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In this paper, a system for energy production from biomass combustion to provide electricity to the national grid of Vietnam was evaluated based on different thermodynamics systems and the cultivation capacity of the local area. A 20:80 mixture of cashew shell and cashew wood chip is considered as fuel source to be combusted utilizing a fixed bed technology with high energy efficiency. Considering a 10 MW production capacity to the national grid, a 20-year Net Present Value analysis and payback time evaluation was considered based on the economic factors in Vietnam. The study demonstrates how the current feed-in tariff in Vietnam is too low to encourage investment in biomass power plant. Following a suggested electricity selling price that is close to the household electric cost, the power plant shows high potential with a short payback period of 9.22 years and a levelized cost of electricity (LCOE) of only 6.4 cents/kWh. Sensitivity analyses were performed for different scenarios of material cost, electricity selling price and initial investment to show that within a 10 % variation in process factors, such project would still be able to reach payback within 20 years, with an overall LCOE of around 5–7 cents/kWh, proving the high potential of biomass-based energy production projects. • An unprecedented cashew nutshell and woodchip fuel blend is used for practicality. • On-site biomass collection and analysis were performed for accurate assessment. • FiT should be adjusted to around the household electric price to achieve payback. • An LCOE of only 6.3 cents/kWh can be attained after a 20-year lifetime. • A 10 % reduction in electricity price can increase 4 years to the payback period. [ABSTRACT FROM AUTHOR]

The southern white-cheeked gibbon Nomascus siki is endemic to Indochina and is classified as critically endangered on the International Union for Conservation of Nature (IUCN) Red List. The most updated information on the status of this species dates back to a decade ago. As hunting has tremendous impacts on wildlife in Southeast Asia, the population of N. siki might have changed a lot in the last decade. Updated information on the status and potential distribution of this species is critically important for conservation and prioritization, especially for N. siki because of its undefined distribution range. The goal of this study was to review the population status of N. siki in Vietnam and Lao People's Democratic Republic (PDR) and to model its potential distribution. In Vietnam, this species has been intensively surveyed in all major areas of occurrence from 2016 to 2021. The total number of N. siki groups recorded and estimated in Vietnam were 324 and 483, respectively. In Lao PDR, the occurrence of N. siki has been confirmed in Nam Kading, Nakai Nam Theun, Hin Nam No, and Phou Hinpoun national protected areas. However, population estimates are generally lacking. The suitable habitat of N. siki was predicted from about 105.00° to 106.80° E longitude and from about 16.60° to 17.90° N latitude located in Quang Binh and Quang Tri provinces (Vietnam), and Khammounan and Savannakhet provinces (Lao PDR). The area of the potential distribution range is about 9894.15 km 2 , both in Vietnam and Lao PDR. Particularly, the high, medium, and low suitable habitats were estimated at around 1229.58 km 2 , 3019.68 km 2 , and 5644.89 km 2 , respectively. The area of suitable habitat of N. siki in Vietnam was predicted to be 4151.25 km 2 , of which only 1257.93 km 2 (30.30%) is in the protected area network. Dong Chau-Khe Nuoc Trong and Bac Huong Hoa Nature Reserves, and Phong Nha-Ke Bang National Park should receive priority for conservation of N. siki in Vietnam. Improving conservation beyond the protected areas' boundaries or transforming the forest enterprises and watershed protection forests into protected areas should also be considered as an alternative for the conservation of N. siki. In Lao PDR, surveys of the species in its entire distribution range should be the first priority., (© 2023. The Author(s), under exclusive licence to Japan Monkey Centre.)

In an effort to identify natural bioactive compounds, three new flavonoids (1-3) and six known compounds (4-9) were isolated from the stem bark of Bougainvillea spectabilis. The structures of these compounds were accomplished using comprehensive spectroscopic methods, including 1D and 2D NMR spectra with references to the literatures, as well as high-resolution mass spectrometric analysis. Their cytotoxicity against KB and HeLa S-3 cell lines was also evaluated., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Four unusual heterodimeric tetrahydroxanthones, usneaxanthones A-D (1-4) were isolated from lichen Usnea aciculifera Vain (Parmeliaceae). Their structures and absolute configurations, particularly the central and axial chiralities, were unambiguously demonstrated by a combination of spectroscopic data (1D, 2D NMR, HRESIMS), electronic circular dichroism (ECD) experiments, and single-crystal X-ray crystallographic analyses. Cytotoxic effects of isolated compounds (1, 2 and 4) were evaluated on HT-29 human colorectal cancer cells. Compound 4 showed potent cytotoxicity against HT-29 with IC 50 values of 2.41 μM., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The methanol extract of Olax imbricata roots afforded one new sesquiterpenoid tropolone and three new 1,2,3,4-tetrahydronaphthalene derivatives, olaximbrisides A-D (1-4). Their structures were determined by 1D and 2D NMR experiments in combination of HRESIMS. The relative configurations were assigned by the NOESY experiments. The absolute configurations were established by a combination of X-ray diffraction analysis and electronic circular dichroism (ECD) experiments. All isolated compounds were evaluated for their cytotoxic effects against some cancer cell lines. Among them, compound 1 exhibited the cytotoxicities against MCF-7, HepG2 and LU cell lines with IC 50 values of 16.3, 34.3 and 8.0 μM, respectively., (Copyright © 2018 Elsevier B.V. All rights reserved.)