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This study aims to determine the dynamics of phosphate removal process in domestic wastewater through wastewater treatment mechanism of constructed wetland with Joyweed (Alternanthera sp.). The experiment was conducted in batches with a retention time of 12 days, the treatments were designed to evaluate the effect of depth of the water with and without Alternanthera sp. on the ability to remove phosphate in wastewater. After 12 days of operation, all experiments reduced phosphate concentration in the effluent. The highest phosphate removal efficiency is at day 9 (about 69\%). Two kinetic equations of first-order and second-order are used to determine the trend of PO43- removal process in the system. The second-order kinetic equation is more suitable for treating PO43- in domestic wastewater by surface flow constructed wetland system. The results of this study show the potential of domestic wastewater treatment of Alternanthera sp. in the constructed wetland.

A single source precursor containing both Hf and Si was employed with oxygen plasma to deposit hafnium silicate thin films using plasma-enhanced atomic layer deposition (PEALD). The self-limiting growth features were observed between 210 °C-280 °C with a constant growth rate of 1.45 A/cycle. The deposited hafnium silicate thin films were amorphous with a composition of Hf0.33Si0.66O2. The mechanism for the surface adsorption of the precursor was investigated by density functional theory (DFT) calculations, which show adsorption reactions of both Hf and Si atoms are viable. Bottom-gated InGaZnO channel thin-film transistors (TFTs) were fabricated to evaluate the electrical characteristics of PEALD hafnium silicate thin films as gate dielectrics. Compared to the conventional SiO2 gate dielectric, TFTs with PEALD hafnium silicate gate dielectric exhibited an improved switching performance, where the turn-on voltage, threshold voltage, saturation mobility, subthreshold slope, and on-off current ratio were −0.456 V, 3.202 V, 15.83 cm2/V·sec, 0.196, and 1.34 × 109, respectively.

Sn(II) dimethylamino-2-methyl-2-propoxy (Sn(dmamp)2) with water and hydrogen sulfide as oxygen and sulfur sources was employed in atomic layer deposition (ALD) of composite tin oxysulfide thin films abbreviated by Sn(O,S) made up of tin oxide (SnO) and tin sulfide (SnS) thin films employed as end members in addition to tin oxide and tin sulfide. Both SnO and SnS thin films demonstrate temperature-independent growth rates per cycle of 0.042nm/cycle and 0.056 nm/cycle, at 100–160 °C and 100–130 °C, respectively. Comparison of two tin-based thin film materials demonstrates dissimilar deposition features depending on the reactivity of the Sn precursors, i.e., Sn(dmamp)2 with anion sources provided by the water and hydrogen sulfide reactants. Density functional theory (DFT) calculations show that surface exchange reaction between *OH and *SH groups determine preference of S incorporation in the Sn(O,S) thin films. The material properties of ALD-based SnO, SnS, and Sn(O,S) thin films were characterized in terms of composition, stoichiometry, crystallinity, band structure, and electronic properties, demonstrating the potential of ALD SnO and SnS as p-type channel materials for transparent electronics.

SnO2 nanowires (NWs) are used in gas sensors, but their response to highly toxic gas H2S is low. Thus, their performance toward the effective detection of low-level H2S in air should be improved for environmental-pollution control and monitoring. Herein, Ag2O nanoparticle decorated SnO2 NWs were prepared by a simple on-chip growth and subsequent dip-coating method. The amount of decorated Ag2O nanoparticles on the surface of SnO2 NWs was modified by changing the concentration of AgNO3 solution and/or dipping times. Gas-sensing measurements were conducted at various working temperatures (200–400 °C) toward different H2S concentrations ranging within 0.1–1 ppm. The selectivity of Ag2O-decorated SnO2 NW sensors for ammonia and hydrogen gases was tested. Results confirmed that the Ag2O-decorated SnO2 NW sensors had excellent response, selectivity, and reproducibility. The gas-sensing mechanism was interpreted under the light of energy-band bending by sulfurization, which converted the p–n junction into n–n, thereby significantly enhancing the sensing performance.

The synthesis of advanced functional nanomaterials for electrochemical applications, such as water splitting, dye-sensitized solar cells (DSCs), and supercapacitor has been the topic of interest in recent years. This work presents the synthesis of ruthenium (Ru)/reduced graphene oxide (RGO) nanocomposite by using a facile and scalable liquid plasma-assisted method and its application as an electrode material in electrochemical applications for supercapacitor and triiodide reduction at counter electrodes (CEs) of DSCs. As the results, Ru nanoparticles have a size in the range of 4–10 nm that were homogenously distributed on the surface of the RGO layer. Electrochemical measurements demonstrated that the synthesized material is suitable for supercapacitor applications, whereas the capacitance is approximately 136.7 F·g−1 at a scan rate of 20 mV·s−1. The developed materials are applied in CEs of DSCs. We found that the efficiency of 6.78% for DSCs with CE fabricated by Ru/RGO which is higher than that of 6.20% for a cell assembled with Pt electrode.

The evolution of influenza viruses is fundamentally shaped by within-host processes. However, the within-host evolutionary dynamics of influenza viruses remain incompletely understood, in part because most studies have focused on within-host virus diversity of infections in otherwise healthy adults based on single timepoint data. Here, we analysed the within-host evolution of 82 longitudinally-sampled individuals, mostly young children, infected with A/H3N2 or A/H1N1pdm09 viruses between 2007 and 2009. For A/H1N1pdm09 infections during the 2009 pandemic, nonsynonymous changes were common early in infection but decreased or remained constant throughout infection. For A/H3N2 viruses, early infection was dominated by purifying selection. However, as infections progressed, nonsynonymous variants increased in frequencies even though within-host virus titres decreased, leading to the maintenance of virus diversity via mutation-selection balance. Our findings suggest that this maintenance of genetic diversity in these children combined with their longer duration of infection may provide important opportunities for within-host virus evolution.

CoOx/magenium silicate catalysts are obtained though precipitation and calcination method. The prepared solids were analyzed by XRD, BET, EDS... Cobalt(II) ions supported-magnesium silicate catalysts expressed as effective catalysts for selective oxidation of benzyl alcohol using tert-butyl hydroperoxide as an oxidizing agent. The experimental results showed very high selectivity to the benzaldehyde product at benzyl alcohol conversion of 18-25%.

Seasonal human influenza viruses continually change antigenically to escape from neutralizing antibodies. It remains unclear how genetic variation in the intrahost virus population and selection at the level of individual hosts translates to the fast-paced evolution observed at the global level because emerging intrahost antigenic variants are rarely detected. We tracked intrahost variants in the hemagglutinin and neuraminidase surface proteins using longitudinally collected samples from 52 patients infected by A/H3N2 influenza virus, mostly young children, who received oseltamivir treatment. We identified emerging putative antigenic variants and oseltamivir-resistant variants, most of which remained detectable in samples collected at subsequent days, and identified variants that emerged intrahost immediately prior to increases in global rates. In contrast to most putative antigenic variants, oseltamivir-resistant variants rapidly increased to high frequencies in the virus population. Importantly, the majority of putative antigenic variants and oseltamivir-resistant variants were first detectable four or more days after onset of symptoms or start of treatment, respectively. Our observations demonstrate that de novo variants emerge, and may be positively selected, during the course of infection. Additionally, based on the 4–7 days post-treatment delay in emergence of oseltamivir-resistant variants in six out of the eight individuals with such variants, we find that limiting sample collection for routine surveillance and diagnostic testing to early timepoints after onset of symptoms can potentially preclude detection of emerging, positively selected variants.

Photolithography of graphene using an organic photoresist (PR), whereby the graphene film is patterned into a desired geometry, is required for the fabrication of graphene-based sensors and electronic devices. However, because the PR hardens during the O2 plasma etching process, its complete removal is difficult. Herein, we present a new route to obtain residue-free patterned graphene by introducing a buffer layer between graphene and the PR. The modified photolithography process allows complete removal of the hardened PR and eliminates poly(methyl methacrylate) residues on the graphene surface during the wet transfer process. Density functional theory calculations revealed that the binding strength between the buffer layer and graphene is weaker than that between the PR and graphene. This led to a clean graphene surface without PR and other organic residues. The graphene films patterned using the modified photolithography process are of superior quality; they have the lowest surface roughness, natural hydrophobicity, and the highest transmittance of 94.1% at the wavelength of 550 nm. In addition, graphene-based field-effect transistors fabricated using the new process present the electron mobility of 800 cm2 V−1 s−1, and their charge neutrality point is located near zero bias, indicating that the unintended doping effect was effectively eliminated. This work demonstrates a new process that is compatible with silicon-based nanosystems and can be readily applied in the mass production of residue-free graphene electronics.

Microalgae cultivation in wastewater for many purposes has been investigated recently decade ago. In this study, Chlorella vulgaris was chosen to culture for examination of its influences on microorganisms of seafood wastewater in particular aerobic bacteria, Coliform and E. coli. The microalgae cultivation was realized in Erlenmeyer flasks containing seafood wastewater medium. Another was also grown in original medium called Sueoka medium for control. All experiments were set up until almost all Chlorella vulgaris decanted or flocculated in the bottom of flasks. The changes of bacteria counts including aerobic bacteria, Coliform and E. coli were measured to evaluate the impact of cultivation of Chlorella vulgaris on them in this sewage. Otherwise, the growth of microalgae has been also recorded for evaluating the effect of a new medium on metabolism of Chlorella vulgaris. The results showed that the bacteria counts were significantly reduced after day 3 of microalgae culture. These results have been calculated the efficiency of aerobic bacteria, Coliform and E. coli elimination out of wastewater medium represented approximately 70%, 81% and 90% respectively. These eliminations provided evidences of difficult metabolism of bacteria under the presence of microalgae as like as Chlorella vulgaris. In other words, the symbiosis of microalgae and bacteria in sewage could prevent the raising of bacteria counts.

Background: The purpose of the study was to prepare acetylated wheat starches which have amylase hydrolysis resistant capacity to use as functional food supporting for diabetes treatment. Method: Acetate wheat starches were prepared by acetylation reaction of native wheat starch with different mole ratios of acetic anhydride. These starches were determined for the physicochemical properties by 1H-NMR, SEM, X-ray, DSC, solubility and swelling capacity, the resistant capacity by amylase hydrolysis in-vitro. Results: Acetate wheat starches were prepared successfully with the increase in acetyl content and degree of substitution corresponding with the increase of anhydride acetic, which resulted in the change of physicochemical properties of the wheat starches, including constitution, solubility, swelling capacity and contributed to the increase in resistant starch content in the acetate wheat starches. The AC150-9 containing 2.42% acetyl with degree of substitution 0,094 and resistant starch 32,11% is acceptable by FDA guideline about food safety. Conclusion: Acetate wheat starches contain low rate of digestive starch, while containing a higher proportion of resistant starch than natural wheat starch, possessing a high resistance to amylase activities. Thus, it is hope that this kind of starch to control the rapid increase of postprandual blood glucose response for diabetes treatments effectively. Key words: Acetate wheat starch, substitution, DS, RS, amylase

This study investigates the effects of rice straw and potential nitrogen fixing Bacillus subtilis (Bacillus sp.) isolated from seafood wastewater on carbohydrate- and nitrogen mineralization from a long-term rice paddy soil by four weeks anaerobic incubation. Soil collected at the depth of 0–15 cm from a long-term rice paddy cultivation, and set up as following: (1) Control (10 g air dry soil), (2) Rice straw (control ＋ 0.2% rice straw w/v), (3) Bacillus sp., and (4) Combine (rice straw 0.2% w/v and Bacillus sp.) was subjected to an incubator in dark at room temperature/ submerge condition for 4 weeks anaerobic incubation. As showed in results, content of decomposed carbohydrate ranged from 83–447 mg kg −1 soil. Content of extracted carbohydrate was not affected by rice straw application, but significant decreased with bacillus or rice straw-bacillus combine inoculation (2.0–2.2 times decreased) compared to Control treatment, which is closely to the initial soil extraction carbohydrate. In contrary, mineralization nitrogen increased 120% in Bacillus sp. inoculation compared to Control treatment, but Rice straw and Combine treatments resulted in immobilization more than nitrogen mineralization. Inoculation of Bacillus subtilis is recommended as a good environment friendly method to enhance the soil fertility and reduce nitrogen immobilization. Further research within rice plant is therefore needed to consolidate the preliminary results.

Panax bipinnatifidus Seem. is a precious medicinal plant belonging to the Araliaceae family. This study qualitatively analyzed saponins of the stem, leaf and rhizome of P. bipinnatifidus by HPLC. Subsequently, by using chromatographic techniques, a major saponin from the leaf of P.bipinnatifidius Seem. was isolated. On the basis of NMR and MS spectroscopic data as well as comparison with those reported in the literature, the isolated saponin’s structure was identified as stipuleanoside R2. To the best our knowledge, this is the first report of saponin from the aerial part of P. bipinnatifidius Seem. Keywords Panax bipinnatifidus, Araliaceae, Stipuleanosid R2, HPLC.. [1] Nguyễn Văn Tập, Các loài thuộc chi Panax L. ở Việt Nam, Tạp chí Dược liệu. 10(3) (2005) 71-76. [2] Nguyễn Văn Tập, Phạm Thanh Huyền, Kết quả nghiên cứu về phân bố, sinh thái sâm vũ diệp và Tam thất hoang ở Việt Nam, Tạp chí Dược liệu. 11(5) (2006) 177-180. [3] Nguyen Huu Tung, Tran Hong Quang, Nguyen Thị Thanh Ngan, Chau Van Minh, Bui Kim Anh, Pham Quoc Long, Nguyen Manh Cuong, Young Ho Kim, Oleanolic triterpenesaponins from the roots of Panax bipinnatifidus, Chem Pharm Bull (Tokyo). 59(11) (2011) 1417-1420. [4] Đỗ Văn Hào, Nguyễn Thị Huệ, Nguyễn Thị Thu Thủy, Đặng Thị Ngần, Đào Thị Hồng Bích, Nguyễn Thị Hoàng Anh, Dương Thị Ly Hương, Nguyễn Hữu Tùng, Thành phần hóa học của phân đoạn ethyl acetat từ rễ cây sâm vũ diệp (Panax bipinnatifidus Seem.) thu hái ở Sa Pa, Lào Cai, Tạp chí Khoa học ĐHQGHN - Khoa học Y Dược. 33(2) (2017) 50-55. [5] Nguyễn Thị Thu Thủy, Nguyễn Thị Huệ, Đặng Thị Thùy, Nguyễn Thị Hoàng Anh, Dương Thị Phượng, Phạm Thị Tuyết Nhung, Hà Vân Oanh, Dương Thị Ly Hương, Nguyễn Hữu Tùng, Thành phần saponin của thân rễ sâm vũ diệp thu hái ở Sa Pa, Lào Cai, Tạp chí Dược liệu. 23(2) (2018) 82-88.[6] Wen-zhi Yang, Ying Hu, Wan-ying Wu, Min Ye, De-an Guo, Saponins in the genus Panax L. (Araliaceae): A systematic review of their chemical diversity, Phytochemistry. 106 (2014) 7-14. [7] Shashi B. Mahato, Asish P. Kundu, 13C NMR spectra of pentacyclic triterpenoids - a complication and some salient features, Phytochemistry. 37 (1994) 1517-1575. [8] Pawan K. Agrawal, NMR spectroscopy in the structural elucidation of oligossacharides and glycosides, Phytochemistry. 31 (1992) 1307-1330. [9] Chun Liang, Yan Ding, Huu Tung Nguyen, Jeong-Ah Kim, Hye-Jin Boo, Hee-Kyoung Kang, Mahn Cuong Nguyen, Young Ho Kim, Oleanane –type triterpenoids from Panax stipuleannatus and their anticancer activities, Bioorg Med Chem Lett. 20 (2010) 7110-7115.

Copper(II) ions are inserted into brucite-like sheets in the Zn-Cu-Al ternary hydroxides via the precipitation route. The amount of octahedral Cu(II) sites in the Zn-Al(OH) interlayers depends on the copper loadings. The square-planar configuration (CuO) was observed in the high-copper content samples. The Cu-inserted zinc aluminum hydroxides have lamellar structure, modest surface area, and hexagonally uniform plate-like particles. All synthesized hydroxides were tested for the liquid-phase oxidation of styrene. The overall conversion of styrene obtained about 60–80 % and styrene oxide selectivity is about 70 %. The catalytic activity is correlated with the electronic configurations of copper(II) ions and reaction variables. The copper(II) ions in the brucite-like sheets proceeded through the oxidation of styrene following the metal-superpoxo pathway while the extra-lattice copper(II) ions underwent reaction with free radical route. The experimental results also indicated Cu-intercalated layered double hydroxide catalysts are more active than copper(II) oxide in the liquid-phase oxidation of styrene under the same conditions.

Indicone films consisting of indium and organic aromatic linker are grown by molecular layer deposition (MLD) using diethyl[1,1,1-trimethyl-N-(trimethylsilyl)-silanaminato]-indium (INCA-1) as the indium precursor and hydroquinone (HQ) as the organic precursor. A constant growth rate typical for MLD is exhibited at temperature between 100 and 250 °C. The structure and the properties of the deposited thin films are analyzed using various experimental and theoretical techniques such as Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculations. Indicone films show time-dependent change upon exposure to ambient air, which is explained by adsorption of H2O. Furthermore, transparent and conducting organic-inorganic hybrid thin films are grown by applying supercycles of atomic layer deposition (ALD) of indium oxide and MLD of indicone. Structural, optical and electrical properties of the hybrid thin films can be adjusted according to the supercycle ratio. Especially, the hybrid film with 99:1 cycle ratio of indium oxide:indicone shows minimal change of electrical resistivity even after repeated bending over 100,000 cycles. Currently developed indicone-based hybrid thin films may have applications for flexible transparent conducting material.

This study is aimed to evaluate the ability of magnesium oxide-coated carbonized rice hull (MCRH) material for ammonium removal in synthetic and real domestic wastewater. The MCRH material was prepared using waste rice hull from a household rice-processing factory and magnesium chloride salt via a simple mixing and annealing method. The material was then characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The effects of magnesium chloride modification and environmental condition such as initial ammonium concentration (20 – 100 mg/L), amount of adsorbent (0.8 –2.0 g/L), and adsorption time (0 –32 h) on the ammonium removal efficiency and adsorption capacity were investigated. Adsorption kinetic and isotherms were also studied for MCRH material. Results showed that magnesium oxide was successfully coated on carbonized rice hull with Mg/C molar ratio of 0.22. Ammonium adsorption isotherm fitted well to Langmuir model with maximum adsorption capacity of 65.36 mg/g. The adsorption was physical process and adsorption kinetic was best described by intra-particle diffusion model with the correlation coefficients ranged from 0.942 – 0.979. Ammonium removal feasibility of MCRH was proved through the treatment of real domestic wastewater containing 80.7±1.6 mg/L initial ammonia concentration with removal efficiency reached 86.8% and the effluent concentration met the allowable value (10 mg/L) as given by QCVN 14 : 2008/BTNMT (column B) - National technical regulation on domestic wastewater. Hence MCRH is potential as a cheap and abundant material in Vietnam and the material after adsorption accumulated ammonium would be the source of fertilizer for soil quality improvement.

A simple zero-velocity method to determine the particle magnetic susceptibility by measuring the magnetophoretic velocity was proposed. The principle is that the magnetophoretic velocity of a particle in a liquid medium must be zero when the magnetic susceptibilities of the medium and the particle are equal, or the gravity force and the magnetophoretic force are balanced. By changing the medium magnetic susceptibility and measuring the magnetophoretic velocity of a particle, the particle magnetic susceptibility was determined from the medium magnetic susceptibility under the zero-velocity condition. The feasibility of the method was demonstrated for polystyrene particles using a Dy(III) solution in the horizontal migration mode and different organic solvents in the vertical migration mode.

Silver nanoparticle (SNP)-containing ceramic filter (SNP-CF) has been widely investigated for water disinfection but the filters usually lose their antibacterial efficacy after short time because of silver leaching. In this study, the SNP-CF has been successfully prepared by an in-situ reduction method in which silver nitrate was first impregnated into activated carbon, which was then added into ceramic mixture for filter production. Silver nitrate in activated carbon got reduced to metallic silver by thermal treatment. Resulting filters were characterized by various techniques including saturated water method, nitrogen adsorption/desorption, scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The utilization of activated carbon as filler produced ceramic filter with high porosity (64%) compared to charcoal (56%) and sawdust (29%), particularly, the porosity of activated carbon ceramic filter was not affected by the addition of SNPs. The SNP-CF having mesopores with pore diameter from 2 to 6 nm and pore volume of 0.02 cm3/g. The SNPs uniformly distributed throughout ceramic structure helps the filter constantly release silver for a long period. Silver concentrations detected in filtrate were 0.04 ppm for SNP-CF prepared by in-situ reduction (0.03 wt% silver) and 0.736 ppm for SNP-coated ceramic filter (0.03 wt% silver). The filter showed a great antibacterial activity with 100% of E. coli and coliform eliminated via filtration for extended period (10 weeks). The success of this work has proposed a novel and facile method to prepare SNP-CF that can be applied for water disinfection.

Thin films of oxide, sulfide, and oxysulfide of zinc can be deposited with atomic layer deposition (ALD) using diethylzinc with H2O and H2S. While the atomic ratio between O and S in zinc oxysulfide can be arbitrarily tuned by varying the supercycles of oxide and sulfide ALD, it is known that the fraction of S incorporated in the film is higher than its ratio in the reactant pulses. To understand the mechanism controlling the composition of ALD zinc oxysulfide thin films, its surface chemical reactions are investigated using density functional theory calculations. It is observed that all half reactions of both oxide and sulfide ALD would be facile and spontaneous, while the reactions for deposition of sulfide are more favorable over those for oxide. Furthermore, an *OH group on the surface can be easily substituted into *SH by reaction with H2S, but the inverse reaction is less likely. As a result, excess S can be contained in the Zn(O,S) ALD thin films due to the exchange reactions between surface moieties. The authors suggest that the differences in the bond energies of O–H versus S–H moieties are the key governing factor for the composition of ALD zinc oxysulfide films.

The methanol extracts of the fruiting bodies of Ganoderma mastoporum collected in Vietnam was purified to afford eight compounds, including three triterpenoids and five steroids. The purified compounds were examined for their inhibitory effects against superoxide anion generation and elastase release. Among the tested compounds, ergosta-4,6,8(14),22-tetraen-3-one (3) exhibited the most significant inhibition towards superoxide anion generation and elastase release with IC50 values of 2.30 ± 0.38 and 1.94 ± 0.50 µg/mL, respectively.

Personal exposure to benzene of selected population groups, and impacts of traffic on commuters in Ho Chi Minh City were investigated. The study was carried out in June, July and November 2010. The preliminary data showed that on average, personal exposure to benzene for non-occupational people in Ho Chi Minh is ~18 μg/m(3) and most of the exposure is due to commuting. Benzene exposure during travelling by bus, taxi and motorcycle is, respectively, 22-30, 22-39 and 185-240 μg/m(3). Motorcycle-taxi drivers, petrol filling employees and street vendors suffer high daily exposures at 116, 52, 32 μg/m(3), respectively. Further measurements are needed for a better risk assessment and finding effective measures to reduce exposure.

This study focused on the comparison among the usage of immobilized porcine pancreas lipase (PPL) on different hydrotalcite carriers (uncalcined and calcined hydrotalcite – like compound Mg /Al) and free lipase as the catalysts to hydrolyze of roselle (Hibiscus sabdariffa L.) seed oil. The reaction conditions were investigated including the ratio of oil to buffer, ratio of enzyme to substrate, the temperature of the hydrolysis, pH. The calcined hydrotalcite showed a higher lipase immobilization yield and a better reusability than the uncalcined hydrotalcite (87.15% and 86.78%, respectively).

Limnophila aromatica is widely used in South East Asian countries to make spices in food and medicine in traditional medicine. The use value of vegetables is known because some of the lesser constituents in plants are called antioxidants. These active ingredients have not been fully researched and their pharmacological effects are underestimated. In this study, the drying temperature at 40 °C was showed that the antioxidant activity decreased the most. The drying temperature of 50 °C is suitable for convection drying method and drying temperature of 60 °C suitable for vacuum drying, as it retains the most antioxidant properties. Regarding the drying method, freeze drying proved to be effective when retaining high antioxidant capacity. Using The convection drying at 50 °C and the vacuum drying at 60 °C, the antioxidant activity of Limnophila aromatica was not different. Over 6 weeks of preservation, the dried product has deterioration in antioxidant properties.

A new home-made diffusive bag-type passive sampler called Lanwatsu was developed for benzene, toluene, ethylbenzene and xylene monitoring in roadside air. The passive samplers were outdoor validated and deployed together with two commercial passive samplers, Ultra I SKC Inc. and Radiello, for daily roadside air monitoring in East Asian cities including HoChiMinh, Hanoi, Cantho, Danang, Vungtau, Hue (Vietnam), Kuala Lumpur (Malaysia), Kyoto, Osaka (Japan), Nanjing (China) and Singapore in 2011. High daily benzene concentrations of 87, 52, 32, 23, 13, 12 and 48 µg/m3 were observed in HoChiMinh, Hanoi, Cantho, Danang, Hue, Vung Tau (Vietnam), and Kuala Lumpur (Malaysia), respectively. Kyoto and Osaka (Japan) were clean with daily benzene concentrations below 2.3 μg/m3. The daily benzene concentrations in Nanjing (China) and Singapore were 5.6 and 6.9 μg/m3, respectively. The three passive samplers were equivalent. Passive sampling by the Lanwatsu passive sampler is acceptable for daily outdoor benzene monitoring.

Nanosilver-based wound dressings were manufactured by immersing non-woven fabric material into a nanosilver solution at a concentration of 500 mg/L with an average particle size of 20–25 nm, which was produced by the aqueous molecular solution method using sodium borohydride as a reducing agent and chitosan as a stabiliser. The bactericidal activity of the nanosilver-based wound dressings has been assessed on three standard bacterial strains Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 25923, as well as P. aeruginosa, S. aureus and Acinetobacter baumannii isolated from patients’ burns. The results showed that these products are effective bactericides against both the standard strains and those isolated from patients’ burns. The effect of the dressings on burn treatment has been investigated using laboratory rabbits. It was proved that for the burn healing, the produced nanosilver-coated wound dressings are as effective as the Chinese Anson's ones.

The J-aggregates of the diprotonated tetraphenylporphin formed in the o/w microemulsions including 2-alkyl alcohol, Triton X-100, toluene, and sulfuric acid, exhibited an induced circular dichroism...

The presence of eight kinds of persistent organic pollutants (POPs) such as DDT and its metabolites (DDTs), hexachlorocyclohexanes (HCHs), chlordane compounds (CHLs), drin compounds (Drins), heptachlor, hexachlorobenzene (HCB), heptachlor-epoxide, polychlorinated biphenyls (PCBs) and sixty-four polycyclic aromatic hydrocarbon compounds (PAHs) was identified using high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) to investigate their distribution in surface sediment from Hanoi, Hue, and Ho Chi Minh in Vietnam. A survey of sediment samples fro mO saka was conducted for comparison. The concentrations of ΣDDTs, ΣCHLs, ΣPCBs and ΣPAHs in Vietnam were 0.19–140, N.D.–9.0, 0.11–110, and 30–5500 ng/gdry, respectively. Concentrations of these compounds in urban areas were higher than those in other areas. In addition, the ΣDDT concentrations in Vietnamese urban areas were higher than those in Osaka. These results suggest that most DDTs would be used as insecticides for the purpose of health services rather than as agricultural chemicals. PAH pollution in urban areas and suburbs is caused mainly by runoff of petrol, whereas in rural areas, the combustion of fossil fuels and biomass is the major pollutant source.

The atmospheric corrosion of marble was evaluated in terms of SO 2 concentration as air pollution and climatic factors such as rainfall, relative humidity, temperature and so on under the field exposure. Marble of calcite type (CaCO 3 ) was exposed to outdoor atmospheric environment with and without a rain shelter at four test sites in the southern part of Vietnam for 3-month, 1- and 2-year periods from July 2001 to September 2003. The thickness loss of marble was investigated gravimetrically. X-ray diffraction and X-ray fluorescent methods were applied to study corrosion products on marble. The corrosion product of marble was only gypsum (CaSO 4 · 2H 2 O) and was washed out by rain under the unsheltered exposure condition. It was found that the most substantial factors influencing the corrosion of marble were rainfall, SO 2 concentration in the air and relative humidity. Based on the results obtained, we estimated the dose–response functions for the atmospheric corrosion of marble in the southern part of Vietnam.

This paper was concerned with evaluating the effect of dry deposition on deterioration of marble. Two types of marble were exposed to atmospheric environment with a rain shelter at four exposure sites in the south of Vietnam for 3-month, 1-year and 2-year periods from July 2001 to September 2003. X-ray diffraction (XRD) and X-ray fluorescent (XRF) methods were applied to study the products of marble deterioration. Ion chromatography was used to analyze dry depositions on marble. The main product of marble deterioration was gypsum (CaSO4·2H2O). The amount of sulfate ions deposited on marble was found to be proportional to SO2 concentration in the air, relative humidity and duration of the exposure. In addition, sulfation of marble caused by SO2 at a relative humidity lower than 70% is almost half of that at relative humidity higher than 70%. Moreover, marble consisting of calcite (CaCO3) was more sensitive to SO2 than marble consisting of dolomite (CaCO3 and MgCO3). A good relation between the amount of sulfate ions deposited on marble and SO2 concentration in the air suggested that marble could serve as an indicator for atmospheric pollution by SO2.

Background Centrostachys aquatica is a perennial emergent macrophyte in marshy places and in rivers. The species was recorded in Senegal and Nigeria, but widespread in tropical Africa, and South and East Asia. Aqueous methanol extracts C. aquatica was found to be toxic to several plant species. However, no phytotoxic substance has been reported in this species. Therefore, we investigated phytotoxic activity and searched for phytotoxic substances with allelopathic activity in C. aquatica. Results An aqueous methanol extract of C. aquatica inhibited the growth of roots and hypocotyls of cress (Lepidium sativum). The extract was then purified by several chromatographic runs and a phytotoxic substance with allelopathic activity was isolated and identified by spectral analysis as loliolide. Loliolide inhibited cress root and hypocotyl growth at concentrations greater than 0.03 μM. The concentrations required for 50% growth inhibition of cress roots and hypocotyls was 0.18 and 0.15 μM, respectively. Conclusion These results suggest that loliolide is a phytotoxic substance and may contribute to the allelopathic effect caused by C. aquatica. Electronic supplementary material The online version of this article (doi:10.1186/s40529-014-0059-1) contains supplementary material, which is available to authorized users.

Monitoring of benzene, toluene and xylenes (BTEX) was conducted along with traffic counts at 17 roadside sites in urban areas of HoChiMinh. Toluene was the most abundant substance, followed by p,m-xylenes, benzene, o-xylene and ethylbenzene. The maximum observed hour-average benzene concentration was 254 μg/m3. Motorcycles contributed to 91% of the traffic fleet. High correlations among BTEX species, between BTEX concentrations and the volume of on-road motorcycles, and between inter-species ratios in air and in gasoline indicate the motorcycle-exhaust origin of BTEX species. Daily concentrations of benzene, toluene, ethylbenzene, p,m-xylenes and o-xylene were 56, 121, 21, 64 and 23 μg/m3, respectively. p,m-xylenes possess the highest ozone formation potential among the BTEX family.

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Although non-viral vectors are relatively safe, they have very low gene transfection efficiency, especially in pancreatic islet cells. To provide information on the use of non-viral vectors for transfecting genes into pancreatic islet cells, a comparative evaluation of non-viral options was performed. In vitro experiments were used to compare the transfection efficiency of three classes of non-viral vectors: Effectene, polyethylenimine (PEI, 25 kDa) and hemagglutinating virus of Japan-envelope (HVJ-E), into insulinoma cells (INS-1) and rat islets. Vascular endothelial growth factor (VEGF) gene with hypoxia-inducible RTP801 promoter was delivered into rat islets with Effectene and VEGF secretion under hypoxia was measured in the culture media. Luciferase activity and GFP assays indicated that Effectene exhibited the highest transfection efficiency, and HVJ-E was not suitable for transfection into pancreatic beta-cells. The cytotoxicity of Effectene was found to be similar to that of 25-kDa PEI by 7-amino actinomycin D (7-AAD) flow cytometry and acridine orange/propidium iodide (AO/PI) assays. When RTP801 promoter-VEGF plasmid was delivered to rat islets with Effectene, VEGF secretion increased specifically in islets under hypoxia. In conclusion, Effectene showed higher gene-delivery efficiency for pancreatic islets compared with other classes of non-viral delivery systems and is promising as a gene delivery agent for pretransplant ex vivo gene therapy of islets.

A passive sampling method was applied to measure the concentrations of air pollutants, such as sulfur dioxide, nitrogen oxides, ammonia, hydrogen chloride, and nitric, formic and acetic acids, in the ambient air at four test sites in the southern region of Vietnam. The monthly averages and the average concentrations of air pollutants during the period from July 2001 to September 2002 are reported here. The concentrations of air pollutants varied widely, depending on the test sites and the sampling periods. The average concentrations of sulfur dioxide in the air during the period from July 2001 to September 2002 at the four test sites were 3.3-16.9 ppb, and those of nitrogen dioxide were 5.4-12.8 ppb. The concentrations of nitrogen monoxide and hydrogen chloride were very low at all of the test sites. The observed concentrations of all of the above-mentioned pollutants were lower than those of the Vietnamese standards of air pollutants.