Search

Highlights • A Mixed-Integer programming model was developed to attain an optimal solution to the MSW management. • The model allocates the various types and amounts of wastes to different processes (recycling, composting and landfilling). • An LFG-to-energy system is designed by considering the dynamic behavior of the LFG generation in the landfill. • The model is applied to a case study in a municipality in Mexico. • Results confirm that LFG used to produce electricity reduces the economic burden of MSW management. Abstract A multi-period approach to municipal solid waste (MSW) management is proposed. The analysis includes the optimization of a MSW network considering waste reduction processes and landfilling. The optimization of the transportation of MSW to its potential destinations has been addressed using a direct-hauling system and an optimally allocated off-municipality transfer station. As the main component in the formulation, an optimal landfill gas (LFG) to energy design is obtained to improve the economics of the landfill operation; the design involves the installation of several harnessing technologies according to the annual increase or decay of the LFG flow rate. A case-study for a municipality in Mexico has been solved through the GAMS® modeling environment. The resulting mixed-integer linear programming (MILP) model has been assessed through several scenarios. The results show that the installation of an LFG-to-electricity system and a materials recycling facility achieve the minimum overall cost of the MSW management. [ABSTRACT FROM AUTHOR]

Research was conducted to examine the variability of the size structure of the phytoplankton community in the deep or subsurface chlorophyll maximum (DCM) layer of the Alboran Sea (southwestern Mediterranean). The position of the Atlantic-Mediterranean interface was used as a tracer for cyclonic or anticyclonic dynamics and their potential biological effects. Results indicate that picoplankton biovolume in the deep fluorescence maxima (DFM) was independent of the type of circulation while nanoplankton increased their absolute and relative presence in the DFM under upswelling dynamics.

Abstract: A review of the pathological features of Hodgkin lymphoma manifesting with exclusive or preponderant lung involvement is given for 5 patients. Three patients were men and 2 were women, with an age range 17 to 48 years (median, 42 years). They presented with nonspecific symptoms including dry cough, fever, or chest pain. Initial clinical assessment suggested a lung tumor. Pathological evaluation was carried out on lung biopsy, wedge resection, lobectomy, or pneumonectomy specimens. All the cases showed diagnostic Reed Sternberg cells within the proper background. Immunopositivity for CD15 and CD30 was documented as well. Nodular sclerosing and mixed cellularity were the documented subtypes. Additional histologic features were a pronounced nodular growth pattern with or without necrosis, a diffuse hypersensitivity pneumonia-like picture, or acute pneumonia-like changes. Our study confirms that the recognition of Hodgkin lymphoma in lung, although based on well-established morphologic criteria, may represent a source of interpretative problems because of the unusual clinical presentation as well as the peculiar histologic changes induced within the pulmonary microenvironment. [Copyright &y& Elsevier]

Abstract: The exudate and seriated extracts from the aerial parts of Baccharis grisebachii (Asteraceae) which is recommended as a digestive and to relieve gastric ulcers in Argentina, showed activity as free radical scavengers and inhibited lipoperoxidation in erythrocytes. Assay-guided isolation led to seven p-coumaric acid derivatives and six flavonoids as the main active constituents of the crude drug. The activity towards the superoxide anion was mainly due to the flavonoid constituents. 5,7,4′-Trihydroxy-6-methoxyflavone and quercetin presented high activity (64 and 79%) even at 12.5μg/ml. The xanthine oxidase inhibitory effect of the extracts can be related with the p-coumaric acid derivatives drupanin, 4-acetyl-3,5-diprenylcinnamic acid and trans-ferulic acid O-hexan-3-onyl-ether which showed IC50 values in the range 28–40μg/ml. Both p-coumaric acid derivatives and flavonoids inhibited lipoperoxidation in erythrocytes. The highest activity was found for the p-coumaric acid derivatives 4-acetyl-3-prenyl-ethoxycinnamate, 3-prenyl-4-(4′-hydroxydihydrocinnamoyloxy)-cinnamate and trans-ferulic acid O-hexan-3-onyl-ether (69–82%) and the flavonoids 5,7,4′-trihydroxy-6-methoxyflavone, quercetin, 5,7,4′-trihydroxy-6,3′-dimethoxyflavone and 5,7,4′-trihydroxy-6,8-dimethoxyflavone (64–84%) at 100μg/ml. The most active free radical scavengers measured by the DPPH decoloration assay were the p-coumaric acid derivatives drupanin and trans-ferulic acid O-hexan-3-onyl-ether (27–35% at 10μg/ml) and the flavonoid quercetin (97 and 23% at 10 and 1μg/ml, respectively). The results support the use of Baccharis grisebachii in Argentinian traditional medicine. [Copyright &y& Elsevier]

A methodology for the machinability assessment of steel is proposed based on the direct measurement of cutting forces and surface roughness, along with the development of an aggregate machinability indicator. Experimental work for the verification of the validity of this testing scheme was carried out at different cutting condition combinations using three grades of steel, namely, 1018 (Low Carbon, Cold-Rolled Steel), 304 (Austenitic Stainless Steel), and 4140 (Low-Alloy Steel) and uncoated carbide inserts as the tool material. Mathematical models are developed for predicting the forces acting on the tool for different cutting conditions and materials. The test results show that the developed indicator provides a number of advantages: (1) an adequate estimate of a material’s machinability; (2) a cost effective method for machinability testing. [Copyright &y& Elsevier]

The labdane diterpene solidagenone 1 and its semisynthetic and biotransformations products 2–7 were assessed for gastroprotective effect in the HCl·EtOH-induced lesions in mice. At 100 mg/kg, solidagenone presented a statistically significant gastroprotective effect (P<0.05) comparable to lansoprazole at 20 mg/kg. The presence of the furan ring was required for the activity of solidagenone while hydroxylation at C-3 or C-6 afforded products with different activity associated with the stereochemistry. Solidagen-6β-ol 7 and 3α-hydroxysolidagenone 2 presented higher activity than solidagenone itself, while its epimers were inactive. [Copyright &y& Elsevier]

Presents a study which analyzed the size structure and the functional composition of the Antarctic phytoplankton. Methods; Results; Discussion.

Abstract: In our search for potential anticancer agents, a series of 8- and 9-phenylamino-3,4-tetrahydro-phenanthridine-1,7,10(2H)-triones with substituent variations at 6-, 8- and 9-positions were prepared using a highly efficient sequence involving: a) solar photoacylation reactions of benzoquinone with arylaldehydes, b) one-pot procedure for the synthesis of 3,4-dihydrophenanthridine-1,7,10(2H)-trione intermediates from acylhydroquinones and c) highly regiocontrolled acid-induced amination reaction of phenanthridinequinones with phenylamines. The members of this series were in vitro evaluated using the MTT colorimetric method against one normal cell line and three human cancer cell lines. The SAR analysis indicates that the location of nitrogen substituents on the quinone nucleus, the presence of methyl, phenyl, furyl and thienyl groups at the 6-position and the aromatization of the angular cycloaliphatic ring of the phenylamino-3,4-tetrahydrophenanthridine-1,7,10(2H)-trione pharmacophore play key roles in the antitumor activity. [Copyright &y& Elsevier]

Abstract: This work evaluates linoleic acid peroxidation reactions initiated by Fe3+-reducing compounds recovered from Eucalyptus grandis, biotreated with the biopulping fungus Ceriporiopsis subvermispora. The aqueous extracts from biotreated wood had the ability to reduce Fe3+ ions from freshly prepared solutions. The compounds responsible for the Fe3+-reducing activity corresponded to UV-absorbing substances with apparent molar masses from 3kDa to 5kDa. Linoleic acid peroxidation reactions conducted in the presence of Fe3+ ions and the Fe3+-reducing compounds showed that the rate of O2 consumption during peroxidation was proportional to the Fe3+-reducing activity present in each extract obtained from biotreated wood. This peroxidation reaction was coupled with in-vitro treatment of ball-milled E. grandis wood. Ultraviolet data showed that the reaction system released lignin fragments from the milled wood. Size exclusion chromatography data indicated that the solubilized material contained a minor fraction representing high-molar-mass molecules excluded by the column and a main low-molar-mass peak. Overall evaluation of the data suggested that the Fe3+-reducing compounds formed during wood biodegradation by C. subvermispora can mediate lignin degradation through linoleic acid peroxidation. [ABSTRACT FROM AUTHOR]

Abstract: Pinus taeda wood chips were treated with the biopulping fungus Ceriporiopsis subvermispora in soybean-oil-amended cultures. The secretion of oxalic acid and the accumulation of thiobarbituric acid reactive substances were significantly increased in soybean-oil-amended cultures. By contrast, the secretion of hydrolytic and oxidative enzymes was not altered in the cultures. Biotreated wood samples were characterized for weight and component losses as well as by in-situ thioacidolysis. Residual lignins were also extracted from biotreated wood using a mild-non-razing extraction procedure. The lignins were characterized by 31P nuclear magnetic resonance (31P-NMR) spectroscopy. Soybean oil amendment in the cultures was found to affect lignin degradation routes; however, it inhibited depolymerization reactions detectable in the residual lignin that was retained in the biotreated wood. As a consequence, chemithermomechanical pulping of the biotreated samples was not improved by soybean oil amendment in the cultures. [ABSTRACT FROM AUTHOR]

Abstract: Current issues in cancer research involve searching for novel anticancer compounds that can be used to regulate the cell cycle and lead to more effective treatments of tumors. In this study, it was hypothesized that possessing a cyclic alkaloid similar to harmine, arborescidines can disrupt the proliferative state of cancer cells and block the activity of topoisomerases. The antiproliferative activity of arborescidines A–C and their derivatives was evaluated in vitro against four human tumor cell lines: gastric adenocarcinoma, lung cancer, bladder carcinoma and leukemia. Assuming the mechanism of action by topoisomerase II binding model, the compounds possessing the greatest activity had nonpolar side-chain into hydrophobic binding region on the DNA/topo II complex. [Copyright &y& Elsevier]

Abstract: A variety of 7-aminoisoquinoline-5,8-quinone derivatives were prepared from 2,5-dihydroxyacetophenone, methyl aminocrotonate, and the corresponding amines, through a highly efficient three-step sequence. The members of this series were tested on normal human fibroblasts and on a panel of three human cancer cell lines and their redox properties were determined by cyclic voltammetry in acetonitrile. Both the cytotoxicity and antitumor activity of 7-phenylaminoisoquinoline-5,8-quinone derivatives showed correlation with their half wave potentials and lipophilicities. [Copyright &y& Elsevier]

Abstract: In the search for new potentially anticancer drugs, isoquinolinequinone-containing polycyclic compounds have been designed and synthesized through highly regiocontrolled cycloaddition reactions of methyl 1,3-dimethyl-5,8-dioxo-5,8-dihydroisoquinoline-4-carboxylate with polarized 1,3-dienes and a thiazole-o-quinodimethane. The new N-heterocyclic quinones were tested on normal human fibroblasts and four distinct human cancer cell lines. Two of the evaluated compounds displayed significant in vitro activity (IC50: 0.44–5.9μM) comparable to that of the reference drug etoposide. [Copyright &y& Elsevier]

The benzoquinone embelin and four alkyl phenols were isolated from an Argentinean collection of Oxalis erythrorhiza. 3-Heptadecyl-5-methoxy-phenol is reported for the first time. The structures were determined by spectroscopic methods. Embelin presented inhibitory effect on methicillin-resistant Staphylococcus aureus, Escherichia coli and the dermatophytic fungi Epidermophyton floccosum, Microsporum canis, Microsporum gypseum, Trichophyton mentagrophytes and Trichophyton rubrum with MICs ranging between 50 and 100 μg/ml. Furthermore, embelin was active against Trypanosoma cruzi trypomastigotes with 100% lysis at 100 μg/ml and cytotoxicity below the trypanocidal concentration. The new alkyl phenol 3-heptadecyl-5-methoxy-phenol was active towards Leishmania amazonensis and Leishmania donovani promastigotes with 100% lysis at 100 μg/ml. The cytotoxicity (IC50) of embelin and the new alkyl phenol on human lung fibroblasts were 739 and 366 μM, respectively. The plant is used to treat heart complains, a symptomatology related to Chagas’ disease which is endemic in the San Juan Province, Argentine. [Copyright &y& Elsevier]