Scavengers for achieving zero formaldehyde emission of wood-based panels     

Nuno A. Costa  João Pereira  João Ferra  Paulo Cruz  Jorge Martins  Fernão D. Magalhães  Adélio Mendes  Luísa H. Carvalho 《Wood Science and Technology》2013,47(6):1261-1272

This work examines the performance of three formaldehyde scavengers in wood-based panels. Sodium metabisulfite, ammonium bisulfite and urea were applied in different physical forms during particleboard production, and the resulting physico-mechanical properties (internal bond strength, thickness swelling, density and moisture content) and formaldehyde emission levels were compared. Formaldehyde content was measured using the perforator method, and formaldehyde emission was evaluated both by desiccator and gas analysis methods. The chemical reactions involved in each formaldehyde scavenging process are proposed and discussed. The tested scavengers showed distinct performances under the different emission testing conditions, which were interpreted in terms of the stability of the chemical compounds formed upon formaldehyde capture. Sodium metabisulfite proved to be an excellent scavenger for all formaldehyde methods allowing the production of particleboard panels with zero formaldehyde emission.  相似文献   

Long term losses caused by foliar diseases on growth and survival of Eucalyptus globulus in Uruguay     

Gustavo Balmelli  Sofía Simeto  Nora Altier  Virginia Marroni  Julio J. Diez 《New Forests》2013,44(2):249-263

Eucalyptus globulus is the most important forest species in Uruguay, with more than 250,000 ha of commercial plantations. Despite its high susceptibility to diseases, production losses caused by foliar diseases have not been properly quantified in this country. This study analyzes the effects of foliar damage on growth and survival using data from a progeny test of E. globulus naturally infected by Teratosphaeria leaf disease and eucalypt rust (Puccinia psidii). The severity of leaf spots and defoliation were quantified 8 months after planting and tree growth and mortality were evaluated 2, 4 and 6 years later. The trial had a high incidence of foliar damage, with a mean leaf spot severity of 28.7% and a mean defoliation of 37%. The greatest impact of foliar damage, both on growth rate and mortality, occurred in the first 2 years after damage was assessed. During this period, leaf spot severity less than 40% and defoliation below 50% did not affect growth, while survival was affected when leaf damage was 70% or greater. By the sixth year both stem growth and survival were affected by severe foliar damage (spotting or defoliation of 80% or more), with a loss of up to 25% in diameter and an accumulated mortality over 70%. It has been established for the first time that under the intensive Uruguayan productive conditions, E. globulus trees can tolerate a relatively high degree of leaf spotting or defoliation but severe foliar damage in the first months can cause considerable production losses, putting at risk the economical viability of this species.  相似文献   

Validity and feasibility of qualitative behavior assessment for the evaluation of Nellore cattle temperament     

Aline C. Sant’Anna  Mateus J.R. Paranhos da Costa 《Livestock Science》2013,157(1):254-262

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Physiological changes in boysenberry fruit during growth and ripening     

R. Ariel Vicente  Lorenza Costa  Fortunato Covatta  A. MartÍnez Gustavo  R. Alicia Chaves  M. Pedro Civello 《The Journal of Horticultural Science and Biotechnology》2013,88(3):525-531

Summary

Boysenberries (Rubus hybrid) were harvested at five developmental stages (green, “turning”, pink, red and purple) to study changes associated with flavour, colour and firmness, with a particular focus on the different enzymes involved in chlorophyll degradation or cell wall degradation. The level of reducing and non-reducing sugars increased 109- and 52-fold, respectively, between the “turning” and the purple stage. Titratable acidity increased by 84% between the green and the pink stage, but dropped by 41% between the red stage and full ripening. Total phenols displayed their highest values in green and “turning” fruit. Chlorophyll a and b degradation occurred mainly during the early stages of development, and was paralleled by a 2.3-fold increase in chlorophyllase activity and a 5-fold increase in Mg-dechelatase activity between the green and the red stages. Chlorophyll peroxidase activity was high at the green stage, but did not change significantly after the “turning” stage. This is the first report on the activity of chlorophyll-degrading enzymes in Rubus spp. fruits. Anthocyanins increased 11-fold between the “turning” and the pink stages, and an additional eight-fold between the pink and the purple stages. Fruit firmness decreased noticeably during ripening, with a concomitant 10.75-fold increase in polygalacturonase activity, beginning at the “turning” stage. Endo- -1,4-glucanase and -galactosidase activities rose 9.2- and 6.7-fold, respectively, after the pink stage and paralleled the major softening process taking place between the pink and purple stages, when fruit firmness decreased from 3.83 N to 0.29 N. Pectin methylesterase activity was high in pink and red fruit, but decreased by 21% as the fruit turned from red to purple. This is the first report on cell wall enzyme activities whose combined action might be required for the breakdown of natural cell wall substrates during ripening in boysenberry, as happens in other soft fruits.  相似文献   

Determining leaf stomatal properties in citrus trees utilizing machine vision and artificial intelligence     

Costa  Lucas  Archer  Leigh  Ampatzidis  Yiannis  Casteluci  Larissa  Caurin  Glauco A. P.  Albrecht  Ute 《Precision Agriculture》2021,22(4):1107-1119

Precision Agriculture - Identifying and quantifying the number and size of stomata on leaf surfaces is useful for a wide range of plant ecophysiological studies, specifically those related to...  相似文献   

Lysergic acid diethylamide: role in conversion of plasma tryptophan to brain serotonin (5-hydroxytryptamine)   总被引：1，自引：0，他引：1  

R C Lin  S H Ngai  E Costa 《Science (New York, N.Y.)》1969,166(902):237-239

Injections of D-lysergic acid diethylamide decrease the turnover rate of 5-hydroxytryptamine of rat brain, as measured from the conversion of (14)C-tryptophan into (14)C-5-hydroxytryptamine. The 2-bromolysergic acid diethylamide given in doses fivefold greater than those of lysergic acid diethylamide fails to change the rate of (14)C-tryptophan conversion into (14)C-5-hydroxytryptamine. The effect of D-lysergic acid diethylamide is discussed with regard to its action on brain serotonergic neurons and its psychotomimetic effects.  相似文献   

An overview of forest loss and restoration in the Brazilian Amazon     

da Cruz  Denis Conrado  Benayas  José Maria Rey  Ferreira  Gracialda Costa  Santos  Sabrina Ribeiro  Schwartz  Gustavo 《New Forests》2021,52(1):1-16

New Forests - Forest restoration is a strategy to reverse forest loss and degradation. We overviewed deforestation in the period 1975–2018 in the Brazilian Amazon and the projects,...  相似文献   

Discovery of powerful gamma-ray flares from the Crab Nebula     

Tavani M  Bulgarelli A  Vittorini V  Pellizzoni A  Striani E  Caraveo P  Weisskopf MC  Tennant A  Pucella G  Trois A  Costa E  Evangelista Y  Pittori C  Verrecchia F  Del Monte E  Campana R  Pilia M  De Luca A  Donnarumma I  Horns D  Ferrigno C  Heinke CO  Trifoglio M  Gianotti F  Vercellone S  Argan A  Barbiellini G  Cattaneo PW  Chen AW  Contessi T  D'Ammando F  DePris G  Di Cocco G  Di Persio G  Feroci M  Ferrari A  Galli M  Giuliani A  Giusti M  Labanti C  Lapshov I  Lazzarotto F  Lipari P  Longo F  Fuschino F  Marisaldi M 《Science (New York, N.Y.)》2011,331(6018):736-739

The well-known Crab Nebula is at the center of the SN1054 supernova remnant. It consists of a rotationally powered pulsar interacting with a surrounding nebula through a relativistic particle wind. The emissions originating from the pulsar and nebula have been considered to be essentially stable. Here, we report the detection of strong gamma-ray (100 mega-electron volts to 10 giga-electron volts) flares observed by the AGILE satellite in September 2010 and October 2007. In both cases, the total gamma-ray flux increased by a factor of three compared with the non-flaring flux. The flare luminosity and short time scale favor an origin near the pulsar, and we discuss Chandra Observatory x-ray and Hubble Space Telescope optical follow-up observations of the nebula. Our observations challenge standard models of nebular emission and require power-law acceleration by shock-driven plasma wave turbulence within an approximately 1-day time scale.  相似文献   

Antibacterial and Antibiofilm Activities of Tryptoquivalines and Meroditerpenes Isolated from the Marine-Derived Fungi Neosartorya paulistensis,N. laciniosa,N. tsunodae,and the Soil Fungi N. fischeri and N. siamensis     

Nelson M. Gomes  Lucinda J. Bessa  Suradet Buttachon  Paulo M. Costa  Jamrearn Buaruang  Tida Dethoup  Artur M.S. Silva  Anake Kijjoa 《Marine drugs》2014,12(2):822-839

A new meroditerpene, sartorypyrone C (5), was isolated, together with the known tryptoquivalines l (1a), H (1b), F (1c), 3′-(4-oxoquinazolin-3-yl) spiro[1H-indole-3,5′]-2,2′-dione (2) and 4(3H)-quinazolinone (3), from the culture of the marine sponge-associated fungus Neosartorya paulistensis (KUFC 7897), while reexamination of the fractions remaining from a previous study of the culture of the diseased coral-derived fungus N. laciniosa (KUFC 7896) led to isolation of a new tryptoquivaline derivative tryptoquivaline T (1d). Compounds 1a–d, 2, 3, and 5, together with aszonapyrones A (4a) and B (4b), chevalones B (6) and C (7a), sartorypyrones B (7b) and A (8), were tested for their antibacterial activity against four reference strains (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa), as well as the environmental multidrug-resistant isolates. Only aszonapyrone A (4a) and sartorypyrone A (8) exhibited significant antibacterial activity as well as synergism with antibiotics against the Gram-positive multidrug-resistant strains. Antibiofilm assays of aszonapyrone A (4a) and sartorypyrone A (8) showed that practically no biofilm was formed in the presence of their 2× MIC and MIC. However, the presence of a sub-inhibitory concentration of ½ MIC of 4a and 8 was found to increase the biofilm production in both reference strain and the multidrug-resistant isolates of S. aureus.  相似文献   

Characterization of a gamma-3 Proteobacteria Responsible for the Syndrome "Basses Richesses" of Sugar Beet Transmitted by Pentastiridius sp. (Hemiptera, Cixiidae)     

Sémétey O  Gatineau F  Bressan A  Boudon-Padieu E 《Phytopathology》2007,97(1):72-78

ABSTRACT The disease syndrome "basses richesses" (SBR) has affected sugar beet crops in Burgundy (France) since 1991. It mainly is associated with an uncultivable phloem-restricted bacterium-like organism (BLO) called SBR BLO. Transmission tests showed that field-collected Pentastiridius sp. (Hemiptera, Cixiidae) were able to transmit the SBR BLO to sugar beet. In the present work, sequences of a 1,507-bp 16S ribosomal (r)DNA fragment of SBR BLO were amplified from DNA extracts of SBR-affected field sugar beet plants, of field-collected Pentastiridius sp. plant-hoppers, and of Pentastiridiussp.-exposed sugar beet seedlings that expressed SBR symptoms. The sequences showed total identity, confirming the role of SBR BLO in the etiology of SBR and the vector role of Pentastiridius sp. Our surveys on SBR-affected sugar beet plants and Pentastiridius sp. planthoppers collected in different fields and different years suggest that a unique BLO was involved in SBR. Furthermore, comparison of 16S rDNA sequences permitted the identification of the SBR BLO as a new plant-pathogenic gamma-3 proteobacteria different from 'Candidatus Phlomobacter fragariae,' another BLO responsible for marginal chlorosis disease of strawberry in France. Phylogenetic analysis revealed a close relationship between the SBR bacterium and several bacteria described as endosymbionts of hemipteran insects.  相似文献