EVALUATION OF THE VULNERABILITY OF THE COASTAL SOCIO-NATURAL SYSTEMS (EXAMPLE FROM KHANH HOA COASTAL ZONE)

Joint Research on Environmental Science and Technology for the Eart

Silicon quantum-dots-based optical probe for fluorometric detection of Cr6+ ions

In this report, silicon quantum dots (SiQDs) with the NH2 functional group were synthesized with the hydrothermal method. The as-prepared SiQDs exhibit a strong fluorescence emission peak               at 441 nm when excited at 355 nm and are effectively quenched upon adding Cr6+ ions. Hence, SiQDs were used as an optical probe to detect Cr6+ ions in solutions. The crystal structure of SiQDs was characterized by using X-ray diffraction (XRD). The Fourier-transform infrared spectroscopy (FT-IR) was used to determine the linker groups on the SiQDs surface. The fluorescence spectroscopic technique with an excitation wavelength of 355 nm was used to quantify the Cr6+ ion concentration in the solutions in the range of 0.1–1000 µM. Competition from common coexisting ions, such as K+, Na+, Al3+, Zn2+, and Pb2+, was ignorable. The test with actual samples showed good linearity for the Cr6+ concentration range of 0.1–50 µM

Construction of a dataset for the gene nrLSU to support the identification of cantharellus at Langbian Mountain, Lam Dong

Fungal species of Cantharellales order are found worldwide including Europe, Africa, Asia, and North America. This clade includes two smaller, separate, but closely related genera Cantharellus and Craterellus. Cantharellus was firstly identified in the middle of the 17th century. Besides traditional classification based on morphology, molecular phylogeny of the nuclear ribosomal large subunit gene (nrLSU) can be an effective tool to provide more information during species identification for this group. In this current report, a dataset of the nrLSU gene including 60 sequences of Cantharellus species and 1 sequence belonging to Craterellus (outgroup), was obtained from Genbank. Phylogenetic analyses by MEGA 6.0 showed a monophyletic relationship between the six well-established clades, namely Cantharellus (Clade 1), Rubrinus (Clade 2), Cinnabarinus (Clade 3), Parvocantharellus (Clade 4), Pseudocantharellus (Clade 5) and subgenus Afrocantharellus (Clade 6) similar to that of morphological classification. Therefore, this dataset is efficient to support the identification of the fungal samples, collected at the Langbian Mountain, Lam Dong

Chemical constituents and biological activities of Balanophora fungosa varietas globosa growing in Vietnam, as well as comparative chromatography with some species of the genus Balanophora J. R. & G. Forst

The chemical composition and biological activities of Balanophora fungosa var. globosa (BFG) were studied for the first time. Also, the chemical composition of some other Balanophora species was established for comparison. Phenolic compounds isolariciresinol, gallic acid, pinoresinol, methyl caffeate, and epipinoresinol-4-O-β-D-glucopyranoside were isolated from Balanophora fungosa var. globosa collected in Vietnam and identified by the NMR analysis. Some in vitro biological activities of the isolated compounds, including the inhibitory effect on NO production and cytotoxic effects, were evaluated. The chromatographic methods were developed to determine the chemical fingerprints of BFG and its very close taxon subsp. indica (Arn.) B. Hansen (BFI), also of the two new species recently recorded for the flora of Vietnam Balanophora tobiracola Makino (BT) and Balanophora subcupularis P.C. Tam (BS). Among the isolated compounds, isolariciresinol showed a moderate inhibitory effect on NO production (I% = 56.02 at concentration of 100 µg/mL), while gallic acid at concentration of 100 μg/mL demonstrated moderate cytotoxicity against cancer cell lines MCF-7 (human breast carcinoma) and PC3 (human prostate gland carcinoma). The HPTLC analysis showed similarities in the chemical compositions of BFG and BFI, as well as the difference between their compositions and these of BT and BS. O-caffeoyl-O-galloyl-glucoside I, caffeic acid glucoside, O-caffeoyl-di-galloyl-β-D-glucoside V, and 1-O-caffeoyl-3-O-galloyl-4,6-HHDP-β-D-glucoside as principal compounds were identified among 31 phenolic substances of BFI and BFG by using HPLC-MS/MS

ONE STEP SYNTHESIS OF WATER-DISPERSIBLE CoFe2O4 MAGNETIC NANOPARTICLES USING TRIETHYLENETETRAMINE AS SOLVENT AND STABILISING LIGAND

Magnetic CoFe2O4 nanoparticles were synthesised by one step synthetic method through thermal decomposition of Co and Fe precursors in triethylenetetramine solvent at high temperature. The advantage of this method is the ability to make monodisperse nanoparticles with high water-dispersibility and stability. The particle size can be tuned in the range of 7-11.3 nm by varying synthetic conditions. The obtained particles with small DLS size (less than 21 nm) are ready to disperse and stable in aqueous solution for weeks without any surface modification

Ultrawideband Near-Field Probe System for Antenna Research

Data management plan for the grant, "Ultrawideband Near-Field Probe System for Antenna Research." The objective of this project is to acquire an ultrawideband near-field probe system to build a highly capable antenna measurement facility which will provide critical support for the research, development, and testing of new antenna designs and concepts at the University of North Texas (UNT). The requested near-field probe system will be integrated with existing hardware at UNT, including a vector network analyzer and an Albatross Projects shielded chamber, to complete the build for the measurement system that is capable of characterizing three-dimensional radiation patterns of antennas-under-test (AUT) over a wide frequency range of 0.65-18 GHz. The measurement facility will be used to not only support ongoing and future federally funded research of the principal investigators but also enhance undergraduate and graduate education and training in RF, microwave, and antenna engineering at UNT

The Application of High-Frequency Microwaves in Tissue Ablation for Cancer Treatment

The study demonstrates the feasibility of using high-frequency microwaves for tissue ablation by comparing the performance of a 10 GHz microwave ablation system with that of a 1.9 GHz system. Two sets of floating sleeve dipole antennas operating at these frequencies were designed and fabricated for use in ex vivo experiments with bovine livers. Combined electromagnetic and transient thermal simulations were conducted to analyze the performance of these antennas. Subsequently, a total of 16 ablation experiments (eight at 1.9 GHz and eight at 10.0 GHz) were conducted at a power level of 42 W for either 5 or 10 minutes. In all cases, the 1.9 GHz and 10 GHz experiments resulted in comparable ablation zone dimensions. Temperature monitoring probes revealed faster heating rates in the immediate vicinity of the 10.0 GHz antenna compared to the 1.9 GHz antenna, along with a slightly delayed onset of heating farther from the 10 GHz antenna, suggesting that heat conduction plays a greater role at higher microwave frequencies in achieving a comparably sized ablation zone. The results obtained from these experiments agree very well with the combined electromagnetic/thermal simulation results. These simulations and experiments show that using lower frequency microwaves does not offer any significant advantages, in terms of the achievable ablation zones, over using higher frequency microwaves. Indeed, it is demonstrated that high-frequency microwave antennas may be used to create reasonably large ablation zones. Higher frequencies offer the advantage of smaller antenna size, which is expected to lead to less invasive interstitial devices and may possibly lead to the development of more compact multi-element arrays with heating properties not available from single-element antennas