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In recent years, landslides in mountainous provinces have been increasing. Whenever the rainy season comes, landslides occur, causing casualties to people and the infrastructure. Bac Can, which has suffered significant damage from landslides, is a mountainous province in the north of Vietnam. This study introduces the applying the analytic hierarchy process (AHP) to study landslides in Bac Can province, Vietnam. Currently, the earth's temperature is rising, and natural and anthropogenic hazards in the mountain are causing hazards. Integrate elements of the DEM model with component maps and different precipitation scenarios as the basis for the author to issue landslide warnings under the climate change scenario with maximum day rain rainfall for 2025 and 2050. [ABSTRACT FROM AUTHOR]

Basalt-related pyrope from Southeast Vietnam occurs as both xenocrysts and xenoliths, and is collected from secondary deposits. The garnet is transparent deep orange to light red when observed with transmitted light. The gemmological characteristics, as well as Raman and FTIR spectra, confirm it is pyrope. The chemical composition yields molar percentages of Py72.0-75.3Al14.8-18.3 Gr9.2-9.9 (where Py = pyrope, Al = almandine and Gr = Grossular) and an average chemical formula of (Mg2.15Fe2+ 0.42Ca0.27Mn0.01)2.85Al2.14(Si2.99O12). The surfaces of the pyrope exhibit resorption that occurred during transport to the surface in basaltic magma. Examination of coronae (kelyphitic texture) surrounding the xenolithic garnets with a petrographic microscope, combined with FTIR spectroscopy, shows that the pyrope originated from a deep garnet peridotite source. [ABSTRACT FROM AUTHOR]

The authors examine the gemological properties and commercial potential of a new source of amber, discovered in 2020 on the Vietnamese island of Phu Quoc. It is the only known amber locality in Vietnam so far. The Phu Quoc amber possesses reddish orange to orangy yellow hues and is transparent, with sizes up to 10 cm. The samples exhibited strong blue fluorescence under ultraviolet light (both long-wave and short-wave). Internally, they displayed disk-like inclusions and gas bubbles, but few botanical inclusions were found. Their characteristic FTIR peaks can be distinguished from those of amber found in other sources worldwide. Although amber from Phu Quoc is a recent discovery and has only been investigated in two small areas, its commercial potential is promising based on the samples' quality and the wide distribution of the host rock on the island. [ABSTRACT FROM AUTHOR]

In southeast Vietnam, gem-quality anorthoclase is found as megacrysts in Cenozoic alkali basalt. The crystals are transparent to translucent with vitreous luster and can be near-colorless, yellow, or brownish gray. Gemological testing confirmed this mineral is alkali feldspar, but the data cannot specify the alkali feldspar subgroup (orthoclase, anorthoclase, microcline, or sanidine). Based on X-ray diffraction analysis and a feldspar composition ternary diagram created from energy-dispersive X-ray fluorescence analysis, this material was identified as anorthoclase. Energy-dispersive X-ray fluorescence determined the composition to be An3.50–8.02, Ab58.83–81.69, and Or11.94–36.96. The Raman spectra displayed differences when compared to those of other alkali feldspars such as sanidine, orthoclase, and microcline. Fourier-transform infrared spectra of this material are similar to those of anorthoclase from around the world and lack any distinctive features that would allow for its separation. Gem-quality anorthoclase from southeast Vietnam has commercial potential, as it is abundant and evenly distributed in the basaltic weathering products. [ABSTRACT FROM AUTHOR]

Late Mesozoic igneous rocks are predominately found in the Dalat zone, but also in smaller volumes to the southwest, in the Bay Nui – Ba Hon area, southwestern Vietnam. Within the latter area three different groups can be distinguished based on petrological features: (1) the Dinhquan intrusive magmatic suite; (2) the Deoca intrusive magmatic suite and (3) the Ankroet suite. The Dinhquan suite comprises mainly diorite, monzodiorite, monzonite, and syenite. The Deoca suite is the major magmatic group and consists mainly of granodiorite and granite. The major and trace element composition point to a calc-alkaline nature of both intrusive suites. Samples collected from the Dinhquan suite are metaluminous, while the Deoca suite rocks are metaluminous to peraluminous and usually contain the minerals amphibole, titanite and allanite. The Dinhquan–Deoca igneous series display a typical fractional crystallization trend similar to Cordilleran I-type batholiths. The trace elements versus silica plots indicate that crystallization of Ti-Fe oxides and ferromagnesian minerals (e.g., amphibole) occurred in both suites.By contrast, the Ankroet suite displays a higher content and narrower variation in silica as well as a peraluminous composition typical for A-type and S-type granitoids. Granites of the Ankroet suite tendentially have a higher content in heavy rare earth elements (HREE) and strong negative Eu, Sr, Ba, Ti anomalies on primitive mantle normalized plots compared to samples from the Dinhquan-Deoca series. The pronounced negative Eu and Ba anomalies suggest fractional crystallization of feldspar. U-Pb zircon ages yield values of 105.0±0.6 for the Dinhquan suite, 86.5±1.9 to 93.0±0.9 Ma for the Deoca suite, and 89.3±0.9 Ma for the Ankroet suite. Several zircons of the Deoca samples show inherited cores with ages similar to those of the Dinhquan suite. The presence of mafic enclaves representing the Dinhquan suite within the Deoca suite as well as similar trends in primitive mantle and chondrite normalized plots indicates a close genetic relationship of both suites. In comparison with the equivalent Cretaceous igneous rock suites from the Dalat zone, the rocks in southwestern Vietnam are generally more basic in composition, contain more potassium, and have a larger variation in Mg# indicating a higher degree in fractional crystallization.Based on the geochemistry we conclude that the Dinhquan-Deoca series are part of the still active continental arc, which existed along the eastern margin of the Eurasian continent during the Late Mesozoic. However, the occurrence of the contemporaneous post-orogenic Ankroet suite indicates a transition in the tectonic setting and may be related to the beginning of extension which lead to the opening of the East Sea (South China Sea). [ABSTRACT FROM AUTHOR]

Introduction: Evidence on post-COVID-19 conditions is emerging. This study aims to assess post-COVID conditions and related factors in COVID-19 patients in Central Vietnam., Methodology: A descriptive cross-sectional study was performed on people who have recovered from COVID-19 at least 2 weeks prior to the online survey. Participants were interviewed face-to-face after 6 and 9 months from the first survey., Results: 53 patients (21.2%) were confirmed to have persistent symptoms, of which, 100% and 94.3% reported prolonged fatigue and full-body weakness respectively. Loss of appetite was reported by 90.6%, while persistent cough, insomnia, and trouble sleeping were reported by 86.3% of patients. Headaches and dyspnea were reported by 69.5% and 56.8% respectively, while other symptoms had lower rates. The prevalence of post-COVID condition showed a statistically significant relationship with the time of infection, duration of illness, treatment place, use of herbal medicine, adherence to the 5K message from Vietnam's Ministry of Health, and daily saltwater mouthwash (p < 0.05). However, the use of medicine and supplements was not related to the post-COVID condition (p > 0.05). After 6 months, 125 participants were interviewed face-to-face, and only 15 people (12.0%) reported having post-COVID symptoms, mainly prolonged fatigue (33.3%) and persistent cough (26.7%). After 9 months, these 15 patients no longer had symptoms related to the post- COVID-19 condition., Conclusions: The post-COVID condition can persist for several weeks or months, but will mostly be in remission after 6 months, and completely resolve after 9 months from the onset of the infection., Competing Interests: No Conflict of Interest is declared, (Copyright (c) 2023 Toan Khanh Tran, Son Nguyen Truong, Loan Tran Thanh, Ngoc Le Hoang Gia, Hieu Pham Trung, Binh Tran Dinh.)