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An optimal spectroscopic feature fusion strategy for MR brain tumor classification using Fisher Criteria and Parameter-Free BAT optimization algorithm

Kaur T., Saini B. S., Gupta S.

Biocybernetics and Biomedical Engineering

2018

Vol. 38, no. 2

409--424

In the present work, a fused metabolite ratio is proposed that integrates the conventional metabolite ratios in a weighted manner to improve the diagnostic accuracy of glioma brain tumor categorization. Each metabolite ratio is weighted by the value generated by the Fisher and the Parameter-Free BAT (PFree BAT) optimization algorithm. Here, feature fusion is formulated as an optimization problem with PFree BAT optimization as its underlying search strategy and Fisher Criterion serving as a fitness function. Experiments were conducted on the magnetic resonance spectroscopy (MRS) data of 50 subjects out of which 27 showed low-grade glioma and rest presented high-grade. The MRS data was analyzed for the peaks. The conventional metabolite ratios, i.e., Choline/N-acetyl aspartate (Cho/NAA), Cho/Creatine (Cho/Cr), were quan-titated using peak integration that exhibited difference among the tumor grades. The difference in the conventional metabolite ratios was enhanced by the proposed fused metabolite ratio that was duly validated by metrics of sensitivity, specificity, and the classification accuracy. Typically, the fused metabolite ratio characterized low-grade and high-grade with a sensitivity of 96%, specificity of 91%, and an accuracy of 93.72% when fed to the K-nearest neighbor classifier following a fivefold cross-validation data partitioning scheme. The results are significantly better than that obtained by the conventional metabolites where an accuracy equal to 80%, 87%, and 89% was attained. Prominently, the results using the fused metabolite ratio show a surge of 4.7% in comparison to Cho/Cr + Cho/NAA + NAA/Cr. Moreover, the obtained results are better than the similar works reported in the literature.

Biodegradowalny polimerowy system uwalniania radiouczulacza - badania in vitro

Buszman A., Kasperczyk J., Jarząbek B., Stokłosa K., Smola A.

Engineering of Biomaterials

2010

Vol. 13, no. 99-101

67--71

W pracy przedstawiono wyniki badań uwalniania radiouczulacza metronidazolu z jednowarstwowych oraz trójwarstwowych matryc kopolimeru glkolidu z laktydem do sztucznego płynu mózgowo rdzeniowego ACFs. Przeprowadzono analizę mikrostruktury łańcuchów polimerowych w oparciu o spektroskopię magnetycznego rezonansu jądrowego. Badanie uwalniania leku prowadzono w systemie dynamicznym z regularną wymianą buforu we fiolkach poddanych wytrząsaniu. Ekstrakty analizowano metodą spektrometrii UV-VIS. Równolegle prowadzono badania degradacji matryc z lekiem pod kątem oceny zmian w mikrostrukturze łańcucha polimerowego. Badania wykazały znacznie szybszą degradację matryc wykonanych z kopolimeru glikolidu z D,L-laktydem w porównaniu z matrycami z kopolimeru glikolidu z L-laktydem. Ponadto wykazano że opłaszczenie matrycy zawierającej lek polimerem bez leku (matryce trójwarstwowe) zapobiega nagłemu wyrzutowi leku z powierzchni w pierwszych dniach uwalniania.

In this paper the results of radiosensitizer metronidazole release investigation from mono- and triple-layered copolymeric matrices in artificial cerebro- spinal fluid solution (ACFs) are presented. The analysis of polymeric chain microstructure by the NMR has been conducted. Drug release study was performed in the dynamic system with regular buffer exchange in constantly stirred glass ampoules. The extracts were analyzed by the UV-VIS spectrometry. Drug carrying matrices degradation research were conducted to evaluate possible changes in polymeric chain microstructure. The results showed that matrices containing poly(glycolide-co-D,L-lactide) demonstrate higher degradation rate than matrices containing poly(glycolide-co-L-lactide). It has been proved that drug carriers coated with drug-free polymer (triplelayered matrices) prevents from burst effect.