The Use of Brine Shrimp to Test for Water Pollutants
The use of brine shrimp nauplii to test for the overall toxicity of sediment samples is proposed. Brine shrimp nauplii were cultured with different concentrations of heavy metals, including chromium (III), copper (II), nickel, lead and zinc, and organic pollutants, including triclosan, oxybenzone, octinoxate and bisphenol A. The brine shrimp nauplii were observed under a dissection microscope to determine the death rate. Results showed that brine shrimp nauplii are more sensitive to copper, cadmium, bisphenol A and oxybenzone. The LC50 (24h) are 55.5, 24.9, 5.6 and 2.7 ppm respectively. Zinc is likely to have synergistic toxic effect with nickel or lead. The synergistic toxic effects of other heavy metals and organic pollutants should be confirmed with further investigations. Brine shrimp nauplii were treated with extracts from sediment samples collected from the oyster culture zone of the Deep Bay, namely Pak Nei, Sha Kiu Tsuen and Hang Hau Tsuen. The sediment samples were extracted with neutral sodium acetate to dissolve the exchangeable heavy metal ions and some organic pollutants. The death rate of brine shrimp nauplii treated with the sediment extract of Hang Hau Tsuen was similar to 1 ppm PBA. It was also about 10 to 20% higher than that of the other two sites (Pak Nei and Sha Kiu Tsuen). Since Hang Hau Tsuen is closer to the residential area and Lau Fau Shan Seafood Market than the other two sites, its sediment sample is likely to have a higher level of environmental pollutants. The results suggest that brine shrimp nauplii may be used as a biomarker to monitor the environmental changes in the overall level of pollutants in sediment samples.
A New Method For Microplastic Removal and Optical Measurement
Microplastics are tiny invisible plastic pieces that are piling up in the marine environment emerging as one of the many environmental issues which our planet is facing today. Researches for the removal of these particles are important because studies that have been made so far haven't come up with an effective solution. This project aimed to detect microplastics and remove them from aqueous environments with an effective and practical method then it was aimed to determine the removal amount of microplastics by optical measurements with the developed system. Firstly, the magnetic carbonanotubes (m-CNT) which is intended to hold onto the surfaces of microplastics was synthesized and added to the mixture of microplastics. Then the magnet within a glass tube was passed through the mixture and the sample was cleared of microplastics. A spectrometer was made to monitor this process and after its calibration, it was used to measure coffees with different concentrations. It has been shown that their concentrations can be determined by calculating the transmission values and Rayleigh scattering. In the end, it has shown that there are no micro or nano-sized plastic particles when removed with M-CNT, within the accountable range of the spectrometer that had been made. Hence the removal of the microplastics: an invisible threat for the environment has been studied by combining nanomaterials with unique surface properties in the removal process and an optical principle such as Rayleigh scattering, a new technique has been developed that can measure quickly, economically,
Anti-bacterial Crab bio-bandages with Bio-dressings 2.0
Commercially available bandages such as hydrocolloid are neither biodegradable nor anti-bacterial. Chitin is known to be the second most naturally available polysaccharide which could be transformed to chitosan which is known to be anti-bacterial (Hasan, 2018) (Chao, 2019) and haemostatic (Okamoto, 2003) (Hu, 2018). Chitosan can be further converted to hydrogel which is bio-degradable and has good water absorbance. Anti-bacterial crab bio-bandages and crab bio-dressings should be bio-degradable as it took 42 days and a month for complete bio-degradation respectively, so they should be better than commercial bandages such as Nexcare Hydrocolloid as the disposal of anti-bacterial crab bio-bandages with bio-dressings would no longer pose burden to landfilling or threat to our environment. Anti-bacterial crab bio-bandages with bio-dressings are anti-bacterial with degree of deacetylation of DD% (measured using FTIR Spectrum II) 82.6% (due to the presence of chitosan) even without the application of other anti-bacterial agents and hence can provide complete protection of wounds from skin and soft tissues infections and haemostatic (due to the presence of chitosan). After testing and certification based on IS997:2004 and BS EN 13726-1, they should meet many requirements specified. Anti-bacterial crab bio-bandages should be eligible for marketing. Some results were as follows: 1.4 Anti-bacterial effect of crab hydrogels and roasted crab hydrogels Pure chitosan, crab chitosan, crab hydrogels and roasted crab hydrogels showed significant anti-bacterial effect. NO oral bacterial colonies were present in drinking water with crab hydrogels. Thus crab hydrogels could serve as effective anti-bacterial wound dressings. 1.6 Basing on IS997:2004 standard, the load per unit of area of anti-bacterial bio-bandages was 342g/m2 which met the minimum requirement of 36g/m2, the anti-bacterial bio-bandages had stronger tension strength (>20N both in dry and wet conditions) than commercial hydrocolloid. (2.7N dry 2.8N wet) which was comparable with that required (50-67N) and pH of about 7 which met the pH range of 4.5-8. 1.7 The FSA Free-Swell Absorbency of synthetic blood of crab hydrogel bio-dressings was 1.86g per 5cm x 5cm dressing which was much higher than that of commercial hydrocolloid (0.299g per 5cm x 5cm dressing) based on BS EN 13726-1.
CONTACTLESS AND NON-DESTRUCTIVE DETECTION OF CHICKEN MEAT CONTAMINATION WITH LASER SPECKLE METHOD
Harmful microorganisms in food can cause deterioration of human health, poisoning and in some cases even death. Especially fresh meat and chicken products create a suitable environment for the growth of microorganisms in terms of the nutrients it contains, water activity and pH level. For this reason, detection of microorganisms in meat products is an important issue in terms of food safety and human health. In this project, it is aimed to detect live microorganisms in meat products, especially chicken meat, in a simple, non-destructive, non-contact and fast way using laser speckle method. Laser speckle images of healthy and stale chicken meat were taken, contrast parameter and correlation analysis of the obtained patterns were made. It was observed that the contrast parameter for staled chicken meat increased by approximately 3 times compared to fresh chicken. This increase provides an understanding of the difference between contaminated chicken and fresh chicken. Speckle density changes over time in relation to the movements of living microorganisms. Thus, the correlation in laser speckle density patterns taken from contaminated tissues is disrupted. In the measurements taken with photodiode, by analyzing the change of light intensity of the speckle patterns on fresh and contaminated tissues over time, the detection of microorganisms was made easier and more precisely without the need for image processing. The proposed measurement system is a new method that detects meat contamination with laser speckle imaging. It can be developed and made portable and can be used easily in homes. Since it is a simple, non-destructive and fast method, it can be used to determine the shelf life of meat in food distribution places and markets. In addition, it has the potential to be calibrated and used for other food products other than meat products. The system developed with this study is cheap and easy to use, and the laser speckle imaging method is used in a different field other than biomedical, contributing to the literature.
BIOINFORMATIC PREDICTION OF CORONAVIRUS (SARS-COV-2) MUTATIONS THAT INCREASE CONTAGIOUSNESS
Inhibitory effects of the secondary metabolite of actinomycete were examined on cell cycle of the yeasts of S. pombe and S. cerevisiae. The secondary metabolite was obtained from cultivation of the actinomycete isolated from the soil of Owakudani in Hakone, Japan. The fifth fraction of the secondary metabolite by ODS column separation (HK-T5), which was soluble to pure methanol, was used in the present experiments. The HK-T5 brought about the delay of forming colonies of S. pombe for about 11 days compared to that cultivated without the HK-T5. The delay of the colony formation was longer for the S. pombe cultivated with more amount of the HK-T5. The cultivation with HK-T5 also brought about the extension of the lifespan of the S. pombe for more than 10 weeks in a liquidus medium. The cell life recovered the ordinary manner by removal of the HK-T5, meaning that the activities of the HK-T5 is reversible. These facts confirm the suppression of cell cycle, and the delay of cell growth by the HK-T5. These phenomena were similarly observed for S. cerevisiae. Comparison of the action of HK-T5 with hydroxyurea, which is an anticancer drug inhibiting the cell cycle at S phase, clarified that the inhibitory action of HK-T5 worked at the phase earlier than S phase. The combined effects of HK-T5 on the cell cycle were evaluated with triamcinolone acetonide (TA), or aspirin, the former of which is a drug synchronizing cancer cells in S phase, and the latter keeping human cells in G1/G0 phases. The combined use of HK-T5 with TA synchronized the cells at the phase slightly proceeding from G1 to S phase without toxicity. On the other hand, the combined use with aspirin made the inhibitory effect of HK-T5 inactive. Hence, the HK-T5 is attractive as a drug for the extension of cell lifespan, and anticancer therapy.
Cross-lingual Information Retrieval
In this project, we evaluate the effectiveness of Random Shuffling in the Cross Lingual Information Retrieval (CLIR) process. We extended the monolingual Word2Vec model to a multilingual one via the random shuffling process. We then evaluate the cross-lingual word embeddings (CLE) in terms of retrieving parallel sentences, whereby the query sentence is in a source language and the parallel sentence is in some targeted language. Our experiments on three language pairs showed that models trained on a randomly shuffled dataset outperforms randomly initialized word embeddings substantially despite its simplicity. We also explored Smart Shuffling, a more sophisticated CLIR technique which makes use of word alignment and bilingual dictionaries to guide the shuffling process, making preliminary comparisons between the two. Due to the complexity of the implementation and unavailability of open source codes, we defer experimental comparisons to future work.