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Enteromorpha prolifera green algae is the main species that causes green tide in China’s Yellow Sea. To effectively realize the resourceful utilization of this biomass, batch experiments were carried out to investigate factors that impact the Acid Bordeaux B (ABB) absorption of E. prolifera powder, such as exposure time, pH, adsorbent dose, and oscillation frequency. The dye adsorption onto adsorbent was confirmed by Fourier transform infrared spectroscopy (FTIR). Results showed that amide, hydroxy, carboxylate, and C-O groups were involved in the adsorption process. The treatment conditions for dye concentration of 100 mg·L⁻¹ were optimized: contact time 60 min, pH value 4 to 9, water temperature 303 to 313 K, adsorbent dosage 0.25 g·L⁻¹ and oscillation frequency 150 rpm. Equilibrium data were analyzed by using the Freundlich and Langmuir models. The data fit well in both models. The maximum equilibrium adsorption capacity calculated by the Langmuir equation was 1,111.11-3,333.33 mg·g⁻¹. To clarify the sorption kinetic, the fitness of the Pseudofirst- order model, the Pseudo-second-order model, and the intra-particle diffusion model were tested, showing that the pseudo-second order model was suitable to describe the adsorption process. The sorption process was complex, and both the boundary of liquid film and intra-particle diffusion contributed to the rate-determining step. Thermodynamic parameters (e.g. ΔG⁰, ΔH⁰, and ΔS⁰) were calculated, which implied the exothermic and spontaneous nature of biosorption as well as the type of adsorption (physisorption). Results illustrate that the removal ratio from the wastewater with 100 mg·L⁻¹ ABB reached 90.86%, indicating that E. prolifera could be a potential biosorbent used for the removal of ABB from industrial effluents.
In order to accurately estimate soil organic carbon storage (SOCS), 2,755 soil profiles and 23,536 soil samples were acquired by grid method, followed by a study on the SOCS, soil bulk density (SBD), gravel content (GC), and distribution characteristics of rock coverage (RC) in a small karst watershed (SKC). Then on the basis of soil profile summation, an investigation was done on the applicability of RC/GC-based soil type method, land utilization type method, and aspect method to the estimation of SOCS in SKC at different depths. As shown by the results, the average soil organic carbon content (SOC) in the soil samples ranged from 5.25 to 24.87 g.kg⁻¹, and decreased with the soil depth increasing; the average SBD ranged from 1.17 to 1.41 g.cm⁻³, which first increased with the soil depth increasing and then tended to be steady; the average GC ranged from 0 to 20.15%, which decreased gradually with the soil depth increasing and finally to zero; the RC ranged from 0 to 86.32% at different sample points. RC and GC greatly affected the estimation of SOCS, so after correction based on RC and GC, the soil type method was adopted for estimation, concluding that SOCS at depths of 0-20 cm, 0-30 cm, and 0-100 cm was 341.82×10⁶ kg, 449.29×10⁶ kg, and 738.351×06 kg, respectively; RC and GC affected white sandy soil the most, as shown by the following SOCS estimated by the land utilization type method: 319.56×10⁶ kg, 416.04×10⁶ kg, and 607.02×10⁶ kg, respectively, at depths of 0-20 cm, 0-30 cm, and 0-100 cm; RC and GC affected wasteland the most, as shown by the following SOCS estimated by the aspect method: 318.64×10⁶ kg, 411.63×10⁶ kg, and 628.46×10⁶ kg, respectively, at depths of 0-20 cm, 0-30 cm, and 0-100 cm; RC and GC affected the SOCS in the south slope the most; in terms of catchment scale, the “vertical stratification + horizontal classification” pattern was expanded to the “land utilization type method” and “aspect method.” For estimating the SOCS in topsoil, the aspect method achieved the best result, while the land utilization type method achieved the best result at a depth of 100 cm.
The hilly region of the Sichuan basin has unique natural topography, geomorphology, geology, and hydrology, with intensive human activities in the area. Therefore, it is of great significance to carry out research on heavy metal characteristics. In this study, taking five villages of Zigong city as a sample, the content of eight kinds of heavy metals in soil was determined (Cu, Cd, As, Pb, Cr, Zc, Ni, and Hg) based on ordinary Kriging. The results showed that Cd, Pb, Ni, and Zn content in the research area was higher than the background value and had a good concentration with all of the heavy metal contents lying within the national standards. Through soil parent material, soil environment, atmospheric environment, and water environment analysis of heavy metals, it was found that higher levels of heavy metals in the research area were mainly affected by agricultural and industrial activities (atmospheric dustfall). This was generally where there were intense areas of human activity – especially in and around transport routes and construction areas. It was also found that the soybean crop exhibited a strong Cd accumulation ability. This soybean planting should be reduced to control the distribution of Cd. Zn and Cu had a positive enrichment effect on rice, soybeans, and other crops, and had little enrichment effect on grapefruit. This study showed the effect human activities have on the quality of soil quality on the crop. This research has great significance for the ecologically sustainable development of society.
To illustrate the distribution pattern of soil organic carbon density (SOCD) in a small karst watershed and its main influencing factors, this research quantitatively analyzed the spatial heterogeneity and distribution characteristics of SOCD using 2,755 thoroughly investigated soil profile samples; field point sampling, laboratory determination, and geo-statistical analysis were used, and the major influencing factors of SOCD were analyzed using a principal components analysis. The results indicated that the SOCD decreased gradually with increasing soil depth in the small karst watershed; in particular, the average SOCD was equal to 12.11 kg·m⁻² at a depth of 100 cm, which is higher than the national level. An optimal fitting model for the SOCD in this Basin was a Gaussian model, which showed a moderately strong spatial correlation. A kriging interpolation suggested that the soil carbon density (SOCD) was higher in the eastern region but lower in the southern region, exhibiting an ascending trend from the middle to the exterior. In the small karst watershed, the SOCD at a depth of 100 cm differs between different vegetation types, different soil utilization types, and different soil types. The soil thickness, rock coverage and altitude were the principal influencing factors on the SOCD in the small karst watershed, among which soil thickness had the largest impact.
In this work, porous HAP nanofibers assembled from nanorods were developed as potential devices for the treatment of Cu(II), Cd(II), and Pb(II) contamination of consumable waters. Two steps were employed in the HAP nanofibers fabrication. First, rod-like HAP nanoparticles were synthesized through a chemical pathway from Ca(NO₃)₂ ·4H₂O, (NH₄)₂ HPO₄, and polyvinylpyrrolidone (PVP) as a capping agent. The subsequent electrospinning was performed to fabricate the PVP/HAP hybrid nanofibers as precursors to obtain pure HAP nanofibers assembled from nanorods via a calcination process. The effects of PVP dosage on morphology was investigated. And a possible formation mechanism of rod-like HAP was proposed. Then the removal efficiency of porous HAP nanofibers toward Cu(II), Cd(II), and Pb(II) were evaluated via sorption kinetics and sorption isotherms. Our results proved that the sorption kinetic data were well fitted by the pseudo second-order rate equation, and the adsorption of Cu²⁺, Cd², and Pb²⁺ ions on HAP nanofibers correlated well with the Langmuir equation as compared to Freundlich isotherm equation under the concentration range studied. These novel porous HAP nanofibers assembled from nanorods promise a feasible advance in the development of new, easy to handle, and low-cost water purifying methods.
Background. Bigeye tuna, Thunnus obesus (Lowe, 1839); yellowfin tuna, Thunnus albacares (Bonnaterre, 1788); and albacore, Thunnus alalunga (Bonnaterre, 1788), are very important species for world fisheries. It is crucial to the future existence of those economically important species that the best possible biological data on the species is provided to fisheries managers. Materials and Methods. The weight–length relations (WLRs) for bigeye tuna, yellowfin tuna, and albacore, collected in the Atlantic, Indian, and eastern Pacific oceans were studied using commonly accepted methodology. Results. Significant differences can be found from the fork length distributions and the WLRs of the above 3 tuna species and the relations of gilled-gutted and whole weight of bigeye and yellowfin tunas collected from the Atlantic, Indian, and Eastern Pacific Oceans. Significant differences of fork length distributions can be found for bigeye tuna, yellowfin tuna, and albacore from the three areas. The growth exponents (b) of bigeye tuna, yellowfin tuna, and albacore collected from the Atlantic, Indian, and eastern Pacific oceans register significant deviations from isometric value of 3. Conclusion. The date collected will be useful for the fisheries management of the three species studied.
Antimony ore tailings slag was used analyze heavy metals, chemical speciation, and leaching characteristics. The results show that the residual silicate phases account for 65.44% of Sb, 77.22% of As, 87.94% of Hg, 58.53% of Pb, 71.27% of Cd, and 96.34% of Zn. Although the exchangeable and carbonate phases account for 7.71% of Sb, 0.71% of As, 3.77% of Hg, 4.82% of Pb, 1.83% of Cd, and 1.73% of Zn, the water-or-acid-soluble phases contribute more to the chemical speciation of heavy metals. Concentrations of Sb, As, and Hg in the leachates increased with increasing solid-liquid ratio, decreasing particle size and increasing temperature. In simulated rainfall conditions, the total quantity increased in the order Sb > As > Hg and were 42.508 mg, 52.940 μg, and 0.876 μg, respectively, at 500 g antimony ore tailings. Under different rainfall intensity simulations, the maximum quantity in the leachates of Sb, As, and Hg were 93.894 mg, 255.451 μg, and 1.690 μg, respectively, and increased in the order of moderate > heavy > rainstorm. Finally, the cumulative leaching of Sb at pH 6.0 is 42.025 mg/L (higher than at 4.0 and 5.0), and the As and Hg at pH 4.0 are 107.097 μg/L and 0.989 μg/L, respectively.
Lovastatin, an inhibitor of cellular cholesterol synthesis, has an apparent anti-cancer property, but the detailed mechanisms of its anti-cancer effects remain poorly understood. We investigated the molecular mechanism of Lovastatin anti-tumor function through the study of its effect on membrane ion flow, gap junctional intercellular communication (GJIC), and the pathways of related signals in MCF-7 mammary cancer cells. After treatment for 24–72 h with 4, 8 or 16 μmol/L Lovastatin, cellular proliferation was examined via the MTT assay, and changes in membrane potential and cellular [Ca2+]i were monitored using confocal laser microscopy. In addition, the expression of plasma membrane calcium ATPase isoform 1 (PMCA1) mRNA was analyzed via RT-PCR, the GJIC function was examined using the scrape-loading dye transfer (SLDT) technique, and MAPK phosphorylation levels were tested with the kinase activity assay. The results showed that Lovastatin treatment significantly inhibited the growth of MCF-7 breast cancer cells. It also increased the negative value of the membrane potential, leading to the hyperpolarization of cells. Moreover, Lovastatin treatment continuously enhanced [Ca2+]i, although the levels of PMCA1 mRNA were unchanged. GJIC was also upregulated in MCF-7 cells, with transfer of LY Fluorescence reaching 4 to 5 rows of cells from the scraped line after treatment with 16 μmol/L Lovastatin for 72 h. Finally, downregulation of ERK1 and p38MAPK phosphorylation were found in Lovastatin-treated MCF-7 cells. It could be deduced that Lovastatin can induce changes in cellular hyperpolarization and intracellular Ca2+ distributions, and increase GJIC function. These effects may result in changes in the downstream signal cascade, inhibiting the growth of MCF-7 cells.
In this study we measured changes in the CODCr, TN, NH4+-N, TP, and DO concentrations and the pH of different layers in an integrated vertical-flow constructed wetland (IVCW) treating eutrophic water. We also examined the composition and diversity of the bacterial community in the IVCW using PCR-DGGE. Our results showed that most of the contaminants were removed during sewage flow from the down-flow chamber to the up-flow chamber. The removal rates of TN, TP, CODCr, and NH4+-N were, respectively, 63.7%, 66.7%, 72.2%, and 67.9% in the down-flow; consequently, the CODCr and TP concentrations of the effluent fell below 10 mg/L and 0.05 mg/L. There were some common microorganisms and specific microorganisms in the different layers of the constructed wetland because of the changes in environmental factors and nutrient levels. The diversity of the bacterial community was highest in the upper layer of the down-flow system, and the similarity in the down-flow system was higher than that in the up-flow system. From the down-flow system to the up-flow system, the diversity of the bacterial community increased from 2.31 to 1.95 and the structural similarity gradually increased from 65.7% to 70.9%. The higher complexity of the bacterial community in the upper layer of the constructed wetland may be supported by plant oxygenation, rhizodeposition, and litter accumulation.
Four major families have been found so far to possess the calmodulin binding IQ motif/s in plants: the IQD, the myosin, the CAMTA and the CNGC family. We have systematically identified and characterized a novel IQ motif-containing protein family, IQM, in Arabidopsis (Arabidopsis thaliana) using bioinformatics methods. IQM family contains six-member proteins (IQM1-6) which share sequence homology with a pea heavy metal-induced protein 6 and a ribosome-inactivating protein, trichosanthin, as well as IQ motif. IQM family can be divided into two groups, IQM3 and the other member proteins, based on sequence similarity and phylogenetic analysis of sequences. Though almost constitutive expression patterns were found in various plant organs of 6-week-old plants for IQM1 and 2, the other genes exhibited distinct organ-specific expression patterns. Light irradiation and treatment with heavy metals such as CdCl₂ or Pb(NO₃)₂ and high concentrations of mannitol or NaCl also changed expression of each IQM gene in a distinct manner in 7-day-old seedlings. However, treatment with various hormones, such as auxin, abscisic acid, gibberellin, methyl jasmonate and ethylene precursor, did not affect gene expression significantly. These results suggest that each IQM family gene plays a different role in plant development and responses to environmental cues.
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