Indonesia has high biodiversity of algae that are under-utilised due to limitations in the processing techniques. Here, we observed the effect of two different extraction methods (cold maceration and ...ultrasonic-assisted extraction (UAE)) on multiple variables of Indonesian brown algae ethanol extracts (
,
,
and
). The variables observed included metabolites screening by untargeted metabolomics liquid chromatography-high-resolution mass spectrometry (LC-HRMS), observation of total phenolic content (TPC), total flavonoid content (TFC), anti-oxidant and B16-F10 melanoma cells cytotoxicity. UAE extracts had higher extraction yield and TPC, but no TFC difference was observed. UAE extract had more lipophilic compounds, such as fatty acids (Palmitic acid, Oleamide, Palmitoleic acid, Eicosapentaenoic acid, α-Linolenic acid, Arachidonic acid), lipid-derived mediators (11,12-Epoxyeicosatrienoic acid ((±)11(12)-EET)), steroid derivatives (Ergosterol peroxide), lipophilic metabolite (Fucoxanthin), and lipid-soluble vitamins (all-trans-retinol). Principle component analysis (PCA) revealed that TPC, not TFC, in the UAE extracts was correlated with the anti-oxidant activities and cytotoxicity of the extracts towards B16-F10 melanoma cells. This means other non-flavonoid phenolic and lipophilic compounds may have contributed to its bioactivity. These results suggest that out of the two methods investigated, UAE could be a chosen method to extract natural anti-melanogenic agents from brown algae.
COVID-19 patients with comorbid DM face more severe outcomes, indicating that hyperglycemic conditions exacerbate SARS-CoV-2 infection. Negative side effects from existing hyperglycemia treatments ...have urged the need for safer compounds. Therefore, sourcing potential compounds from marine resources becomes a new potential approach. Algal lipids are known to possess beneficial activities for human health. However, due to limitations in analyzing large amounts of potential anti-hyperglycemic and anti-COVID-19-related marine metabolites, there is an increasing need for new approaches to reduce risks and costs. Therefore, the main aim of this study was to identify potential compounds in macroalgae
,
, and
lipophilic extracts for treating DM and COVID-19 by an integrated approach utilizing in vitro anti-oxidant, in vivo anti-hyperglycemic, and metabolomic-integrated in silico approaches. Among them,
and
showed potential anti-hyperglycemic activity, with
showing the highest anti-oxidant activity. A GC-MS-based untargeted metabolomic analysis was used to profile the lipophilic compounds in the extracts followed by an in silico molecular docking analysis to examine the binding affinity of the compounds to anti-DM and anti-COVID-19 targets, e.g., α-amylase, α-glucosidase, ACE2, and TMPRSS2. Notably, this study reveals for the first time that steroid-derived compounds in the macroalgae
had higher binding activity than known ligands for all the targets mentioned. Studies on drug likeliness indicate that these compounds possess favorable drug properties. These findings suggest the potential for these compounds to be further developed to treat COVID-19 patients with comorbid DM. The information in this study would be a basis for further in vitro and in vivo analysis. It would also be useful for the development of these candidate compounds into drug formulations.
A single cylindrical neutron spectrometer (SCNS) with a gold activation foil was designed for mono-directional high-flux neutron spectrum measurement applications. A total of seven gold activation ...foils with a diameter of 11 mm and a thickness of 0.2 mm were placed in the moderator as detectors with a depth variation of 15 mm. The moderator was cylindrical with a diameter of 8 cm and a length of 16 cm and made of polyethylene. Outside the moderator is a neutron shield made of 3 mm boron-rubber and 0.5-mm cadmium and covered with an aluminum casing of 5 mm thickness. The response value of each detector was determined by simulation using the Monte Carlo MCNPX 2.7 program. The simulated response detectors was then partially validated by comparing the simulation and the measurement result with an AmBe neutron source, where the difference is around 3%. The obtained results showed that SCNS with a gold activation foil could be used to measure the neutron spectrum in a high-flux neutron field.
•The SCNS–Au spectrometer is accurate for high flux neutron spectrum measurements.•The detector response matrix is calculated with MCNPX 2.7 for 112 neutron energy.•SCNS–Au validated with AmBe source with 3% difference.
Measuring the neutron spectrum in the reactor core is quite difficult to do. The commonly used technique is using a multi-foil activation-based neutron spectrometer. This technique provides precise ...positional measurement but low accuracy and is difficult and expensive to manufacture. A technique for measuring the neutron spectrum in the reactor core has been developed using a single moderator-based neutron spectrometer. This technique is simple, easy to make, and inexpensive. The measurement time is relatively fast, and the results are quite accurate. This technique uses a single cylindrical moderator and places seven passive Au detectors with varying depths. The response of each detector is calculated using the Monte Carlo program MCNPX. The neutron spectrum measurement in the reactor core was carried out by placing the spectrometer above the core for a few minutes. The foil activity was measured using a gamma counter, and the neutron spectrum was calculated using the UMG unfolding program. After measuring the neutron spectrum with a single moderator-based neutron spectrometer in the Triga Mark II reactor core, Kartini, compared with the simulation results, the comparison results show values that are close to the same, where the difference is around 2.2%.
•Subcooled boiling is predicted to initiate at a thermal power of 223 kW.•The transition to saturated nucleate boiling occurs between 326 kW and 640 kW of thermal power.•Direct comparisons were made ...between calculated results and actual fuel temperatures measured by Instrumented Fuel Elements (IFE).•From a Departure from Nucleate Boiling Ratio (DNBR) perspective, the reactor remains within safety limits when operated between 223 kW and 427 kW thermal power.
The TRIGA® (Training, Research, Isotopes production by General Atomics) 2000 research reactor in Bandung (TRIGA® 2000 Bandung) has undergone fuel reshuffling, and therefore there is a potential for subcooled nucleate boiling to occur in the reactor core, thus it is necessary to conduct a thorough investigation by calculation to explain whether the TRIGA® 2000 Bandung reactor can still operate below the operation safety limit. Herein, the optimization of the neutronic and thermal–hydraulic calculations using the MCNP® and COOLOD-N2 codes, respectively, has been carried out to reveal the main parameters to justify the operating safety limits, including superheat temperature and Departure from Nucleate Boiling Ratio (DNBR). The calculation results show that the predicted subcooled boiling condition occurs at a thermal power of 223 kW, while saturated nucleate boiling occurs at a reactor thermal power of 326 kW – 640 kW. The calculation results were also compared with the fuel temperature measured by Instrumented Fuel Element (IFE) at each power variation. Meanwhile, from the DNBR value perspective, the reactor still meets the operating safety limit if the reactor power is operated at 223 kW – 427 kW thermal power.
Molten salt is an essential topic to study as a working fluid in circulation loop trials. Experimental and computational studies were presented to analyse the phase transition of nitrate salts and ...provide parameters that could support the consideration of the working fluid in molten salt loop testing. The NaNO
3
salt, KNO
3
salt, and the eutectic mixture of both were studied in the present work. The salt phase transition was studied in an apparatus built following the molten salt loop heater section. The apparatus was constructed by winding nichrome wire around a stainless steel pipe 2.667 cm in diameter and 20 cm long. The nichrome wire was connected to an adjustable AC voltage regulator to obtain variations in heating power in the experiment. The data acquisition integrated K-type thermocouple was used to acquire temperature change data in the centre of the apparatus. The conventional and thermal cameras were used to support the visual observation of the top surface of the apparatus. Modelling was conducted with the help of ANSYS Fluent software based on input from experimental results. At the same power, the difference in efficiency between the eutectic salt and KNO
3
salt reached 72.2%, while with NaNO
3
salt, it reached 97.7%. The results showed that the low melting temperature and the low latent heat are crucial characteristics of salt as a working fluid consideration for efficient heating in the molten salt loop.
This study aimed to quantify the individual external radiation exposure in Mamuju, Indonesia. A SmartRad portable personal dosimeter was utilized for this purpose, and data was collected over a ...period of 30 days. The findings indicate that the dose rate varies from 0.152 to 4.200 μSv/h and cumulatively ranges from 0.1 to 8.4 μSv/day based on an average measurement duration of 160 minutes. The average dose rate in areas with mineral deposits is 11.02 mSv per year. In contrast, the average effective dose in areas without radioactive mineral deposits is 2.6493 mSv per year. The annual average effective dose for individuals was measured at 6.8347 mSv. These findings imply that personal exposure to radiation among the public in Mamuju exceeds the threshold recommended by the International Commission of Radiological Protection.
