14 research outputs found
ĐẶC ĐIỂM TƯỚNG ĐÁ - CỔ ĐỊA LÝ PLEISTOCEN MUỘN-HOLOCEN KHU VỰC CỬA SÔNG BA LẠT
Lithofacies and paleogeographical characteristics of late Pleistocene-Holocene deposits are related to three sedimentary system tracts: Lowstand systems tract (LST) corresponds to the low regressive phase from 50 ka BP to 18 ka BP. The sedimentary accumulative space is situated from the boundary of weathering crust to the 100 m water depth. In Ba Lat rivermouth area, the lowstand systems tract is dominated by the alluvial silty sand facies group (arLST); Transgressive systems tract (TST) in Ba Lat rivermouth area constitutes a lithofacies section including three facies in upward direction as follows: (1) Transgressive alluvial silty - sand facies (atTST). (2) Transgressive estuary sandy - mud facies (amtTST). (3) Lagoonal maximum transgressive greenish clay facies (mtTST); Highstand systems tract (HST) in the downstream Red river delta area constitutes a deltaic plain structure consisting of three parts: High subaerial delta, low subaerial delta and subaqueous delta, which had been formed from 5 ka BP.Đặc điểm tuớng đá - cổ địa lý trầm tích Pleistocen muộn-Holocen khu vực cửa sông Ba Lạt gắn liền với ba miền hệ thống trầm tích: Miền hệ thống trầm tích biển thấp (LST) tương ứng với pha biển thoái thấp từ 50.000 năm BP đến 18.000 năm cách ngày nay. Không gian tích tụ của miền hệ thống này được giới hạn từ ranh giới miền xâm thực (vỏ phong hóa) đến độ sâu 100 m nước. Trong khu vực cửa Ba Lạt nhóm tướng aluvi biển thoái thống trị (arLST); Miền hệ thống trầm tích biển tiến (TST) trong khu vực cửa sông Ba Lạt cấu thành một mặt cắt gồm ba tướng từ dưới lên: (1) tướng cát bột aluvi biển tiến (atTST), (2) tướng bùn cát cửa sông biển tiến (amtTST) và (3) tướng sét xám xanh vũng vịnh biển tiến cực đại (mtTST); Miền hệ thống trầm tích biển cao (HST) trong khu vực hạ lưu châu thổ sông Hồng tạo nên một cấu trúc đồng bằng châu thổ bao gồm: Đồng bằng châu thổ cao, Đồng bằng châu thổ thấp và châu thổ ngập nước có tuổi từ 5.000 năm BP
THÀNH PHẦN HÓA HỌC VÀ HOẠT TÍNH KHÁNG VI SINH VẬT GÂY BỆNH CỦA TINH DẦU TỪ VỎ BƯỞI DA XANH (Citrus maxima (Burm.) Merr.)
Pomelo is a Vietnam’s plant species with high nutritional and economic value. Besides, pomelo essential oil contains numerous compounds with high biological activity. The essential oil is extracted by using steam distillation, and its chemical composition is determined by means of GC-MS. The major components are limonene (91.19%), b-myrcene (2.92%), a-phellandrene (1.98%), and a-pinene (1.19%). The antimicrobial activity of essential oils is tested against pathogenic Gram-positive bacteria (Bacillus cereus, Staphylococcus aureus), Gram-negative bacteria (Escherichia coli), and Aspergillus flavus at different concentrations with the agar well diffusion method. This essential oil is active against B. cereus, S. aureus, and E. coli with inhibition diameter zones at 8.3–11.3, 10.3–18.7, and 9.0–11.7 mm, respectively, and inhibits A. flavus mold with 18.9–65.0% efficiency.Bưởi là loài cây không chỉ có giá trị cao về mặt dinh dưỡng mà còn có giá trị cao về mặt kinh tế và được trồng phổ biến ở Việt Nam. Ngoài ra, tinh dầu bưởi chứa nhiều hợp chất có hoạt tính sinh học cao. Tinh dầu bưởi được chiết xuất bằng phương pháp chưng cất lôi cuốn hơi nước và thành phần hóa học được phân tích bằng phương pháp GC-MS. Thành phần chính của tinh dầu gồm limonene (91,19%), b-myrcene (2,92%), a-phellandrene (1,98%) và a-pinene (1,19%). Hoạt tính kháng vi sinh vật của tinh dầu được khảo sát với vi khuẩn Gram dương (Bacillus cereus, Staphylococcus aureus), Gram âm (Escherichia coli) và nấm mốc Aspergillus flavus ở nồng độ 5, 10, 25 và 50% bằng phương pháp khuếch tán giếng thạch. Tinh dầu có khả năng kháng B. cereus, S. aureus và E. coli với đường kính vòng kháng khuẩn lần lượt là 8,3–11,3, 10,3–18,7 và 9,0–11,7 mm và ức chế sự phát triển của A. flavus (18,9–65,0%)
A modern purification by accelerated solvent extraction and centrifugal partition chromatography and biological evaluation of capsaicin from Capsicum chinense
A special alkaloid compound known as capsaicin, which can only be found in the fruit of the Capsicum plant, was isolated and tested for its anti-inflammatory activity. The purpose of this work is to establish a simple and quick approach for capsaicin purification utilizing centrifugal partition chromatography (CPC) as well as an effective method - accelerated solvent extraction (ASE), for extracting capsaicin from Capsicum chinense. After purification, capsaicin was validated by HPLC-DAD at 281 nm to be > 90% purity. The in vivo anti-inflammatory activity of the isolated capsaicin was also investigated, and the IC50 value of the capsaicin was determined to be 57.61 µg/mL. The current work emphasizes how an ASE and CPC system may combine to extract high-purity capsaicin from Capsicum chinense, which have the anti-inflammatory activity, as we evaluated in the experiment
Successful Psoriasis Treatment Using NB-UVB with Methotrexate: The Vietnamese Experience
AIM: To compare the effectiveness of narrowband ultraviolet B (NBUVB) and oral methotrexate (MTX) to oral MTX alone in Vietnamese psoriasis patients, from May 2016 to May 2018.
METHODS: We conducted a non-randomized trial on 70 patients with plaque-type psoriasis of moderate to severe. Thirty-five patients apply NBUVB once/day in 5 days/week for 4 weeks plus oral MTX 7.5 mg/week and 35 patients oral MTX 7.5 mg/week and both two groups treatment for 3 months. The extent of the lesion was assessed by the Psoriasis Area and Severity Index (PASI).
RESULTS: The proportion of decreasing PASI was comparable (68.49% in NBUVB and MTX versus 57.62% in MTX alone); p < 0.05. Inside, good 28.58%, moderate 68.57% and poor 2.85% in NBUVB and MTX better than good 2.85%, moderate 71.4% and poor 25.72% in MTX alone; p < 0.05. The recurrence rate after 24 months of the NBUVB and MTX group (42.9%) was lower than the MTX alone group (71.4%); p < 0.05.
CONCLUSION: NBUVB and oral MTX have affected treatment with chronic plaque psoriasis better than oral MTX alone
Opracowanie zestawu kryteriów ustalania priorytetów środków redukcji emisji gazów cieplarnianych w sektorze metalurgicznym
Prioritizing climate change mitigation measures could help to identify most feasible or most nationally appropriated mitigation actions. This process can also provide important inputs for the development of national climate change strategies or policies. The paper applies Delphi method to prioritize criteria for potential climate change mitigation technology in the metallurgical sector in Vietnam. The consultation process has been done with ten experts in only two cycle to reach Kendall (W) value over 0.5. Then, 11 out of 21 criteria have been selected for Multi-Criteria Decision Analysis (MCDA) in prioritizing mitigation options in iron and steel, lead, zinc, tin and aluminium productions. Mitigation options with highest scores will be proposed for mitigation target of the metallurgical sector which could be inputs for NDC of industrial sector. The selected criteria include 01 indicator in emission reduction (GPT1), 01 indicator in environmental impacts (MT1), 01 indicators in social impacts (XH3), 02 indicators in economic impacts (KT1, KT2), 02 indicators in sustainable development impacts (PTBV1, PTBV2) and 04 indicators in MRV (MRV1, MRV2, MRV3, MRV4).Nadanie priorytetu środkom łagodzenia zmiany klimatu może pomóc w zidentyfikowaniu najbardziej wykonalnych lub najbardziej odpowiednich na szczeblu krajowym działań łagodzących. Proces ten może również stanowić ważny wkład w rozwój krajowych strategii lub polityk w zakresie zmian klimatu. W artykule, zastosowano metodę Delphi do priorytetyzacji kryteriów dotyczących potencjalnej technologii łagodzenia zmian klimatycznych w sektorze metalurgicznym w Wietnamie. Proces konsultacji został przeprowadzony z 10 ekspertami w zaledwie dwóch cyklach, aby osiągnąć wartość Kendalla (W) powyżej 0,5. Następnie 11 z 21 kryteriów zostało wybranych do analizy decyzji wielokryterialnej (MCDA) w ustalaniu priorytetów opcji łagodzenia w produkcji żelaza i stali, ołowiu, cynku, cyny i aluminium. Opcje łagodzenia z najwyższymi wynikami zostaną zaproponowane jako cel łagodzenia dla sektora metalurgicznego, który mógłby stanowić wkład dla NDC sektora przemysłowego. Wybrane kryteria obejmują 01 wskaźnik redukcji emisji (GPT1), 01 wskaźnik wpływu na środowisko (MT1), 01 wskaźniki wpływu społecznego (XH3), 02 wskaźniki skutków gospodarczych (KT1, KT2), 02 wskaźniki wpływu na zrównoważony rozwój (PTBV1 , PTBV2) i 04 wskaźników w MRV (MRV1, MRV2, MRV3, MRV4)
Dry reforming of methane over calcium-deficient hydroxyapatite supported cobalt and nickel catalysts
National audienceCalcium-deficient hydroxyapatite (HAP) non-porous supports were synthesized from Ca(NO3)2 and NH4H2PO4 (conventional synthesis route, HAP_N support) and from CaCO3 and H3PO4 (new synthesis route, HAP_C support) by wet chemical precipitation method. Monometallic and bimetallic supported catalysts were prepared by incipient wetness impregnation using Co(NO3)2 and Ni(NO3)2 salts. The size of Co- and Ni-based particles varied from some nm to dozens nm. Dry reforming of methane (DRM) tests at 700 °C, and 1.6 bar shows that HAP-supported cobalt catalysts were systematically more active than HAP-supported nickel catalysts, which is a new finding in DRM. Increasing the molar ratio of Ca/P from 1.43 (HAP_N) to 1.60 (HAP_C) support led to a slight decrease of the catalytic activity but an improvement of the catalytic stability. Thus, HAP_C support synthesized from CaCO3 and H3PO4 is a good candidate for designing an efficient catalyst for the DRM reaction
Discovered changes in rice occupation with satellite images based on random forest approach
International audienceAlthough agricultural production contributed a significant share of Vietnam's total production, the advancement and proficiency of remote sensing are still narrowly applied in this sector. Recent years, by the open access to satellite products of sufficient characteristics, the agriculture with satellite images supporting is being boosted. This paper focuses on identifying land use and its long-term changes in the selected regions of the Mekong Delta
Cellobiose dehydrogenase from the agaricomycete Coprinellus aureogranulatus and its application for the synergistic conversion of rice straw
From the biotechnological viewpoint, the enzymatic disintegration of plant lignocellulosic biomass is a promising goal since it would deliver fermentable sugars for the chemical sector. Cellobiose dehydrogenase (CDH) is a vital component of the extracellular lignocellulose-degrading enzyme system of fungi and has a great potential to improve catalyst efficiency for biomass processing. In the present study, a CDH from a newly isolated strain of the agaricomycete Coprinellus aureogranulatus (CauCDH) was successfully purified with a specific activity of 28.9 U mg(-1). This pure enzyme (MW = 109 kDa, pI = 5.4) displayed the high oxidative activity towards beta-1-4-linked oligosaccharides. Not least, CauCDH was used for the enzymatic degradation of rice straw without chemical pretreatment. As main metabolites, glucose (up to 165.18 +/- 3.19 mg g(-1)), xylose (64.21 +/- 1.22 mg g(-1)), and gluconic acid (5.17 +/- 0.13 mg g(-1)) could be identified during the synergistic conversion of this raw material with the fungal hydrolases (e.g., esterase, cellulase, and xylanase) and further optimization by using an RSM statistical approach
Usefulness of Hospital Admission Chest X-ray Score for Predicting Mortality and ICU Admission in COVID-19 Patients
We aimed to investigate the performance of a chest X-ray (CXR) scoring scale of lung injury in prediction of death and ICU admission among patients with COVID-19 during the 2021 peak pandemic in HCM City, Vietnam. CXR and clinical data were collected from Vinmec Central Park-hospitalized patients from July to September 2021. Three radiologists independently assessed the day-one CXR score consisting of both severity and extent of lung lesions (maximum score = 24). Among 219 included patients, 28 died and 34 were admitted to the ICU. There was a high consensus for CXR scoring among radiologists (κ = 0.90; CI95%: 0.89–0.92). CXR score was the strongest predictor of mortality (tdAUC 0.85 CI95% 0.69–1) within the first 3 weeks after admission. A multivariate model confirmed a significant effect of an increased CXR score on mortality risk (HR = 1.33, CI95%: 1.10 to 1.62). At a threshold of 16 points, the CXR score allowed for predicting in-hospital mortality and ICU admission with good sensitivity (0.82 (CI95%: 0.78 to 0.87) and 0.86 (CI95%: 0.81 to 0.90)) and specificity (0.89 (CI95%: 0.88 to 0.90) and 0.87 (CI95%: 0.86 to 0.89)), respectively, and can be used to identify high-risk patients in needy countries such as Vietnam
Quality of Life in Psoriasis Vietnamese Patients Treated with Metformin in Combination with Methotrexate
A cross-sectional study was performed on 48 psoriasis Vietnamese patients treated with metformin as an add-on for methotrexate and 48 psoriasis patients treated methotrexate alone. The mean PASI scores were 5.25 ± 5.72. Total QOL scores had a slight difference between patients treated metformin combined with methotrexate and methotrexate alone (62.32 ± 18.1 vs 60.91 ± 19.63). Combined therapy with metformin and methotrexate contributes to significantly improve the quality of life for patients with psoriasis