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A sensor based on graphite nanosheets was fabricated through the electrochemical expansion of a graphite electrode in dimethyl sulfoxide for the sensitive electrochemical determination of enrofloxacin. The modified electrode surface exhibited a distinctive structure of nanoplates, characterized by layer thickness ranging from a few nanometers to ten nanometers. The developed electrode displayed notable electrochemical properties, including a faster charge transfer rate and a larger electrochemically active surface area, which was 1.3 times greater compared to the unmodified electrode. As a result, the sensor improved square wave voltammetric signals for enrofloxacin, exhibiting a 2.4-fold enhancement compared to the unmodified electrode. By optimizing the experimental parameters such as electrode fabrication conditions, pH of analytical solution, and adsorption time for enrofloxacin, the sensor demonstrated good reproducibility and a strong linear correlation over two ranges of enrofloxacin concentrations from 0.05–0.15 μM and 0.1–20 μM. The limit of detection was determined to be 0.002 μM. The sensor was successfully employed for the determination of enrofloxacin in spiked surface water samples before and after treating enrofloxacin by a photocatalytic method. The obtained results exhibited consistency with those obtained using a liquid chromatography-tandem mass spectrometry reference method, and a high recovery rate of 105.5% further confirmed the reliability of the proposed method for enrofloxacin detection. [ABSTRACT FROM AUTHOR]

Hierarchically bimetallic Zr-Cu metal–organic framework combined with 1,3,5-benzenetricarboxylic acid (Zr-CuBTC MOFs) was synthesized using hydrothermal reaction and used as modifier for investigation of non-electroactive glyphosate. These MOFs were dropcasted on a glassy carbon electrode (GCE) and non-electroactive glyphosate were tested by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). Glyphosate in water was recognized by the difference of currents in spiked and non-spiked glyphosate samples. At the same time, CuBTC and Fe-CuBTC were investigated for the best material for sensor development. The results showed the bimetallic Zr-CuBTC MOF is the most promising for the determination of glyphosate. Morphological and structural studies showed the coordination of Cu2+ with the presence of Zr4+ ions with BTC ligands provided a highly porous framework with active surface area up to 1337 m2 g−1. The pore diameter and pore volume increased to 1.75 nm and 0.687 cm3 g−1, respectively. Under optimal conditions, Zr-CuBTC modified on GCE (Zr-CuBTC/GCE) sensor is able to indirectly detect glyphosate in a water environment at a detection limit as low as 9 × 10−13 M. The developed sensor was employed to determine glyphosate in the surface water samples collected from the Red River, North Vietnam. The results showed good recoveries (94.6–107.1%) which were in agreement with liquid chromatography coupled tandem mass spectrometry (LC-MS/MS) measurements. These results demonstrate the possibility of using this MOF material in sensor applications to determine trace pesticides in the contaminated water. [ABSTRACT FROM AUTHOR]

Abstract Data were collected from 30 strains of Vibrio and sampled on different organs (brain, hemorrhagic site and digestive tract) of Sciaenops ocellatus infection. The results showed that the nucleotide sequences 16S rRNA region are highly similar to those of V. alginolyticus, V. azureus, V. fluvialis, V. natriengens and V. orientalis, which were published on Genbank and other, ranging from 98.05 to 100%. The digestive tract has the most common Vibrio strains (V. alginolyticus [16] V. azureus [7] and V. fluvialis). Thereout, 25 of 30 strains of Vibrio contained 1 to 3 toxin genes, except V. parahaemolyticus. Six parameters were used to measure the DNA polymorphism of 33 homologous DNA sequences in this Vibrio bacteria population. The results indicated that number of separate polymorphic sites (S), total number of mutant sites (Eta), number of haplotype (h), haplotype diversity (Hd), average number of nucleotide differences (k), nucleotide diversity (Pi) were 98 (S), 103 (Eta), 9 (h), 0.887 ± 0.032 (Hd), 25.789 (k) and 17.980 × 10–3 ± 0.003 (Pi), respectively (P

Cancer is a global concern and the potential targeting of cancer stem cells (CSCs) has gained major attention in anticancer drug discovery research. Various natural compounds have shown promising effects in suppressing cancer, prompting scientific interest. In this study, we investigated the anti-CSC properties of schisandracaurin C, a novel compound derived from the Vietnamese plant Schisandra cauliflora. To evaluate its anti-CSC efficacy, we employed the MTT assay, flow cytometry analysis, the caspase-3 assay and a three-dimensional cell culture method, focusing on the teratocarcinoma NTERA-2 cells. Our findings revealed that schisandracaurin C inhibited the growth of NTERA-2 cells with an IC50 value of 16.61±0.13 μM, which was significantly lower than that on HEK-293A healthy embryonic kidney cells (22.72±0.02 μM) (P<0.05). Schisandracaurin C was toxic to NTERA-2 cells within three-dimensional tumorspheres (IC50: 33.47±1.45 μM). The anti-CSC effects of schisandracaurin C on NTERA-2 cells were mediated through apoptosis, as evidenced by increased caspase-3 activity. Schisandracaurin C induced cell cycle arrest at the S phase in NTERA-2 cells. These findings highlight the potential of schisandracaurin C as a promising anti-CSC compound, which warrants further mechanistic and clinical investigations. [ABSTRACT FROM AUTHOR]

Trong nghiên cứu trước đây, chúng tôi nhận thấy vi khuẩn Vibrio vulnificus khá phổ biến trên cá nuôi bị xuất huyết ở tỉnh Thừa Thiên Huế. Vi khuẩn này là một mầm bệnh cơ hội trên người, có thể gây nhiễm trùng máu nguyên phát, nhiễm trùng vết thương và viêm dạ dày, ruột. Vì vậy, chúng tôi thực hiện nghiên cứu nhằm phát triển một chỉ thị phân tử dựa trên kỹ thuật đa hình các đoạn khuếch đại ngẫu nhiên (RAPD) để xác định nhanh chóng V. vulnificus. Tổng cộng có 20 mồi ngẫu nhiên đã được sử dụng cho phản ứng PCR-RAPD để phát hiện đa hình DNA giữa các loài Vibrio. Trong đó, mồi OPA-09 tạo ra một sản phẩm khuếch đại đặc hiệu cho loài V. vulnificus có chiều dài là 1356 bp. Trình tự này được thiết kế mồi đặc hiệu và chuyển thành chỉ thị SCAR có chiều dài 938 bp (A9-938). Cặp mồi đặc hiệu (Vvul-1F/Vvul-938R) khếch đại một băng duy nhất ở tất cả các chủng V. vulnificus nhưng không xuất hiện ở các loài Vibrio khác. Đây là chỉ thị có độ đặc hiệu cao và có thể sử dụng để nhận diện sự có mặt của V. vulnificus có trong các mẫu hải sản.

In the present work, we reported the simple way to fabricate an electrochemical sensing platform to detect Bisphenol A (BPA) using galvanostatic deposition of Au on a glassy carbon electrode covered by cetyltrimethylammonium bromide (CTAB). This material (CTAB) enhances the sensitivity of electrochemical sensors with respect to the detection of BPA. The electrochemical response of the modified GCE to BPA was investigated by cyclic voltammetry and differential pulse voltammetry. The results displayed a low detection limit (22 nm) and a linear range from 0.025 to 10 µm along side with high reproducibility (RSD = 4.9% for seven independent sensors). Importantly, the prepared sensors were selective enough against interferences with other pollutants in the same electrochemical window. Notably, the presented sensors have already proven their ability in detecting BPA in real plastic water drinking bottle samples with high accuracy (recovery range = 96.60%–102.82%) and it is in good agreement with fluorescence measurements.

Ciprofloxacin (Cip), a fluoroquinolone antibiotic, was determined by linear sweep adsorptive stripping voltammetric method using multilayer reduced graphene oxide electrode (m-rGO). The m-rGO electrode was fabricated directly, simply and promptly from graphite platform by potentiostatic technique without further modification. The produced electrode exhibited excellent performance for ciprofloxacin (Cip) determination with a much higher signal of Cip than that on the initial graphite electrode (13.4 times). This dominance of the m-rGO electrode resulted from the large electrochemically active surface area, electrochemical catalysis, suitable functional groups on the electrode surface. Experimental conditions such as the electrode fabrication time, the supporting solution, and accumulation time were optimised to obtain the Cip highest signal. A Cip analytical method established under the optimal conditions had a good linear relationship between the Cip signal with its concentration range from 0.5 to 20 µM (R2 = 0.9953). The method showed a low detection limit (LOD = 0.078 µM), satisfactory reproducibility (RSD = 1.50%), and high accuracy. Cip concentration in a spiked lake water sample determined by the proposed method with acceptable precision (RSD = 5.59%) and trueness (recovery = 94.2–106.3%) was comparable with LC-MS/MS method. [ABSTRACT FROM AUTHOR]

Vibrio spp. cause vibriosis in many saltwater and freshwater aquatic species, such as fish, crustaceans, and mollusks. Vibrio parahaemolyticus and Vibrio alginolyticus are among the few Vibrio species commonly found in infections in fish. This study aimed at investigating the chemical composition and evaluating the antibacterial activities of Salix babylonica L. The ethyl acetate (LL2) and methanolic (LL3) extracts were used to evaluate the resistance of strains as V. parahaemolyticus LBT6 and VTCC 12233, and two strains of V. alginolyticus, NG20 and ATCC 17749, and compared their efficacy with cefotaxime in order to find an alternative to antibiotics in the treatment of vibriosis. The obtained results show that the LL2 extract, with its major components identified as chrysoeriol, luteolin, and β-sitosterol, exhibited a bacteriostatic effect against all the tested strains. In parallel, the LL3 extract, with the four major compounds luteolin-7-O-β-D-glucopyranoside, salicin, p-hydroxy benzoic acid, and β-sitosterol-3-O-β-D-glucopyranoside, showed significant bactericidal activity against these four strains; the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) varied from 2.0 to 3.0 μg/mL and from 3.5 to 5.0 μg/mL, respectively. Moreover, the LL3 extract could effectively increase the survival rate of the challenged fish at a dose of 5% (w/w) for the zebrafish (Danio rerio) and 3% (w/w) for the sea bass (Lates calcarifer). The LL3 extract showed a potential application of S. babylonica L. in the prevention and treatment of vibriosis in fish. [ABSTRACT FROM AUTHOR]

This paper presents the use of the smart city solution for the protection of urban biodiversity. This biodiversity is crucial for human wellbeing and sustainable development. The paper presents first the urban biodiversity, then the risk of its deterioration by urban activity (change in land-use; pollution of air, soil and water; noise pollution; light pollution; alien species; construction, flood). Finally, the paper presents briefly the Smart City solution including data collection, data analysis and reporting and control and how this solution could be used for the protection of biodiversity.

A new compound, physalucoside A (1), together with seven withanolides (2–8) and three flavonoids (9–11), were isolated from Physalis angulata L. (Solanaceae), a medicinal plant native to Vietnam. The chemical structures of these compounds were elucidated by one- and two-dimensional NMR spectra, high-resolution electrospray ionization mass spectrometry analyses, and chemical reactivity. The anti-inflammatory and cytotoxic activities of isolated compounds were also evaluated. These data suggest that the anti-inflammatory activity of P. angulata is due primarily to its withanolide content. This study demonstrates the potential of withanolides as promising candidates for the development of new anti-inflammatory drugs. [ABSTRACT FROM AUTHOR]

The present paper reports the fabrication of inverse opal photonic crystals (IOPCs) by using SiO2 spherical particles with a diameter of 300 nm as an opal photonic crystal template and poly(ethylene glycol) diacrylate (PEGDA) as an inverse opal material. Characteristics and fluorescence properties of the fabricated IOPCs were investigated by using the Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), reflection spectroscopy, and fluorescence microscopy. The results clearly showed that the IOPCs were formed comprising of air spheres with a diameter of ∼270 nm. The decrease in size led to a decrease in the average refractive indexes from 1.40 to 1.12, and a remarkable stopband blue shift for the IOPCs was thus achieved. In addition, the obtained results also showed a fluorescence enhancement over 7.7-fold for the Fluor® 488 dye infiltrated onto the IOPCs sample in comparison with onto the control sample. [ABSTRACT FROM AUTHOR]

The European Union of Aquarium Curators (EUAC) boasts a membership of 150 dedicated individuals, standing as a vital cornerstone within the European public aquarium community. Since 2004, the EUAC Conservation Fund has granted over a quarter of a million euros to approximately 50 conservation projects spanning the globe. These initiatives, diverse in nature and scale, have yielded tangible impacts on local populations and their focal species. This paper delves into the outcomes of these conservation endeavors and proposes enhancements to ensure that the funding is unequivocally channeled towards conservation efforts. One resounding observation gleaned from the array of projects spotlighted in this study is the profound community engagement that emerges, irrespective of the final project outcomes. These endeavors serve as a catalyst for local communities, shedding light on subjects that would otherwise remain shrouded in obscurity. Furthermore, the EUAC-backed projects illuminate the expansive reach of public aquarium initiatives, transcending the confines of acrylic tank walls and institutional boundaries to resonate globally, heightening local awareness about the imperative to safeguard biodiversity. These findings underscore a prospective trajectory for both the EUAC and the public aquaria it comprises: an intensified advocacy and collaboration with legislative bodies to fortify in situ conservation measures. In essence, it is imperative that the public comprehends the pivotal role played by aquaria in preserving a multitude of species and acknowledges that their visits directly contribute to funding projects aimed at safeguarding species within their natural habitats. [ABSTRACT FROM AUTHOR]

In this study, a sensitive and selective electrochemical sensor based on a zirconia oxide-decorated gold nanoflake nanocomposite-modified glassy carbon electrode (AuNP/ZrO2/GCE) for the detection of 2,4-dichlorophenol (2,4-DCP) was developed. ZrO2 was first synthesized using the sol–gel method and then drop-cast onto the electrode surface, followed by electrodeposition of AuNPs by chronoamperometry under acidic conditions. The as-prepared ZrO2 nanoparticles had porous structures with pore sizes of 3.25 nm and particle sizes of 20–30 nm. The combination of an electrocatalytic and porous material ZrO2 and a highly conductive material AuNPs might help to improve the electrochemical signals. Under the optimal conditions, the AuNP/ZrO2/GCE sensor is able to detect 2,4-DCP in a water environment at a detection limit as low as 0.053 µM within a wide linear range from 1.5 to 24 µM. The developed sensor was also employed for real samples collected from West Lake and showed good recoveries (95.4–101.8%). This is valuable when considering practical field applications of the sensor, especially in terms of on-site measurements. [ABSTRACT FROM AUTHOR]

Following the end of the 20-year war against the US and its allies in 1975, Vietnam gradually opened its doors in terms of market-oriented trade reforms in the late 1980s. The Vietnamese tourism sector simultaneously started to grow and, during the last decade, has shown rapid expansion with major contributors being countries who fought against Vietnam. However, very little scientific research has been published in relation to inbound tourism in Vietnam. This study aims to fill this gap by identifying the factors that attract tourists to Vietnam and analyzing to what extent the improved relationship with the West has impacted on its tourism sector. Our results indicate that the level of income of the travelers, the exchange rate of the country of origin, word of mouth from travelers, the relative price differential between the country of origin and Vietnam, and the normalization of relationship between Vietnam and the country of origin are the major determinants of demand for tourism. One of the policy recommendations from this study is that, to increase inbound tourism, the Vietnamese government should introduce policies that would reduce the local cost of tourism in Vietnam. [ABSTRACT FROM AUTHOR]

It is essential to develop new nanomaterials able to improve sensing performance of electrochemical sensors for determination of heavy metal pollutants. In this work, a novel nanoscale metal–organic-framework material (Yb-MOF) with Ytterbium (Yb) rare-earth metal core and benzenetricarboxylic (BTC) ligands was prepared in aqueous conditions using hydrothermal approach. The results have revealed highly porous structure of the as-synthesized material with specific active area up to 1166 m2 g−1. A sensing platform was then constructed by drop-casting Yb-MOF onto glassy carbon electrode for detection of two most commonly found heavy metal ion pollutants (Cd2+ and Pb2+) in water sources. The nanoporous structure of Yb-MOF is very profitable to the selective preconcentration of targeted metal ions. The detection limits were estimated to be 3.0 ppb, 1.6 ppb for Cd2+ and Pb2+ species, respectively. This work provides a new electrochemical sensing platform for fast and sensitive in-situ detection of water contaminants. [ABSTRACT FROM AUTHOR]

Data were collected from 30 strains of Vibrio and sampled on different organs (brain, hemorrhagic site and digestive tract) of Sciaenops ocellatus infection. The results showed that the nucleotide sequences 16S rRNA region are highly similar to those of V. alginolyticus, V. azureus, V. fluvialis, V. natriengens and V. orientalis, which were published on Genbank and other, ranging from 98.05 to 100%. The digestive tract has the most common Vibrio strains (V. alginolyticus [16] V. azureus [7] and V. fluvialis). Thereout, 25 of 30 strains of Vibrio contained 1 to 3 toxin genes, except V. parahaemolyticus. Six parameters were used to measure the DNA polymorphism of 33 homologous DNA sequences in this Vibrio bacteria population. The results indicated that number of separate polymorphic sites (S), total number of mutant sites (Eta), number of haplotype (h), haplotype diversity (Hd), average number of nucleotide differences (k), nucleotide diversity (Pi) were 98 (S), 103 (Eta), 9 (h), 0.887 ± 0.032 (Hd), 25.789 (k) and 17.980 × 10–3 ± 0.003 (Pi), respectively (P < 0,05). The G + C content above 1434 sites positions of nucleotide sequences accounted for 0.542. The phylogenetic tree showed that these strains are divided into six groups. As observed, the appearance of isolated Vibrio on 3 organs of fish (S. ocellatus) hemorrhagic are V. azureus (27,67%), V. alginolyticus (50%), V. orientalis (6,67%) and V. fluvialis (16,67%). Through this result, we found that the diversity of Vibrio species that appeared on the red drum was used in the 16S rRNA region and the presence of toxin genes in these Vibrio species. [ABSTRACT FROM AUTHOR]

In the present work, we reported the simple way to fabricate an electrochemical sensing platform to detect Bisphenol A (BPA) using galvanostatic deposition of Au on a glassy carbon electrode covered by cetyltrimethylammonium bromide (CTAB). This material (CTAB) enhances the sensitivity of electrochemical sensors with respect to the detection of BPA. The electrochemical response of the modified GCE to BPA was investigated by cyclic voltammetry and differential pulse voltammetry. The results displayed a low detection limit (22 nm) and a linear range from 0.025 to 10 µm along side with high reproducibility (RSD = 4.9% for seven independent sensors). Importantly, the prepared sensors were selective enough against interferences with other pollutants in the same electrochemical window. Notably, the presented sensors have already proven their ability in detecting BPA in real plastic water drinking bottle samples with high accuracy (recovery range = 96.60%–102.82%) and it is in good agreement with fluorescence measurements. [ABSTRACT FROM AUTHOR]