Investigation of the Antiproliferative Properties of Natural Sesquiterpenes from Artemisia asiatica and Onopordum acanthium on HL-60 Cells in Vitro

Plants and plant extracts play a crucial role in the research into novel antineoplastic agents. Four sesquiterpene lactones, artecanin (1), 3β-chloro-4α,10α-dihydroxy-1α,2α-epoxy-5α,7αH-guaia-11(13)-en-12,6α-olide (2), iso-seco-tanapartholide 3-O-methyl ether (3) and 4β,15-dihydro-3-dehydrozaluzanin C (4), were isolated from two traditionally used Asteraceae species (Onopordum acanthium and Artemisia asiatica). When tested for antiproliferative action on HL-60 leukemia cells, these compounds exhibited reasonable IC₅₀ values in the range 3.6–13.5 μM. Treatment with the tested compounds resulted in a cell cycle disturbance characterized by increases in the G1 and G2/M populations, while there was a decrease in the S phase. Additionally, 1–3 elicited increases in the hypodiploid (subG1) population. The compounds elicited concentration-dependent chromatin condensation and disruption of the membrane integrity, as revealed by Hoechst 33258–propidium staining. Treatment for 24 h resulted in significant increases in activity of caspases-3 and -9, indicating that the tested sesquiterpenes induced the mitochondrial pathway of apoptosis. The proapoptotic properties of the sesquiterpene lactones were additionally demonstrated withannexin V staining. Compounds 1 and 2 increased the Bax/Bcl-2 expression and decreased the expressions of CDK1 and cyclin B2, as determined at the mRNA level by means of RT-PCR. These experimental results indicate that sesquiterpene lactones may be regarded as potential starting structures for the development of novel anticancer agents.     

New sesquiterpenes fromMaytenus species (Celastraceae). Taxonomic and chemotaxonomic considerations concerning chileanMaytenus

Three new dihydro--agarofuran sesquiterpenes from two species ofMaytenus were isolated and their structures were elucidated by means of¹H and¹³C NMR studies. The differences and similarities noted in the chemical content of the dihydro--agarofuran sesquiterpenes from the fourMaytenus species from Chile are in line with the taxonomic characterization of these species; their geographical distribution is also given.     

An automated system for use in collecting volatile chemicals released from plants

A system is described for the collection of volatiles produced by plants that minimizes stress on the plant in an environment that is free from chemical impurities. Air entering a volatile collection chamber containing a plant is purified using a nonwoven fabric media infused with charcoal. A multitasking, computer-automated system is described that can simultaneously collect volatilized chemicals from plants as well as monitor and record environmental conditions associated with those collections. Collection of up to 16 samples can be made in varying sampling order, flow rates, and user-specified time periods, without disturbing the sampling environment. During the same time period, this system is capable of simultaneously monitoring up to eight environmental parameters using any type of sensor with electrical signal outputs. A multiport base assembly was designed to fit around the base of the plant permitting air samples to be collected at the bottom of the chamber. The chamber can pass ambient light so the plant may follow its natural photocycles. The entire system can be configured for continuous laboratory duty or portable field use by utilizing components that run on DC voltages. For the purpose of testing the system's performance, we determined the periodicity of the release of volatiles from red and yellow flowering four o'clock plants,Mirabilis jalaba (Nyctaginaceae). The major chemical released from four o'clocks was identified as ocimene. The onset of release occurred between 1400 and 1600 hr and increased with time with maximum amount of ocimene released during 1800–2000 hr, followed by a decrease in emission. No ocimene was detected after 2400 hr. Determination of the amount of ocimene released per flower was calculated for the 1800- to 2000-hr time period. Based on the number of open flowers during the 1800- to 2000-hr period, yellow four o'clock's released 80.9 (±7.3 SD) ng/hr/flower, while the red flowers released 51.9 (±7.0 SD) ng/hr/flower.     

New Filling Technique and Performance Evaluations of the Cr3C2?C Peritectic Fixed Point

The Cr₃C₂?C peritectic fixed point was investigated to test its capability to serve as a practical high-temperature fixed point. An improved filling technique where C/C sheet works as a wick and graphite paper as a hopper was applied successfully, and the long-term stability of the peritectic cell was evaluated by means of radiation thermometry. The repeatability of the melting point in one day was 7 mK with a melting range of approximately 100 mK. The cell was aged for 7 days, and the evaluated 56 melting temperatures during this period all fall within 90 mK, with a standard deviation of 19 mK. X-ray transmission photos showed that the ingot was filled uniformly in the crucible. After the evaluation of long-term stability, no clear degradation of the ingot shape and no leakage of molten metal were observed. From these results, it can be concluded that the Cr₃C₂?C peritectic cell has good stability and robustness, and the new filling technique was established. The impurity effect on the Cr₃C₂?C peritectic cell was also investigated by adding tungsten powder to another cell as the impurity component. After the observation of melting and freezing plateaux, the cell was cut in half to analyze the microstructure by means of electron probe microanalysis (EPMA) and laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS). The high concentration of impurity was observed in the area of the chromium-rich domain (eutectic mixture of Cr₇C₃ and Cr₃C₂), which suggests that impurities were rejected from the Cr₃C₂ peritectic phase during the peritectic freezing and were accumulated in the Cr₇C₃?Cr₃C₂ eutectic phase. This explains why the impurity effect is more severe for the Cr₇C₃?Cr₃C₂ eutectic point than for the Cr₃C₂?C peritectic point.     

A comparative assessment of biofiltration and activated sludge diffusion for odour abatement

The deodorization performance of a biofilter and an activated sludge diffusion (AS) system was comparatively evaluated in terms of removal efficiency (RE) and process stability at empty bed residence times (EBRT) ranging from 94 to 32s. Both bioreactors were fed with a synthetic odorous emission containing H(2)S, butanone and toluene at 23.6-43.3, 4.3-6.3 and 0.4-0.6 mg m(-3), respectively. While the outlet H(2)S concentration was always lower than 1.4 mg m(-3), the REs for butanone and toluene remained higher than 95% in both bioreactors regardless of the EBRT. The continuous supply of wastewater in the AS unit did not affect removal and appeared to be a requirement for efficient pollutant abatement. Despite the narrow carbon source spectrum treated, the AS system maintained a large bacterial diversity over time. Therefore, the results obtained confirmed the potential of AS systems as a robust and efficient biotechnology for odour treatment in WWTPs.     

Off-plane anastigmatic imaging in Offner spectrometers

In this paper, the imaging performance of an Offner concentric imaging spectrometer is analyzed when the spectrometer entrance slit is disposed arbitrarily on the plane that is parallel to the grating grooves and contains the common center of curvature. Astigmatism-corrected designs are obtained for off-plane incidence on the grating if one point on the slit is located on the Rowland circle of the primary mirror. In this case, the combined system of primary mirror plus diffraction grating provides two astigmatic line images oriented parallel and orthogonal to the plane of diffraction, with the former located on the same plane as the slit. Consequently, these images can be brought to a single focus on this plane by the tertiary mirror if its radius of curvature is chosen properly. In addition, coma aberration is simultaneously removed. These results can be applied to the design of two-mirror or three-mirror spectrometers, generalizing the concept of the best imaging circle and providing solutions to get anastigmatic imaging for two object points and two wavelengths.     

Improving SCImago Journal &; Country Rank (SJR) subject classification through reference analysis

In order to re-categorize the SCImago Journal & Country Rank (SJR) journals based on Scopus, as well as improve the SJR subject classification scheme, an iterative process built upon reference analysis of citing journals was designed. The first step entailed construction of a matrix containing citing journals and cited categories obtained through the aggregation of cited journals. Assuming that the most representative categories in each journal would be represented by the highest citation values regarding categories, the matrix vectors were reduced using a threshold to discern and discard the weakest relations. The process was refined on the basis of different parameters of a heuristic nature, including (1) the development of several tests applying different thresholds, (2) the designation of a cutoff, (3) the number of iterations to execute, and (4) a manual review operation of a certain amount of multi-categorized journals. Despite certain shortcomings related with journal classification, the method showed a solid performance in grouping journals at a level higher than categories—that is, aggregating journals into subject areas. It also enabled us to redesign the SJR classification scheme, providing for a more cohesive one that covers a good proportion of re-categorized journals.     

Two-Bands Superconductivity with Intra- and Interband Pairing for Synthetic Superlattices

We consider a model for superconductivity in a two-band superconductor, having an anisotropic electronic structure made of two partially overlapping bands with a first hole-like and a second electron-like Fermi surface. In this pairing scenario, driven by the interplay between interband V _i,j and intraband V _i,i pairing terms, we have solved the two gap equations at the critical temperature T=T _c and calculate T _c and the chemical potential μ as a function of the number of carriers n for various values of pairing interactions, V _1,1, V _2,2, and V _1,2. The results show the complexity of the physics of condensates with multiple order parameters with the chemical potential near band edges.     

Thermotropic polyester: the influence of the spacer on the physical properties

Thermotropic polyesters prepared from series of 4,4-dihydroxy-,w-diphenoxy alkanes and 4,4-dichloroformyl-,w-diphenoxy alkanes are well known. The substitution of a methylenic spacer by an oxyethylenic spacer in the main chain of these polyesters drastically modifies their physical properties, particularly the mesogenic transition temperatures, as can be observed by DSC and thermooptical analysis. The thermal stability and the polymer solubility in common organic solvents of these polymers did not show a significant change. The physical properties of the two thermotropic polyesters prepared in diphenyl ether were evaluated.