Dynamic performance of a fungal biofilter packed with perlite for the abatement of hexane polluted gas streams using SIFT-MS and packing characterization with advanced X-ray spectroscopy

The use of Fusarium solani fungi in an expanded perlite packed biofilter was investigated for the treatment of a hexane polluted waste gas stream using selected ion flow tube mass spectrometry (SIFT-MS). The latter analytical technique proved to be of utmost importance to evaluate the performance of the biofilter at high time resolution (seconds) under various transient conditions, analogous to industrial situations. The biofilter was operational for 277 days with inlet loads varying between 1 and 14 g m^-3 h^-1 and applying an empty bed residence time of 116 s. The results showed a positive behaviour of the biofilter against different types of disruptions such as: (i) changes in the relative humidity of the inlet gas, (ii) stopping the carbon supply for 1, 5 and 10 days, (iii) varying the inlet hexane concentration (step increases and intermittent pulses) and (iv) limiting the availability of nutrients. X-ray imaging (both conventional 2D μCT and X-ray fluorescence, XRF) was applied for the first time on biofilter media in order to get insight in the internal structure of expanded perlite and to visualise the biomass growth. The latter in combination with online porosity measurements using SIFT-MS provides fundamental information regarding the biofiltration process.

Photocatalytic oxidation of selected gas-phase VOCs using UV light, TiO2, and TiO2/Pd

Heterogeneous photocatalytic oxidation systems using titanium dioxide (TiO₂) have been extensively studied for the removal of several volatile organic compounds (VOCs). The addition of noble metals such as palladium on TiO₂ may improve photocatalytic activity by increasing charge separation efficiency. In this work, palladium was impregnated on TiO₂ and the efficiency of the new catalyst was tested and compared with that of pure TiO₂. Pd was impregnated on TiO₂ by the reduction method, using NaBH₄, and was characterized by XRD, XPS, UV-Vis, and H₂ chemisorption. The photocatalytic tests were performed in an annular coated-wall reactor using octane, isooctane, n-hexane, and cyclohexane at inlet concentrations varying from 100 to 120 ppmv. Compared with pure TiO₂ film, the photocatalytic activity of TiO₂ impregnated with 1 wt% of palladium was improved. All the aforementioned analytical techniques confirmed the presence of Pd incorporated into the structure of TiO_2, and the conversion rates were studied in a broad range of residence times, yielding up to 90 % or higher rates in 40 s of residence time, thus underscoring the relevant contribution of the technology.

Absorption and recovery of n-hexane in aqueous solutions of fluorocarbon surfactants

n-Hexane is widely used in industrial production as an organic solvent. As an industrial exhaust gas, the contribution of n-hexane to air pollution and damage to human health are attracting increasing attention. In the present study, aqueous solutions of two fluorocarbon surfactants (FSN100 and FSO100) were investigated for their properties of solubilization and dynamic absorption of n-hexane, as well as their capacity for regeneration and n-hexane recovery by thermal distillation. The results show that the two fluorocarbon surfactants enhance dissolution and absorption of n-hexane, and their effectiveness is closely related to their concentrations in solution. For low concentration solutions (0.01%-0.30%), the partition coefficient decreases dramatically and the saturation capacity increases significantly with increasing concentration, but the changes for both are more modest when the concentration is over 0.30%. The FSO100 solution presents a smaller partition coefficient and a greater saturation capacity than the FSN100 solution at the same concentration, indicating a stronger solubilization for n-hexane. Thermal distillation is a feasible method to recover n-hexane from these absorption solutions, and to regenerate them. With 90sec heating at 80-85°C, the recovery of n-hexane ranges between 81% and 85%, and the regenerated absorption solution maintains its original performance during reuse. This study provides basic information on two fluorocarbon surfactants for application in the treatment of industrial n-hexane waste gases.

Hematological and lipid profile evaluation of a hexane fraction of Costus afer leaves in arthritic rats

CONTEXT

Costus afer Ker Gawl. (Costaceae) is an ethnomedical plant used as therapy against inflammatory disorders.

OBJECTIVE

The objective of this study was to evaluate the hematological and lipid profile analysis of hexane fraction of C. afer leaves (CAHLF) in arthritic rats.

MATERIALS AND METHODS

Male albino rats were randomly distributed into seven groups of six rats each. Rats were induced with arthritis using formaldehyde and Complete Freund's Adjuvant (CFA) for 7 and 21 d, respectively. The animals were administered orally with 50, 100, and 250 mg/kg CAHLF, 10 mg/kg diclofenac and prednisolone, 0.9% NaCl (control), and 0.9% NaCl (normal). At the end of treatment periods, blood samples were withdrawn and subjected to hematological and biochemical analysis using auto-analyzer and spectrophotometric methods.

RESULTS

Hematological analysis revealed that in formaldehyde- and CFA-induced arthritic rat models, 250 mg/kg CAHLF-treated groups had significantly reduced (p < 0.05) hematocrit counts (HC) (30.98 ± 1.59% and 33.55 ± 1.10%), white blood cell counts (WBC) (5.50 ± 0.35 and 4.15 ± 0.82 × 10(9)/L), and platelet counts (PC) (401.50 ± 48.94 and 246.33 ± 5.54 × 10(9)/L) compared with control HC (46.90 ± 1.92 and 41.88 ± 2.19%), WBC (11.09 ± 0.26 and 7.37 ± 0.34 × 10(9)/L), and PC (783.67 ± 59.51 and 593.83 ± 36.3 × 10(9)/L). Furthermore, blood analysis showed that CAHLF-treated groups had reduced total cholesterol, low-density lipoprotein cholesterol, and triglycerides while they had an elevated high-density lipoprotein compared with the control group.

DISCUSSION AND CONCLUSION

Findings from this study indicated that CAHLF could possess immunomodulatory and hypolipidemic properties in arthritic rats. CAHLF could be considered as a source of biopharmaceutical agents in anti-arthritis drug discovery process.

Neural networks and differential evolution algorithm applied for modelling the depollution process of some gaseous streams

The depollution of some gaseous streams containing n-hexane is studied by adsorption in a fixed bed column, under dynamic conditions, using granular activated carbon and two types of non-functionalized hypercross-linked polymeric resins. In order to model the process, a new neuro-evolutionary approach is proposed. It is a combination of a modified differential evolution (DE) with neural networks (NNs) and two local search algorithms, the global and local optimizers, working together to determine the optimal NN model. The main elements that characterize the applied variant of DE consist in using an opposition-based learning initialization, a simple self-adaptive procedure for the control parameters, and a modified mutation principle based on the fitness function as a criterion for reorganization. The results obtained prove that the proposed algorithm is able to determine a good model of the considered process, its performance being better than those of an available phenomenological model.

Hexane abatement and spore emission control in a fungal biofilter-photoreactor hybrid unit

The performance of a fungal perlite-based biofilter coupled to a post-treatment photoreactor was evaluated over 234 days in terms of n-hexane removal, emission and deactivation of fungal spores. The biofilter and photoreactor were operated at gas residence times of 1.20 and 0.14min, respectively, and a hexane loading rate of 115±5gm(-3)h(-1). Steady n-hexane elimination capacities of 30-40gm(-3)h(-1) were achieved, concomitantly with pollutant mineralization efficiencies of 60-90%. No significant influence of biofilter irrigation frequency or irrigation nitrogen concentration on hexane abatement was recorded. Photolysis did not support an efficient hexane post-treatment likely due to the short EBRT applied in the photoreactor, while overall hexane removal and mineralization enhancements of 25% were recorded when the irradiated photoreactor was packed with ZnO-impregnated perlite. However, a rapid catalyst deactivation was observed, which required a periodic reactivation every 48h. Biofilter irrigation every 3 days supported fungal spore emissions at concentrations ranging from 2.4×10(3) to 9.0×10(4)CFUm(-3). Finally, spore deactivation efficiencies of ≈98% were recorded for the photolytic and photocatalytic post-treatment processes. This study confirmed the potential of photo-assisted post-treatment processes to mitigate the emission of hazardous fungal spores and boost the abatement performance of biotechnologies.

Composition and Antimicrobial Activity of Essential Oil and HexaneÐEther Extract of Tanacetum santolinoides (DC.) Feinbr. and Fertig

The essential oil of the aerial parts of Tanacetum santolinoides was analyzed by capillary GLC and GLC-MS. Altogether 30 components were identified. The main constituents were thymol (18%), trans-thujone (17.5%), trans-chrysanthenyl acetate (13.2%), cis-chrysanthenyl acetate (9.2%), umbellulone (9.7%) and 1,8-cineole (4.7%). Similar essential oil pattern in addition to palmitic acid methyl ester, palmitic acid, stigmasterol, sitosterol and two flavonoidal aglycons were found in the n-hexane-ether extract. The oil showed strong in vitro activity against E. coli, Bacillus subtilis and Candida albicans.

A membrane bioreactor for the simultaneous treatment of acetone, toluene, limonene and hexane at trace level concentrations

The performance of a flat-membrane biofilm reactor (MBR) for the removal of acetone, toluene, limonene and hexane at concentrations ranging from 1.3 to 3.2 mg m(-3) was investigated at different gas residence times (GRT): 60, 30, 15 and 7 s. A preliminary abiotic test was conducted to assess the mass transport of the selected volatile organic compounds (VOCs) through the membrane. A reduced transport of limonene and hexane was observed with water present over the dense side of the membrane. The presence of a biofilm attached on the dense side of the membrane following bioreactor inoculation significantly increased VOC transport. High acetone and toluene removals (>93%) were recorded in the MBR regardless of the GRT. To remediate the low hexane removal performance (RE < 24%) recorded at the initial stages of the process, a re-inoculation of the membrane with a hexane-degrading consortium embedded in silicon oil was performed. Although hexane removal did not exceed 27%, this re-inoculation increased limonene removals up to 90% at a GRT of 7 s. The absence of inhibition of hexane biodegradation by substrate competition confirmed that hexane removal in the MBR was indeed limited by the mass transfer through the membrane. Despite the low carbon source spectrum and load, the microbiological analysis of the communities present in the MBR showed high species richness (Shannon-Wiener indices of 3.2-3.5) and a high pair-wise similarity (84-97%) between the suspended and the attached biomass.

Effect of methanol on the biofiltration of n-hexane

This study investigated the removal of recalcitrant compounds in the presence of a hydrophilic compound. n-Hexane is used as a model compound to represent hydrophobic compounds. Methanol has been introduced in mixture with n-hexane in order to increase the bioavailability of n-hexane in trickle-bed-air-biofilters (TBABs). The mixing ratios investigated were: 70% methanol:30% n-hexane, and 80% methanol:20% n-hexane by volume. n-Hexane loading rates (LRs) ranged from 0.9 to 13.2 g m(-3) h(-1). Methanol LRs varied from 4.6 to 64.5 g m(-3) h(-1) and from 2.3 to 45.2 g m(-3) h(-1) depending upon the mixing ratio used. Biofilter performance, effect of mixing ratios of methanol to n-hexane, removal profile along biofilter depth, COD/nitrogen consumption and CO(2) production were studied under continuous loading operation conditions. Results have shown that the degradation of n-hexane is significantly enhanced by the presence of methanol for n-hexane LRs less than 13.2 g m(-3) h(-1). For n-hexane LR greater than 13.2 g m(-3) h(-1), even though methanol had impacted n-hexane biodegradation, its removal efficiency was higher than our previous study for biodegradation of n-hexane alone, in presence of surfactant, or in presence of benzene. On the other hand, the degradation of methanol was not impacted by the presence of n-hexane.

Separation of n-hexane/acetone mixtures by pervaporation using high density polyethylene/ethylene propylene diene terpolymer rubber blend membranes

Polymer membranes were prepared by blending high density polyethylene (HDPE) with ethylene propylene diene terpolymer rubber (EPDM). These blend membranes were evaluated for the selective separation of n-hexane from acetone. The flux and selectivity of the membranes were determined both as a function of the blend composition and feed mixture composition. Results showed that polymer blending method could be very useful to develop new membranes with improved selectivity. Pervaporation properties could be optimized by adjusting the blend composition. The effects of blend ratio, feed composition, and penetrant size on the pervaporation process were analyzed. The permeation properties have been explained on the basis of interaction between the membrane and solvents and blend morphology. Flux increases with increasing alkane content in the feed composition.

Developing the procedure of modifying the denture soft liner by silver nanoparticles

Colonization of denture soft lining materials by fungi and denture plaque leads to infections of mucosa. Microorganisms such as Candida albicans colonize not only the surface of the soft liners, but they also penetrate inside those materials. Therefore the use of common disinfectants, e.g., surface active cleaners, is not a perfect solution for keeping a proper hygiene of soft linings. Modifying soft lining by silver nanoparticles (AgNP) seems to be a right way to overcome those problems. The procedure of modifying two-component silicone material by silver nanoparticles (AgNP) is presented in the article. The solubility tests for both material components have been carried out in the first stage of examinations. On the basis of test results, a solvent has been selected, being a dispersion medium for AgNPs and both soft liner components. The effective method for evaporating a solvent from the composition has been developed. Material components with various AgNP concentrations (10, 20, 40, 80, 120 and 200 ppm) have been obtained. Cured samples of the composites have been examined by SEM to confirm the effectiveness of the procedure.

Treatment of benzene and n-hexane mixtures in trickle-bed air biofilters

Trickle-bed air biofilters (TBABs) are suitable for treatment of hydrophilic volatile organic compounds, but they pose a challenge for hydrophobic compounds. Three laboratory-scale TBABs were used for the treatment of an airstream contaminated with different ratios of n-hexane and benzene mixtures. The ratios studied were 1:1, 2:1, and 1:3 n-hexane:benzene by volume. Each TBAB was operated at a pH of 4 and a temperature of 20 degrees C. The use of acidic-buffered nutrient solution was targeted for changing the microorganism consortium to fungi as the main biodegradation element. The experimental plan was designed to investigate the long-term performance of the TBABs with an emphasis on different mixture loading rates, removal efficiency with TBAB depth, volatile suspended solids, and carbon mass balance closure. n-Hexane loading rate was kept constant in the TBABs for comparison reasons and ranged from 4 to 22 g/(m3 x hr). Corresponding benzene loadings ranged from 4 to 43 g/(m3 x hr). Generally, benzene behavior in the TBAB was superior to that of n-hexane because of its higher solubility. n-Hexane showed improved performance in the 2:1 mixing ratio as compared with the other two ratios.

Effect of aggregate structure on VOC gas adsorption onto volcanic ash soil

The understanding of the gaseous adsorption process and the parameters of volatile organic compounds such as organic solvents or fuels onto soils is very important in the analysis of the transport or fate of these chemicals in soils. Batch adsorption experiments with six different treatments were conducted to determine the adsorption of isohexane, a gaseous aliphatic, onto volcanic ash soil (Tachikawa loam). The measured gas adsorption coefficient for samples of Tachikawa loam used in the first three treatments, Control, AD (aggregate destroyed), and AD-OMR (aggregate destroyed and organic matter removed), implied that the aggregate structure of volcanic ash soil as well as organic matter strongly enhanced gas adsorption under the dry condition, whereas under the wet condition, the aggregate structure played an important role in gas adsorption regardless of the insolubility of isohexane. In the gas adsorption experiments for the last three treatments, soils were sieved in different sizes of mesh and were separated into three different aggregate or particle size fractions (2.0-1.0mm, 1.0-0.5mm, and less than 0.5mm). Tachikawa loam with a larger size fraction showed higher gas adsorption coefficient, suggesting the higher contributions of macroaggregates to isohexane gas adsorption under dry and wet conditions.

DC corona electric discharges for air pollution control. Part 1. Efficiency and products of hydrocarbon processing

A large (ca 0.7 L) wire-cylinder benchtop reactor was developed and tested for DC corona processing of VOC (volatile organic compound)-contaminated air at room temperature and pressure. The aim of our research is the identification and rationalization of the chemical reactions responsible for VOC removal. Model hydrocarbons, n-hexane and 2,2,4-trimethylpentane (i-octane), were used to characterize the process and compare the effects of DC corona polarity and of humidity on its energy efficiency and products. n-Hexane and i-octane behave very similarly. For both, the energy efficiency is significantly better with negative than with positive DC corona, especially in humid air. The effect of humidity is most interesting. Thus, while with -DC corona the process efficiency is significantly better in humid air, a slight inhibition is observed with +DC corona. Differences between +DC and -DC corona are also found in the amounts of volatile products formed, which include CO2, CO, and minor quantities of organic byproducts (aldehydes, ketones, alcohols, and lower hydrocarbons). A significant fraction of the carbon originally present as VOC is, however, unaccounted for by the analysis of gaseous and volatile organic products and must, therefore, end up as nonvolatile materials and aerosols.

Enhanced selective extraction of hexane from hexane/soybean oil mixture using binary gas mixtures of carbon dioxide

Carbon dioxide (CO2) can effectively separate hexane from a mixture of soybean oil (SBO) and hexane with a slight coextraction of SBO. Previous research demonstrated that CO2 entrained with helium significantly reduced SBO solubility in CO2. In this study, CO2 was mixed with three gases (He, N2, or Ar) (0.5-30 vol %) to decrease SBO solubility while attempting to maintain hexane solubility. The binary gas mixtures (at 25 degrees C and 9.31 MPa) were passed through a 25 wt % hexane/SBO mixture inside a 2.5 m fractionation column. Coextracted SBO was inversely proportional to binary gas concentration, whereas residual hexane in the raffinate was proportional to binary gas concentration. The 10% binary mixture of N2 or Ar was the best compromise to obtain both low residual hexane levels (i.e., 26 ppm) and low SBO coextraction (i.e., only 40 mg). This carry-over of SBO represents a 95% reduction in SBO carry-over compared to neat CO2.

Supercritical fluid chromatographic analysis for on-line monitoring of hexane removal from soybean oil miscella using liquid carbon dioxide

Liquid carbon dioxide (L-CO2) can be used to separate hexane from hexane/soybean oil (SBO) mixtures (i.e., miscella). An on-line supercritical fluid chromatographic (SFC) method was developed to monitor this separation. L-CO2 (25 degrees C and 9.31 MPa) was passed through 50 mL of a 25% (w/w) hexane miscella and then directed on-line through a SFC injector. After passing 300-L expanded CO2, the hexane concentrations in the L-CO2 were 0.05% and 0.04% for n-hexane and isohexane, respectively and the residual hexane concentrations in the SBO were 3.8 and 3.3 ppm, respectively. This technique provided real time on-line monitoring of the hexane separation process.

Comparative study on the gas-phase adsorption of hexane over zeolites by calorimetry and inverse gas chromatography

The scope of this work is to carry out a systematic comparison of inverse gas chromatography (IGC) and microcalorimetry as tools for the study of the gas-phase adsorption of organic vapours (using hexane as model compound) on zeolitic materials (using different Mn, Co and Fe-exchanged NaX and CaA zeolites). Adsorption isotherms were recorded using both techniques in the temperature range of 150-250 degrees C, being observed that the shape of the isotherms obtained with the dynamic (IGC) and static (microcalorimetry) techniques was surprisingly similar in the pressure range at which both techniques are applicable (low surface coverages). Concerning to the measurement of the strength of the adsorption, calorimetric data provide two parameters related to the adsorption enthalpy: the initial differential heat and the isosteric adsorption enthalpy. A great coincidence was found between the last one and the adsorption enthalpy determined by IGC (4-20% of difference, depending on the studied material). The behaviour of the initial differential heat depends strongly on the studied material, being in some cases closely related to the other two parameters and temperature-independent (in the case on Mn-exchanged zeolites), whereas for the Co-CaA and Fe-CaA zeolites, it is temperature-dependent, being not correlated with the other parameters in this case. The main conclusion of this work is that IGC is an attractive alternative to the static microcalorimetric data for obtaining information on the adsorption of organic compounds on microporous materials.

Hypoglycaemic and antidiabetic activity of acetonic extract of Vernonia colorata leaves in normoglycaemic and alloxan-induced diabetic rats

The aqueous extract of Vernonia colorata (Willd.) Drake (Composeae) leaves is used by African traditional medicine practitioners as a remedy for the treatment of diabetes. Our previous studies have shown the hypoglycaemic activity of the aqueous extract of Vernonia colorata leaves (300 mg/kg, per os) in normoglycaemic rats. The aim of the present study was to investigate the hypoglycaemic and antidiabetic activity of acetonic and hexanic extracts of the leaves of Vernonia colorata in order to further discriminate the type of extract which provides a better antidiabetic activity. Experiments were performed in normoglycaemic and alloxan-induced diabetic rats. The acetonic extract of the leaves of Vernonia colorata (AELVC) (100 mg/kg, per os) induced a significant decrease of blood glucose in normoglycaemic rats. The glycaemia varied from 4.72+/-0.11 to 3.72+/-0.22 mmol/l (p<0.05, n=5) 3 h after AELVC administration per os. In contrast, the hexanic extract of the leaves of Vernonia colorata (HELVC) increased significantly the glycaemia in normoglycaemic rats. Like glibenclamide, AELVC has an antihyperglycaemic effect in oral glucose tolerance test (OGTT) and alloxan-induced diabetic rats. These results have shown that: (i) AELVC and HELVC have an opposite effect on basal blood glucose in normoglycaemic rats, suggesting that the mechanisms of action of both above-mentioned extracts are different; (ii) AELVC has also an antidiabetic activity in hyperglycaemic rat models.

Improving hexane removal by enhancing fungal development in a microbial consortium biofilter

The removal of hydrophobic pollutants in biofilters is often limited by gas liquid mass transfer to the biotic aqueous phase where biodegradation occurs. It has been proposed that the use of fungi may improve their removal efficiency. To confirm this, the uptake of hexane vapors was investigated in 2.6-L perlite-packed biofilters, inoculated with a mixed culture containing bacteria and fungi, which were operated under neutral or acid conditions. For a hexane inlet load of around 140 g.m-3.h-1, elimination capacities (EC) of 60 and 100 g.m-3.h-1 were respectively reached with the neutral and acid systems. Increasing the inlet hexane load showed that the maximum EC obtained in the acid biofilter (150 g.m-3.h-1) was twice greater than in the neutral filter. The addition of bacterial inhibitors had no significant effect on EC in the acid system. The biomass in the acid biofilter was 187 mg.g-1 (dry perlite) without an important pressure drop (26.5 mm of water.m-1reactor). The greater efficiency obtained with the acid biofilter can be related to the hydrophobic aerial hyphae which are in direct contact with the gas and can absorb the hydrophobic compounds faster than the flat bacterial biofilms. Two fungi were isolated from the acid biofilter and were identified as Cladosporium and Fusarium spp. Hexane EC of 40 g.m-3.h-1 for Cladosporium sp. and 50 g.m-3.h-1 for Fusarium sp. were obtained in short time experiments in small biofilters (0.230 L). A biomass content around 30 mg.g-1 (dry perlite) showed the potential for hexane biofiltration of the strains.

Performance of an Internal-Loop Airlift Bioreactor for Treatment of Hexane-Contaminated Air

Hexane is a toxic volatile organic compound that is quite abundant in gas emissions from chemical industries and printing press and painting centers, and it is necessary to treat these airstreams before they discharge into the atmosphere. This article presents a treatment for hexane-contaminated air in steady-state conditions using an internal-loop airlift bioreactor inoculated with a Pseudomonas aeruginosa strain. Bioprocesses were conducted at 20-mL/min, a load of 1.26 gm3 of C6H14, and a temperature of 28 degrees C. The results of hexane removal efficiencies were presented as a function of the inoculum size (approx 0.07 and 0.2 g/L) and cell reuse. Bioprocess monitoring comprises quantification of the biomass, the surface tension of the medium, and the hexane concentration in the fermentation medium as well as in the inlet and outlet airstreams. The steady-state results suggest that the variation in inoculum size from 0.07 to 0.2 g/L promotes hexane abatement from the influent from 65 to 85%, respectively. Total hydrocarbon removal from the waste gas was achieved during experiments conducted using reused cells at an initial microbial concentration of 0.2 g/L.

Anxiogenic activity of Myristica fragrans seeds

In the present study, the n-hexane extract of Myristica fragrans (MF) seeds, acetone-insoluble part of the n-hexane extract (AIMF) and trimyristin (TM) were assessed for their anxiogenic activity. The MF (10 and 30 mg/kg), AIMF (30, 100, and 300 mg/kg), and TM (10, 30, and 100 mg/kg) administered intraperitoneally exhibited anxiogenic activity in elevated plus-maze (EPM) paradigm. The open-field test and hole-board test were also used to assess anxiogenic activity of AIMF and TM. In the EPM test, MF, AIMF, and TM decreased the time spent by mice in the open arm and the entries in the open arm. Further, the effect of diazepam (1 mg/kg i.p.), serotonin 5-HT3 receptor antagonist, ondansetron (1 mg/kg i.p.), and 5-HT1A receptor agonist, buspirone (1 mg/kg i.p.), on the occupancy in open arm and entries in open arm was significantly reduced by TM. In the open-field test, AIMF as well as TM reduced the number of rearing and locomotion. Both TM and AIMF reduced the number of head pock in the hole-board test. Inhibition of anxiolytic activity of ondansetron (5-HT3 receptor antagonist), buspirone (5-HT1A receptor agonist), and diazepam [acting on gamma-aminobutyric acid (GABAA) receptor] suggests a nonspecific anxiogenic activity of TM and also a link between 5-HT and GABA systems in the anxiogenic activity of TM.

Enantiomer separation of hydrocarbons in preparation for ROSETTA's "chirality-experiment"

Until now the favored method for separating racemic pairs of underivatized alcohols, diols, and phenylsubstituted amines has been gas chromatography on cyclodextrin phases. However, certain enantiomers of saturated chiral hydrocarbons could not be resolved in this way because they lack the functional groups necessary to undergo "intensive" diastereomeric interactions with the cyclodextrins. The present study describes a gas-chromatographic technique for resolution of saturated aliphatic hydrocarbons into their enantiomers and presents a brief discussion of the possible applications. The (enantiomer) separations were performed in preparation for the Cometary Sampling and Composition Experiment on board the cometary lander RoLand, part of ESA's cornerstone mission ROSETTA. This experiment has been designed to investigate the hypotheses that biomolecular asymmetry has an interstellar origin and to separate and identify a wide range of organic enantiomers in situ on the surface of a comet's nucleus.