208 research outputs found

    MACRO-ZOOPLANKTON ABUNDANCE IN RELATION TO METAL ACCUMULATION AND WATER QUALITY IN TRUC BACH LAKE

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    Urban lake pollution is one of the serious issues due to suffering of waste discharged from householders. However, there is a gap of knowledge about the diversity of zooplankton species and how metals accumulate in zooplankton in urban ecosystems. We addressed this by determining the rule of blooming macro-zooplankton in Truc Bach lake and levels of two essential metals: copper (Cu), and zinc (Zn) and of three non-essential metals: arsenic (As), and lead (Pb) in water samples were determined. The results showed that Cladocerans and copepods are macro-zooplankton dominant species in Truc Bach Lake. Water temperature significantly affects the variety of copepod blooming. Arsenic concentration in water collected from the lake exceeded the safety level of current Vietnamese regulation. As concentration in macro-zooplankton positively correlated with metal concentrations in the water (p 0.05) while the concentration of Cu, Zn, and Pb in water has no significant correlation with the metal in zooplankton’s body. The relative abundance of adult copepods in Truc Bach lake had a negative correlation with As concentration in water (p = 0.01). The higher As concentration in water, the lower relative abundance of copepods was found in the sample

    Production of gamma-aminobutyric acid by lactic acid bacteria of marine origin from Vietnam

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    Gamma-aminobutyric acid (GABA) is a non-proteinogenic amino acid, which functions as a neurotransmitter in the central nervous system. GABA has been shown to have several positive effects on human health, including reducing anxiety and promoting relaxation. In this study, various fermented fish products were screened for their ability to produce GABA. A total of 35 acid lactic producing strains were isolated from 8 samples of marine organism, 10 strains were found to have GABA-producing abilities. These strains were identified using 16S rDNA sequencing. The GABA concentrations produced by the 10 isolates ranged from 725 to 5590 mg/L. Lactobacillus brevis GB111 is the best isolated GABA producing strain, with a conversion rate up to 90.3%, which suggests that these strains may have potential applications in the food and pharmaceutical industries as a source of GABA

    Effects of palladium on the optical and hydrogen sensing characteristics of Pd-doped ZnO nanoparticles

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    Abstract The effect of palladium doping of zinc oxide nanoparticles on the photoluminescence (PL) properties and hydrogen sensing characteristics of gas sensors is investigated. The PL intensity shows that the carrier dynamics coincides with the buildup of the Pd-related green emission. The comparison between the deep level emission and the gas sensing response characteristics allows us to suggest that the dissociation of hydrogen takes place at Pd Zn -vacancies ([Pd 2+ (4d 9 )]). The design of this sensor allows for a continuous monitoring in the range of 0-100% LEL H 2 concentration with high sensitivity and selectivity. 126

    Using metagenomics tool to evaluate the enrichment efficiency of methanogens in marine sediment in Truong Sa archipelage, Khanh Hoa province, Vietnam

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    Methanogens (archaea bacteria that produce methan) play an important role in the anaerobic digestion of organic waste, however, in marine environment, the low density of methanogens makes anaerobic digestion very slow. In this study, we used methagenomics tool to evaluate the enrichment efficiency of methanogens communities in marine sediments as a basis for building a anaerobic microbial formulation to treat organic waste in marine environment. The results of determination of methanogen density by MPN method have shown that methanogen has been accumulated with higher density (up to 3.2.107 MNP/ml) through 2 times of enrichment in artificial seawater with CH3COONa 10 mM substrate. In addition, metagenomics data have also shown a decrease in the number of archaea species through each enrichment, indicating that methanogenic species have gradually dominated the microbial community. This is the first study on using metagnenomics tools to evaluate the enrichment of methanogens in marine sediment samples in Truong Sa archipelago, Vietnam. Metagenomics data help provide more reliable evidence in microbial studies, especially in obligate anaerobes such as methanogens

    Globalization And Its Effect On Post-Millennium Literature

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    Globalization, as a slowly spreading risk factor, covers almost the whole country with its full force. Literature and literary studies have evolved into a space for the evocation, promotion and interpretation of various social, political, literary and cultural ideas in the world of globalization. Indian Literature after Independence of India has seen some significant changes in the literary writings. Today, the younger generation in the country is searching for a new identity and they are at the intersection of Individuality, Culture and Society. In the world of literature, the call-center generation sees itself as India’s cultural commissars, projecting India as a land of illumination and emancipation. The major Samson of the youth lies in the power of the youth through the unlimited consumption of natural and human resources. The novels of the millennium assist us in dispelling the myth that contemporary writing is only for the light entertainment of the younger generations. &nbsp

    Exploiting secure performance of full-duplex decode and forward in optimal relay selection networks

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    In the presence of an illegitimate user, we investigate the secrecy outage probability (SOP) of the optimal relay selection (ORS) networks by applying decode-and-forward (DnF) based full-duplex (FD) relaying mode. The closed-form expressions for the allocations of the end-to-end signal-to-interference-plus-noise ratio (SINR) in each wireless network are derived as well as the closed-form expression for the exact SOP of the proposed ORS system is presented under Rayleigh fading schemes. As an important achievement, SOP is also compared between orthogonal multiple access (OMA) and non-orthogonal multiple access (NOMA) schemes. Our results reveal that the SOP of the suggested scheme can be considerably influenced by several parameters involved, including the number of relays, the average signal-to-noise ratio (SNR) of eavesdropper links, transmit power and the average residual self-interference (SI) enforced on the FD relays.Web of Science244767

    Facile Synthesis of Carbon Quantum Dots by Plasma-liquid Interaction Method

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    Carbon quantum dots (CQDs) are a novel type of fluorescent nano-materials with various unique properties. They are recently attracting enormous interest due to their superiority in water solubility, chemical inertness, low toxicity, ease of functionalization as well as resistance to photo-bleaching and potential applications in biomedical indication, photo-catalysis, energy conversion, optoelectronics, and sensing. In this work, we present a facile and environmentally friendly synthesis of CQDs based on plasma - liquid interaction method. This is a single-step method and does not use toxic chemicals. The size distribution of obtained CQDs is rather uniform at approximately 3 nm. The emission peak of CQDs shifts from 427 nm to 523 nm as the excitation wavelength is varied from 340 nm to 460 nm. The non-equilibrium reactive chemistry of plasma liquid interaction is responsible for acceleration of the CQDs formation process

    Multifunctional nanocarriers of Fe3O4@PLA-PEG/curcumin for MRI, magnetic hyperthermia and drug delivery

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    Background: Despite medicinal advances, cancer is still a big problem requiring better diagnostic and treatment tools. Magnetic nanoparticle (MNP)-based nanosystems for multiple-purpose applications were developed for these unmet needs. Methods: This study fabricated novel trifunctional MNPs of Fe3O4@PLA-PEG for drug release, MRI and magnetic fluid hyperthermia. Result: The MNPs provided a significant loading of curcumin (∼11%) with controllable release ability, a high specific absorption rate of 82.2 W/g and significantly increased transverse relaxivity (r2 = 364.75 mM-1 s-1). The in vivo study confirmed that the MNPs enhanced MRI contrast in tumor observation and low-field magnetic fluid hyperthermia could effectively reduce the tumor size in mice bearing sarcoma 180. Conclusion: The nanocarrier has potential for drug release, cancer treatment monitoring and therapy.The authors are grateful for the financial support by AOARD under award FA2386-17-1-4042. The Spanish government is acknowledged for the “Nanotechnology in translational hyperthermia (HIPERNANO)” research network (RED2018102626-T) and for funding under the project number MAT2017-83631-C3. NTK Thanh thanks EPSRC (EP/M015157/1). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed
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