401 research outputs found
Inheritance of resistance to Puccinia psidii G. Winter in a eucalyptus interspecific hybrid progeny evaluated under conditions of natural infection
A ferrugem, causada pelo fungo Puccinia psidii, Ă© atualmente a mais importante doença do eucalipto. Esta doença estĂĄ amplamente disseminada pelo Brasil e causa sĂ©rios danos em viveiros e plantaçÔes. A identificação de germoplasma resistente aliado ao conhecimento da base genĂ©tica da resistĂȘncia sĂŁo os requerimentos primordiais para o sucesso de programas de melhoramento visando Ă produção de cultivares resistentes. Estudos anteriores sobre a herança da resistĂȘncia em condiçÔes controladas sugerem tanto uma herança monogĂȘnica como a participação de pelo menos 2 genes conferindo resistĂȘncia Ă doença. O objetivo deste estudo foi avaliar a resistĂȘncia a P. psidii, em condiçÔes de campo em quatorze progĂȘnies obtidas a partir de cruzamentos e auto-cruzamentos controlados entre quatro clones hĂbridos de Eucalyptus grandis Hill ex Maiden x Eucalyptus urophylla ST Blake,que contrastam para a resistĂȘncia ao fungo. Os resultados indicam que a resistĂȘncia pode ser explicada por um loco com efeito principal e pelo menos trĂȘs alelos diferentes, com interaçÔes entre os alelos, resultando no fenĂłtipo de resistĂȘncia ou suscetibilidade. Entretanto, locos com menor efeito devem influenciar a resistĂȘncia, uma vez que foram observadas variaçÔes nas classes de severidade da escala utilizada. Nenhuma diferença na segregação para a resistĂȘncia foi observada entre cruzamentos recĂprocos, sugerindo que nĂŁo existe influĂȘncia citoplasmĂĄtica no controle deste carĂĄter.Rust caused by the fungus Puccinia psidii is currently the most important disease of eucalyptus. It is widely disseminated in Brazil, and causes serious damage in nurseries and plantation areas. The identification of resistant germplasm along with knowledge of the genetic basis of resistance heredity are the first requirements for the success of breeding programs aiming to develop resistant varieties. Earlier studies carried out under controlled conditions suggested a monogenic control as well as the participation of at least two genes promoting resistance to rust. The goal of this study was to evaluate the resistance to P. psidii under field conditions in fourteen progenies from controlled crosses and self-crosses among four hybrid clones of Eucalyptus grandis Hill ex Maiden x Eucalyptus urophylla ST Blake that contrast for resistance to the fungus. Results indicated that resistance could be explained by one locus with main effects and at least three different alleles. However, loci with minor effects may influence the resistance, since variation on severity classes was observed. Differences in segregation of resistance between reciprocal crosses were not observed, indicating absence of cytoplasmic effects.Votorantim Celulose e PapelConselho Nacional de Desenvolvimento CientĂfico e TecnolĂłgico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de NĂvel Superior (CAPES
Photocatalytic Hydrogen Production Of Co(oh)2 Nanoparticle-coated α-fe2o3 Nanorings
The production of hydrogen from water using only a catalyst and solar energy is one of the most challenging and promising outlets for the generation of clean and renewable energy. Semiconductor photocatalysts for solar hydrogen production by water photolysis must employ stable, non-toxic, abundant and inexpensive visible-light absorbers capable of harvesting light photons with adequate potential to reduce water. Here, we show that α-Fe 2O3 can meet these requirements by means of using hydrothermally prepared nanorings. These iron oxide nanoring photocatalysts proved capable of producing hydrogen efficiently without application of an external bias. In addition, Co(OH)2 nanoparticles were shown to be efficient co-catalysts on the nanoring surface by improving the efficiency of hydrogen generation. Both nanoparticle-coated and uncoated nanorings displayed superior photocatalytic activity for hydrogen evolution when compared with TiO2 nanoparticles, showing themselves to be promising materials for water-splitting using only solar light. © The Royal Society of Chemistry 2013.51993109316Navarro Yerga, R.M., Ălvarez GalvĂĄn, M.C., Del Valle, F., Villoria De La Mano, J.A., Fierro, J.L.G., (2009) ChemSusChem, 2, pp. 471-485Fujishima, A., Honda, K., (1972) Nature, 238, pp. 37-38Kudo, A., Miseki, Y., (2009) Chem. Soc. Rev., 38, pp. 253-278Sivula, K., Le Formal, F., Gratzel, M., (2011) ChemSusChem, 4, pp. 432-449Yerga, R.M.N., Galvan, M.C.A., Del Valle, F., De La Mano, J.A.V., Fierro, J.L.G., (2009) ChemSusChem, 2, pp. 471-485Chen, X.B., Shen, S.H., Guo, L.J., Mao, S.S., (2010) Chem. Rev., 110, pp. 6503-6570Hernandez-Alonso, M.D., Fresno, F., Suarez, S., Coronado, J.M., (2009) Energy Environ. Sci., 2, pp. 1231-1257Kudo, A., (2003) Catal. Surv. Asia, 7, pp. 31-38Wender, H., Feil, A.F., Diaz, L.B., Ribeiro, C.S., Machado, G.J., Migowski, P., Weibel, D.E., Teixeira, S.R., (2011) ACS Appl. Mater. Interfaces, 3, pp. 1359-1365Khan, S.U.M., Al-Shahry, M., Ingler, W.B., (2002) Science, 297, pp. 2243-2245Sreethawong, T., Ngamsinlapasathian, S., Suzuki, Y., Yoshikawa, S., (2005) J. Mol. Catal. A: Chem., 235, pp. 1-11Li, Z.H., Chen, G., Tian, X.J., Li, Y.X., (2008) Mater. Res. Bull., 43, pp. 1781-1788Meng, F.K., Hong, Z.L., Arndt, J., Li, M., Zhi, M.J., Yang, F., Wu, N.Q., (2012) Nano Res., 5, pp. 213-221Pei, D.H., Luan, J.F., (2012) Int. J. Photoenergy, , 10.1155/2012/262831Sun, J.W., Liu, C., Yang, P.D., (2011) J. Am. Chem. Soc., 133, pp. 19306-19309Nann, T., Ibrahim, S.K., Woi, P.M., Xu, S., Ziegler, J., Pickett, C.J., (2010) Angew. Chem., Int. Ed., 49, pp. 1574-1577Higashi, M., Domen, K., Abe, R., (2011) Energy Environ. Sci., 4, pp. 4138-4147Maeda, K., Higashi, M., Siritanaratkul, B., Abe, R., Domen, K., (2011) J. Am. Chem. Soc., 133, pp. 12334-12337Ikeue, K., Shiiba, S., Machida, M., (2011) ChemSusChem, 4, pp. 269-273Yu, J.G., Yang, B., Cheng, B., (2012) Nanoscale, 4, pp. 2670-2677Yashima, M., Ogisu, K., Domen, K., (2008) Acta Crystallogr., Sect. B: Struct. Sci., 64, pp. 291-298Yan, Q., Zhu, J., Yin, Z., Yang, D., Sun, T., Yu, H., Hoster, H.E., Zhang, H., (2013) Energy Environ. Sci., 6 (3), pp. 987-993Tahir, A.A., Wijayantha, K.G.U., Saremi-Yarahmadi, S., Mazhar, M., McKee, V., (2009) Chem. Mater., 21, pp. 3763-3772Rangaraju, R.R., Panday, A., Raja, K.S., Misra, M., (2009) J. Phys. D: Appl. Phys., 42Satsangi, V.R., Kumari, S., Singh, A.P., Shrivastav, R., Dass, S., (2008) Int. J. Hydrogen Energy, 33, pp. 312-318Saremi-Yarahmadi, S., Vaidhyanathan, B., Wijayantha, K.G.U., (2010) Int. J. Hydrogen Energy, 35, pp. 10155-10165Lin, Y., Xu, Y., Mayer, M.T., Simpson, Z.I., McMahon, G., Zhou, S., Wang, D., (2012) J. Am. Chem. Soc., 134, pp. 5508-5511Kumar, P., Sharma, P., Solanki, A., Tripathi, A., Deva, D., Shrivastav, R., Dass, S., Satsangi, V.R., (2012) Int. J. Hydrogen Energy, 37, pp. 3626-3632Kronawitter, C.X., Vayssieres, L., Shen, S.H., Guo, L.J., Wheeler, D.A., Zhang, J.Z., Antoun, B.R., Mao, S.S., (2011) Energy Environ. Sci., 4, pp. 3889-3899Vayssieres, L., Sathe, C., Butorin, S.M., Shuh, D.K., Nordgren, J., Guo, J.H., (2005) Adv. Mater., 17, pp. 2320-2323Jia, C.-J., Sun, L.-D., Luo, F., Han, X.-D., Heyderman, L.J., Yan, Z.-G., Yan, C.-H., Raabe, J.R., (2008) J. Am. Chem. Soc., 130, pp. 16968-16977De La Peña, F., Barrett, N., Zagonel, L.F., Walls, M., Renault, O., (2010) Surf. Sci., 604, pp. 1628-1636De La Peña, F., Berger, M.H., Hochepied, J.F., Dynys, F., Stephan, O., Walls, M., (2011) Ultramicroscopy, 111, pp. 169-176Chen, S.-Y., Gloter, A., Zobelli, A., Wang, L., Chen, C.-H., Colliex, C., (2009) Phys. Rev. B: Condens. Matter Mater. Phys., 79, p. 104103Gonçalves, R.V., Migowski, P., Wender, H., Eberhardt, D., Weibel, D.E., Sonaglio V. F, C., Zapata, M.J.M., Teixeira, S.R., (2012) J. Phys. Chem. C, 116, pp. 14022-14030Zhao, Y., Feltes, T.E., Regalbuto, J.R., Meyer, R.J., Klie, R.F., (2010) J. Appl. Phys., 108, pp. 063704-063707Zhang, Z., (2007) Ultramicroscopy, 107, pp. 598-603Liu, B., Nakata, K., Liu, S., Sakai, M., Ochiai, T., Murakami, T., Takagi, K., Fujishima, A., (2012) J. Phys. Chem. C, 116, pp. 7471-7479An, W.-J., Wang, W.-N., Ramalingam, B., Mukherjee, S., Daubayev, B., Gangopadhyay, S., Biswas, P., (2012) Langmuir, 28, pp. 7528-7534Jang, J.S., Choi, S.H., Kim, D.H., Jang, J.W., Lee, K.S., Lee, J.S., (2009) J. Phys. Chem. C, 113, pp. 8990-8996Li, Z., Wang, Y., Liu, J., Chen, G., Li, Y., Zhou, C., (2009) Int. J. Hydrogen Energy, 34, pp. 147-152Shimizu, K.-I., Tsuji, Y., Hatamachi, T., Toda, K., Kodama, T., Sato, M., Kitayama, Y., (2004) Phys. Chem. Chem. Phys., 6, pp. 1064-106
ÎČ-Lactam antibiotics and vancomycin inhibit the growth of planktonic and biofilm Candida spp.: An additional benefit of antibiotic-lock therapy?
AbstractThe aim of this study was to evaluate the effects of cefepime, meropenem, piperacillin/tazobactam (TZP) and vancomycin on strains of Candida albicans and Candida tropicalis in planktonic and biofilm forms. Twenty azole-derivative-resistant strains of C. albicans (n=10) and C. tropicalis (n=10) were tested. The susceptibility of planktonic Candida spp. to the antibacterial agents was investigated by broth microdilution. The XTT reduction assay was performed to evaluate the viability of growing and mature biofilms following exposure to these drugs. Minimum inhibitory concentrations (MICs) ranged from 0.5mg/mL to 2mg/mL for cefepime, TZP and vancomycin and from 0.5mg/mL to 1mg/mL for meropenem and the drugs also caused statistically significant reductions in biofilm cellular activity both in growing and mature biofilm. Since all of the tested drugs are commonly used in patients with hospital-acquired infections and in those with catheter-related infections under antibiotic-lock therapy, it may be possible to obtain an additional benefit from antibiotic-lock therapy with these drugs, namely the control of Candida biofilm formation
- âŠ