Browsing by Author "Akhter, Nasrin"

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A deep learning approach for pneumonia classiﬁcation from chest X-Ray images with ensemble modelling and explainable AI
(BRAC University, 6/8/2021) Akhter, Nasrin; Alam, Md. Ashraful
Pneumonia is one of those frightening diseases that has a high mortality rate among children and the elderly, with an estimated 2 million fatalities per year. Pneumonia aﬀects the poorest people in Africa and Asia the most, due to a lack of medical surveillance in such areas. It is responsible for 28 percent of all child fatalities in Bangladesh each year, and the number is likely to be considerably higher. In recent years, a number of computer-assisted diagnostic methods have been developed to assist in the detection of pneumonia. In this study, an eﬃcient model PNEXAI is proposed to identify pneumonia utilizing Chest X-Ray images. We gathered and classiﬁed data using VGG16, VGG19, ResNet 50, ResNet 101 and Inception v3. The accuracy rate of 97.17% was reached by VGG16, 97.69% by VGG19, 97.35%by ResNet50, 95.63% by ResNet101, and 94.86% by Inception V3, respectively. We then developed an ensemble model containing the top three classiﬁcations (VGG16, VGG19 and ResNet50) which delivered 98.46 % of best overall accuracy. Finally, to better comprehend our categorization, we included explainable artiﬁcial intelligence in our model.
A Pre-clinical investigation on hepatotoxicity and osteoporosis induced by amphetamine derivative (methamphetamine and 3, 4-methylenedioximethamphetamine) with associated metabolic pathways using rat
(University of Dhaka, 2017-05-08) Akhter, Nasrin
Abuse of amphetamine derivative as methamphetamine (Meth, Yaba) or 3, 4-methylenedioximethamphetamine (MDMA, Ecstasy) is on a raising trend globally and Bangladesh is not an exception of this. The long term effects of abusing these drugs include risk of developing permanent brain damage with various psychological, cognitive and behavioral effects that may manifest as depression, anxiety, memory loss and various neuropsychotic disorders. Many studies, survey and case reports have described the clinical manifestations associated with the abuse of these drugs included mental disorder, cardiac disorder, jaundice, tooth decay, etc. But yet surprisingly little is known about the toxic effect of these drugs on vital organs like liver and bone. The purpose of this study was to look insight and reveal the effects of Yaba and Ecstasy on liver and bone using rat model. The present study was conducted to determine the toxic effects of amphetamine derivatives using two representative tablets, Yaba and Ecstasy, where Yaba was subjected to measure liver and bone toxicity and Ecstasy to monitor the cytochrome P450 mediated metabolic pathways in vivo. Along with methamphetamine Yaba also contain a significant amount of caffeine. So the toxic action of Yaba might be due to the contribution of its both components. To clarify this, a separate study was also carried out with caffeine to determine its effect on liver and bone in vivo.The in vivo study performed with Yaba tablet used Long Evans rats for eight weeks to investigate liver and bone toxicities. ALT, AST, ALP level of plasma; AOPP, MDA, NO, Catalase, Glutathione and SOD level of plasma and tissue were measured. Histopathological study of rat liver was done with H&E and Picro Sirius Red staining. Rat tibias were tested by digital X-ray. Study with caffeine was performed following the same schedule as Yaba. The third experiment carried out with Ecstasy (3, 4-methylenedioximethamphetamine, MDMA) used Sprague Dawley rats, pretreated with phenobarbital (PB) or β-naphthoflavone (BNF), to monitor the metabolic pathways of MDMA in liver by measuring urine drug metabolites concentration and liver CYP isozymes content. Liver inflammation was observed in Yaba treated rat liver with significantly elevated plasma level of ALT, AST, and ALP. Plasma and liver tissue level of MDA and NO were significantly increased. AOPP, Catalase, GSH, SOD activity in plasma and liver found unchanged as compared to control. In caffeine treated rat, liver transaminases, ALT, AST, ALP; oxidation end product, AOPP, MDA and oxidative stress indicator, NO increased significantly, Catalase & GSH remained unchanged but SOD decreased significantly as compared to control. Histology of liver tissue showed invasion of inflammatory cells and progressive deposition of collagen fibre in both Yaba and caffeine treated group. Digital X-ray of rat tibia treated with Yaba showed radiolucency not significant as compared to control. In urine analysis of MDMA treated rats, end product of N-demethylation, 3, 4-methylenedioxiamphetamine (MDA) concentration was significantly decreased in PB and BNF treated rats and end product of O-methylation, 4-hydroxy 3-methoxy methamphetamine (HMMA) concentration was significantly increased in PB and BNF treated rats as compared to control. Hepatic enzyme assays showed increased activities of CYP1A1(600-fold), CYP1A2(4-fold), CYP2B(4-fold) and CYP3A(2-fold) related enzymes after 24 hours of MDMA administration in the inducer pretreated rats as compared to control. In PB treated rat urine MDMA concentration decreased significantly. The total percent dose recoveries of MDMA and three metabolites in urine samples was less than 35% of the administered dose. The overall results suggested that methamphetamine tablet Yaba produced inflammation and fibrogenesis in liver. Caffeine, the second ingredient of Yaba showed similar liver toxicity in histochemical study. However, the extent of biochemical changes, notably higher in caffeine treated group than those of Yaba, suggested that methamphetamine in combination with caffeine might follow dissimilar pathways for liver toxicity to that followed by caffeine separately. The effect of Yaba on rat bone turnover was inconclusive. Metabolic pathway study results of 3,4-methylenedioximethamphetamine (MDMA) suggested that PB and BNF induced CYP isozymes might have inhibitory effects on N-demethylation of MDMA to MDA in rats. HHMA, the precursor of HMMA, increased through the process of O-demethylenation of MDMA by induced CYP isozymes. Decreased urinary concentration of MDMA in PB pretreated rats indicated its increased metabolism. The truly low percent recoveries of MDA, HMMA and HMPA in inducer pretreated rats suggested that other major pathways of MDMA metabolism might exist which were activated through inducer pretreatment.
Study on elemental image generation algorithms for integral imaging 3D display systems
(BRAC University, 2017) Akhter, Nasrin; Suchi, Nusrat Jahan; Afiunnahar; Alam, Dr. Md. Ashraful
In recent years, demands of three dimensional (3D) displays have increased due to its attractive application. Nowadays, Integral Imaging (II) is one of the most promising and fascinating research topic since it can fulfill all requirements of a true 3D display. In this thesis, different algorithms of elemental image generation for 3D integral imaging display systems is studied and analyzed. Integral imaging is an attractive autostereoscopic 3D display techniques that produces full color, full parallax, continues true 3D images without any eyeglass or supplementary devices. Despite tremendous benefits it has some drawbacks like-insufficient resolution, small viewing angle, shallow image depth. A numerous researches have been conducted to solve the problems. Elemental image generation algorithms play an important role for integral imaging 3D display systems. We studied and analyzed several elemental image generation algorithms to identify and suggest the effective algorithm for efficient 3D integral imaging display systems. The experimental data for the analysis are presented in this thesis. At first, we studied about direct pickup method of integral imaging 3D display system. In this method, the object information are captured through a array of small lenses called elemental lenses and each lens produce an elemental image by tracing the ray emanating from the object specific lenslet of the lens array. As a result, an array of elemental images can be directly captured by a CCD camera. This method causes noise with the captured elemental image. Secondly, we studied computer generated elemental image (CGEI) method which allows to reduce the noises that causes in direct pickup method. Several algorithms for CGEI method have been studied and analyzed. CGEI method can only generate elemental images from synthesized 3D object points from a 2D image which are not real depths of a 3D object. Thirdly, we studied about elemental image generation method using real depth and color information of a real object which can overcome the limitation of CGEI method. Hence, viewing angle is a problem of this method. Lastly, we studied the Directional Elemental Image Generation and Resizing (DEIGR) algorithm and multi-directional projection schemes that could be a breakthrough of integral image display.
SUPPLEMENTATION OF BOVINE SERUM ALBUMIN AND OVURELIN HORMONE TO DETERMINE AN EFFECTIVE MEDIA ON IN VITRO MATURATION AND FERTILIZATION OF CATTLE OOCYTES
(DEPARTMENT OF ANIMAL NUTRITION, GENETICS AND BREEDING, 2021) Akhter, Nasrin
The present experiment has been undertaken to know the effect of hormone and protein supplementation on in vitro maturation and fertilization of cattle oocytes. Ovaries from slaughter were brought to the laboratory and washed in a saline solution at 30℃ for 2 to 3 times. Cumulus oocytes complexes (COCs) were collected by aspiration method and 475 follicles were aspirated out of 631 visible follicles on the surface of both ovaries from CL group (Luteal phase) and without CL (Follicular phase),Where the COCs were classified as normal (Grade A and Grade B) and abnormal (Grade C and Grade D) groups, the highest numbers of normal COCs were found in the ovary without CL (3.11±0.21%). The COCs were matured for 48 hours in TCM-199 basic medium supplemented 10% Bovine Serum Albumin (BSA) and Gonadotropin Hormone (Ovurelin). Cumulus Cell expansion of COCs were studied in TCM-199 cultured media with Ovurelin and 10% BSA. COCs were fertilized with frozen semen after maturation in TCM-199 supplemented with 10% BSA and 10.15µg/ml Ovurelin. The maturation rate is significantly higher at (66.25±2.67%) when 10% BSA and 10.15µg/ml Ovurelin used combined. Similarly, the fertilization rate was significantly higher (P<0.05) and high number of normal pronuclei formation (2PN) (66.25±2.67%) was found when supplemented with 10% BSA and 10.15µg/ml Ovurelin. Thus, it can be concluded that the combined media of 10% BSA and Ovurelin might be used as a good supplement for in vitro maturation and fertilization of this study.