Bone density and asymmetry are not related to DDT in House Sparrows: Insights from micro-focus X-ray computed tomography

Chemosphere ◽  
2018 ◽  
Vol 212 ◽  
pp. 734-743
Author(s):  
L. Steyn ◽  
J. Hoffman ◽  
H. Bouwman ◽  
A.W. Maina ◽  
J.N. Maina
2021 ◽  
Vol 6 (2) ◽  
pp. 158-162
Author(s):  
A. V. Bambuliak ◽  
◽  
N. B. Kuzniak ◽  
R. R. Dmitrenko ◽  
S. V. Tkachik ◽  
...  

The restoration processes of damaged or lost bone tissue are an important and topical issue of surgical dentistry and maxillofacial surgery today. According to statistics, diseases that are accompaning by destructive changes in bone tissue occupy one of the dominant places among the nosologies of MFA. Along with the use of updated methods of surgical technique, both before and now the problem of choice of bone-plastic material is relevant, because it is known that osteoplasty opens up great opportunities for complete rehabilitation of patients. The purpose of the study was to determine the effectiveness of our developed osteoplastic composition for the restoration of bone defects in dentistry. Materials and methods. X-ray computed tomography to determine bone density was performed in 26 patients with bone defect replacement "Kolapan-L" (group A), 28 people during augmentation of our proposed osteoplastic composition "Kolapan-L" + multipotent mesenchymal stromal cells + platelet-rich plasma) (group B), and 25 patients where the healing of the bone defect occurred spontaneously (group B). X-ray computed tomography was performed on a 16-slice spiral computed tomography Siemens Somatom Emotionc. Image processing was performed using the program "Dicom". Statistical processing of research results was carried out using conventional methods of variation statistics. Results and discussion. After 1 year of research, the average value of the bone density in patients of group B was probably higher: 1.5 times and 1.8 times relative to the corresponding data in groups A and B. At the same time, the minimum value of the bone density in patients of subgroups A and B was 1.5 times and 1.8 times lower than in persons of group B (p <0.01, p1 <0.01). At the same time, the maximum values of the bone density in patients of group B, where the augmentation of bone defects was performed using our proposed composition, were 1.4 times (p <0.01) and 1.8 times (p <0.05, p1 <0.01) higher than in group A, in the replacement of bone defects "Kolapan-L" and in group B, where the healing of the bone defect was spontaneous, respectively. It was found that in patients of group B after 12 months of studies, the average density of osteoregeneration was 1036.69±55.53 (HU), which was 1.5 times and 1.8 times more than in group A (p <0.01) and in group B patients (p <0.05, p1 <0.01) respectively. Conclusion. The use of tissue equivalent of bone tissue, proposed by us to replace a bone defect based on multipotent mesenchymal adipose tissue cells, contributed to the maximum increase in bone density, with a slightly lower effect of increasing bone density in the augmentation of bone defects


1999 ◽  
Vol 11 (1) ◽  
pp. 199-211
Author(s):  
J. M. Winter ◽  
R. E. Green ◽  
A. M. Waters ◽  
W. H. Green

2013 ◽  
Vol 19 (S2) ◽  
pp. 630-631
Author(s):  
P. Mandal ◽  
W.K. Epting ◽  
S. Litster

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.


Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 591
Author(s):  
Manasavee Lohvithee ◽  
Wenjuan Sun ◽  
Stephane Chretien ◽  
Manuchehr Soleimani

In this paper, a computer-aided training method for hyperparameter selection of limited data X-ray computed tomography (XCT) reconstruction was proposed. The proposed method employed the ant colony optimisation (ACO) approach to assist in hyperparameter selection for the adaptive-weighted projection-controlled steepest descent (AwPCSD) algorithm, which is a total-variation (TV) based regularisation algorithm. During the implementation, there was a colony of artificial ants that swarm through the AwPCSD algorithm. Each ant chose a set of hyperparameters required for its iterative CT reconstruction and the correlation coefficient (CC) score was given for reconstructed images compared to the reference image. A colony of ants in one generation left a pheromone through its chosen path representing a choice of hyperparameters. Higher score means stronger pheromones/probabilities to attract more ants in the next generations. At the end of the implementation, the hyperparameter configuration with the highest score was chosen as an optimal set of hyperparameters. In the experimental results section, the reconstruction using hyperparameters from the proposed method was compared with results from three other cases: the conjugate gradient least square (CGLS), the AwPCSD algorithm using the set of arbitrary hyperparameters and the cross-validation method.The experiments showed that the results from the proposed method were superior to those of the CGLS algorithm and the AwPCSD algorithm using the set of arbitrary hyperparameters. Although the results of the ACO algorithm were slightly inferior to those of the cross-validation method as measured by the quantitative metrics, the ACO algorithm was over 10 times faster than cross—Validation. The optimal set of hyperparameters from the proposed method was also robust against an increase of noise in the data and can be applicable to different imaging samples with similar context. The ACO approach in the proposed method was able to identify optimal values of hyperparameters for a dataset and, as a result, produced a good quality reconstructed image from limited number of projection data. The proposed method in this work successfully solves a problem of hyperparameters selection, which is a major challenge in an implementation of TV based reconstruction algorithms.


2021 ◽  
Author(s):  
Katherine A. Wolcott ◽  
Guillaume Chomicki ◽  
Yannick M. Staedler ◽  
Krystyna Wasylikowa ◽  
Mark Nesbitt ◽  
...  

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