of metastasis caused by metastatic foci. ICG liposome accumulation by the EPR effect was not detected. Histology identified metastatic foci in lung arterioles. The lack of an EPR effect after the formation of metastatic foci in lung arterioles makes conventional systemic chemotherapy ineffective for lung metastasis. Thus, alternative therapeutic methods of drug delivery are needed.

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