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1.
Data Brief ; 54: 110486, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38770039

ABSTRACT

Deep learning has been studied in recent years to identify periapical lesions- a significant indicator of periapical periodontitis in radiographs. An accurate dataset is essential for constructing an efficient learning model for detecting periapical lesions. In order to achieve this goal, we gathered and created a database of panoramic radiographs containing periapical lesions from the High-quality Dental Treatment Centre, School of Dentistry, Hanoi Medical University, between January 2016 and March 2021. Out of 16,519 radiographs, three experienced dentists identified 3,926 images of periapical lesions and annotated those lesions based on the Periapical Lesions Classification. By applying well-known data processing techniques (e.g. scaling, mirroring, and flipping), the amount of data is increased to 17,004 images through generating additional images for machine learning. The dataset has three folders: one for the original photos, one for the post-augmentation images, and the rest for the annotation of periapical lesions. The information could assist researchers in developing a predictive machine model for detecting periapical lesions in radiographs.

2.
Biodivers Data J ; 11: e105314, 2023.
Article in English | MEDLINE | ID: mdl-38327301

ABSTRACT

Background: The Mekong River is the 10th largest river in the world. It is recognised as the most productive river in Southeast Asia and economically essential to the region, with an estimated 60-65 million people living in the lower Mekong Basin. The Mekong Delta within Vietnam is considered a highly vulnerable ecosystem under threat from increasing anthropogenic pressure, such as dam construction and, as a consequence, the Delta is sinking and altering the natural hydrological cycle. Dams also lead to eutrophication and pollution of downstream water from regulated water flux and water stagnation. Another threat is climate change coupled with the lower rainfall, which could lead to an increased risk of drought in the Mekong Delta Basin. Thus, these project data represent an important baseline reference. The ecological health of the Mekong Delta's environment, as indicated by the quality and availability of its water and biological resources, largely determines the economic and social development of the region, which produces about half of the agriculture and aquaculture products of Vietnam. New information: This paper reports quantitative data on the biodiversity of six groups of aquatic organisms: bottom and pelagic fish, macrozoobenthos, microorganisms, phyto- and zooplankton in the Mekong Delta within Vietnam, as well as data on the physicochemical parameters of water and bottom sediments. The data were collected during 2018-2022 as part of the Ecolan E-3.4 programme within the framework of the research plan of the Joint Russian-Vietnamese Tropical Research and Technological Center. All presented datasets are published for the first time.

3.
Environ Pollut ; 297: 118747, 2022 Mar 15.
Article in English | MEDLINE | ID: mdl-34979172

ABSTRACT

For the first time, a quantitative assessment of this pollutant was made at the bottom of the rivers of the Mekong basin, and the features of its accumulation and dynamics in bottom sediments and relationship with abundance of fish and decapods were investigated. Sampling of materials for the research was carried out by bottom trawls in the Mekong delta in Vietnam. The amount of macroplastic caught by the trawl from the bottom averaged 33.4 g/100 m2. The maximum values of the waste content (up to 923.2 g/100 m2) were confined to the districts of large cities. The distribution of macroplastic was characterized by high spatio-temporal variability. Its amount was significantly (p < 0.05) higher in branches with low monthly flow, in shallow-water areas, as well as in the low-water period. During the flood period, which usually lasts from July to November, the amount of macroplastic at the bottom decreased by an average of 2.5 times. In this study a significant relationship between the number of animals and the mass of macroplastics was statistically proven for most species of fish and decapods. The substrate, containing a significant amount of plastic fragments, attracted aquatic organisms. All in all, we present results for poorly understood processes of transport, deposition and influence of plastic debris in large rivers in regions of monsoon subequatorial climate and show that more efforts should be dedicated to further unravel potentially complex pathways of the plastic exposure to water ecosystems.


Subject(s)
Decapoda , Rivers , Animals , Ecosystem , Environmental Monitoring , Plastics
4.
Light Sci Appl ; 5(4): e16058, 2016 Apr.
Article in English | MEDLINE | ID: mdl-30167156

ABSTRACT

We present the design, fabrication and characterization of hydraulically-tunable hyperchromatic lenses for two-dimensional (2D) spectrally-resolved spectral imaging. These hyperchromatic lenses, consisting of a positive diffractive lens and a tunable concave lens, are designed to have a large longitudinal chromatic dispersion and thus axially separate the images of different wavelengths from each other. 2D objects of different wavelengths can consequently be imaged using the tunability of the lens system. Two hyperchromatic lens concepts are demonstrated and their spectral characteristics as well as their functionality in spectral imaging applications are shown.

5.
Chemosphere ; 90(9): 2396-402, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23182686

ABSTRACT

Concentration and distribution of PCBs, PCB 11, and PBDEs in both surficial sediment and soil samples, taken from a zone subject to recent accelerated development, were investigated to assess the environmental quality and understand both natural and anthropogenic processes that influence contaminant behaviors. Values of PCB and PBDE are in the lower range of those reported in literature, typical of low impacted coastal zones. This could be due to efficient processes of resuspension and removal. Contaminants in the lagoon showed higher concentrations in sediments from sites close to the city and the outfalls of the industrial area, while soils showed maximum values in the northern samples. In addition, congener patterns and statistical analyses suggest the presence of effective degradation processes, especially for PBDEs, with the exception of the most concentrated samples that may indicate a direct input. PCB 11 is a significant component (up to 18%) in most lagoon sediments. Its presence is strongly associated with fine particles, thus the distribution seems to be driven mainly by the system hydrodynamic and does not trace the sources. Due to evaporation, only flooded agricultural soils show a similar relative abundance of this congener.


Subject(s)
Geologic Sediments/chemistry , Halogenated Diphenyl Ethers/analysis , Polychlorinated Biphenyls/analysis , Soil Pollutants/analysis , Soil/chemistry , Water Pollutants, Chemical/analysis , Environmental Monitoring , Environmental Pollution/statistics & numerical data , Seawater/chemistry , Vietnam
6.
Opt Express ; 21(23): 27611-21, 2013 Nov 18.
Article in English | MEDLINE | ID: mdl-24514279

ABSTRACT

A new approach for confocal hyperspectral sensing based on the combination of a diffractive optical element and a tunable membrane fluidic lens is demonstrated. This highly compact lens system is designed to maximize the longitudinal chromatic aberration and select a narrow spectral band by spatial filtering. Changing the curvature of the fluidic lens allows the selected band to be scanned over the whole given spectrum. A hybrid prototype with an integrated electro-magnetic micro-actuator has been realized to demonstrate the functionality of the system. Experimental results show that the spectrum transmitted by the system can be tuned over the entire visible wavelength range, from 450 to 900 nm with a narrow and almost constant linewidth of less than 15 nm. Typical response time for scanning the spectrum by 310 nm is less than 40 ms and the lens system shows a highly linear relationship with the driving current.

7.
PLoS One ; 7(11): e50401, 2012.
Article in English | MEDLINE | ID: mdl-23308088

ABSTRACT

UNLABELLED: Fibroblast Growth Factor (FGF)-10 promotes the proliferation and survival of murine hepatoblasts during early stages of hepatogenesis through a Wnt-ß-catenin dependent pathway. To determine the mechanism by which this occurs, we expanded primary culture of hepatoblasts enriched for progenitor markers CD133 and CD49f from embryonic day (E) 12.5 fetal liver and an established tumor initiating stem cell line from Mat1a(-/-) livers in media conditioned with recombinant (r) FGF10 or rFGF7. FGF Receptor (R) activation resulted in the downstream activation of MAPK, PI3K-AKT, and ß-catenin pathways, as well as cellular proliferation. Additionally, increased levels of nuclear ß-catenin phosphorylated at Serine-552 in cultured primary hepatoblasts, Mat1a(-/-) cells, and also in ex vivo embryonic liver explants indicate AKT-dependent activation of ß-catenin downstream of FGFR activation; conversely, the addition of AKT inhibitor Ly294002 completely abrogated ß-catenin activation. FGFR activation-induced cell proliferation and survival were also inhibited by the compound ICG-001, a small molecule inhibitor of ß-catenin-CREB Binding Protein (CBP) in hepatoblasts, further indicating a CBP-dependent regulatory mechanism of ß-catenin activity. CONCLUSION: FGF signaling regulates the proliferation and survival of embryonic and transformed progenitor cells in part through AKT-mediated activation of ß-catenin and downstream interaction with the transcriptional co-activator CBP.


Subject(s)
CREB-Binding Protein/metabolism , Liver Neoplasms/pathology , Liver/cytology , Proto-Oncogene Proteins c-akt/metabolism , Receptors, Fibroblast Growth Factor/metabolism , Signal Transduction , beta Catenin/metabolism , Animals , Cell Cycle , Cell Proliferation , Cell Survival , Embryonic Stem Cells/cytology , Extracellular Signal-Regulated MAP Kinases/metabolism , Humans , Liver/pathology , Methionine Adenosyltransferase/deficiency , Mice , Mice, Inbred C57BL , Neoplastic Stem Cells/metabolism , Neoplastic Stem Cells/pathology
8.
Mar Pollut Bull ; 62(5): 1013-24, 2011 May.
Article in English | MEDLINE | ID: mdl-21397915

ABSTRACT

PCBs were analysed in surficial sediments and selected sediment cores collected between 2002 and 2008 in Central Vietnam coastal lagoons. The aim was to determine contamination levels and trends, and to evaluate the effects of anthropogenic pressures and natural events. Samples were mostly fine-grained with low total PCB concentrations (0.367-44.7 µg kg(-1)). Atmospheric transport and post depositional processes modify to some degree the fingerprint of PCB inputs to the environment favouring the predominance of 3, 4 and 5 chlorinated congeners. The similarity of congener distributions in contemporary surficial samples also suggests the presence of a unique source over the entire study area, probably connected to mobilisation and long range transports from land-based stocks. The removal of consistent sediment layers is hypothesised based on repeated samplings of the same area. Natural meteorological events (such as typhoons) are suspected to be responsible for these sediment losses.


Subject(s)
Polychlorinated Biphenyls/analysis , Seawater/chemistry , Water Pollutants, Chemical/analysis , Atmosphere/chemistry , Environmental Monitoring , Geologic Sediments/chemistry , Porosity , Vietnam , Water Movements , Water Pollution, Chemical/statistics & numerical data
9.
J Environ Monit ; 13(5): 1383-92, 2011 May.
Article in English | MEDLINE | ID: mdl-21409204

ABSTRACT

Trace element concentrations have been measured in soil and sediment samples taken from the Thua Thien Hue (TT-H) Province and the Tam Giang-Cau Hai (TG-CH) Lagoon in 2002 and 2004. Results show that the lagoon is only slightly contaminated by elements such as Ag, Cd, Cr, Cu, Ni, Pb and Zn, whereas As, probably naturally enriched in this Asian region, reaches values above the lowest internationally accepted sediment quality guidelines. Concentrations in soils are ascribable to natural sources and distributions in the TG-CH Lagoon are mainly influenced by river inputs, with Ag and Cd undergoing estuarine desorption processes. However, concentration-depth profiles of most trace elements in sediments show a recent increasing trend that might be linked to the economic development of the area. The comparison of porosity and (210)Pb depth profiles (confirmed also by Cd and As) from repeated samplings of the same core locations in the TG-CH Lagoon seems to account for a loss of 5-10 cm of surficial sediment that took place during the time interval between the two samplings. It is hypothesized that extreme meteorological events (e.g. a major typhoon that hit the area in November 2003) could be responsible for such sediment displacement.


Subject(s)
Geologic Sediments/chemistry , Soil Pollutants/analysis , Soil/chemistry , Trace Elements/analysis , Water Pollutants, Chemical/analysis , Cyclonic Storms , Environmental Monitoring , Vietnam
10.
Mar Pollut Bull ; 60(12): 2303-10, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20952038

ABSTRACT

Samples from nine Central Vietnam coastal lagoons, together with three soils and sediments collected in two freshwater reservoirs of the Thua Thien-Hué province, were analysed for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Total concentrations are low, from 192 to 2912 pg g(-1) and depth profiles in Tam Giang-Cau Hai (TG-CH) sediment cores show only minor changes over time in PCDD/F input and composition. Octachloro dibenzo-p-dioxin (OCDD) is the prevailing congener (approximately 90%), indicating combustion as the main PCDD/F source to these coastal systems, whereas natural formation might be partly responsible for the presence at depth. 2,3,7,8-Tetrachloro dibenzo-p-dioxin (TCDD), largely sprayed together with Agent Orange over the study areas during the war (1961-1971), is absent or very low. This result supports the hypothesis of strong degradation soon after spraying. Multivariate statistical analyses account for the presence of local, short-range sources as observed in the northern part of the TG-CH lagoon.


Subject(s)
Benzofurans/analysis , Polychlorinated Dibenzodioxins/analogs & derivatives , Polychlorinated Dibenzodioxins/analysis , Polymers/analysis , Water Pollutants, Chemical/analysis , Environmental Monitoring , Seawater/chemistry , Soil/chemistry , Vietnam
11.
J Asian Nat Prod Res ; 10(11-12): 1035-8, 2008.
Article in English | MEDLINE | ID: mdl-19031243

ABSTRACT

From the ethyl acetate extract of the aerial parts of Jasminum subtriplinerve Blume (Oleaceae), 6'-O-menthiafoloylverbascoside (1), rutin (2), isoverbascoside (4), isooleoverbascoside (6), apiosylverbascoside (7), astragalin (9), isoquercitrin (10), and verbascoside (11) were isolated. Their structures were elucidated by extensive MS and NMR spectroscopy. Amongst 6'-O-menthiafoloylverbascoside (1) is a new phenylpropanoid glycoside.


Subject(s)
Glycosides/chemistry , Jasminum/chemistry , Phenols/chemistry , Molecular Structure , Plant Components, Aerial
13.
Environ Pollut ; 131(3): 401-8, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15261403

ABSTRACT

Levels of butyltin (BT) and phenyltin (PT) compounds were determined in sediments and clam Meretrix spp. collected from north and central coastal areas in Vietnam. Concentrations of TBT in sediments ranged from 0.89 to 34 ng g(-1) dry wt and those in clams ranged from 1.4 to 56 ng g(-1) wet wt. The levels of TBT in sediments and clams from Vietnam were within limits reported from other countries. Further, the TBT level in clams was lower than the tolerable average residue level (TARL) estimated based on tolerable daily intake (TDI). Trace amounts of PTs were also found in both sediment and clam samples. In sediments from north and central Vietnam, the concentrations of TBT were highest in the order of Hue (28 ng g(-1) dry wt), Cua Luc (15 ng g(-1) dry wt), Sam Son (6.3 ng g(-1) dry wt), and Tra Co (5.5 ng g(-1) dry wt). Among the clams from north and central Vietnam, the levels of TBT in clams from Cua Luc were dramatically high at 47 ng g(-1) wet wt. TBT formed the principal butyltin species in sediment at all sites studied. The ratios of TBT in sediment were higher among BT compounds at all study sites. Of total BTs, TBT was the dominant species in clams from almost all sites studied. In spatial distribution, TPT showed a pattern similar to TBT, suggesting the use of TPT as an antifouling paint. The partition coefficient between sediment and calms was calculated. The partition coefficients of TBT and TPT were 2.01 (0.56-5.5) and 9.23 (3.1-20), respectively. These results show that sediment-bound TBT is a source of contamination to clams in addition to dissolved TBT.


Subject(s)
Bivalvia/chemistry , Environmental Monitoring/methods , Geologic Sediments/chemistry , Organotin Compounds/analysis , Soil Pollutants/analysis , Animals , Vietnam
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