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1.
Widespread invasion of riparian ecosystems by the large bamboo-like grass Arundo donax L. has altered community structure and ecological function of streams in California. This study evaluated the influence of wildfire on A. donax invasion by investigating its relative rate of reestablishment versus native riparian species after wildfire burned 300 ha of riparian woodlands along the Santa Clara River in southern California in October 2003. Post-fire A. donax growth rates and productivity were compared to those of native woody riparian species in plots established before and after the fire. Arundo donax resprouted within days after the fire and exhibited higher growth rates and productivity compared to native riparian plants. Arundo donax grew 3–4 times faster than native woody riparian plants—up to a mean of 2.62 cm day−1—and reached up to 2.3 m in height less than 3 months after the fire. One year post-fire, A. donax density was nearly 20 times higher and productivity was 14–24 times higher than for native woody species. Three mechanisms—fire-adapted phenology, high growth rate, and growth response to nutrient enrichment—appear to promote the preemption of native woody riparian species by A. donax after fire. This greater dominance of A. donax after wildfire increased the susceptibility of riparian woodlands along the Santa Clara River to subsequent fire, potentially creating an invasive plant-fire regime cycle. Moreover, A. donax infestations appear to have allowed the wildfire to cross the broad bed of the Santa Clara River from the north, allowing thousands of acres of shrubland to the south to burn.  相似文献   

2.
In order to assess the impact of seed removal and seedling establishment for four species of pines, we designed experiments with and without the exclusion of seed removers in three vegetation types (pine forest, oak-alder forest, and subalpine grassland). Seed removal was significantly different between species of pines (P < 0.01), as was the interaction between the vegetation types and category of exclusion (remover) (P < 0.0001). The significant difference in terms of seed removal was between P. patula and P. montezumae (33.0 and 17.9%, respectively). Seed removal was significant between pine forest—without exclusion (20.0%) versus oak-alder forest—without exclusion (7.0%). There was significant interaction between seedling establishment of the pine species and vegetation type (P < 0.0001). Highlighting differences between the pine forest—P. teocote (84.1%) versus oak-alder forest—P. patula (19.0%), oak-alder forest—P. pseudostrobus (45.0%), pine forest—P. patula (20.2%), pine forest—P. pseudostrobus (45.6%), subalpine grassland—P. montezumae (24.3%), subalpine grassland—P. patula (27.9%), and subalpine grassland—P. pseudostrobus (17.5%). The impact of the food preferences of rodents and other granivores for P. patula and P. pseudostrobus seeds, as well as the poor survival of seedlings of these species in the pine and oak-alder forest are both factors which may explain the dominance of P. teocote in the study region.  相似文献   

3.
The analysis presents earthworm distribution in eight designated tectonic units (C—Cyprus, EP—East Pondites, ET—East Taurus block, Sc—Sakarya continent, Kb—Kırşehir block, L—the Levant, TM—Taurus–Menderes block, WP—West Pondites) in the East Mediterranean region (EM). It represents a full list of earthworm species (N = 81) of the region and reveals significant faunal similarities between Sc + WP, and between Kb + TM. The new Sc + WP unit is characterized by the presence of archaic (Spermophorodrilus) as well as modern earthworm fauna. In contrast, the second newly established Kb + TM unit is characterized by poorly presented earthworm autochthonous fauna and by a lack of endemic species. The analysis done on the species list (N = 73) representing the autochthonous family Lumbricidae showed statistically supported separation of L and EP between themselves and from other designated units. The Levant, part of the Arabian tectonic plate, is characterized by a high level of endemism in ancient (Healyella) and modern (Dendrobaena, Perelia) genera, and by the lack of archaic genera. The EP harbors unique species representing archaic (Eophila), ancient (Healyella), and modern (Allolobophora, Aporrectodea, Dendrobaena and Eisenia) earthworm genera in the EM. The analysis also indicates origin of earthworm fauna in TM and faunistic relationships among the designated units. Clearly, the present-day division of the EM earthworm fauna shows recognizable influences of tectonic history.  相似文献   

4.
The indriid genus Propithecus comprises the sifakas, medium-sized lemurs endemic to the forests of Madagascar. Traditionally, scientists divided the genus into only 2 or 3 species —Propithecus diadema, P. verreauxi, and, since 1988, P. tattersalli— with 4 or 5 subspecies in each of the first 2 taxa, but recent authors have suggested that many more distinct species should be recognized. We draw from quantitative and qualitative studies of craniodental traits to evaluate further the phenetic distinctiveness and taxonomic status of each named form of Propithecus. We recognize 9–10 species in the genus. The 4 or 5 species of the Propithecus diadema group —P. diadema, P. candidus, P. perrieri, P. edwardsi, and perhaps P. holomelas, if distinct— share several derived features, including large average body size and a mandible specialized for rotational chewing, and clearly comprise a closely related complex. The 5 species of the Propithecus verreauxi group —P. verreauxi, P. coquereli, P. deckenii, P. coronatus, P. tattersalli— are each highly distinctive morphologically and likely do not comprise a monophyletic group. In particular, we point out the highly distinctive cranial features of Propithecus coronatus, which researchers have traditionally largely overlooked.  相似文献   

5.
A collection of fossils sampled during the 1898–1902 expedition of theFram to the Canadian Arctic Islands includes abundant bryozoans from the Lower Permian (Artinskian) Great Bear Cape Formation of Ellesmere Island. From this material a new genus with one new species —Nansenopora peculiaris n. gen., n. sp. — as well as three new species —Streblotrypella arctica n. sp.,Phragmophera patricki n. sp. andKallodictyon spinatum n. sp. — are described. Furthermore, the speciesUlrichotrypa ramulosa Bassler, 1929 is reported for the first time from the Lower Permian of the Arctic region.  相似文献   

6.
This study was designed primarily to investigate the antibacterial and antifungal activity of the extracts from fruits of six Rumex L. species: R. acetosa L., R. acetosella L., R. confertus Willd., R. crispus L., R. hydrolapathum Huds. and R. obtusifolius L. The 7 Grampositive and 7 Gram-negative bacteria strains and 5 fungal ones were tested by agar and broth dilution method. Determination of minimal inhibitory concentration (MIC) revealed that the extracts from R. confertus, R. crispus, R. hydrolapathum and R. obtusifolius exerted differential inhibitory effect on the growth of Gram-positive bacteria — staphylococci (MIC=62.5–125 μg/mL) and Gramnegative bacteria — Escherichia coli ATCC 3521, Proteus mirabilis, Pseudomonas aeruginosa (MIC=125→500 μg/mL); MIC values determined by agar dilution method were somewhat higher. The same extracts inhibited also the growth of fungi — Candida spp. or Trichophyton mentagrophytes ATCC 9533 (MIC=250–500 μg/mL), as found by agar dilution method. The total content of polyphenols (11.66–78.36 mg/g), anthracene derivatives (0.26–12.93 mg/g) and tannins (4.00–11.16%) was also determined.  相似文献   

7.
Candida parapsilosis is yeast capable of forming biofilms on medical devices. Novel approaches for the prevention and eradication of the biofilms are desired. This study investigated the anticandidal activity of sixteen essential oils on planktonic and biofilm cultures of C. parapsilosis complex. We used molecular tools, enumeration of colony-forming units, the colourimetric MTT assay, scanning electron microscopy (SEM) and a chequerboard assay coupled with software analyses to evaluate the growth kinetics, architecture, inhibition and reduction in biofilms formed from environmental isolates of the Candida parapsilosis complex; further, we also evaluated whether essential oils would interact synergistically with amphotericin B to increase their anticandidal activities. Of the environmental C. parapsilosis isolates examined, C. parapsilosis and C. orthopsilosis were identified. Biofilm growth on polystyrene substrates peaked within 48 h, after which growth remained relatively stable up to 72 h, when it began to decline. Details of the architectural analysis assessed by SEM showed that C. parapsilosis complex formed less complex biofilms compared with C. albicans biofilms. The most active essential oil was cinnamon oil (CO), which showed anticandidal activity against C. orthopsilosis and C. parapsilosis in both suspension (minimum inhibitory concentration—MIC—250 and 500 μg/ml) and biofilm (minimum biofilm reduction concentration—MBRC—1,000 and 2,000 μg/ml) cultures. CO also inhibited biofilm formation (MBIC) at concentrations above 250 μg/ml for both species tested. However, synergism with amphotericin B was not observed. Thus, CO is a natural anticandidal agent that can be effectively utilised for the control of the yeasts tested.  相似文献   

8.
In the laboratory we examined the effect of pH (5–10 with one interval) on survival, reproduction, egg viability and growth rate (intrinsic growth rate—r m and population growth rate—r) of five Brachionus rotifer species (Bcalyciflorus, Bquadridentatus, Burceolaris, B. patulus and Bangularis). The pH was shown to exert a major influence on egg viability and growth rate (r m and r) for each species. The age-specific survivorship curves within a species were not significantly different at pH 6–10. The optimal pH for each species is near-neutral pH (pH 6–8), and the fecundity decreased as the pH deviated from these values. For each Brachionus species, there was no significant difference between age-specific fecundity curves at pH 7 and 8. At acid pH (pH 5 or 6) higher egg mortality was observed for each species. The r m and population r of the five Brachionus species incubated at different pHs were significantly influenced by pH. The pH supporting the highest r m or r was obtained at pH 6–8, but varied due to species. In this study Burceolaris and Bpatulus could tolerate a broad range of pH, while the populations of Bcalyciflorus, Bquadridentatus and Bangulari declined at acid conditions.  相似文献   

9.
Food limitation was tested in the laboratory by individual growth and reproduction of two cladoceran species, Ceriodaphnia richardi and Daphnia gessneri, from the shallow tropical Brazilian Lake Monte Alegre. The cladocerans were fed cultivated green alga Scenedesmus spinosus in concentrations of 0.20, 0.10, 0.05, and 0.025 mg C l−1. Higher biomass and growth rates occurred in the two highest-food concentrations; the two lowest ones negatively affected clutch size and first reproduction. The threshold food concentration is lower than 0.025 mg C l−1 and the incipient limiting level is a value between 0.10 and 0.20 mg C l−1. The largest species, D. gessneri, was more sensitive to low food concentrations. The effects of low and high temperatures (19 and 27°C) were evaluated by life table experiments with three cladocerans from the lake—Daphnia ambigua, D. gessneri, and Moina micrura—with no food limitation (1 mg C l−1 of S. spinosus). Higher population growth rates for the three species were found at 27°C; better performance in most life table parameters was observed for the former two species at the highest temperature, D. gessneri being the most sensitive to the lowest temperature. There are indications that temperature is an important abiotic factor that constrains populations of cladocerans for a short period in winter in the lake, when temperature decreases to 18–19°C. However, its influence cannot be separated from a biotic factor such as food, whose effect is stronger in the cool season, when concentrations are lower and contribution of inedible algae is relatively higher.  相似文献   

10.
Edmunds PJ 《Oecologia》2005,146(3):350-364
To date, coral death has been the most conspicuous outcome of warming tropical seas, but as temperatures stabilize at higher values, the consequences for the corals remaining will be mediated by their demographic responses to the sub-lethal effects of temperature. To gain insight into the nature of these responses, here I develop a model to test the effect of increased temperature on populations of three pocilloporid corals at One Tree Island, near the southern extreme of the Great Barrier Reef (GBR). Using Seriatopora hystrix, S. caliendrum and Pocillopora damicornis as study species, the effects of temperature on growth were determined empirically, and the dynamics of their populations determined under natural temperatures over a 6-month period between 1999 and 2000 [defined as the study year (SY)]. The two data sets were combined in a demographic test of the possibility that the thermal regime projected for the southern GBR in the next 55–83 years—warmer by 3°C than the study year (the SY+3 regime), which is equivalent to 1.4°C warmer than the recent warm year of 1998—would alter coral population trajectories through the effects on coral growth alone; the analyses first were completed by species, then by family after pooling among species. Laboratory experiments showed that growth rates (i.e., calcification) varied significantly among species and temperatures, and displayed curvilinear thermal responses with growth maxima at ∼27.1°C. Based on these temperature-growth responses, the SY+3 regime is projected to: (1) increase annualized growth rates of all taxa by 24–39%, and defer the timing of peak growth from the summer to the autumn and spring, (2) alter the intrinsic rate of population growth (λ) for S. hystrix (λ decreases 26%) and S. caliendrum (λ increases 5%), but not for P. damicornis, and (3) have a minor effect on λ (a 0.3% increase) for the Pocilloporidae, largely because λ varies more among species than it does between temperatures. Ten-year population projections suggest that the effects of a sub-lethal increase in temperature (i.e., the SY+3 regime) are relatively small compared to the interspecific differences in population dynamics, but nevertheless will alter the population size and increase the relative abundance of large colonies at the expense of smaller colonies for all three species, as well as the Pocilloporidae. These effects may play an important role in determining the nuances of coral population structure as seawater warms, and their significance may intensity if the coral species pool is depleted of thermally sensitive species by bleaching.  相似文献   

11.
Productivity of aridland plants is predicted to increase substantially with rising atmospheric carbon dioxide (CO2) concentrations due to enhancement in plant water-use efficiency (WUE). However, to date, there are few detailed analyses of how intact desert vegetation responds to elevated CO2. From 1998 to 2001, we examined aboveground production, photosynthesis, and water relations within three species exposed to ambient (around 38 Pa) or elevated (55 Pa) CO2 concentrations at the Nevada Desert Free-Air CO2 Enrichment (FACE) Facility in southern Nevada, USA. The functional types sampled—evergreen (Larrea tridentata), drought-deciduous (Ambrosia dumosa), and winter-deciduous shrubs (Krameria erecta)—represent potentially different responses to elevated CO2 in this ecosystem. We found elevated CO2 significantly increased aboveground production in all three species during an anomalously wet year (1998), with relative production ratios (elevated:ambient CO2) ranging from 1.59 (Krameria) to 2.31 (Larrea). In three below-average rainfall years (1999–2001), growth was much reduced in all species, with only Ambrosia in 2001 having significantly higher production under elevated CO2. Integrated photosynthesis (mol CO2 m−2 y−1) in the three species was 1.26–2.03-fold higher under elevated CO2 in the wet year (1998) and 1.32–1.43-fold higher after the third year of reduced rainfall (2001). Instantaneous WUE was also higher in shrubs grown under elevated CO2. The timing of peak canopy development did not change under elevated CO2; for example, there was no observed extension of leaf longevity into the dry season in the deciduous species. Similarly, seasonal patterns in CO2 assimilation did not change, except for Larrea. Therefore, phenological and physiological patterns that characterize Mojave Desert perennials—early-season lags in canopy development behind peak photosynthetic capacity, coupled with reductions in late-season photosynthetic capacity prior to reductions in leaf area—were not significantly affected by elevated CO2. Together, these findings suggest that elevated CO2 can enhance the productivity of Mojave Desert shrubs, but this effect is most pronounced during years with abundant rainfall when soil resources are most available.  相似文献   

12.
Two Coffea arabicaHemileia vastatrix incompatible interactions (I1: coffee cv. Caturra — rust race VI and I2: coffee cv S4 Agaro — rust race II) and a compatible interaction (coffee cv. Caturra — rust race II) were compared in relation to the infection process and chitinase activity. In the two incompatible interactions the fungus ceased growth in the early infection stages, while in the compatible interaction no fungus growth inhibition was observed. A high constitutive level of chitinase activity was detected in the intercellular fluid of healthy leaves. Upon infection, chitinase isoforms were more abundant in incompatible interactions than in the compatible interaction. Immunodetection showed that class I chitinases are particularly relevant in the incompatible interactions and might participate in the defence response of the coffee plants.  相似文献   

13.
Viable bacteria of several species have the capability to incorporate 3′,6′-diacetyl fluorescein (FDA) and rapidly hydrolyze it to fluorescein, which is stored intracellularly. However, several strains of viableEscherichia coli andAlcaligenes faecalis do not evolve and accumulate significant amounts of fluorescein when incubated on glass slides in the presence of FDA. In the present study, 105–107 E. coli orA. faecalis bacteria (viability more than 95%) were accumulated in separate experiments on 0.45-μm membrane filters and then stained for 5–10 min with FDA diluted immediately before use in phosphate-buffered saline, freshly prepared nutrient broth, or nutrient broth preconditioned by overnight growth of the respective bacteria. It was shown that in all cases about 20% of the bacteria did evolve significant amounts of fluorescein, thus enabling a visual observation of these cells in the fluorescence microscope.Bacillus cereus bacteria—that evolved and accumulated fluorescein on glass slides—were shown to be fluorescent on membrane filters after FDA staining. 100%, 40%, or 70% of the bacteria were stained if the FDA solution used had been prepared in nutrient broth preconditioned by overnight growth of the same bacteria, fresh nutrient broth, or phosphate-buffered saline, respectively. This preliminary study indicates the necessity of determining the technical conditions required for FDA staining for each bacterial species under study.  相似文献   

14.
Summary A new dasyclad alga—Acicularia boniae n.sp.—is discribed from Middle Triassic (?Ladinian) of the Piano del Minatore Formation, outcropping in the Cozzo del Pellegrino area (Calabria, southern Italy). The systematic position of this species, with respect to the genusAcicularia and morphogeneraAciculella andTerquemella, is discussed.
Riassunto Viene descritta una nuova specie di dasicladale—Acicularia boniae—proveniente dal Triassico Medio della formazione del Piano del Minatore affiorante nel massiccio del Cozzo del Pellegrino (Calabria, Italia meridionale). Viene discussa la posizione sistematica rispetto al genereAcicularia ed ai morfogeneriTerquemella edAciculella.
  相似文献   

15.
Giambattista Brocchi’s (1814) monograph (see Dominici, Evo Edu Outreach, this issue, 2010) on the Tertiary fossils of the Subappenines in Italy—and their relation to the living molluscan fauna—contains a theoretical, transmutational perspective (“Brocchian transmutation”). Unlike Lamarck (1809), Brocchi saw species as discrete and fundamentally stable entities. Explicitly analogizing the births and deaths of species with those of individual organisms (“Brocchi’s analogy”), Brocchi proposed that species have inherent longevities, eventually dying of old age unless driven to extinction by external forces. As for individuals, births and deaths of species are understood to have natural causes; sequences of births and deaths of species produce genealogical lineages of descent, and faunas become increasingly modernized through time. Brocchi calculated that over 50% of his fossil species are still alive in the modern fauna. Brocchi’s work was reviewed by Horner (1816) in Edinburgh. Brocchi’s influence as a transmutational thinker is clear in Jameson’s (1827) “geological illustrations” in his fifth edition of his translation of Cuvier’s Theory of the Earth (read by his student Charles Darwin) and in the anonymous essays of 1826 and 1827 published in the Edinburgh New Philosophical Journal—which also carried a notice of Brocchi’s death in 1827. The notion that new species replace older, extinct ones—in what today would be called an explicitly phylogenetic context—permeates these essays. Herschel’s (1830) discussion of temporal replacement of species and the modernization of faunas closely mirrors these prior discussions. His book, dedicated to the search for natural causes of natural phenomena, was read by Charles Darwin while a student at Cambridge. Darwin’s work on HMS Beagle was in large measure an exploration of replacement patterns of “allied forms” of endemic species in time and in space. His earliest discussions of transmutation, in his essay February 1835, as well as the Red Notebook and the early pages of Notebook B (the latter two written in 1837 back in England), contain Brocchi’s analogy, including the idea of inherent species longevities. Darwin’s first theory of the origin of species was explicitly saltational, invoking geographic isolation as the main cause of the abrupt appearance of new species. We conclude that Darwin was testing the predicted patterns of both Brocchian and Lamarckian transmutation as early as 1832 at the outset of his work on the Beagle.  相似文献   

16.
Gigantism in isolated ponds in the absence of sympatric fish species has previously been observed in nine-spined sticklebacks (Pungitius pungitius). Patterns in sexual size dimorphism suggested that fecundity selection acting on females might be responsible for the phenomenon. However, the growth strategy behind gigantism in pond sticklebacks has not been studied yet. Here, we compared von Bertalanffy growth parameters of four independent nine-spined stickleback populations reared in a common laboratory environment: two coastal marine (typical size) and two pond (giant size) populations. We found that both pond populations had larger estimated final size than marine populations, which in turn exhibited higher intrinsic growth rates than the pond populations. Female growth strategies were more divergent among marine and pond populations than those of males. Asymptotic body size and intrinsic growth rate were strongly negatively correlated. Hence, pond versus marine populations exhibited different growth strategies along a continuum. Our data suggest that quick maturation—even with the cost of being small (low fecundity)—is favoured in marine environments. On the contrary, growth to a giant final size (high fecundity)—even if it entails extended growth period—is favoured in ponds. We suggest that the absence (ponds) versus presence (marine environment) of sympatric predatory fish species, and the consequent change in the importance of intraspecific competition are responsible for the divergence in growth strategies. The sex-dependence of the patterns further emphasizes the role of females in the body size divergence in the species. Possible alternative hypotheses are also discussed.  相似文献   

17.
Cell respiratory activity of protoplasts obtained from the wild type of Neurospora crassa and photoreceptor complex WCC—white collar 1 (wc-1) and white collar 2 (wc-2)—mutants of Neurospora crassa strains was investigated. Respiration inhibition by KCN in the presence of 25 mM succinate was similar in all strains and did not exceed 83–85% against control. The significant induction of KCN-resistant respiratory pathway occurred under 1% glucose oxidation in wc-1 and wc-2 mutants if compared with the wild type strains. The inhibitors of the main (cytochrome) pathway of electron transfer in mitochondria—1 mM KCN and antimycin A (4 μg/ml)—blocked the respiration rate of the protoplasts from N. crassa wild type by 75%, while the cell respiration of wc-1 and wc-2 strains was suppressed by approximately 50%. The specific inhibitor of alternative oxidase—10 mM salicylhydroxamic acid (SHAM)—in combination with the blockers of mitochondrial electron transfer chain caused the total suppression of respiratory activity of protoplasts in all studied strains. It is supposed that an increase of KCN-resistance in WCC mutants under glucose oxidation is connected with alternative oxidase activation as the result of failure in reception and signal transduction of active oxygen species.  相似文献   

18.
To examine the natural colonisation of native mangrove species into remediated exotic mangrove stands in Leizhou Bay, South China, we compared soil physical–chemical properties, community structure and recruitments of barren mangrove areas, native mangrove species plantations, and exotic mangrove species—Sonneratia apetala Buch.Ham—between plantations and natural forest. We found that severely degraded mangrove stands could not regenerate naturally without human intervention due to severely altered local environments, whereas some native species had been recruited into the 4–10 year S. apetala plantations. In the first 10 years, the exotic species S. apetala grew better than native species such as Rhizophora stylosa Griff and Kandelia candel (Linn.) Druce. The mangrove plantation gradually affected soil physical and chemical properties during its recovery. The exotic S. apetala was more competitive than native species and its plantation was able to restore soil organic matter in about 14 years. Thus, S. apetala can be considered as a pioneer species to improve degraded habitats to facilitate recolonisation by native mangrove species. However, removal to control proliferation may be needed at late stages to facilitate growth of native species. To ensure sustainability of mangroves in South China, the existing mangrove wetlands must be managed as an ecosystem, with long-term scientific monitoring program in place.  相似文献   

19.
Liparidae from stomachs of Antarctic toothfish Dissostichus mawsoni Norman, 1937 (Nototheniidae) caught in the Ross Sea (Pacific sector of Antarctica) have been identified. Two new species of deep-water liparids of the genus Paraliparis Collett, 1879—P. caninus sp. nov. (at a depth of 1182–1651 m) and P. vipera sp. nov. (1700 m)—were described. Both species that turned out to be most similar to P. neelovi Andriashev, 1982, from the Kerguelen area (the Indo-Oceanic sector of the South Ocean) are combined with it into a species group “P. neelovi.” According to meristic characters, pattern of dentition, and the size of gill opening, species of “P. neelovi” are close to the species group “P. copei.” In collections from a depth of 1700 m, also two individuals of P. andriashevi Stein et Tompkins, 1989, known previously from only two types from the northern boundary of the Ross Sea were found. The new finding supports species validity and extends the known limits of its range. The wide distribution of bathybenthal Paraliparis having low fecundity and leading a near-bottom mode of life can be explained by the presence of mesopelagic juveniles and their dispersal via currents.  相似文献   

20.
Bacterial cultures from a wastewater treatment plant degraded a toxic azo dye (methyl red) by decolourization. Complete decolourization using a mixed-culture was achieved at pH 6, 30 °C within 6 h at 5 mg/l methyl red concentration, and 16 h at 20—30 mg/l. Four bacterial species were isolated that were capable of growth on methyl red as the sole carbon source, and two were identified, namely Vibrio logei and Pseudomonas nitroreducens. The Vibrio species showed the highest methyl red degradation activity at the optimum conditions of pH 6--7, and 30—35 °C. Analysis by NMR showed that previously reported degradation products 2-aminobenzoic acid and N,N-dimethyl-1,4-phenylenediamine were not observed. The decolourized dye was not toxic to a monkey kidney cell line (COS-7) at a concentration of 250 μM. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

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