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Zirconium metal–organic frameworks ZrOBDC (where BDC = C6H4(COOH)2, terephthalic acid) doped and co-doped with rare earth ions Ln (ZrOBDC:Ln3+, where Ln3+ = Eu3+ and Tb3+ as well as Er3+ and Yb3+) were used as precursors for the design of tetragonal rare earth doped zirconia nanoparticles (t-ZrO2:Ln3+ NPs) through annealing process. Preparation, characterization and luminescence properties of ZrOBDC:Ln3+ and ZrO2:Ln3+ NPs were investigated. The as-obtained t-ZrO2:Ln3+ NPs have high purity with an average size of 20–30 nm. The luminescence spectra of ZrOBDC:Tb3+ and ZrOBDC:Eu3+ display strong green and red emission at around 544 and 611 nm which correspond to 5D4 → 7F5 and 5D0 → 7F2 transitions of Tb3+ and Eu3+ ions, respectively. The green and red up-conversion emissions of ZrO2:Er3+,Yb3+ NPs due to 2H11/2, 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2 transitions of the Er3+ ions are observed under 976 nm laser excitation.

In the present study, we reported the codetermination of highly bioactive compounds, namely, hydroxychavicol, eugenol, and gallic acid in the Piper betle Linn. leaf extract by high‐performance liquid chromatography method. These compounds are of great interest in the pharmaceutical field and also in other food‐related applications owing to their impressive biological and pharmaceutical properties. Moreover, antibacterial and antioxidant activities of the extracts produced by different extracting solvents were also investigated in detail. The methanol extract was found to contain the highest amounts of hydroxychavicol and gallic acid thus offering the strongest antioxidant activity in 1,2‐diphenyl‐2‐picrylhydrazyl free radical scavenging assay. All the three compounds were found at low levels in the hexane extract. However, the solvent type did not affect significantly on the concentration of extracted eugenol. The ethanol, methanol, and ethyl acetate extracts exhibited strong inhibitory effects against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Salmonella typhimurium whereas the hexane extract showed negligible antibacterial activity. These findings suggest that ethyl acetate is a good choice to produce a highly antibacterial extract but methanol and ethanol are more suitable when the antioxidant activity of the extract is more concerned.

The number of research on ginger microrhizome production is low, despite awareness of the drawbacks to the traditional method of cultivation and the known health benefits associated with ginger essential oils. We examined the effects of several factors on microrhizome induction in order to create a production protocol for the cultivar found in Hue, Vietnam. To determine the optimal conditions for ginger microrhizome production, different concentrations of sucrose, plant growth regulators, ammonium nitrate, and silver nitrate were investigated. Microrhizome fresh weight and diameter were increased to the maximum values with application of BAP (6-benzyl amino purine), NAA (α- naphthaleneacetic acid), IBA (indole-3-butyric acid), and a low ammonium nitrate concentration, with 0.433 g at 9.03 mm, 0.437 g at 9.73 mm, 0.478 g at 10.80 mm, and 0.449 g at 9.53 mm, respectively. Additionally, we demonstrated that kinetin has an inhibitory effect on microrhizome growth. The biggest microrhizomes were grown on MS media containing the optimal concentrations for each factor – 80 g/L sucrose, 1.9 mg/L AgNO3, 550 mg/L ammonium nitrate, 4 mg/L BAP, 6 mg/L NAA, and 4 mg/L IBA.

In this work, the existence of different crystal field sites for the rare-earth-doped tin dioxide nanopowder and RE-doped SiO2-SnO2 glass-ceramics is investigated. The slightly different crystal field symmetries have been resolved by using site-selective fluorescence line-narrowing spectroscopy. The obtained results show that a variety of optically non equivalent sites exist for the europium ion in the tin dioxide oxide structure associated to different allowed positions of the oxygen vacancies, whereas additional spectral disorder is found in the case of the glass-ceramic matrix. Ultrafast spectroscopy performed on Eu3+-doped tin dioxide nanocrystals shows that host-rare earth energy transfer occurs at a transfer rate of about 1.5×106 s-1. Similar experiments carried out for the Er3+-doped glass-ceramic system also validate the hypothesis that both host and matrix-excited RE emissions are decoupled due to the different origins of the involved physical mechanisms.

The theoretical model of rare earth doped optical devices based on the rate equations and the power propagation equations can be employed for recovering, via an indirect approach, the rare earth spectroscopic parameters. As an example, the model for an erbium doped silica-tin dioxide, SiO2 - SnO2 : Er3+, glass ceramic waveguide is considered. Two different pumping schemes are employed to excite the erbium ions, the direct pumping at 378 nm and the indirect pumping at 307 nm via the tin dioxide. The achievable optical gain per unit length at 1533 nm is then evaluated for both pumping cases. The ratio between the two simulated optical gains is compared with the emission intensity measurements to estimate the value of the SnO2-Er3+ energy transfer coefficient. The particle swarm optimization algorithm is applied in order to find the SiO2 - SnO2 : Er3+ glass ceramic spectroscopic parameters which properly match the simulated optical gains ratio with the experimentally measured emission ratios. In the same way, the pump power coupled in the glass ceramic waveguide is also recovered. The SnO2-Er3+ energy transfer coefficient is estimated to be about 6.1 × 10-22 m3/s.

The influences of annealing temperature on structure, morphology, vibration, optical properties and photocatalytic ability of g-C 3 N 4 nanosheets synthesized from urea in Ar atmosphere were investigated in detail by using x-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), Fourier transform infrared spectroscopy (FTIR), UV–vis absorption, and photoluminescence (PL). It was found that the preparation temperature had a great effect on structure and physical properties of g-C 3 N 4 . As the processing temperature increased from 450 °C to 650 °C, the interlayer stacking distance of g-C 3 N 4 decreased from 3.281 A to 3.217 A and the lattice parameter a decreased from 5.010 A to 4.934 A. This indicated a denser packing fashion of g-C 3 N 4 at high annealing temperature. Moreover, the FTIR spectra and SEM images revealed a large fraction of small polymer segments containing only a few heptazine units as annealing temperature increased. BET result indicated an increasing specific surface area as preparation temperature increased. UV–vis absorption spectra showed a decrease of the band gap energy with increasing calcination temperature which agrees well with the measured PL spectra. It was demonstrated that samples annealed at 550 °C exhibited the strongest photocatalytic activity. A decomposition of 80% and 100% of rhodamine B was obtained within respectively 1 h and 2 h under Xenon lamp irradiation. Photocatalytic result could be adequately explained based on evidences of specific surface area, average pore volume and pore size, and recombination rate of photoinduced electron-hole pairs.

Introduction Cancer is a disease with a global burden and is a major and increasing threat to public health. The demand for new modalities to treat and prevent cancer is high. Given the toxic side effects of standard treatments, such as chemotherapy, there is greater research interest in naturally derived compounds due to their selective toxicity to cancer cells. This study aimed to test the anticancer activity of a crude extract of Hopea odorata on hepatocellular carcinoma (HCC) HepG2 cell line. Methods Methanol extracts of H. odorata were prepared from the bark of H. odorata plants (H. odorata extract). The in vitro cytotoxicity of H. odorata extracts on human HCC cell line HepG2 compared to normal human fibroblasts (HFs) was assessed by Alamar Blue assay. Caspase-3/7 was detected using a reagent that consists of DEVD peptide conjugated to a nucleic acid-binding dye. Apoptosis induction by the H. odorata plant extract on HepG2 was evaluated by Annexin V/7-AAD using flow cytometry. Disintegrated nuclei of plant-treated cells were observed under a fluorescent microscope using Hoechst and propidium iodide (PI) staining. In addition, using the Hoechst/PI staining technique, the ratio of dead to total cells was determined by distinguishing Hoechst and PI fluorescent signals. Results We found that the IC50 value of H. odorata extract on HepG2 was 12.67±5 µg/mL and on HF was 44±3 µg/mL. The IC50 value of doxorubicin on HepG2 was 153.3±15 ng/mL and on HF was 6.3±0.6 ng/mL. The selectivity index (SI) of H. odorata extract for HepG2 cells was ~3.48, while the SI of doxorubicin for HepG2 cells was ~0.04. The ratio of dead to total cells increased in a dose-dependent manner for HepG2 cells when observed under a fluorescent microscope, while the ratio of dead to total cells barely changed for HF cells. The H. odorata extract inhibited HepG2 cells via the activation of caspase-3/7. At 250 µg/mL concentration of the H. odorata extract, 35% of HepG2 cells were induced into apoptosis, and the cells exhibited disintegrated nuclei under a fluorescent microscope. Conclusion These findings demonstrate that the methanolic bark extracts of H. odorata plant induce apoptosis and selective cytotoxicity toward HepG2 but not HF. Therefore, purification of compounds from H. odorata bark extracts may be useful as anticancer agents, and thus, more studies are warranted to investigate the anticancer properties of H. odorata.

This paper describes a facile synthesis of NaYF4:Er3+,Yb3+ nanoparticles embraced in metal–organic frameworks (MOFs), known as NaYF4:Er3+, Yb3+@MOFs core/shell nanostructures, by using iron(III) carboxylate (MIL-100) and zeolitic imidazolate frameworks (ZIF-8). Morphological, structural and optical characterization of these nanostructures were investigated by field emission-scanning electron microscopy, Fourier transform infrared spectroscopy, x-ray diffraction, and up-conversion luminescence measurements. Results showed that spherical-shaped NaYF4:Er3+,Yb3+@MIL-100 nanocomposites with diameters of 150–250 nm, and rod-shaped NaYF4:Er3+,Yb3+@ZIF-8 nanocomposites with lengths of 300–550 nm, were successfully synthesized. Under a 980-nm laser excitation at room temperature, the NaYF4:Er3+,Yb3+@MOFs nanocomposites exhibited strong up-conversion luminescence with two emission bands in the green part of spectrum at 520 nm and 540 nm corresponding to the 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 transitions of Er3+ ions, respectively, and a red emission band at 655 nm corresponding to the 4F9/2 → 4I15/2 transition of Er3+ ions. The above properties of NaYF4:Er3+,Yb3+@MOFs make them promising candidates for applications in biotechnology.

Trabajo presentado en la 21st International Conference on Transparent Optical Networks (ICTON), celebrada en Angers (Francia), del 9 al 13 de julio de 2019, Since the pioneering work of Tick, Borrelli, Cornelius, and Newhouse on transparent glass ceramics performed in 1995, the research regarding photonic glass-ceramics is growing fast. From the considerable number of published studies, covering a broad spectrum of applications, it appears that reliable fabrication techniques and realization of effective photonic devices are the two crucial pivots for an important advance in this glass photonics area. The important results already obtained in rare earth-activated oxyfluoride, fluoride, and silicate transparent glass ceramics are well known. Regarding silicate-based photonic glass-ceramics the binary system SiO 2 -SnO 2 is really appealing when we look at the two above mentioned objectives.In this communication, a brief review of the state of art, consolidated results and recent advances in erbium doped SnO 2 -SiO 2 transparent glass-ceramics, obtained by sol-gel technology will be presented, and short-term perspectives will be outlined.

In this work, we focus on synthesizing g-C3N4 nanosheets with a large surface area for enhanced solar light photocatalytic performance via a simple thermal polymerization of a low-cost urea precursor in enclosed conditions. The effects of annealing duration on the phase formation, structure, and optical and photocatalytic properties of the g-C3N4 nanosheets were investigated. The characterization analysis revealed that g-C3N4 nanosheets with different textures, including stacked-layer, porous and ultrathin morphologies, were obtained by controlling the annealing time. The prepared g-C3N4 samples offer a large specific surface area, narrow band gap and efficient separation of photogenerated electron-hole pairs with increasing annealing duration. The photocatalytic properties of the as-synthesized g-C3N4 samples were examined by measuring the degradation of rhodamine B (RhB) under simulated solar irradiation. With a 100% RhB solution (10 ppm) decomposed by exposure to solar irradiation for 60 min, ultrathin g-C3N4 shows considerable potential in practical applications concerning environmental remediation, especially in large-scale applications in industry.

The development of efficient luminescent systems, such as microcavities, solid-state lasers, integrated optical amplifiers, and optical sensors is the main topic in glass photonics. The building blocks of these systems are glass-ceramics activated by rare-earth ions because they exhibit specific morphologic, structural, and spectroscopic properties. Among various materials that could be used as nanocrystals to be imbedded in a silica matrix, tin dioxide presents some interesting peculiarities, e.g., the presence of tin dioxide nanocrystals allows an increase in both solubility and emission of rare-earth ions. Here, we focus our attention on Er3+&mdash, doped silica&mdash, tin dioxide photonic glass-ceramics fabricated by a sol-gel route. Although the SiO2-SnO2:Er3+ could be fabricated in different forms, such as thin films, monoliths, and planar waveguides, we herein limit ourselves to the monoliths. The effective role of tin dioxide as a luminescence sensitizer for Er3+ ions is confirmed by spectroscopic measurements and detailed fabrication protocols are discussed.

International audience; This work focuses on the fabrication processes and photonic assessment of SiO2-SnO2:Er3+ monoliths. To obtain the crack-free and densified system, the sol-gel derived synthesis protocols and heat-treatment processes were optimized. The absorption measurements were employed to assess the effect of the heat-treatment on the samples and specially to estimate the –OH content. The XRD patterns were used to investigate the crystallization as well as the structure of the monoliths. The emission spectra, performed at different excitation wavelengths, evidence the presence of Er3+ in the SnO2 nanocrystals and the energy transfer from SnO2 to the rare earth ions. In addition, the efficient role of SnO2 nanocrystals as Er3+ sensitizers are also experimentally confirmed in this system.

Six methodologies for extracting DNA in cocoa and cocoa-derived products (cocoa leaves, cocoa beans, cocoa powder, cocoa butter, cocoa mass, and dark chocolate) are described. These DNA extraction methods included four commercial kits DNeasy Plant kit, DNeasy Plant kit with polyvinyl polypyrrolidone (PVPP), QIAamp DNA Stool kit, Wizard Genomic DNA kit, and two CTAB based methods, CTAB-Proteinase K procedure and CTAB-SDS (sodium dodecyl sulfate) procedure. The DNA yield, purity, and quality for six different cocoa matrices are discussed. The yield and purity were determined through spectrophotometry. Three different conventional PCR reactions were used to assess the quality of the DNA extracted. The Wizard Genomic DNA kit and the CTAB-Proteinase K method were found to be the best for DNA quality and PCR detection in cocoa leaves. The CTAB-Proteinase K procedure is highly recommended for cocoa beans, while the Wizard Genomic DNA kit revealed the best PCR performance when applied to cocoa powder. The cocoa b...

In this work, due to the challenge for improving the efficiency of photonic materials actived by Rare Earth ions (RE), Tin dioxide (SnO 2 ) nanocrystals based glass ceramic was employed and it was proved as a viable photonic material. The base material for doping RE ions was formed by embedding Tin dioxide nanocrystals into silica. The properties of the material were investigated by both simulations and experimental characterisation. The material was fabricated by sol-gel routes in different geometrical systems : thin films, monoliths and planar waveguides. The characterisation of the thin films showed the fundamental properties of the material : structural, morphological and optical properties. The presence of Tin dioxide nanocrystals led to the increase of both solubility and emission of RE ions. The energy transfer from the nanocrystals to the RE ions was proved by experiments and the result was again clarified by the simulations on the structure and the bandstructure of Er3+ ions substituting for Sn4+ ions in the nanocrystals. The results confirmed the advantages of Tin dioxide as luminescence sensitizer [1] for Er3+. Following the approaches of Tin dioxide based thin films, monoliths and planar waveguides have been fabricated for further processing into photonic devices : fibers, solid lasers and integrated circuits. In order to obtain the crack-free and densified monoliths, the synthesis and heat-treatment process of the xerogels have been optimized. Thermal analyses were performed in order to identify the heat-treatment stategy. Up to now, heat-treatment at 950°C for 100h has shown the best performance on H 2 O removal, densification of the monoliths and crystallization of SnO 2 nanocrystals. By characterisation of the exictation and emission of the monoliths, the indirect excitation due to energy transferring from SnO 2 into Er3+ has been shown to be more efficient than the other direct excitations. The monoliths excited at 335nm, which corresponds to the bandgap of SnO 2 nanocrystals, showed the highest emission intensity at 1534nm (Figure 1). The Tin dioxide based waveguides have shown the good transparency with transmittance higher than 90% in UV-Vis-NIR regions and waveguiding properties (Figure 2) with low losses.

Glass photonics are widespread, from everyday objects around us to high-tech specialized devices. Among different technologies, sol-gel synthesis allows for nanoscale materials engineering by exploiting its unique structures, such as transparent glass-ceramics, to tailor optical and electromagnetic properties and to boost photon-management yield. Here, we briefly discuss the state of the technology and show that the choice of the sol-gel as a synthesis method brings the advantage of process versatility regarding materials composition and ease of implementation. In this context, we present tin-dioxide-silica (SnO2-SiO2) glass-ceramic waveguides activated by europium ions (Eu3+). The focus is on the photorefractive properties of this system because its photoluminescence properties have already been discussed in the papers presented in the bibliography. The main findings include the high photosensitivity of sol-gel 25SnO(2):75SiO(2) glass-ceramic waveguides; the ultraviolet (UV)-induced refractive index change (Delta n similar to -1.6 x 10(-3)), the easy fabrication process, and the low propagation losses (0.5 +/- 0.2 dB/cm), that make this glass-ceramic an interesting photonic material for smart optical applications.

Silica-tin dioxide thin films doped with Er3+ ions were fabricated and investigated. Different parameters such as heat-treatment temperatures, molar concentrations of SnO2 as well as Er3+ ions concentration were changed in order to obtain the best properties of presented thin films. Using several techniques, thin films were characterized and proved to be crack-free, water-free and smooth after a heat-treatment at 1200 °C. Aiming to application in optics, the transparency of thin films was also evidenced by transmission spectra. Based on the photoluminescence measurements, the mechanism of energy transfer from SnO2 nanocrystals to Er3+ ions was examined and discussed.

In this work, (100-x)SiO2-xSnO2 (with x = 10, 20 and 30% mol) doped with 1mol% Er3+ nanocomposite thin films were prepared by sol-gel method. The effect of SnO2 concentration in the structure and the distribution of erbium ions in ceramic-glass structure were investigated by FT-IR spectroscopy, X-ray diffraction (XRD) and Atomic Force Microscopy (AFM). SnO2 nanoparticles with size about 50nm were formed in films heat-treated at 1000oC. Photoluminescence and 3D spectroscopies show that there is the energy transfer from SnO2 nanocrystal to erbium ions and the ions exist in amorphous environment and in the nanoparticles.

Coordination polymers (metal–organic frameworks or MOFs) offer the opportunity for fine-tuning the luminescence behavior because of the possibility to entrap in the network pores molecules that can influence the lanthanide (Ln) emission. In this study, Zn (II) and polycarboxylate based MOFs were first pre-formed by solvothermal method, then considered as host-matrix for in situ doping of low-input concentration of Eu3+ and Tb3+ (two most commonly used lanthanides in life science assays), and afterwards lanthanide doped luminescent materials were synthesized. Different characterizations (X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-Dispersive Spectroscopy (EDS)) were carried out to confirm accordingly MOF's crystallinity, the structure and chemical composition. The study on luminescent properties of the material has revealed an efficient energy transfer from the ligand excited states to the Eu3+ and Tb3+ f-excited states. With quite low input concentrations (8–15%) of doped rare earth ions, these complexes displayed intense emissions at room temperature and proved to be good candidates for red and green emitter luminescent materials. Generally, this design concept can be extended for the preparation of other rare earth coordination polymers.

Rosemary essential oil has been widely used in folk medicine for treatment of anxiety, memory deficit and cancer thanks to its high antioxidant activity and antibacterial properties. Composition of rosemary essential oil largely depends on the geographical position of the cultivated plant and conditions of the extraction process. In this study, fresh and dried rosemary leaves were used for extraction of essential oil using hydrodistillation method. The extraction performance, composition and antioxidant activity of the essential oil were measured. The oil yield for dried leaves (1.2 ml/g) is significantly lower than that for fresh leaves (3.16 ml/g). However, the difference on chemical profile and antioxidation activity of the two oil samples was indistinguishable. The most remarkable finding was the presence of Levoverbenone at very high concentration in rosemary essential oil, accounting for 10.87% and 12.12% of the oil sample extracted from fresh and dried leaves respectively.

The rapid development of whiteleg shrimp farming in the Mekong delta of Vietnam has an adverse impact on the environment due to large amount of nitrogen and phosphorus content in wastewater and pond sludge/sediment. Phytoremediation is a promising technique to use plant for mitigating environmental impacts from intensively whiteleg shrimp culture. Growth responses, nitrogen and phosphorus removal of Typha orientalis and Scirpus littoralis were assessed at three water levels of +15 cm, +30 cm and +45 cm. They were arranged in a completely randomized design with three replications. The plants were supplied wastewater from intensive whiteleg shrimp tanks once every two weeks. Waterlogged assessment was conducted for 71 days. Water levels significantly affected plant growth rate and nutrient removal capacity. S. littoralis grew well with a lower mortality rate and had no statistical reduction of biomass compared to T. orientalis at the highest water level of +45 cm. T. orientalis had the best perfromance in growth and biomass responses to waterlogged at water levels of +15 cm and +30 cm. The results indicated that S. littoralis was the best of choice to grow in waterlogged condition of the shrimp pond for maintaining water quality.

Nanorods Y(OH)3:Eu, nanotubes Tb (OH)3, and nanocomposites silica‐titania‐ and silica‐zirconia‐doped erbium and ytterbium were prepared by liquid‐phase methods. Structures and photonic properties such as long decay time (7.4 ms) and waveguide loss were studied in detail in the concentration and temperature dependence. The application of the nanocomposites for planar waveguide systems is presented.

In this paper we present the new results of fabrication, characterisation and upconversion emission process of NaYF4 nanoparticles doped with Er3+ or Tm3+and Yb3+ as sensitiser. In order to fabricate α–, β–NaYF4:2%Er3+, 19%Yb3+and α–, β–NaYF4:2%Tm3+, 19%Yb3+ nanoparticles the soft template method in isopropylamine at 140C and diethylene glycol (DEG) at 180C has been used. The morphology, structures and emission properties were studied by X–ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and luminescence spectroscopy. The upconversion luminescence (UCL) spectra of α and β crystalline forms of NaYF4:2%Er3+, 19%Yb3+and NaYF4:2%Tm3+, 19%Yb3+ nanoparticles were investigated upon diode laser excitation at 976 nm. The strong emissions in the green and red spectral regions were observed upon this excitation. The spectral lines of the UCL could be assigned to the upconversion radiative transitions of the Er3+ or Tm3+ ions with Yb3+ sensitiser. The upconversion emission spectra dependent on laser excitation powers have been investigated in order to elucidate the upconversion emission paths which could take place. We found the significant influence of the type of nanocrystalline structure on the upconverting radiative transition mechanisms in NaYF4:2%Er3+, 19%Yb3+and NaYF4:2%Tm3+, 19%Yb3+ nanoparticles.

A Cu3BTC2 metal–organic framework (MOF) with large specific surface area of 1350 m2/g, where BTC = benzene–1,3,5–tricarboxylate, was synthesised by hydrothermal method. It was then used as a starting material for the preparation of a novel MOF based photocatalyst containing titanium dioxide. This photocatalyst, namely, TiO2@Cu3BTC2, has been prepared by hydrolysis of titanium (IV) isopropoxide under hydrothermal condition. The synthesised materials were then characterised by X–ray diffraction (XRD), scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET) techniques. The photocatalytic discolouration of methylene blue dye (MB) in aqueous solution was investigated under UV–VIS light irradiation at different illumination times using the photocatalyst TiO2@Cu3BTC2 metal–organic frameworks and a control sample of commercial TiO2 nano powder (Degussa P25). It is interesting to note that TiO2@Cu3BTC2 exhibits very strong photocatalytic activity for MB discolouration, much better than lone TiO2 nano–particles P25. Thus, this novel photocatalytic material based on copper–centred MOFs may serve as an excellent class of photocatalytic materials for different environmental applications.

Two new phenylbenzofuran-type stilbenoids named stemofurans X and Y (1, 2) were isolated from the roots of Stemona pierrei and S. tuberosa, respectively, together with ten known compounds. These compounds were stemanthrenes B-C (3, 4), (+)-syringaresinol (5), maistemonine (6), isomaistemonine (7) and sesamin (8) from S. pierrei, and stemophenanthrenes A-C (9–11) and isopinosylvin A (12) from S. tuberosa. Stemofurans X-Y (1, 2) showed moderate cytotoxicity against the four cancer cell lines KB (human epidermal carcinoma), MCF7 (human breast carcinoma), SK-LU-1 (human lung carcinoma), and Hep-G2 (hepatocellular carcinoma).

Acetyl groups on cell wall polysaccharides can be rapidly and conveniently quantified by 1H NMR spectroscopy following their liberation by acid hydrolysis in D2SO4−D2O. The method works equally well for O and N-acetyl substituents. The method has been used to measure total acetyl groups in walls from grass and legume forage plants.

Superparamagnetic iron oxide nanoparticles (SPION) coated with suitable bio-compatible substances have been used in biomedicine, particularly in magnetic resonance imaging (MRI), tissue engineering, and hyperthermia and drug delivery. In this study, we describe the synthesis of SPION and its surface modification for in-vitro experiments. The particle diameter and structure were estimated by FESEM, TEM, XRD analyses. The saturation magnetization was characterized. SPION with a mean size of 12 nm have been prepared under N2 atmosphere, with support of natural polymeric starch, by controlling chemical coprecipitation of magnetite phase from aqueous solutions containing suitable salts ratios of Fe2+ and Fe3+. The surface of SPION-nanoparticles was treated with a coordinatable agent for higher dispersion ability in water and remaining the superparamagnetic behavior. The prepared iron oxide nanoparticles were coated with starch, dextran, PEG or MPEG to extend the application potential in the quite different engineering field of nano biomedicine.

Resume L'oxydation electrochimique de la galene (PbS) a ete etudiee dans la zone de pH 9–10, par electrolyse a potential controle, en utilisant une cellule particuliere. En absence de xanthate, l'oxydation conduit a la formation de soufre elementaire,de thiosulfate et d'especes de plomb(II) telles que Pb(OH) 2 . L'oxydation simultanee de galene et de xanthate a egalement ete etudiee et les produits de reaction ont ete caracterises par spectrophotometrie uv -visible. L'oxydation conduit a la formation de xanthate de plomb et de dixanthogene. Il a ete etabli que le xanthate de plomb provient d'une reaction d'echange d'ions entre l'exces de xanthate en solution, et les especes de plomb(II) resultant de l'oxydation de PbS.

From an acarid mite, Lardoglyphus konoi (Sasa et Asanuma) (Acarina: Acaridae), with its culture medium, an aggregation pheromone was isolated. The structure of the pheromone was determined as 1,3,5,7-tetramethyldecyl formate and identified by 11 steps of organic synthesis. The absolute configuration of C1 was assigned as R. The compound has been assigned the trivial name lardolure. The synthesized diastereomeric mixture of racemates showed one-tenth of the activity of the natural pheromone against the test mite, Carpoglyphus lactis.

The one-dimensional (1D) crystalline nanostructures of Y(OH) 3 :Eu/Tb have been synthesized using softemplate method at temperature range of 180 – 200 °C for 24 h. The studies by Field Emission Scanning Electron Microscopy (FESEM) have been determined that the outer and interior hollow diameter of Y(OH) 3 :Eu/Tb nanotubes was obtained range from 150 to 500 nm and 100 to 300 nm, respectively and of the length up to several micrometers, respectively. The Y 2 O 3 :Eu/Tb nanorod/tubes have been obtained from Y(OH) 3 :Eu/Tb counterparts by crucial annealing. The Xray diffraction (XRD) patterns indicated that the Y(OH) 3 :Eu/Tb and Y 2 O 3 :Eu/Tb nanorods and nanotubes obtained has hexagonal and cubic phase with high crystaline. The luminescence and excitation properties of Y(OH) 3 :Eu/Tb and Y 2 O 3 :Eu/Tb nanorods and nanotubes were investigated in details. It found that crystal form and nanomorphology of Y(OH) 3 and Y 2 O 3 have played a great role on the emission properties of the doped Eu 3+ ions.