Origin of Magnetism in Hydrothermally Aged 2-Line Ferrihydrite Suspensions.

As an iron oxyhydroxide, nanosized ferrihydrite (Fh) is important in Earth science, biology, and industrial applications. However, its basic structure and origin of its magnetism have long been debated. We integrate synchrotron-based techniques to explore the chemical structures of 2-line ferrihydrite and to determine the origin of its magnetism during hydrothermal aging in air. Our results demonstrate that both the magnetism and X-ray magnetic circular dichroism (XMCD) signal of 2-line ferrihydrite are enhanced with aging time, and that XMCD spectral patterns resemble that of maghemite (γ-Fe2O3) rather than magnetite (Fe3O4). Fe L-edge and K-edge X-ray absorption spectroscopy (XAS) further indicate formation of both maghemite and hematite (α-Fe2O3) with increasing concentrations with longer hydrothermal aging time. Thus, magnetic enhancement with longer hydrothermal aging time is attributed to increasing maghemite concentration instead of a magnetically ordered ferrihydrite as previously reported. Moreover, L-edge and K-edge XAS spectra with different probing depths yield different ratios of these Fe oxides, which suggest the formation of a core (ferrihydrite-rich)-shell (with a mixture of both allotropes; α-Fe2O3 and γ-Fe2O3) structure during hydrothermal aging. Our results provide insights into the chemical evolution of 2-line ferrihydrite that reveal unambiguously the origin of its magnetism.

[Study on preparation process and stability of beta-cyclodextrin inclusion compound in volatile oil of Cinnamomum longepaniculatum leaves].

To study the optimum preparation process and stability of beta-cyclodextrin inclusion compound in volatile oil of Cinnamomum longepaniculatum leaves. The saturated aqueous solution method was adopted to prepare inclusion compounds for an orthogonal test. The inclusion compound productivity and the inclusion rate were taken as indexes for screening the inclusion processes. The inclusion effect was evaluated with the infrared spectrophotometry and TLC, and the stability under conditions of high temperature, high humidity and strong light was detected. Under optimum preparation conditions for inclusion, the ratio between volatile oil and beta-cyclodextrin was 1: 8 (mL: g), that between beta-cyclodextrin and water was 1: 15, the inclusion temperature was 40 degrees C, and the inclusion time was 3 h. The results of spectrophotometry and TLC showed that the optimum conditions can generate beta-cyclodextrin inclusion compound in volatile oil of C. longepaniculatum leaves with certain light resistance, thermo-stability and hygro-stability. Therefore the optimum inclusion process features simple operation and stable inclusion compounds.

Anthelmintic activity of the crude extracts, fractions, and osthole from Radix angelicae pubescentis against Dactylogyrus intermedius in goldfish (Carassius auratus) in vivo.

A bioassay-guided fractionation was performed to evaluate the anthelmintic activity of the crude extract fractions and osthole from Radix angelicae pubescentis against Dactylogyrus intermedius in goldfish (Carassius auratus) in vivo. Among four extracts (petroleum ether, ethyl acetate, acetone, and ethanol), only ethanol extract exhibited the best anthelmintic efficacy with 100% mortality of Dactylogyrus and no death of fish at the optimal anthelminthic concentration of 120 mg/L. Therefore, ethanol extract was subjected to column chromatography to obtain sixteen fractions. The activity was found in fraction F with 100% mortality of Dactylogyrus and no toxicity to fish at dose of 2.0 mg/L. A white crystal was isolated from fraction F and identified as osthole which exhibited the optimal activity with 100% mortality of Dactylogyrus at 1.6 mg/L had and no toxicity to fish at dose up to 6.2 mg/L. This is the first report on the isolation and identification of anthelmintic active compound from R. angelicae pubescentis against D. intermedius in goldfish (C. auratus) in vivo.

Acaricidal activity of four fractions and octadecanoic acid-tetrahydrofuran-3,4-diyl ester isolated from chloroform extracts of neem (Azadirachta indica) oil against Sarcoptes scabiei var. cuniculi larvae in vitro.

Four fractions obtained from chloroform extracts of neem (Azadirachta indica) oil by column chromatography were investigated for acaricidal activity against Sarcoptes scabiei var. cuniculi larvae in vitro. Octadecanoic acid-tetrahydrofuran-3,4-diyl ester was isolated from an active fraction of the chloroform extract and its toxicity against S. scabiei larvae was tested in vitro. A complementary log-log model was used to analyse the toxicity data. Activity was found in the third fraction, with 100% corrected mortality after 4.5 h of exposure at a concentration of 200 mg ml(-1). This fraction was repeatedly re-crystallised in acetone to yield a white amorphous powder, identified as octadecanoic acid-tetrahydrofuran-3,4-diyl ester, with a median lethal concentration (LC(50)) of 0.1 mg ml(-1) at 24 h post-treatment. The median lethal time (LT(50)) for this compound was 15.3 h at a concentration of 7.5 mg ml(-1).

Interaction of Copper Phthalocyanine with Nitrogen Dioxide and Ammonia Investigation Using X-ray Absorption Spectroscopy and Chemiresistive Gas Measurements.

The interaction site of phthalocyanine (Pc) with nitrogen dioxide (NO2) has been characterized using different methods and found to be conflicting. By knowing the interaction site, the Pc molecule can be better customized to improve the gas sensitivity. In this article, the interaction sites of copper phthalocyanine (CuPc) with oxidizing NO2 or with reducing gas (ammonia, NH3) were identified using in situ X-ray absorption spectroscopy (XAS). The sensitivity of CuPc to sub-ppm levels of the tested gases was established in the CuPc chemoresistive gas sensors. The analyte-sensor interaction sites were identified and validated by monitoring the Cu K-edge XAS before and during gas exposure. From the X-ray absorption near-edge structure and its first derivative, a low or lack of axial coordination on the Cu metal center of CuPc is evident. Using the extended X-ray absorption fine structure with molecular orbital information of the involved molecules, the macrocycle interaction between CuPc and NO2 or NH3 was proposed to be the dominant sensing mechanism on CuPc sensors.

Acaricidal activity of extracts of neem (Azadirachta indica) oil against the larvae of the rabbit mite Sarcoptes scabiei var. cuniculi in vitro.

The acaricidal activity of the petroleum ether extract, the chloroform extract and the acetic ether extract of neem (Azadirachta indica) oil against Sarcoptes scabiei var. cuniculi larvae was tested in vitro. A complementary log-log (CLL) model was used to analyze the data of the toxicity tests. The results showed that at all test time points, the petroleum ether extract demonstrated the highest activity against the larvae of S. scabiei var. cuniculi, while the activities of the chloroform extract and the acetic ether extract were similar. The activities of both the petroleum ether extract and the chloroform extract against the larvae showed the relation of time and concentration dependent. The median lethal concentration (LC50) of the petroleum ether extract (1.3 microL/mL) was about three times that of the chloroform extract (4.1 microL/mL) at 24 h post-treatment. At the concentrations of 500.0 microL/mL, the median lethal time (LT50) of the petroleum ether extract and the chloroform extract was 8.4 and 9.6 h, respectively.

[Hypoglyceminc effect of flavonoids from Prinsepia utilis on alloxan-induced diabetic mice].

OBJECTIVE: To evaluate the hypoglycemic effect of flavonoids from Prinsepia utilis Royle in alloxan-induced diabetic mice. METHODS: The hypoglycemic effects were investigated in alloxan-induced diabetic mice after oral administration of 300 mg/kg of flavonoids from Prinsepia utilis Royle for four weeks. The blood glucose (GLU), total cholesterol (TC), triglyceride (TG), very low density lipoprotein cholesterol (VLDL-C), alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN) and body weight of mice were determined. RESULTS: Flavonoids from Prinsepia utilis Royle had influence on body weight increasing of diabetic mice in three weeks, but had no influence in the fourth week. Flavonoids from Prinsepia utilis Royle exhibited hypoglycemic effects. Among these fractions, flavonoids from Prinsepia utilis Royle significantly reduced GLU, TG and AST level in diabetic mice compared with model control group (P<0.01), markedly reduced VLDL-C, ALT and BUN level in diabetic mice compared with model control group (P<0.05), but had little influence on TC. CONCLUSION: Flavonoids from Prinsepia utilis Royle possess significant hypoglycemic activities, they can improve hypothepatia of diabetic mice and have protective effect on renal function of diabetic mice.

Nanostructured Three-Dimensional Percolative Channels for Separation of Oil-in-Water Emulsions.

Separation of oil/water mixtures has been one of the leading green technologies for applications such as oil recovery and water purification. Conventional methods to separate oil from water are based on phase separation via physical settlement or distillation. However, challenges still remain in the effective extraction of micron-sized oil droplets dispersed in water, in which case gravity fails to work as separating force. Here, we conformably decorate porous titanium (average pore size 30 µm) with superhydrophilic nanotubes. The resulting three-dimensional superhydrophilic micro channels thus provide a driving force for oil-water separation at the nanotube/emulsion interface, enhancing significantly the water infiltration rate. The high efficiency (>99.95%, with oil droplets of average diameter 10 µm) and strong mechanical durability make the structure a reusable oil/water separator. Our findings pave the way for future applications of oil-in-water emulsion separation, which can be readily scaled up for massive demulsification.

Modified method combining in situ detoxification with simultaneous saccharification and cofermentation (SSCF) as a single step for converting exploded rice straw into ethanol.

This paper reports an improved fermentation process that includes simultaneous saccharification, detoxification, and cofermentation as steps for producing bioethanol. Rice straw was first steam exploded (SE) or butanone solution exploded (BSE) and then cofermented with Saccharomyces cerevisiae and Candida shehatae. To overcome the inhibitors, the exploded rice straw was continuously and slowly introduced into a 10 L ventilated fermenter. When the fermentation conditions were set to 1.0% initial dry matter, 10% total dry matter, addition rate of 120 mg/min, total fermentation time of 234 h, and dose of 0.1% (NH4)2SO4, yields of 25.8 g/100 g of dry matter ethanol and 88% total sugar use were obtained for BSE rice straw. The ethanol yields were not significantly different between detoxified materials and non-detoxified materials. Most of the furfural, hydroxymethylfurfural (5-HMF), acetic acid, and butanone were removed during the fermentation of non-detoxified materials, and the sugar concentrations were very low. The in situ detoxification and fermentation was effective and inexpensive when the pre-detoxification of exploded materials and the pre-adaptation of strains steps were omitted.

γ-terpineol inhibits cell growth and induces apoptosis in human liver cancer BEL-7402 cells in vitro.

To investigate the effect of γ-terpineol on cell proliferation and apoptosis of human hepatoma BEL-7402 cells to elucidate its molecular mechanism. Here, BEL-7402 cells were treated with various concentrations (40, 80, 160, 320 and 640 µg/ml) of γ-terpineol for 48 h, cell proliferation was determined by 3-(4,5-dimethyl-thiazolyl-2)-2,5-diphenyl tetrazolium bromides (MTT) assay. Cell colony inhibition was determined by soft agar assay. Apoptosis and possible molecular mechanisms were evaluated by morphological observation, flow cytometry analysis, and DNA fragmentation assay. The γ-terpineol significantly suppressed BEL-7402 cell proliferation in a dose-dependent manner. Characteristic morphological and biochemical changes associated with apoptosis such as cells shrinkage, deformation and vacuolization of mitochondria, nuclear chromatin condensation and fragmentation, formation of apoptotic bodies were observed after BEL-7402 cells treated with γ-terpineol for 24 h and 48 h. Cell cycle were displayed by flow cytometry analysis, the γ-terpineol treatment resulted in accumulation of cells at G1 or S phase and a blockade of cell proliferation compared to control group. Treating BEL-7402 cells with 320 µg/ml of γ-terpineol for 36 h and 48 h, a typical apoptotic "DNA ladder" was observed using DNA fragmentation assay. The present study demonstrated that possible anti-cancer mechanism of γ-terpineol on human hematomas cells is through inducing cell apoptosis to suppress tumor cell growth.

Anti-inflammatory activity of leaf essential oil from Cinnamomum longepaniculatum (Gamble) N. Chao.

The anti-inflammatory activity of the essential oil from C. longepaniculatum was evaluated by three experimental models including the dimethyl benzene-induced ear edema in mice, the carrageenan-induced paw edema in rat and the acetic acid-induced vascular permeability in mice. The influence of the essential oil on histological changes and prostaglandin E2 (PGE2), histamine and 5-hydroxytryptamine (5-HT) production associated with carrageenan-induced rat paw edema was also investigated. The essential oil (0.5, 0.25, 0.13 ml/kg b.w.) showed significantly inhibition of inflammation along with a dose-dependent manner in the three experimental models. The anti-inflammatory activity of essential oil was occurred both in early and late phase and peaked at 4 h after carrageenan injection. The essential oil resulted in a dose dependent reduction of the paw thickness, connective tissue injury and the infiltration of inflammatory cell. The essential oil also significantly reduced the production of PGE2, histamine and 5-HT in the exudates of edema paw induced by carrageenan. Both the essential oil and indomethacin resulted relative lower percentage inhibition of histamine and 5-HT than that of PGE2 at 4 h after carrageenan injection.

Antibacterial activity of leaf essential oil and its constituents from Cinnamomum longepaniculatum.

Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Salmonella enteritidis CMCC (B) 50041, were used in the antibacterial tests of Cinnamomum longepaniculatum leaf essential oil and its five chemical constituents. The effect of 1, 8-cineole on the ultrastructural structure of the bacteria (S. aureus and E. coli) was also investigated by transmission electron microscopy. The C. longepaniculatum leaf essential oil and the five chemical constituents showed variable levels of inhibition. Their MIC ( minimum inhibitory concentration ) and MBC (minimal bacteriocidal concentration) values were all in the range of 0.781 µL/mL~6.25 µL/mL and 0.781 µL/mL~12.5 µL/mL respectively except γ-terpinene. The MIC values of γ-terpinene against E. coli and S. aureus were all higher than 50 µL/mL, but the MIC and MBC values of γ-terpinene against S. enteritidis was only 3.125 µL/mL. Among them, α-terpineol possessed the best antibacterial activity. Under the transmission electron microscope, cell size of treated E. coli decreased, cell wall and cell membrane ruptured, and nucleoplasm was reduced and gathered onto the side. After the S. aureus was treated with 1, 8-cineole, the cell size and shape were damaged and nucleus cytoplasm was concentrated or reduced or agglomerated on the side. These results suggest that C. longepaniculatum leaf essential oil and its constituents have excellent antibacterial activities, the antibacterial mechanism of 1, 8-cineole against E. coli and S. aureus might attributable to its hydrophobicity.

Acute and subacute toxicity study of 1,8-cineole in mice.

The effects of acute and subacute toxicity of 1,8-cineole in Kunming mice were studied. After acute oral administration, the LD50 value (95% CL) was 3849 mg/kg (3488.8~4247.1 mg/kg). In the subacute toxicity study, there were no significant differences in body weight and relative organ weight between the control group and 1,8-cineole treatment groups. The histopathological examinations showed that granular degeneration and vacuolar degeneration appeared in liver and kidney tissue after administration of high dose of 1,8-cineole. Under electron microscopy, a series of ultrastructural changes were observed: The electron microscopy assays indicated that the influence of 1,8-cineole on the target organ at the subcellular level were mainly on the mitochondria, endoplasmic reticulum and other membrane type structure of liver and kidney.

Isolation and identification of the antibacterial active compound from petroleum ether extract of neem oil.

From a petroleum ether extract of neem oil (Azadirachta indica A. Juss) the new tetrahydrofuranyl diester 1 was isolated as an anti-bacterial constituent. 1 showed significant activities against three standard bacterial strains, including Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Salmonella enteritidis CMCC (B) 50041.

The preparation of neem oil microemulsion (Azadirachta indica) and the comparison of acaricidal time between neem oil microemulsion and other formulations in vitro.

The preparation of neem oil microemulsion and its acaricidal activity in vitro was developed in this study. In these systems, the mixture of Tween-80 and the sodium dodecyl benzene sulfonate (SDBS) (4:1, by weight) was used as compound surfactant; the mixture of compound surfactant and hexyl alcohol (4:1, by weight) was used as emulsifier system; the mixture of neem oil, emulsifier system and water (1:3.5:5.5, by weight) was used as neem oil microemulsion. All the mixtures were stired in 800 rpm for 15 min at 40 degrees C. The acaricidal activity was measured by the speed of kill. The whole lethal time value of 10% neem oil microemulsion was 192.50 min against Sarcoptes scabiei var. cuniculi larvae in vitro. The median lethal time value was 81.7463 min with the toxicity regression equations of Y=-6.0269+3.1514X. These results demonstrated that neem oil microemulsion was effective against Sarcoptes scabie var. cuniculi larvae in vitro.

[Interaction mechanism between Zn(II) and Saccharomyces cerevisiae using EXAFS].

The extended X-ray absorption fine structure spectroscopy (EXAFS) was used to investigate the mechanisms of interaction between Zn(II) and Saccharomyces cerevisiae. The nature of the zinc center in the yeast cells exposed to different Zn(II) concentrations and initial pH was determined by Zn K-edge X-ray absorption spectroscopy. The experimental results suggested that the adsorbed zinc ion on the yeast was the mixture of tetrahedron and octahedron structure, and Zn-O bond length changed within 0.197-0.203 nm and coordination number varied between 4.3 and 3.2 under different conditions. Increase of the initial concentration of Zn(II) and initial pH value decreased the coordination number of Zn-O. Zn-O bond length and coordination number of the live cells of the yeast was lower than that of dead cells.