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901.
Miriam Ahuactzin-Pérez Saúl Tlécuitl-Beristain Jorge García-Dávila Ericka Santacruz-Juárez Manuel González-Pérez María Concepción Gutiérrez-Ruíz Carmen Sánchez 《Fungal biology》2018,122(10):991-997
Dibutyl phthalate (DBP) is a plasticizer, whose presence in the environment as a pollutant has attained a great deal of attention due to its reported association with endocrine system disturbances on animals. Growth parameters, glucose uptake, percentage of removal efficiency (%E) of DBP, biodegradation constant of DBP (k) and half-life of DBP biodegradation (t1/2) were evaluated for Pleurotus ostreatus grown on media containing glucose and different concentrations of DBP (0, 500 and 1000 mg l?1). P. ostreatus degraded 99.6 % and 94 % of 500 and 1000 mg of DBP l?1 after 312 h and 504 h, respectively. The k was 0.0155 h?1 and 0.0043 h?1 for 500 and 1000 mg of DBP l?1, respectively. t1/2 was 44.7 h and 161 h for 500 and 1000 mg of DBP l?1, respectively. Intermediate compounds of biodegraded DBP were identified by GC-MS and a DBP biodegradation pathway was proposed using quantum chemical calculation. DBP might be metabolized to benzene and acetyl acetate, the first would be oxidated to muconic acid and the latter would enter into the Krebs cycle. P. ostreatus has the ability to degrade DBP and utilizes it as source of carbon and energy. 相似文献
902.
Tomasz Müller Marcin Czarnoleski Anna Maria Labecka Anna Cichy Katarzyna Zając Dominika Dragosz-Kluska 《Hydrobiologia》2015,742(1):59-70
Mussels are intermediate hosts of digenean trematodes, but determinants of these infections remain unknown. To address this problem, we collected duck mussels Anodonta anatina in eighteen lakes from northeastern Poland and examined how mussel age, sex, and the encrustation with zebra mussels Dreissena polymorpha and environmental conditions in lakes influenced infection rates. We also assessed parasitic preferences to host gonads and hepatopancreas and the impact of parasites on female fertility. Mussels were infected with Rhipidocotyle campanula and Phyllodistomum sp. Infection rates were higher in older and female mussels but were unrelated to the biomass of encrusting D. polymorpha and the trophy, thermal conditions, and Ca2+ availability. Parasites occupied gonads more often than hepatopancreas. Infected females were less likely to carry glochidia and incubated fewer glochidia. We suggest that the risk of infection by digenean trematodes increases with the amount of water processed by filter-feeding hosts and/or that parasites actively seek hosts which can provide them with abundant resources. This mechanism explains why parasites more often occupied older and female mussels and targeted their gonads. Future research on trematode-mussel interactions should integrate knowledge on different elements of the complex trematode life cycles, including effects of higher-order hosts such as fish. 相似文献
903.
A phage-typing scheme for Salmonella virchow 总被引:3,自引:0,他引:3
R.M. Chambers P. McAdam J.D.H. de Sa L.R. Ward B. Rowe 《FEMS microbiology letters》1987,40(2-3):155-157
904.
905.
Sexual differentiation in cucumber: Abscisic acid and gibberellic acid contents of various sex genotypes 总被引:2,自引:0,他引:2
The AbA content of cucumber shoot tips was determined by GLC.Shoot tips of monoecious plants had a higher AbA content thanthose of gynoecious ones, and SD conditions caused higher AbAcontent than LD conditions. AbA content per unit dry weightof young floral buds was 5- to 9-fold higher than in older ones. A GLC method was developed to allow parallel identificationand quantitative determinations of GA3 and AbA with the samesample. The shoot tip contents of both growth substances weredetermined at four developmental stages of the monoecious plant.Both significantly increased until the 12th day after plantingthen decreased; the GA3 content decreased markedly. A general hypothesis for the role of growth substances in regulatingsex expression of cucumber is presented and discussed. (Received January 7, 1977; ) 相似文献
906.
Şerife Saçmacı Yakup Yılmaz Şenol Kartal Murat Kaya Fatih Duman 《Biological trace element research》2014,159(1-3):254-262
In this study, the resting eggs of aquatic creatures living in freshwater (Daphnia, Cladocera, Crustacean) ecosystems were used as a novel biosorbent extractant for synchronous preconcentration of trace Cd(II), Co(II), Cu(II), Mn(II), and Ni(II) previous to measurement by flame atomic absorpiton spectrometry (FAAS). Using column procedures, optimization studies were conducted to realize the effective adsorption of the analyte ions such as the solution pH, amount of the biosorbent, volume of the sample, interfering ions, etc. A high preconcentration factor of 67 and low relative standard deflection of ≤4.1 % (n?=?8) were obtained. The invention constrains based on the 3 s/b criterion were 2.4 for Cd(II), 41.4 for Co(II), 4.2 for Cu(II), 3.0 for Mn(II), and 9.6 μg L?1 for Ni(II). The accuracy of the method was verified by analysis of a certified standard reference material. The used procedure was applied to the definition of the analytes in diverse environmental samples with convincing results. Consequently, the resting eggs of Daphnia can be used as a biosorbent for preconcentration and biosorption studies. 相似文献
907.
TRANSPARENT TESTA10 encodes a laccase-like enzyme involved in oxidative polymerization of flavonoids in Arabidopsis seed coat 总被引:10,自引:0,他引:10 下载免费PDF全文
Pourcel L Routaboul JM Kerhoas L Caboche M Lepiniec L Debeaujon I 《The Plant cell》2005,17(11):2966-2980
The Arabidopsis thaliana transparent testa10 (tt10) mutant exhibits a delay in developmentally determined browning of the seed coat, also called the testa. Seed coat browning is caused by the oxidation of flavonoids, particularly proanthocyanidins, which are polymers of flavan-3-ol subunits such as epicatechin and catechin. The tt10 mutant seeds accumulate more epicatechin monomers and more soluble proanthocyanidins than wild-type seeds. Moreover, intact testa cells of tt10 cannot trigger H2O2-independent browning in the presence of epicatechin and catechin, in contrast with wild-type cells. UV-visible light detection and mass spectrometry revealed that the major oxidation products obtained with epicatechin alone are yellow dimers called dehydrodiepicatechin A. These products differ from proanthocyanidins in the nature and position of their interflavan linkages. Flavonol composition was also affected in tt10 seeds, which exhibited a higher ratio of quercetin rhamnoside monomers versus dimers than wild-type seeds. We identified the TT10 gene by a candidate gene approach. TT10 encodes a protein with strong similarity to laccase-like polyphenol oxidases. It is expressed essentially in developing testa, where it colocalizes with the flavonoid end products proanthocyanidins and flavonols. Together, these data establish that TT10 is involved in the oxidative polymerization of flavonoids and functions as a laccase-type flavonoid oxidase. 相似文献
908.
909.
910.
Sergej Tomi? Jelena ?oki? Sa?a Vasiliji? Nina Ogrinc Rebeka Rudolf Primo? Pelicon Dragana Vu?evi? Petar Milosavljevi? Sr?a Jankovi? Ivan An?el Jelena Rajkovi? Marjan Slak Rupnik Bernd Friedrich Miodrag ?oli? 《PloS one》2014,9(5)
Gold nanoparticles (GNPs) are claimed as outstanding biomedical tools for cancer diagnostics and photo-thermal therapy, but without enough evidence on their potentially adverse immunological effects. Using a model of human dendritic cells (DCs), we showed that 10 nm- and 50 nm-sized GNPs (GNP10 and GNP50, respectively) were internalized predominantly via dynamin-dependent mechanisms, and they both impaired LPS-induced maturation and allostimulatory capacity of DCs, although the effect of GNP10 was more prominent. However, GNP10 inhibited LPS-induced production of IL-12p70 by DCs, and potentiated their Th2 polarization capacity, while GNP50 promoted Th17 polarization. Such effects of GNP10 correlated with a stronger inhibition of LPS-induced changes in Ca2+ oscillations, their higher number per DC, and more frequent extra-endosomal localization, as judged by live-cell imaging, proton, and electron microscopy, respectively. Even when released from heat-killed necrotic HEp-2 cells, GNP10 inhibited the necrotic tumor cell-induced maturation and functions of DCs, potentiated their Th2/Th17 polarization capacity, and thus, impaired the DCs'' capacity to induce T cell-mediated anti-tumor cytotoxicity in vitro. Therefore, GNP10 could potentially induce more adverse DC-mediated immunological effects, compared to GNP50. 相似文献