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Untranslated regions (UTRs) of eukaryotic mRNAs plav crucial roles in post-transcriptional regulation of gene expression via the modulation of nucleocytoplasmic mRNA transport, translation efficiency, subcellular localization, and message stability. Single-nucleotide polymorphisms (SNPs) in UTRs of a candidate gene may also change the post-transcriptional regulation of a gene or function by nucleotide mutation. For species that have not been entirely sequenced genomically, new methods need to be devised to discover SNPs in noncoding regions of candidate genes. In this study, based on the expressed sequence tag (EST) of Pinus radiata (Monterey pine), we obtained all the sequences of UTRs of the actin gene by using a chromosome walking method. We also detected all the SNPs in and around the coding region of the actin gene. In this way, the full genomie sequence (2154 bp) of the actin gene was identified, including the 5'UTR, introns, the coding sequence, and the 3'UTR. PCR amplification and DNA fragment sequencing from 200 unrelated P. radiata trees revealed a total of 21 SNPs in the actin gene, of which 3 were located in the 5'UTR, 3 in the introns, 10 in the coding sequence, and 5 in the 3'UTR. We show that chromosome walking can be used for obtaining the sequence of UTRs, and then, based on this sequence, to discover SNPs in the noncoding regions of candidate genes from this species without an entire genomic sequence.
The feasibility of total petroleum hydrocarbon-contaminated (TPH) soil remediation was studied using persulfate oxidation. Factors tested included type of activator, persulfate concentration, number of persulfate applications, and reaction time. Probe chemicals were used to study effi ciency of the persulfate oxidation mechanism. The best activation method used Fe2+, which achieved 40.8% TPH degradation at 24 h with an initial TPH concentration of 14,432.5 mg/kg. For alkaline (high pH) and hydrogen peroxide activation treatments, TPH degradation effi ciencies were 35.2% and 21%, respectively. Thermal activation effi ciency was relatively low (15.6%). Kinetic experiments demonstrated that the oxidation reaction was substantially completed within 60 min. A one-time addition of persulfate was superior to multiple applications. The addition of probe compounds produced sulfate radicals, hydroxyl radicals, and reductants. The results indicate that activated persulfate is reasonably effective for remediation of TPH-contaminated soils.
To evaluate potential interactive effects of metals and polycyclic aromatic hydrocarbons (PAHs) on biomarker responses, groups of the freshwater fish crucian carp (Carassius auratus) were exposed to single and binary combinations of copper (Cu) (0.01-0.16 mg L-1) with fluorene (Fl) or fluoranthene (Fluo) (2-10 mg kg⁻¹) for 96 h. Dose-dependent increases in the activities of phases I and II metabolic enzymes [7-ethoxyresorufin O-deethylase (EROD) and glutathione-S-transferase (GST), respectively] were observed in fish liver exposed to Fl and Fluo, but these enzyme activities did not differ significantly from the controls when co-treated with higher concentrations of Cu, suggesting an inhibiting interaction on the metabolic enzymes. Although Cu did not alter catalase (CAT) activity, CAT activity was decreased in fish liver exposed to the two PAHs alone or in combination with Cu. Although metallothionein (MT) content in gills was significantly increased following exposure to Cu alone or in combination with Fl and Fluo, the induction folds of MT decreased under co-exposure. Co-exposures to these chemicals invoked complex biomarker responses in fish liver and gills. These results highlight the need for careful consideration of the interactive effects of multiple environmental stressors on fish.
Groundwater level rises rapidly when mine drainage systems stop functioning after mine closures. Free-form polycyclic aromatic hydrocarbons (PAHs) in residual pillaring and abandoned mining levels could continue to migrate because of eluviation leaching. Moreover, other aquifers are polluted with mine water through mining-induced fractures, faults, and poorly sealed drill holes. Therefore, the distributions of 16-PAHs in raw coal mined in China and the factors influencing these distributions were analyzed to assist mine closures. The results showed that the average concentration of PAHs was 10.540±7.973 μg/g in the raw coal samples, and PAHs with low molecular weights had the highest abundances, accounting for 44% of the total PAH concentration obtained. The highest concentration of 16-PAHs was observed in bituminous coals, followed by that in lignite, and the lowest is anthracite. The influence factors analysis reveals that carbon content, volatile matter, H/C, and O/C have a significant effect on PAH content in raw coals. The volatile matter and molar ratio of H/C play a leading role in the changing process in 16 PAHs, accounting for more than 60% of the total contribution.
To get insights into the functional difference of CPD (constitutive photomorphogenesis and dwarfism) between herb and woody plants, a full-length Populus euphratica L. cDNA homologous to Arabidopsis thaliana CPD (AtCPD), named PeCPD, was introduced to Arabidopsis thaliana cpd mutant (CM) and corresponding wild type (WT), resulting in a series of CM-PeCPD and WT-PeCPD transgenic lines. All the CM-PeCPD lines differentially displayed evident restoration in phenotype and fertility compared to cpd mutant, but still showed differences from WT in some respects. All the WT-PeCPD lines displayed obvious overexpression phenotype compared to WT plants. The transcription levels (TLs) of PeCPD in the CM-PeCPD lines were positively correlated, and that in the WT-PeCPD lines uncorrelated, with the level of their phenotype restoration/change. In the CM-PeCPD lines, the TLs of AtDWF4, AtBR6OX2 and AtTCH4 were negatively, and of AtBAS1 and AtSAUR-AC1 positively correlated with PeCPD TLs, whereas in the WT-PeCPD lines, their TLs were uncorrelated, and positively or negatively correlated to PeCPD TLs. The level of total endogenous BRs was basically negatively correlated to the level of phenotype restoration/change and PeCPD TLs in the PeCPD transgenic plants. The findings indicate that PeCPD also plays important role in regulation of plant growth and development through participating in BR biosynthesis.
Aggregate has been recognized as a key element in the stabilization of soil organic carbon (SOC). Several researchers have done outstanding work on identifying and isolating aggregates and their physiochemical properties. However, thermal stability of SOC in soil aggregates has not yet been adequately explored. The main objective of the study was to clarify the protection of aggregation on SOC from thermal characters, and provide evidence on whether thermal analysis could be a potential rapid method to determine SOC stability in aggregates. We separated 20-cm surface soil into six fractions (>2, 1-2, 0.5-1, 0.25-0.5, 0.053-0.25 and <0.053mm) before and after 23-yr continuous soybean cultivation. The study measured the change of SOC and its thermal characteristics across aggregates using thermogravimetry-differential scanning calorimetry (TG-DSC), which also showed that the thermal stability mechanism of SOC is protected by aggregates. Results showed that 23-yr continuous soybean cultivation led to an SOC increase in 0.053-0.5 mm size aggregates, but a decrease in other large-size aggregates. Energy density in the > 0.5 mm fraction was decreased by 23-yr continuous soybean cultivation, but increased to < 0.5 mm size fraction. The largest energy density was in < 0.053 mm size fractions. In conclusion, long-term continuous soybean cultivation led to more energy transferred to micro-aggregates associated with the protection of micro-aggregates on soil SOC.
Neural precursor cells (NPCs), which are capable of self-renewing, migrating to specific sites, and differentiating into the three main CNS lineages, neurons, astrocytes and oligodendrocytes, have been used experimentally to repair the damaged nervous system, either by grafting of cells grown in vitro or by activating endogenous NPCs. The grafting of NPCs, however, is limited by its lower viability and undesired glial differentiation. Understanding the mechanism underlying these events, therefore, is essential for the potential future use of NPCs. In the present study, we investigated the role of histone deacetylase (HDAC) inhibition on survival, proliferation, differentiation and migration of the rat NPCs. We observed that NPCs derived from the E14.5 rat brain constitutively expressed both class I and class II HDAC mRNA. Inhibition of HDAC by trichostatin A (TSA) blocked the proliferation, increased neuronal differentiation and decreased astrocyte differentiation of the NPCs. Meanwhile, TSA had no significant effects on survival and migration of the NPCs. Finally, we found that HDAC inhibition regulated proliferation and neuronal differentiation of the NPCs was associated with a reduction of class II and but not class I HDAC transcription. These findings collectively demonstrate that in the situation of not affecting survival and migration, HDAC inhibition may induce more neuronal differentiation.
Aneuploidy often presents large variations in morphology, physiology, biochemistry, and genetics owing to karyotypic imbalance. This study aimed to evaluate the efficacy of aneuploid breeding in Echinacea purpurea L, an important medicinal plant. Reciprocal crosses between diploid and triploid plants were performed to generate aneuploid plants. Cross with triploid as female parent resulted in increased production of aneuploid individuals (19 of 23; 82.61%), while using diploid as female parent yielded much higher percentage of diploid progenies (130 of 133; 97.74%). Each aneuploid had particular karyotypic characteristics compared to the parents. The proportions of median, submedian, and subterminal centromere location chromosomes in gross chromosomes among aneuploids and two parents showed large variations. Although aneuploids had relatively lower adventitious bud regeneration rates than their parents, almost half of them looked morphologically normal, with high survival rates when transplanted to ex vitro conditions. Among the bioactive compounds assessed, cichoric acid and chlorogenic acid contents were extremely encouraging. Most aneuploids had higher cichoric acid and chlorogenic acid contents than their parents. For example, A2 had the highest cichoric acid content of 21.98 mg/g dry weight, more than twice the values of diploid and triploid. Meanwhile, A21 had the highest chlorogenic acid content of 1.84 mg/g, approximately five times more than the parental values. Eleven superior aneuploid lines were successfully screened as breeding candidates. The present findings indicated E. purpurea is highly tolerant of karyotypic imbalance and aneuploid plants could serve as prospective breeding resources in E. purpurea.
This study investigates the effects of bird droppings on mercury pollution levels in soil, specifically on the speciation and total concentration of mercury (Hg) in soil from Tongli Wetland, East China. Thirty soil samples and four bird dropping samples were collected from Tongli Wetland along with fifteen eggshells and five feathers from Heron Branch birds. Results indicated that bird droppings affect local soil’s physic-chemical properties and Hg accumulation. Additionally, heron feathers were found to contain more total mercury (HgT) than their eggshells. Hg concentration in soil that is affected by bird dropping was determined to be 0.194±0.026 mg/kg; concentration in soil without bird droppings was 0.104±0.039 mg/kg. Therefore, HgT concentration in the former exceeded that of the latter (86.54%). Numerical analysis revealed that concentrations of water-soluble (F1), acid-soluble (F2), alkali-soluble (F3), hydrogen peroxide-soluble (F4), and residual mercury (F5) in soil that is affected by bird dropping were higher in soil that isn’t affected by bird droppings. However, concentrations of F1 remained mostly stable. We found a positive correlation between Hg concentrations in soil and excrement and concentrations of total carbon (Ctot), total nitrogen (Ntot), and hydrogen (H), in addition to an exponential proportional relationship between C/N and Hg/C. We concluded that fresh bird droppings in soil may promote mercury enrichment. Furthermore, bird droppings and highly decomposed humus increase soil HgT concentration when they remain in soil for an extended period of time.
Salix matsudana is thought to be an ideal woody plant for use in phytoremediation programs in China. This study deals with the characterization of early responses to Cd in accumulation and its effects on other metals, and relative gene expression in roots exposed to 50 μM of Cd for 1 to 24 hours. The Cd content in roots exposed to Cd for 1, 3, 6, 12, and 24 hours of treatment was approximately 280, 587, 605, 622, and 795 μg/g DW, respectively. After 24 hours, Cd stress caused a decrease of iron (Fe) (34.1%), manganese (Mn) (60.1%), zinc (Zn) (40.7%) and calcium (Ca) (26.5%). After 24 hours of exposure, the relative expression of IRT1 was 6.7 times that of control treatment (P<0.05). A 160.8% increase was detected for the relative expression of NRAMP1 after exposure to Cd treatment for one hour. After three hours of stress, the expression of ZIP1 was 10 times that of control (P<0.05). The tolerance of plants to Cd involves gene expression, protein modification, and alterations in the coordination of major and secondary metabolites, which is a complex physiological and biochemical process.
Background: The regulation of microglial function via mitochondrial homeostasis is important in the development of neuroinflammation. The underlying mechanism for this regulatory function remains unclear. In this study, we investigated the protective role of mitochonic acid 5 (MA-5) in microglial mitochondrial apoptosis following TNFα-induced inflammatory injury. Methods: TNFα was used to induce inflammatory injury in mouse microglial BV-2 cells with and without prior MA-5 treatment. Cellular apoptosis was assessed using the MTT and TUNEL assays. Mitochondrial functions were evaluated via mitochondrial membrane potential JC-1 staining, ROS flow cytometry analysis, mPTP opening assessment, and immunofluorescence of cyt-c. Mitophagy was examined using western blots and immunofluorescence. The pathways analysis was carried out using western blots and immunofluorescence with a pathway blocker. Results: Our results demonstrated that TNFα induced apoptosis in the microglial BV-2 cell line by activating the caspase-9-dependent mitochondrial apoptotic pathway. Mechanistically, inflammation reduced mitochondrial potential, induced ROS production, and contributed to the leakage of mitochondrial pro-apoptotic factors into the cytoplasm. The inflammatory response reduced cellular energy metabolism and increased oxidative stress. By contrast, treatment with MA-5 reduced mitochondrial apoptosis via upregulation of mitophagy. Increased mitophagy degraded damaged mitochondria, disrupting mitochondrial apoptosis, neutralizing ROS overproduction, and improving cellular energy production. We also identified that MA-5 regulated mitophagy via Bnip3 through the MAPK–ERK–Yap signaling pathway. Inhibiting this signaling pathway or knocking down Bnip3 expression prevented MA-5 from having beneficial effects on mitochondrial homeostasis and increased microglial apoptosis. Conclusions: After TNFα-induced inflammatory injury, MA-5 affects microglial mitochondrial homeostasis in a manner mediated via the amplification of protective, Bnip3-related mitophagy, which is mediated via the MAPK–ERK–Yap signaling pathway.
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