EVALUATION OF ANTIOXIDANT AND ANTI-AGING EFFICACIES OF COFFEA ROBUSTA EXTRACT ON HUMAN FIBROBLAST

The extract of Coffea robusta was evaluated via the antioxidant and anti-aging efficacies on human dermal fibroblast. Coffea robusta green beans harvested in Buon Ma Thuot - Vietnam were roasted and extracted by hot water. The anti-oxidant activity of the extract was measured by the DHHP assay. Additionally, the extract was dosed to fibroblast and proteome analysis using 2-D was conducted to observe the changes of proteins involving in aging process. The results show that the extract is a strong anti-oxidant factor with low IC50 value for DPPH scavenging (33.2 mg/L), and significant up-regulation of 5 natural antioxidant enzymes (GPX2, GCLM, PRDX4, GSTA1 and NQO1), as well as down-regulation of 2 supporting-free-radicals proteins (NF-kB1 and TNF-alpha) of human fibroblast.  Furthermore, the extract is a potential anti-aging factor with the down-regulation of 4 proteins related to the degradation of elastin and dermal extracellular matrix (CELA2B, CELA3A, CELA3B and MMP3)

DERIVATION VIABILITY OF RESISTANT STARCH FROM SOME COMMON FRUIT SEEDS IN VIET NAM FOR INDUSTRIAL PRODUCTION

The study aimed to compare the ability of extracting resistant starch (RS) from three common fruit seeds in Vietnam, namely avocado, jackfruit and mango seed. Avocado (Persea Americana) seeds, jackfruit (Artocarpus heterophyllus) seeds and mango (Mangifera indica L.) seeds were collected from local markets in Ho Chi Minh City, processed and extracted of starch. Three starch granules were then analyzed for RS content according to AOAC Standard 2002.02. Simultaneously, the effects of temperature (100, 120 oC), time (10, 15, 20 minutes) and heating methods (drying, steaming) on RS content in three starch granules were also investigated to evaluate heat-stability of these RS. The content of RS (% dry matter) in avocado seeds, jackfruit seeds and mango seeds was 23.59 %, 27.06 % and 32.12 %, respectively. Heat-stability of avocado seed RS was the least, mean while heat-stability of mango seed RS and jackfruit seed RS were higher and similar. The RS content slightly decreases after 10 and 15 minutes of heating, but significantly decreases after 20 minutes of heating. Drying reduces the RS content of the materials more than steaming. The results suggest that jackfruit seed seems to be better than avocado and mango seeds in the content and heat-stability of RS. Further studies should be conducted to choose a potential seed type for building an RS extracting processing in industrial production

Robust Adaptive Cerebellar Model Articulation Controller for 1-DOF Nonlaminated Active Magnetic Bearings

This paper presents a robust adaptive cerebellar model articulation controller (RACMAC) for 1-DOF nonlaminated active magnetic bearings (AMBs) to achieve desired positions for the rotor using a robust sliding mode control based. The dynamic model of 1-DOF nonlaminated AMB is introduced in fractional order equations. However, it is challenging to design a controller based on the model\u27s parameters due to undefined components and external disturbances such as eddy current losses in the actuator, external disturbance, variant parameters of the model while operating. In order to tackle the problem, RACMAC, which has a cerebellar model to estimate nonlinear disturbances, is investigated to resolve this problem. Based on this estimation, a robust adaptive controller that approximates the ideal and compensation controllers is calculated. The online parameters of the neural network are adjusted using Lyapunov\u27s stability theory to ensure the stability of system. Simulation results are presented to demonstrate the effectiveness of the proposed controller.The simulation results indicate that the CMAC multiple nonlinear multiple estimators are close to the actual nonlinear disturbance value, and the effectiveness of the proposed RACMAC method compared with the FOPID and SMC controllers has been studied previously

Application of multispectral UAV to estimate mangrove biomass in Vietnam: A case study in Dong Rui commune, Quang Ninh Province

Mangroves play an important role in coastal estuarine areas with different ecological functions, such as reducing the impact of waves and currents, accumulating biomass and sequestering carbon. However, estimation of terrestrial biomass in mangrove areas, especially in Vietnam, has not been fully studied. The application of unmanned aerial vehicles (UAV), mounted with multispectral cameras combined with field verification is an effective method for estimating terrestrial biomass for mangroves, as it reduces field survey time and allows for greater spatial range research. In this study, ground biomass was estimated for the mangrove area in the Dong Rui commune, based on multispectral image data obtained from UAV and survey results in 16 standard cells measuring actual biomass according to four regression models: Log-Log, Log-Lin, Lin-Log and Lin-Lin. The results of comparing the data from these four models show that the log-log model has the highest accuracy with a high correlation coefficient (R2 = 0.831). Based on the results of the analysis and selection of ground-based biomass estimation models, a biomass map was established for the UAV flying area in the Dong Rui mangrove forest with biomass values ranging from 20 Mg/ha to 150 Mg/ha. In summary, we present a biomass estimation method through four basic linear regression models for mangrove areas, based on multispectral image data obtained from ultrahigh-resolution UAV. The resulting research results can serve as a basis for managers to calculate and synchronise the payment of carbon services, thus contributing to effectively promoting the livelihoods of local people

Ownership, technology gap and technical efficiency of small and medium manufacturing firms in Vietnam: A stochastic meta frontier approach

The ownership - efficiency relationship in a firm has always been an important topic. In this paper, we focus on the state owned versus non-state-owned status of Vietnamese manufacturing firms, to shed light into the relationship between these two variables when using a more state-of-the-art method as a stochastic meta-frontier method. Applying the method for two periods: one during the global economic crisis and the other after the end of the crisis, the study determines that in both periods, there was a strong evidence that non-state-owned firms performed much better than state owned counterpart. We also found that the difference became even larger during the harsh time and sub-industries with non-state-owned firms could outperform the state-owned firms, significantly

Using Solvent Vapor Annealing for the Enhancement of the Stability and Efficiency of Monolithic Hole-conductor-free Perovskite Solar Cells

In the last few years, perovskite solar cells have attracted enormous interest in the photovoltaic community due to their low cost of materials, tunable band gap, excellent photovoltaic properties and easy process ability at low temperature. In this work, we fabricated hole-conductor-free carbon-based perovskite solar cells with the monolithic structure: glass/FTO/bl-TiO$_{2}$/(mp-TiO$_{2}$/mp-ZrO$_{2}$/mp-carbon) perovskite. The mixed 2D/3D perovskite precursor solution composed of PbI$_{2}$, methylammonium iodide (MAI), and 5-ammoniumvaleric acid iodide (5-AVAI) was drop-casted through triple mesoporous TiO$_{2}$/ZrO$_{2}$/carbon electrode films. We found that the isopropyl alcohol (IPA) solvent vapor annealing strongly influenced on the growth of mixed 2D/3D perovskite on triple mesoscopic layers. It resulted in the better pore filling, better crystalline quality of perovskite layer, thus the improved stability and efficiency of perovskite solar cell was attributed to lower defect concentration and reduced recombination

Development and Characterization of Soy Lecithin Liposome as Potential Drug Carrier Systems for Codelivery of Letrozole and Paclitaxel

In the present work, a dual-drug-loaded soy lecithin liposomal system was developed by coencapsulation of Letrozole (LET) with Paclitaxel (PTX) to improve the efficacy in breast cancer therapy. Liposomes were synthesized by the thin film layer hydration. To sufficiently evaluate the characteristics of these liposomes, the particle size, zeta potential, morphology, drug encapsulation, in vitro drug release, and cytotoxicity were ascertained. Results showed promisingly anticancer potentials, as the following parameters indicated: nanosize diameter (around 193 nm) and negative surface charge. Data collected from the coloaded drug liposomes showed suitable encapsulation efficiency (50.56% for PTX and 31.13% for LET). Controlled and sustained releases were achieved up to 72 h for both the loaded drugs following the diffusion mechanism. In addition, the in vitro cytotoxicity study on the human breast cancer cell line (MCF-7) given the dual-drug-loaded liposome showed greater inhibition of cell growth than the single drug. Consequently, LET and PTX coloaded liposomes made from soy lecithin are expected to be an ingenious drug-delivery system for combination chemotherapy

Proposed Techniques to Supplement the Loss in Nutrient Cycling for Replanted Coffee Plantations in Vietnam

Nutrient cycling of the coffee ecosystem is often characterized by nutrient losses during the harvest, tree’s growth, leaching and erosion. The “Coffee Rejuvenation Strategies in Vietnam” has risked not being complete on schedule, with the low survival rate of seedlings on replanted soil, due to the nutrient loss and imbalance supplements after a long-term of monoculture and intensive cultivation. In this study, measures, including biochemical and organic treatments were applied to replanted coffee farm, in order to supplement the loss of nutrient cycling. Survival rate, growth indicators, and soil properties from the controls and treatments, were monitored and compared during the experimental periods. The results suggested the optimal tillage model as follow: Remove old coffee trees with their stumps and roots; liming 1.5 tons/ha; dry tillage soil for the first 6 months; Intercrop Mexican marigold (Tagetes erecta) with new coffee plants for the next 6 months; From the second year, apply 5 kg of microbial organic fertilizer /hole/year; bury 30 kg of green manure/hole/2–3 years; apply NPK fertilizers according to the governmental recommended procedure. This would be a proposed integrating tillage method to supplement the lost nutrients and restore the fertility of replanted coffee soil in Vietnam

Retrovirus Drugs-Loaded PEGylated PAMAM for Prolonging Drug Release and Enhancing Efficiency in HIV Treatment

Polyamidoamine dendrimer (PAMAM) with its unique characteristics emerges as a potential drug delivery system which can prolong releasing time, reduce the side effects but still retaining treatment efficiency. In this study, methoxy polyethylene glycol modified PAMAM generation 3.0 (G3.0@mPEG) is prepared and characterized via 1H-NMR, FT-IR, and TEM. Subsequently, two antiretroviral agents (ARV) including lamivudine (3TC) and zidovudine (AZT) are individually encapsulated into G3.0@mPEG. The drug-loading efficiency, drug release profile, cytotoxicity and anti-HIV activity are then evaluated. The results illustrate that G3.0@mPEG particles are spherical with a size of 34.5 ± 0.2 nm and a drug loading content of about 9%. Both G3.0@mPEG and [email protected]@mPEG show no cytotoxicity on BJ cells, and G3.0@mPEG loading 3TC and AZT performs sustained drug release behavior which is best fitted with the Korsmeyer–Peppas model. Finally, the anti-HIV activity of ARV via Enzymatic Assay of Pepsin is retained after being loaded into the G3.0@mPEG, in which about 36% of pepsin activity was inhibited by AZT at the concentration of 0.226 mM. Overall, PAMAM G3.0@mPEG is a promising nanocarrier system for loading ARV in HIV treatment and prevention