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

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

Kangaroo Mother Care in Vietnam: A National Survey of a Middle-Income Country

Background: Kangaroo mother care (KMC) is a low-cost intervention that is indicated to be a highly effective practice for which adoption and implementation are lacking. We investigated the current provision of KMC in Vietnam and explored differences among levels of healthcare facility. Methods: A survey form was sent to 187 hospitals in Vietnam, representing the three levels (central, provincial and district) of public hospital-based maternity services. Results: Overall response rate was 74% (138/187 hospitals). Routine KMC implementation was estimated in 49% of the hospitals. Where KMC was implemented or was being introduced, half of the hospitals had a written protocol and a KMC-dedicated room, and held educational courses on KMC. KMC was mainly performed by the mother. Skin-to-skin contact was mostly performed for <12 h/day (55%), exclusive breastfeeding at discharge was very frequent (89%) and early discharge was considered in half of the hospitals (54%), while follow-up was not performed in 29% of the hospitals. Participants considered follow-up after discharge as the main barrier to KMC implementation, and indicated education (of both parents and health caregivers) and environment upgrades (KMC-dedicated room and equipment) as the most important facilitators. Conclusions: Our survey estimated a limited implementation of KMC in Vietnamese maternity hospitals, with marked variations across the different levels of maternity services. Areas of improvements include increasing the duration of skin-to-skin contact, arranging dedicated spaces for KMC, involving the relatives (especially at district level), extending the availability of a written protocol, improving the eligibility process, and implementing early discharge and follow-up monitoring

Comparative Study of the Silver Nanoparticle Synthesis Ability and Antibacterial Activity of the Piper Betle L. and Piper Sarmentosum Roxb. Extracts

Piper betle (P. betle) and Piper sarmentosum (P. sarmentosum) are the two members of the Piper genus, have been reported to be rich in phytochemicals and essential oils, which showed strong reducing power, antibacterial, and antifungal activities. P. betle recently has been studied and applied in several commercial products in the antimicrobial respect, meanwhile its relatives, P. sarmentosum has been lesser-known in this field. In this study, the two Piper species—P. betle and P. sarmentosum were studied to compare their ability in silver nanoparticle synthesis and efficacy in antibacterial activity. P. betle and P. sarmentosum were extracted by distilled water at different temperatures and times. Subsequently, their total reducing capacity was determined by DPPH scavenging and Folin-Ciocalteu assays to choose the appropriate extraction conditions. The silver nanoparticle solutions prepared by the extracts of P. betle (Pb.ext) and P. sarmentosum (Ps.ext) were characterized by Dynamic light scattering (DLS), Zeta potential, UV-vis, and Fourier-transform infrared (FTIR) measurements. Finally, the antibacterial activity of the synthesized silver nanoparticle solutions was tested against Escherichia coli using the agar diffusion well–variant method. The Pb.ext showed stronger reducing power with higher total polyphenol content (~125 mg GAE/mL extract) and better DPPH activity (IC50~1.45%). Both the green synthesized silver nanoparticle solutions (Pb.AgNP and Ps.AgNP) performed significantly stronger antibacterial activity on Escherichia coli compared to their initial extracts. Antibacterial tests revealed that Ps.AgNP showed remarkably better growth inhibition activity as compared to Pb.AgNP. This study would contribute useful and important information to the development of antibacterial products based on green synthesized silver nanoparticles fabricated by the extracts of P. betle and P. sarmentosum

Silver Nanoparticles Ecofriendly Synthesized by Achyranthes aspera and Scoparia dulcis Leaf Broth as an Effective Fungicide

This study describes an inexpensive, simple and green method to form silver nanoparticles from different leaf extracts of Achyranthes aspera and Scoparia dulcis plants. The silver nitrate is reduced by Achyranthes aspera and Scoparia dulcis leaf extracts respectively to generate two silver nanoparticle types symbolized as AA.AgNPs and SD.AgNPs. The optical absorption, size and morphology of silver nanoparticles are significantly impacted by extract types. The ultraviolet visible spectrum of AA.AgNPs shows a 433-nm peak being more broadened than that of SD.AgNPs. The Fourier infrared transform spectra of two of these silver nanoparticles revealed that their surface is modified by organic constituents from extracts, and thus they are stabilized in solution without any additional reaction. Images from transmission electron microscopy and scanning electron microscope indicate that AA.AgNPs are in clusters with the size of 8&ndash;52 nm almost possessing oval shape, while SD.AgNPs are smaller size of 5-45 nm separated well in diversified shapes (spherical, triangle, quadrilateral and hexagonal). Moreover, both AA.AgNPs and SD.AgNPs exhibit the highly antifungal effect against Aspergillus niger, Aspergillus flavus and the most strong impact on Fusarium oxysporum. For these obtained results, two new silver nanoparticles are promising fungicides for various applications of medical and agricultural fields

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 &plusmn; 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&ndash;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

Modified Carboxyl-Terminated PAMAM Dendrimers as Great Cytocompatible Nano-Based Drug Delivery System

Polyamidoamine (PAMAM) dendrimers are extensively researched as potential drug delivery system thanks to their desirable features such as controlled and stable structures, and ease of functionalization onto their surface active groups. However, there have been concerns about the toxicity of full generation dendrimers and risks of premature clearance from circulation, along with other physical drawbacks presented in previous formulations, including large particle sizes and low drug loading efficiency. In our study, carboxyl-terminated PAMAM dendrimer G3.5 was grafted with poly (ethylene glycol) methyl ether (mPEG) to be employed as a nano-based drug delivery system with great cytocompatibility for the delivery of carboplatin (CPT), a widely prescribed anticancer drug with strong side effects so that the drug will be effectively entrapped and not exhibit uncontrolled outflow from the open structure of unmodified PAMAM G3.5. The particles formed were spherical in shape and had the optimal size range (around 36 nm) that accommodates high drug entrapment efficiency. Surface charge was also determined to be almost neutral and the system was cytocompatible. In vitro release patterns over 24 h showed a prolonged CPT release compared to free drug, which correlated to the cytotoxicity assay on malignant cell lines showing the lack of anticancer effect of CPT/mPEG-G3.5 compared with CPT

Analysis of the 56-kDa type specific antigen gene of Orientia tsutsugamushi from northern Vietnam.

Scrub typhus has been documented since 1932 in Vietnam, however, the disease burden of scrub typhus remains poorly understood in the country. We conducted this study to describe the phylogenetic analysis of the 56-kDa type-specific antigen (TSA) gene of Orientia tsutsugamushi associated with PCR positive cases of scrub typhus. Of 116 positive samples, 65 type-specific antigen gene sequences were obtained and classified into 3 genogroups: Karp, Kato and Gilliam. The Karp genogroup was the most frequently detected phylogenetic cluster in the study with 30 samples (46%), followed by Kato and Gilliam with 20 (31%) and 15 (23%), respectively. All sequences showed 94-100% nucleotide similarity to reference sequences collected in the central part of Vietnam in 2017. Patients infected with Karp genogroup were more likely to have significant thrombocytopenia than the other genogroups. These results suggest that any scrub typhus vaccine considered for use in Vietnam should provide protection against each of these 3 genogroups