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2. Knowledge Distillation for Efficient Audio-Visual Video Captioning

Author

Çaylı, Özkan, Liu, Xubo, Kılıç, Volkan, and Wang, Wenwu

Subjects
Electrical Engineering and Systems Science - Audio and Speech Processing
Abstract

Automatically describing audio-visual content with texts, namely video captioning, has received significant attention due to its potential applications across diverse fields. Deep neural networks are the dominant methods, offering state-of-the-art performance. However, these methods are often undeployable in low-power devices like smartphones due to the large size of the model parameters. In this paper, we propose to exploit simple pooling front-end and down-sampling algorithms with knowledge distillation for audio and visual attributes using a reduced number of audio-visual frames. With the help of knowledge distillation from the teacher model, our proposed method greatly reduces the redundant information in audio-visual streams without losing critical contexts for caption generation. Extensive experimental evaluations on the MSR-VTT dataset demonstrate that our proposed approach significantly reduces the inference time by about 80% with a small sacrifice (less than 0.02%) in captioning accuracy., Comment: European Signal Processing Conference (EUSIPCO 2023)

Published
2023

3. Dual Transformer Decoder based Features Fusion Network for Automated Audio Captioning

Author

Sun, Jianyuan, Liu, Xubo, Mei, Xinhao, Kılıç, Volkan, Plumbley, Mark D., and Wang, Wenwu

Subjects
Electrical Engineering and Systems Science - Audio and Speech Processing, Computer Science - Sound
Abstract

Automated audio captioning (AAC) which generates textual descriptions of audio content. Existing AAC models achieve good results but only use the high-dimensional representation of the encoder. There is always insufficient information learning of high-dimensional methods owing to high-dimensional representations having a large amount of information. In this paper, a new encoder-decoder model called the Low- and High-Dimensional Feature Fusion (LHDFF) is proposed. LHDFF uses a new PANNs encoder called Residual PANNs (RPANNs) to fuse low- and high-dimensional features. Low-dimensional features contain limited information about specific audio scenes. The fusion of low- and high-dimensional features can improve model performance by repeatedly emphasizing specific audio scene information. To fully exploit the fused features, LHDFF uses a dual transformer decoder structure to generate captions in parallel. Experimental results show that LHDFF outperforms existing audio captioning models., Comment: INTERSPEECH 2023. arXiv admin note: substantial text overlap with arXiv:2210.05037

Published
2023

4. Visually-Aware Audio Captioning With Adaptive Audio-Visual Attention

Author

Liu, Xubo, Huang, Qiushi, Mei, Xinhao, Liu, Haohe, Kong, Qiuqiang, Sun, Jianyuan, Li, Shengchen, Ko, Tom, Zhang, Yu, Tang, Lilian H., Plumbley, Mark D., Kılıç, Volkan, and Wang, Wenwu

Subjects
Electrical Engineering and Systems Science - Audio and Speech Processing, Computer Science - Artificial Intelligence, Computer Science - Multimedia, Computer Science - Sound
Abstract

Audio captioning aims to generate text descriptions of audio clips. In the real world, many objects produce similar sounds. How to accurately recognize ambiguous sounds is a major challenge for audio captioning. In this work, inspired by inherent human multimodal perception, we propose visually-aware audio captioning, which makes use of visual information to help the description of ambiguous sounding objects. Specifically, we introduce an off-the-shelf visual encoder to extract video features and incorporate the visual features into an audio captioning system. Furthermore, to better exploit complementary audio-visual contexts, we propose an audio-visual attention mechanism that adaptively integrates audio and visual context and removes the redundant information in the latent space. Experimental results on AudioCaps, the largest audio captioning dataset, show that our proposed method achieves state-of-the-art results on machine translation metrics., Comment: INTERSPEECH 2023

Published
2022

5. Automated Audio Captioning via Fusion of Low- and High- Dimensional Features

Author

Sun, Jianyuan, Liu, Xubo, Mei, Xinhao, Plumbley, Mark D., Kilic, Volkan, and Wang, Wenwu

Subjects
Computer Science - Sound, Computer Science - Machine Learning, Electrical Engineering and Systems Science - Audio and Speech Processing
Abstract

Automated audio captioning (AAC) aims to describe the content of an audio clip using simple sentences. Existing AAC methods are developed based on an encoder-decoder architecture that success is attributed to the use of a pre-trained CNN10 called PANNs as the encoder to learn rich audio representations. AAC is a highly challenging task due to its high-dimensional talent space involves audio of various scenarios. Existing methods only use the high-dimensional representation of the PANNs as the input of the decoder. However, the low-dimension representation may retain as much audio information as the high-dimensional representation may be neglected. In addition, although the high-dimensional approach may predict the audio captions by learning from existing audio captions, which lacks robustness and efficiency. To deal with these challenges, a fusion model which integrates low- and high-dimensional features AAC framework is proposed. In this paper, a new encoder-decoder framework is proposed called the Low- and High-Dimensional Feature Fusion (LHDFF) model for AAC. Moreover, in LHDFF, a new PANNs encoder is proposed called Residual PANNs (RPANNs) by fusing the low-dimensional feature from the intermediate convolution layer output and the high-dimensional feature from the final layer output of PANNs. To fully explore the information of the low- and high-dimensional fusion feature and high-dimensional feature respectively, we proposed dual transformer decoder structures to generate the captions in parallel. Especially, a probabilistic fusion approach is proposed that can ensure the overall performance of the system is improved by concentrating on the respective advantages of the two transformer decoders. Experimental results show that LHDFF achieves the best performance on the Clotho and AudioCaps datasets compared with other existing models

Published
2022

6. Deep Neural Decision Forest for Acoustic Scene Classification

Author

Sun, Jianyuan, Liu, Xubo, Mei, Xinhao, Zhao, Jinzheng, Plumbley, Mark D., Kılıç, Volkan, and Wang, Wenwu

Subjects
Electrical Engineering and Systems Science - Audio and Speech Processing, Computer Science - Artificial Intelligence, Computer Science - Machine Learning, Computer Science - Sound
Abstract

Acoustic scene classification (ASC) aims to classify an audio clip based on the characteristic of the recording environment. In this regard, deep learning based approaches have emerged as a useful tool for ASC problems. Conventional approaches to improving the classification accuracy include integrating auxiliary methods such as attention mechanism, pre-trained models and ensemble multiple sub-networks. However, due to the complexity of audio clips captured from different environments, it is difficult to distinguish their categories without using any auxiliary methods for existing deep learning models using only a single classifier. In this paper, we propose a novel approach for ASC using deep neural decision forest (DNDF). DNDF combines a fixed number of convolutional layers and a decision forest as the final classifier. The decision forest consists of a fixed number of decision tree classifiers, which have been shown to offer better classification performance than a single classifier in some datasets. In particular, the decision forest differs substantially from traditional random forests as it is stochastic, differentiable, and capable of using the back-propagation to update and learn feature representations in neural network. Experimental results on the DCASE2019 and ESC-50 datasets demonstrate that our proposed DNDF method improves the ASC performance in terms of classification accuracy and shows competitive performance as compared with state-of-the-art baselines., Comment: Submitted to the 30th European Signal Processing Conference (EUSIPCO), 5 pages, 2 figures

Published
2022

7. Leveraging Pre-trained BERT for Audio Captioning

Author

Liu, Xubo, Mei, Xinhao, Huang, Qiushi, Sun, Jianyuan, Zhao, Jinzheng, Liu, Haohe, Plumbley, Mark D., Kılıç, Volkan, and Wang, Wenwu

Subjects
Electrical Engineering and Systems Science - Audio and Speech Processing, Computer Science - Artificial Intelligence, Computer Science - Sound
Abstract

Audio captioning aims at using natural language to describe the content of an audio clip. Existing audio captioning systems are generally based on an encoder-decoder architecture, in which acoustic information is extracted by an audio encoder and then a language decoder is used to generate the captions. Training an audio captioning system often encounters the problem of data scarcity. Transferring knowledge from pre-trained audio models such as Pre-trained Audio Neural Networks (PANNs) have recently emerged as a useful method to mitigate this issue. However, there is less attention on exploiting pre-trained language models for the decoder, compared with the encoder. BERT is a pre-trained language model that has been extensively used in Natural Language Processing (NLP) tasks. Nevertheless, the potential of BERT as the language decoder for audio captioning has not been investigated. In this study, we demonstrate the efficacy of the pre-trained BERT model for audio captioning. Specifically, we apply PANNs as the encoder and initialize the decoder from the public pre-trained BERT models. We conduct an empirical study on the use of these BERT models for the decoder in the audio captioning model. Our models achieve competitive results with the existing audio captioning methods on the AudioCaps dataset., Comment: Submitted to the 30th European Signal Processing Conference (EUSIPCO), 5 pages, 2 figures

Published
2022

10. Intensity Particle Flow SMC-PHD Filter For Audio Speaker Tracking

Author

Liu, Yang, Wang, Wenwu, and Kilic, Volkan

Subjects
Computer Science - Sound, Electrical Engineering and Systems Science - Audio and Speech Processing
Abstract

Non-zero diffusion particle flow Sequential Monte Carlo probability hypothesis density (NPF-SMC-PHD) filtering has been recently introduced for multi-speaker tracking. However, the NPF does not consider the missing detection which plays a key role in estimation of the number of speakers with their states. To address this limitation, we propose to use intensity particle flow (IPF) in NPFSMC-PHD filter. The proposed method, IPF-SMC-PHD, considers the clutter intensity and detection probability while no data association algorithms are used for the calculation of particle flow. Experiments on the LOCATA (acoustic source Localization and Tracking) dataset with the sequences of task 4 show that our proposed IPF-SMC-PHD filter improves the tracking performance in terms of estimation accuracy as compared to its baseline counterparts., Comment: In Proceedings of the LOCATA Challenge Workshop - a satellite event of IWAENC 2018 (arXiv:1811.08482 )

Published
2018

14. Smartphone Based Colorimetric Detection via Machine Learning

Author

Mutlu, Ali Y., Kılıç, Volkan, Özdemir, Gizem K., Bayram, Abdullah, Horzum, Nesrin, and Solmaz, Mehmet E.

Subjects
Computer Science - Computer Vision and Pattern Recognition
Abstract

We report the application of machine learning to smartphone based colorimetric detection of pH values. The strip images were used as the training set for Least Squares-Support Vector Machine (LS-SVM) classifier algorithms that were able to successfully classify the distinct pH values. The difference in the obtained image formats was found not to significantly affect the performance of the proposed machine learning approach. Moreover, the influence of the illumination conditions on the perceived color of pH strips was investigated and further experiments were carried out to study effect of color change on the learning model. Test results on JPEG, RAW and RAW-corrected image formats captured in different lighting conditions lead to perfect classification accuracy, sensitivity and specificity, which proves that the colorimetric detection using machine learning based systems is able to adapt to various experimental conditions and is a great candidate for smartphone based sensing in paper-based colorimetric assays.

Published
2017
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15. Mobile Application Based Automatic Caption Generation for Visually Impaired

Author

Çaylı, Özkan, Makav, Burak, Kılıç, Volkan, Onan, Aytuğ, Kacprzyk, Janusz, Series Editor, Pal, Nikhil R., Advisory Editor, Bello Perez, Rafael, Advisory Editor, Corchado, Emilio S., Advisory Editor, Hagras, Hani, Advisory Editor, Kóczy, László T., Advisory Editor, Kreinovich, Vladik, Advisory Editor, Lin, Chin-Teng, Advisory Editor, Lu, Jie, Advisory Editor, Melin, Patricia, Advisory Editor, Nedjah, Nadia, Advisory Editor, Nguyen, Ngoc Thanh, Advisory Editor, Wang, Jun, Advisory Editor, Kahraman, Cengiz, editor, Cevik Onar, Sezi, editor, Oztaysi, Basar, editor, Sari, Irem Ucal, editor, Cebi, Selcuk, editor, and Tolga, A. Cagri, editor

Published
2021
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16. Fuzzy Classifier Based Colorimetric Quantification Using a Smartphone

Author

Mercan, Öykü Berfin, Kılıç, Volkan, Kacprzyk, Janusz, Series Editor, Pal, Nikhil R., Advisory Editor, Bello Perez, Rafael, Advisory Editor, Corchado, Emilio S., Advisory Editor, Hagras, Hani, Advisory Editor, Kóczy, László T., Advisory Editor, Kreinovich, Vladik, Advisory Editor, Lin, Chin-Teng, Advisory Editor, Lu, Jie, Advisory Editor, Melin, Patricia, Advisory Editor, Nedjah, Nadia, Advisory Editor, Nguyen, Ngoc Thanh, Advisory Editor, Wang, Jun, Advisory Editor, Kahraman, Cengiz, editor, Cevik Onar, Sezi, editor, Oztaysi, Basar, editor, Sari, Irem Ucal, editor, Cebi, Selcuk, editor, and Tolga, A. Cagri, editor

Published
2021
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21. Visually-Aware Audio Captioning With Adaptive Audio-Visual Attention

Author

Liu, Xubo, primary, Huang, Qiushi, additional, Mei, Xinhao, additional, Liu, Haohe, additional, Kong, Qiuqiang, additional, Sun, Jianyuan, additional, Li, Shengchen, additional, Ko, Tom, additional, Zhang, Yu, additional, Tang, Lilian H., additional, Plumbley, Mark D., additional, Kılıç, Volkan, additional, and Wang, Wenwu, additional

Published
2023
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25. Particle Flow SMC-PHD Filter for Audio-Visual Multi-speaker Tracking

Author

Liu, Yang, Wang, Wenwu, Chambers, Jonathon, Kilic, Volkan, Hilton, Adrian, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Weikum, Gerhard, Series editor, Tichavský, Petr, editor, Babaie-Zadeh, Massoud, editor, Michel, Olivier J.J., editor, and Thirion-Moreau, Nadège, editor

Published
2017
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29. Poly(2-Hydroxyethyl Methacrylate) Hydrogel-Based Microneedles for Metformin Release

Author

Sharma, Manoj, Kap, Özlem, Abdelmohsen, Hend, Ashton, Mark, Harper, Garry, Firlak, Melike, Aaltonen, Jasmine, Bolland, Kerry, Bragg, Ryan, Deeley, Sarah, Francis, Ella, Kazi, Nahin, Mapley, Bethany, Oikonomou, Vasileios, Aljohani, Amal Dhaifallah, Cheneler, David, Kılıç, Volkan, Horzum, Nesrin, and Hardy, John

Abstract

The release of metformin, a drug used in the treatment of cancer and diabetes, from poly(2-hydroxyethyl methacrylate), pHEMA, hydrogel-based microneedle patches is demonstrated in vitro. Tuning the composition of the pHEMA hydrogels enables preparation of robust microneedle patches with mechanical properties such that they would penetrate skin (insertion force of a single microneedle to be ≈40 N). Swelling experiments conducted at 20, 35, and 60 °C show temperature-dependent degrees of swelling and diffusion kinetics. Drug release from the pHEMA hydrogel-based microneedles is fitted to various models (e.g., zero order, first order, second order). Such pHEMA microneedles have potential application for transdermal delivery of metformin for the treatment of aging, cancer, diabetes, etc.

Published
2023

31. Polymer hydrogel-based microneedles for metformin release

Author

Sharma, Manoj, Kap, Özlem, Abdelmohsen, Hend, Harper, Garry, Firlak, Melike, Aaltonen, Jasmine, Bolland, Kerry, Bragg, Ryan, Deeley, Sarah, Francis, Ella, Kazi, Nahin, Mapley, Bethany, Oikonomou, Vasileios, Aljohani, Amal, Halcovitch, Nathan, Cheneler, David, Kılıç, Volkan, Horzum, Nesrin, Hardy, John, Sharma, Manoj, Kap, Özlem, Abdelmohsen, Hend, Harper, Garry, Firlak, Melike, Aaltonen, Jasmine, Bolland, Kerry, Bragg, Ryan, Deeley, Sarah, Francis, Ella, Kazi, Nahin, Mapley, Bethany, Oikonomou, Vasileios, Aljohani, Amal, Halcovitch, Nathan, Cheneler, David, Kılıç, Volkan, Horzum, Nesrin, and Hardy, John

Abstract

Drug delivery devices ensure the effective delivery of a broad range of therapeutics to millions of patients worldwide on a daily basis.1 Microneedles are a class of drug delivery device that provide pain free transdermal delivery with improved patient compliance.2-4 The release of metformin, a drug used in the treatment of cancer and diabetes, from polymer hydrogel-based microneedle patches was demonstrated in vitro. Tuning the composition of the polymer hydrogels enabled preparation of robust microneedle patches with mechanical properties such that they would penetrate skin (insertion force of a single microneedle to be ca. 40 N). Swelling experiments conducted at 20°C, 35°C and 60°C show temperature dependent degrees of swelling and kinetics (Fickian diffusion). Drug release from the hydrogel-based microneedles was fitted to various models (e.g., zero order, first order, second order, Korsmeyer-Peppas, Peppas-Sahlins), observing the best fit for the zero-order model. Such microneedles have potential application for transdermal delivery of metformin for the treatment of cancer and diabetes.

Published
2022

33. Colorimetric detection of H2O2 with Fe3O4@Chi nanozyme modified µPADs using artificial intelligence.

Author

Şen, Mustafa, Yüzer, Elif, Doğan, Vakkas, Avcı, İpek, Ensarioğlu, Kenan, Aykaç, Ahmet, Kaya, Nusret, Can, Mustafa, and Kılıç, Volkan

Subjects
ARTIFICIAL intelligence, LEARNING classifier systems, FISHER discriminant analysis, COLORIMETRY, COLORIMETRIC analysis, MACHINE learning, MICROFLUIDICS, OXYGEN consumption
Abstract

Peroxidase mimicking Fe3O4@Chitosan (Fe3O4@Chi) nanozyme was synthesized and used for high-sensitive enzyme-free colorimetric detection of H2O2. The nanozyme was characterized in comparison with Fe3O4 nanoparticles (NPs) using X-ray diffraction, Fourier-transform infrared spectroscopy, dynamic light scattering, and thermogravimetric analysis. The catalytic performance of Fe3O4@Chi nanozyme was first evaluated by UV–Vis spectroscopy using 3,3′,5,5′-tetramethylbenzidine. Unlike Fe3O4NPs, Fe3O4@Chi nanozyme exhibited an intrinsic peroxidase activity with a detection limit of 69 nM. Next, the nanozyme was applied to a microfluidic paper-based analytical device (µPAD) and colorimetric analysis was performed at varying concentrations of H2O2 using a machine learning-based smartphone app called "Hi-perox Sens++." The app with machine learning classifiers made the system user-friendly as well as more robust and adaptive against variation in illumination and camera optics. In order to train various machine learning classifiers, the images of the µPADs were taken at 30 s and 10 min by four smartphone brands under seven different illuminations. According to the results, linear discriminant analysis exhibited the highest classification accuracy (98.7%) with phone-independent repeatability at t = 30 s and the accuracy was preserved for 10 min. The proposed system also showed excellent selectivity in the presence of various interfering molecules and good detection performance in tap water. [ABSTRACT FROM AUTHOR]

Published
2022
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39. Grafen içeren poliimid köpüklerin sentezi ve karakterizasyonu

Author

Kılıç, Volkan, Çakır, Mustafa, and Metalurji ve Malzeme Mühendisliği Anabilim Dalı

Subjects
Metallurgy, Metalurji
Abstract

Poliimid köpükler, yüksek termal ve mekanik özellikleri nedeniyle, havacılık ve uzay endüstrisi gibi ileri endüstriler için uygun malzemelerdir. Bu çalışmada izosiyanat bazlı poliimid köpükler tek basamaklı sentez yöntemi ve yarı-prepolimer yaklaşımı ile sentezlenmiştir. Çalışmada benzofenon tetrakarboksilik asit anhidrit (BTDA) ve piromellitik anhidrit (PMDA) olmak üzere iki farklı anhidrit ile %0, %0,25, %0,50, %0,75 ve %1 oranlarda grafen oksit (GO) içeren köpükler sentezlenmiş, konik kalorimetre ve limit oksijen indeksi analizleri ile termal özellikleri incelenmiştir. Bunun yanında basma testi ile mekanik özellikler, taramalı elektron mikroskobu ile de morfolojik özellikleri incelenmiştir. GO içeren sistemlerin dışında BTDA ile farklı oranlarda su ve surfaktan içeren iki ayrı sistem daha sentezlenmiş, bu köpükler de basma testi ile mekanik ve SEM ile morfolojik açıdan incelenmiştir.--------------------Polyimide foams are highly useful materials for advanced industries such as aerospace and aviation because of their great thermal and mechanical properties. Isocyanate based graphene oxide containing polyimide foams were synthesised by the one-pot method and the semi-prepolymer approach in this study. There are two different anhydride monomer that was used as 3,3’ ,4,4’ benzophenone tetracarboxylic acid dianhydrate (BTDA), pyromellitic dianhydrate (PMDA) with different graphene oxide ratios such as 0 wt.%, 0,25 wt.%, 0,50 wt.%, 0,75 wt.%, 1 wt.% respectively. Thermal properties of synthesised foams were investigated via Cone Calorimeter and Limiting Oxygen Index analysis. Mechanical properties of foams were studied via compression analysis, and morphological properties were observed via Scanning Electron Microscope (SEM). On the other hand, two different foam system were synthesized with BTDA that includes water and surfactant with different ratios and not including graphene oxide. These foams mechanical properties also researched via compression test and morphological properties observed via SEM analysis.

Published
2019

40. ANTIOXIDATIVE RESPONSES IN Tubifex tubifex AGAINST THALLIUM INDUCED OXIDATIVE STRESS

Author

Kılıç, Volkan, Aydoğan-Kılıc, G., Anadolu Üniversitesi, Fen Fakültesi, Biyoloji Bölümü, Kılıç, Volkan, and Aydoğan-Kılıc, G.

Subjects
Ortak Disiplinler
Abstract

Talyum (Tl)'un canlı sistemler üzerindeki etkisi son yıllarda önemli bir sorun haline gelmiştir. Bununla birlikte, sucul sistemlerin Tl'a maruz kalmasının sonuçları ile ilgili çok az bilgi mevcuttur. Bu çalışmanın amacı, sucul oligoket Tubifex tubifex'in antioksidan biyolojik belirteçlerinde (metallotionein (MT), toplam glutatyon (GSH), glutatyon peroksidaz (GPx), glutatyon S-transferaz (GST) ve katalaz (CAT)), TI'un subletal dozlarına yanıt olarak meydana gelen değişikliklerin araştırılmasıdır. Deney grupları 0.25, 0.5 ve 1 µg l-1'lik konsantrasyonlarda, 7 ve 15 günlük süreler boyunca talyum asetat'a maruz bırakılmıştır. MT seviyelerinde ilgi çekici bir azalma gözlenmiştir. 0.25 µg l-1' lık konsantrasyon toplam GSH, GPx ve GST aktiviteleri üzerinde etki göstermezken, 0.5 ve 1 µg l-1' lık konsantrasyonlar toplam GSH ve GPx aktivitelerini 7 günün sonunda indüklemiştir. Daha uzun maruz kalma süresi GPx ve GST aktiviteleri ile birlikte toplam GSH'un da tüm konsantrasyonlarda azalmasına neden olmuştur. CAT aktivitesinde tüm deney gruplarında gözlenen anlamlı artışa rağmen, lipid peroksidasyonunun (LP) artan konsantrasyon ve süreye bağlı olarak arttığı gözlenmiştir. Sonuçlar Tl ile indüklenen oksidatif strese karşı, T. tubifex'in antioksidan sisteminin olası hareket mekanizmasını ortaya koymakta ve Tl'un sucul ekosistemlerdeki etkileri ile ilgili gelecekte yapılacak değerlendirmeler için önemli bir bilgi kaynağı oluşturmaktadır, Thallium (Tl) impact on living systems has become an important issue in recent years. However very few data exist about the consequences of Tl exposure in freshwater aquatic systems. The aim of the present study is to investigate alterations in the levels of antioxidative biomarkers (metallothionein (MT), total glutathione (GSH), glutathione peroxidase (GPx), glutathione S-transferase (GST) and catalase (CAT)) in the aquatic oligochaete Tubifex tubifex, in response to sublethal doses of Tl. Experimental groups were exposed to thallium acetate at 0.25, 0.5 and 1 µg l-1 concentrations during 7 or 15 days. MT levels were observed to be interestingly decreased. 0.25 µg l-1 concentration had no effect on total GSH, GPx and GST activities while 0.5 and 1 µg l-1 concentrations induced total GSH and GPx activitiy after 7 days. Longer exposure time resulted in a decrease in total GSH along with GPx and GST activities at all concentrations of Tl. Despite the significant elevation of CAT activity in all experimental groups, lipid peroxidation (LP) was observed to be induced depending on the increasing exposure concentration and time. The results suggested the possible mechanism of action in the antioxidant system of T. tubifex in response to Tl induced oxidative stress (OS) and provide useful information for the future evaluation of Tl impact on aquatic ecosystems

Published
2017

41. Citalopram Induces Reproductive Toxicity in Male Rats

Author

Ilgın, Sinem, Aydoğan-Kılıc, G., Baysal, Merve, Kılıç, Volkan, Korkut, Büşra, Uçarcan, Şeyda, Atlı Eklioğlu, Özlem, Anadolu Üniversitesi, Eczacılık Fakültesi, Farmasötik Toksikoloji Anabilim Dalı, Ilgın, Sinem, Aydoğan-Kılıc, G., Kılıç, Volkan, Uçarcan, Şeyda, and Atlı Eklioğlu, Özlem

Subjects
Oxidative Stress, Dna Damage, Citalopram, Reproductive Toxicity
Abstract

WOS: 000399733100002, PubMed ID: 28398617, Background: Citalopram hydrobromide (CTL) has been shown to cause sexual dysfunction; however, its reproductive toxicity potential has not been sufficiently elucidated in men. Therefore, we aimed to clarify the toxic effects of CTL on the reproductive system of male rats. Methods: For this purpose, CTL was administered at 5, 10, and 20 mg/kg/day to rats orally for 28 days. Sperm concentration, motility, and morphology were investigated using a computer-assisted sperm analysis system, and sperm DNA damage was detected using a Comet assay. The testes were histopathologically examined. Serum follicle-stimulating hormone, luteinizing hormone, and testosterone levels were measured and the oxidative status of testes was investigated. Results: Our results showed that sperm concentration was reduced, and abnormal sperm morphology and sperm DNA damage were increased in CTL-administered groups. Additionally, histopathological changes were observed in the testes of CTL-administered rats. Luteinizing hormone levels were increased in CTL-administered groups, while testosterone levels were increased in the 5 and 10 mg/kg CTL-administered groups. Decreased glutathione signaled enhanced oxidative stress in the 10 and 20 mg/kg CTL-administered groups. Conclusion: Thus, we concluded that CT induced testicular damage in male rats; this testicular damage was accompanied by oxidative stress and hormonal changes, which are considered as the important causes of reproductive disorders

Published
2017

42. Super toughened and highly ductile PLA/TPU blend systems by in situ reactive interfacial compatibilization using multifunctional epoxy‐based chain extender.

Author

Kahraman, Yusuf, Özdemir, Burcu, Kılıç, Volkan, Goksu, Yonca Alkan, and Nofar, Mohammadreza

Subjects
IMPACT strength, COMPATIBILIZERS, POLYLACTIC acid, EPOXY resins, POLYURETHANES, SUPERABSORBENT polymers
Abstract

This study investigates the influence of using multifunctional epoxy Joncryl ADR 4468 chain extender (CE) on the properties of various polylactide (PLA)/thermoplastic polyurethane (TPU) (75 wt/25 wt) blend systems. The blends were based on two different TPU grades with ether‐ and ester‐based soft segment as the dispersed phase (i.e., TPUether and TPUester) and an amorphous and a semicrystalline PLA grades as the matrix (i.e., aPLA and scPLA). PLA appeared to be more compatible with the TPUester, which caused the enhancement of the impact strength and strain at break values of the blends more remarkably. The dynamic rheological experiments also confirmed that the CE revealed a better reactivity with TPUester than TPUether. This further enhanced the interfacial compatibility between the PLA and TPUester and thereby dramatically improved the impact strength and ductility of the PLA/TPUester blends, specifically those with 0.5 wt% CE. Meanwhile, aPLA as the matrix reflected the TPUs toughening effect more efficiently than scPLA. This was due to the possible shrinkage caused by the crystallization of scPLA matrix, which could deteriorate the interfacial interactions between the phases in the corresponding blends. [ABSTRACT FROM AUTHOR]

Published
2021
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45. ENTEROCOCCUS DURANS İLE EKSTRASELÜLER LİPAZ ÜRETİMİ VE KAREKTERİZASYONU.

Author

Acu, Esra, Kılıç, Volkan, and Kıvanç, Merih

Subjects
*ENZYME stability, *LACTIC acid bacteria, *DAIRY products, *MEAT, *SEQUENCE analysis, *LIPASES
Abstract

Lipase activity of 50 lactic acid bacteria isolated from milk and milk products were screened. E114 and E114.11 isolates were chosen for enzyme production due to their high activity. Sequence analysis results of test bacteria according to 16S rRNA gene region were determined as Enterococcus durans. Optimum production conditions for lipase production have been determined. These conditions are: Providing a medium prepared with 5% peptone and 5% glucose as nitrogen and carbon source, shaking at 120 rpm for 48 hours at pH 6.5 and incubating at 40-60°C. Enzymes belonging to E. durans isolates showed the highest activity in the environment with pH 9 and containing 20% salt. It has been found that the effects of various cations and surfactants are different. Enzymes show activity at low and high temperatures. Stability of enzyme activity for 48 hours at 5°C is also important for the food industry. Its usability in fermented products such as meat and dairy products is promising. [ABSTRACT FROM AUTHOR]

Published
2021
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46. Risperidone induced reproductive toxicity in male rats targeting leydig cells and hypothalamic–pituitary–gonadal axis by inducing oxidative stress.

Author

Görmüş, Gözde, Ilgın, Sinem, Baysal, Merve, Karaduman, Abdullah Burak, Kılıç, Volkan, Aydoğan‐Kılıç, Gözde, Karagöz, Onur, and Atlı‐Eklioğlu, Özlem

Subjects
LEYDIG cells, OXIDATIVE stress, MALE reproductive organs, RISPERIDONE, SUPEROXIDE dismutase, HYPOTHALAMIC-pituitary-gonadal axis
Abstract

Risperidone (RIS), a commonly used drug during a lifetime for the treatment of schizophrenia, causes some adverse effects in the male reproductive system; however, there is no comprehensive reproductive toxicity study of RIS. For this purpose, male rats were administered orally for 1.25, 2.5 and 3 mg/kg RIS for 28 days and the sperm count, motility, morphology, DNA damage and the histological changes in testicular tissue were evaluated. Follicle‐stimulating hormone (FSH), luteinising hormone (LH) and serum levels of testosterone, which are the main hormonal regulators of reproduction, and testicular glutathione (GSH), catalase (CAT), superoxide dismutase (SOD) and malondialdehyde (MDA) levels as the indicators of oxidative stress were determined. Normal sperm morphology was decreased in RIS groups and histopathological degeneration occurred in testis tissue dose‐dependently. Serum LH levels were not altered; however, FSH and testosterone levels decreased in the high‐dose group. Histopathologic examination showed RIS toxicity targeted Leydig cells, which might be associated with impairment of the hypothalamic–pituitary–gonadal (HPG) axis. GSH levels were decreased and MDA levels were increased in the high‐dose group which was evaluated as indicators of oxidative stress. In conclusion, RIS caused reproductive toxicity in male rats by inducing oxidative stress and disrupting hormonal regulation. [ABSTRACT FROM AUTHOR]

Published
2021
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48. Comparison of Biofilm Formation Capacities of Two Clinical Isolates of Staphylococcus Epidermidis with and without icaA and icaD Genes on Intraocular Lenses

Author

Kıvanç, Argun Sertaç, Kıvanç, Merih, Kılıç, Volkan, Özmen, Tuncer Ahmet, Anadolu Üniversitesi, Fen Fakültesi, Biyoloji Bölümü, and Kıvanç, Merih

Subjects
Göz Hastalıkları
Abstract

Amaç: Biyofilm oluşturma kapasiteleri bilinen iki Staphylococcus epidermidis (S. epidermidis) izolatının daha önce çalışılmamış dört farklı göz içi lensi (GİL) üzerinde biyofilm oluşturma özelliklerinin karşılaştırılmasıdır.Gereç ve Yöntem: Daha önceki çalışmalarda oküler yüzeyden izole edilip Anadolu Üniversitesi Fen Fakültesi, Biyoloji Anabilim Dalı Mikrobiyoloji Laboratuvarı'nda -86 oC'de %15 gliserol içinde muhafaza edilen icaA, icaD ve bap pozitif ve yüksek biyofilm oluşturduğu bilinen S. epidermidis KA 15,8 izolatı (İCA+) ile icaA, icaD ve bap negatif biyofilm oluşturmadığı bilinen S. epidermidis KA 14,5 (İCA-) izolatı saflaştırılarak kullanıldı. Biyofilm oluşturma özellikleri dört farklı GİL üzerinde karşılaştırıldı. İki tanesi katlanabilir akrilik lens idi [UD613(GİL A) Türkiye; SA60AT(GİL B), ABD]. Diğer iki tanesi ise polimetilmetakrilat (PMMA) [B60130C(GİL C), Hindistan; B55125C(GİL D), Hindistan] lensti. Lenslerin üzerinde oluşan biyofilmlerde bakteri sayımı ve optik yoğunluk ölçümü yapıldı. Oluşan biyofilmler scanning elektron mikroskobu ile görüntülendi. Bulgular: Biyofilm üretici olduğu bilinen İCA lokusu bulunan suş ile lensler üzerinde ortalama bakteri sayısının 7,1±0,4 log10 CFU/mL, İCA lokusu negatif (İCA-) olan izolatla ise 6,7±0,8 log10 CFU/mL bulundu, istatistiksel olarak anlamlı fark saptanmadı. Biyofilm oluşumu akrilik lenslerde, PMMA lenslere göre her iki suş ile de daha düşük olarak bulundu (p=0,009 ve p=0,013). Her iki izolat ile de en yüksek biyofilm oluşumu bir PMMA lens olan GİL C üzerinde (p, Objectives: To compare biofilm formations of two Staphylococcus epidermidis (S. epidermidis) isolates with known biofilm formation capacities on four different intraocular lenses (IOL) that have not been studied before.Materials and Methods: Two isolates obtained from ocular surfaces and identified in previous studies and stored at -86 °C in 15% glycerol in the microbiology laboratory of the Anadolu University Department of Biology were purified and used in the study. The isolates were S. epidermidis KA 15.8 (ICA+), a known biofilm producer isolate positive for icaA, icaD and bap genes, and S. epidermidis KA 14.5 (ICA-), known as a non-biofilm producer isolate negative for icaA, icaD and bap genes. The biofilm formation capacities of the 2 isolates on 4 different IOLs were compared. Two of the IOLs were acrylic (UD613 [IOL A], Turkey; SA60AT [IOL B], USA), and the other two were polymethyl methacrylate (PMMA) (B60130C [IOL C], India; B55125C [IOL D], India). Bacterial enumeration and optical density measurements were done from biofilms that formed on the IOLs. Biofilms were imaged using scanning electron microscopy. Results: Mean bacterial counts on the IOLs were 7.1+-0.4 log10 CFU/mL with the ICA+ isolate, and 6.7+-0.8 log10 CFU/mL with the ICA- isolate; there were no statistically significant differences. Biofilm formation was lower with acrylic lenses than PMMA lenses with both isolates (p=0.009 and p=0.013). The highest biofilm production was obtained on IOL C (PMMA) (p>0.001) and the lowest was obtained on IOL A (hydrophilic acrylic) (p>0.001).Conclusion: Bacterial counts after biofilm formation were lower on acrylic lenses, especially hydrophilic acrylic with hydrophobic properties. Further animal and in vivo studies are required to support the findings of this study.

Published
2017

49. Metallothioneins, Oxidative Stress Responses and Histopathological Changes in the Earthworm (Aporrectodea Caliginosa) in Metal Contaminated Agricultural Soils of Sakarya River Basin (Turkey)

Author

Kılıç, Volkan, Aydoğan-Kılıc, G., Anadolu Üniversitesi, Fen Fakültesi, Biyoloji Bölümü, Kılıç, Volkan, and Aydoğan-Kılıc, G.

Subjects
Oxidative Stress, Metal, Earthworm, Histopathology, Metallothionein, Antioxidant
Abstract

WOS: 000366880400008, Metal accumulation in agricultural soils threaten human and environmental health in the first place but also constitute a risk for animals living in their natural habitat. Chemical analysis alone does not provide adequate information concerning the biotoxicity of these metals. Hence, the present study assessed a suite of biomarkers in Aporrectodea caliginosa collected from ten sampling sites along Sakarya River Basin (Turkey) to better understand the early organismal responses of this worm against metal contamination in agricultural soils. Soil and earthworm concentration of metals (Cd, Cr, Cu, Ni, Pb and Zn) were determined. Significant accumulation of Cd, Cr, Cu and Ni were detected in soil samples. Metal binding protein, metallothionein (MT), increased in four sites with the highest body burden of Zn. Total glutathione (GSH) and glutathione peroxidase (GPx) activity elevated but catalase (CAT) was inhibited in animals from six sites with significant body burden of Cu. Glutathione S-transferase (GST) and superoxide dismutase (SOD) activities were induced in most sites along with peroxidation of tissue lipids. Necrosis was observed in alimentary canal of the worms. These results constitute useful endpoints for the evaluation of biotoxicity of metals in agricultural soils while emphasizing A. caliginosa as a sensitive indicator of metal contamination., Anadolu University Research Fund [1001F34], This study was supported by Anadolu University Research Fund [1001F34]. The authors gratefully acknowledge and thank Prof. Dr Ahmet OZATA for his support and to the management and workers of Anadolu University BIBAM for ICP-OES analysis.

Published
2015

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