P53 is a transcription factor highly inducible by many stress signals such as DNA damage, oncogene activation, and nutrient deprivation. Cell-cycle arrest and apoptosis are the most prominent ...outcomes of p53 activation. Many studies showed that p53 cell-cycle and apoptosis functions are important for preventing tumor development. p53 also regulates many cellular processes including metabolism, antioxidant response, and DNA repair. Emerging evidence suggests that these noncanonical p53 activities may also have potent antitumor effects within certain context. This review focuses on the cell-cycle arrest and apoptosis functions of p53, their roles in tumor suppression, and the regulation of cell fate decision after p53 activation.
•This paper analyses the factors affecting CO2 emissions of OECD.•LMDI decomposition and decoupling analysis methods are combined.•We find that the impact of population distribution on CO2 emissions ...is negligible.•Energy intensity and per capita GDP are the main impact factors of CO2 emissions.•Technical factors have a greater impact on decoupling elasticity.
Under the framework of the Kaya identity, this paper uses the Logarithmic Mean Divisia Index (LMDI1Abbreviation: LMDI, the Logarithmic Mean Divisia Index.1) decomposition method to explore the impacts of CO2 emission intensity of fossil energy, energy consumption structure, energy intensity, per capita Gross Domestic Product (GDP2Abbreviation: GDP, Gross Domestic Product.2), population distribution, and population size on CO2 emissions in the Organisation for Economic Co-operation and Development (OECD3Abbreviation: OECD, the Organisation for Economic Co-operation and Development.3) from 2001 to 2015. Additionally, the Tapio decoupling analysis is used to explore the decoupling relationships between the above influencing factors and CO2 emissions. Moreover, the LMDI decomposition formula is embedded into the decoupling analysis to analyze the influences of technical and non-technical factors on above decoupling elasticity. The results indicate that energy intensity and per capita GDP are the main factors affecting CO2 emissions. The former is the main reason for the decrease in CO2 emissions, and the latter is the main reason for the increase in CO2 emissions. The impact of population distribution on CO2 emissions is negligible. The decoupling states between the overall CO2 emission intensity of fossil energy, energy consumption structure, energy intensity, per capita GDP, and population size and CO2 emissions during 2001–2015 are recessive decoupling, recessive decoupling, weak negative decoupling, strong decoupling, and strong decoupling, respectively. Moreover, the influence of technical factors is greater than that of non-technical factors, and their influence directions are always opposite. In addition to our primary contributions, there are three marginal contributions in this paper. First, the population distribution is included in LMDI factorization. Second, LMDI decomposition is combined with Tapio decoupling analysis to explore the decoupling relationships between CO2 emissions and the above factors. Finally, the findings related to the impacts of technical and non-technical factors are novel.
•GO enhances the adsorptive and catalytic performance of Fe3O4-GO.•Fe3O4-GO shows excellent catalytic activity for phenol degradation in a heterogeneous photo-Fenton process.•The enhanced catalytic ...activity is attributed to the synergetic effect of GO and Fe3O4.•The redox cycle between Fe(II) and Fe(III) can be accelerated in photo-Fenton process.•UV-light improves significantly the phenol removal in photo-Fenton process.
Hybridizing zero-dimensional nanoparticles with two-dimensional graphene oxide nanosheets has been regarded as one of the most promising way to improve the adsorptive and catalytic performance of nanomaterials. Graphene oxide–iron oxide (Fe3O4-GO) nanocomposites were synthesized using a co-precipitation combining hydrothermal method, and then characterized using XRD, TEM, BET, XPS and VSM to study their structures and functionalities. Fe3O4-GO was used to degrade phenol in a heterogeneous photo-Fenton process. The effects of different parameters, such as GO loading, catalyst dosage, initial concentration of H2O2 and initial pH of the phenol solution on the degradation efficiency were assessed. The results showed that under optimal conditions with UV-light irradiation, about 98.8% phenol and 81.3% TOC of a phenol solution could be removed after 120min photo-Fenton degradation. It can be seen that UV-light improves significantly the phenol removal in photo-Fenton process. The introduction of GO in the catalyst promotes the photo-Fenton reaction via three roles: increasing adsorption capacity, offering more active sites and accelerating the Fe3+/Fe2+ cycle under UV light irradiation. It was also observed that Fe3O4-GO still showed high catalytic activity after five cycles.
Using provincial data on energy-related CO2 emissions in China from 1997 to 2014 and the CO2 emission Gini coefficient (CEG), this study evaluates China's spatial inequality in energy-related CO2 ...emissions. Further, we decompose this inequality and its variation from the perspectives of production and residential energy consumption, using the source decomposition and source increment decomposition methods. This paper presents a new CEG source increment decomposition method that can achieve complete decomposition. The results reveal a downward trend in China's overall, production sector and residential sector CO2 emissions inequality. Although the Gini coefficient of CO2 emissions from the residential sector is larger than that from the production sector, the contribution of the latter to the overall CEG is higher. The impacts of the spatial inequality of CO2 emissions from China's production and residential sectors depend on the type of energy. The concentration effect is the primary factor responsible for inducing changes in China’s overall and production sector CO2 emissions inequality, but it is not the only dominant factor for the residential sector CO2 emissions inequality.
•We propose a CO2 emission Gini coefficient source increment decomposition method.•We decompose emissions inequality by production and residential consumption.•Residential emissions inequality is greater than production and overall inequality.•Production emissions inequality contributes more to overall emissions.•The concentration effect leads to production and overall inequality changes.
China's carbon peak greatly impacts global climate targets. Limited studies have comprehensively analyzed the influence of the COVID-19 pandemic, changing emission network, and recent carbon ...intensity (CI) reduction on the carbon peak and the corresponding mitigation implications. Using a unique dataset at different levels, we project China's CO
emission by 2035 and analyze the time, volume, driver patterns, complex emission network, and policy implications of China's carbon peak in the post- pandemic era. We develop an ensemble time-series model with machine learning approaches as the projection benchmark, and show that China's carbon peak will be achieved by 2021-2026 with > 80% probability. Most Chinese cities and counties have not achieved carbon peaks response to the priority-peak policy and the current implementation of CI reduction should thus be strengthened. While there is a "trade off" between the application of carbon emission reduction technology and economic recovery in the post-pandemic era, a close cooperation of interprovincial CO
emission is also warranted.
In this paper, we respectively decompose and study different effects of technological progress on carbon emissions in China based on the combination of the logarithmic mean Divisia index method, the ...Solow residual model, and spatial econometrics. Furthermore, we propose an improved approach to estimate the rebound effect index. By comparing the different effects of technological progress on carbon emissions, our results indicate that China's overall domestic technological progress reduced its carbon emissions over this period. As for the rebound effect index, the estimated results are higher than in previous studies because of the spatial rebound effect, which was ignored by previous studies. Regionally, although the eastern region had high rebound effects, the western region is at the greatest risk from the rebound effects. Finally, we present specific environmental policy proposals for China's sustainable development based on empirical results.
p53 suppresses tumor development by responding to unauthorized cell proliferation, growth factor or nutrient deprivation, and DNA damage. Distinct pathways have been identified that cause p53 ...activation, including ARF-dependent response to oncogene activation, ribosomal protein-mediated response to abnormal rRNA synthesis, and ATM-dependent response to DNA damage. Elucidating the mechanisms of these signaling events are critical for understanding tumor suppression by p53 and development of novel cancer therapeutics. More than a decade of research has established the ATM kinase as a key molecule that activates p53 after DNA damage. Our recent study revealed that ATM phosphorylation of MDM2 is likely to be the key step in causing p53 stabilization. Upon activation by ionizing irradiation, ATM phosphorylates MDM2 on multiple sites near its RING domain. These modifications inhibit the ability of MDM2 to poly-ubiquitinate p53, thus leading to its stabilization. MDM2 phosphorylation does not inactivate its E3 ligase activity per se, since MDM2 self-ubiquitination and MDMX ubiquitination functions are retained. The selective inhibition of p53 poly-ubiquitination is accomplished through disrupting MDM2 oligomerization that may provide a scaffold for processive elongation of poly ubiquitin chains. These findings suggest a novel model of p53 activation and a general mechanism of E3 ligase regulation by phosphorylation.
Acute myocardial infarction (AMI) is a common cardiovascular disease with high mortality. Astragaloside IV (AS-IV) was reported to have cardioprotective effect after AMI. We hypothesize that the ...cardioprotective role of AS-IV is exerted by enhancing angiogenesis via regulating PTEN/PI3K/Akt signaling pathway. To valid our hypothesis, AMI rats and human umbilical vein endothelial cells (HUVECs) were employed in our study.
After treatment, cardiac function, survival rate, infarct size, pathological changes and fibrosis, cell apoptosis, ultrastructural changes, angiogenesis and expression of PTEN/PI3K/Akt signaling pathway were evaluated, respectively. In vitro study we detected proliferation, tube formation and signaling pathway activation of HUVECs treated with AS-IV, lentivirus overexpressed PTEN was employed to elucidate the potential mechanism. The results indicated that AS-IV administration significantly improved cardiac function and survival rate, limited infarct size, ameliorated pathological changes and fibrosis deposition, inhibited apoptosis, relieved ultrastructure injury and enhanced angiogenesis, PTEN/PI3K/Akt signaling pathway was activated simultaneously compared to the model group. In vitro study suggested that AS-IV treatment promoted cell proliferation and tube formation, and induced PTEN/PI3K/Akt signaling pathway activation. Importantly, overexpression of PTEN by lentivirus abolished AS-IV-induced angiogenesis.
Our study indicated that AS-IV could promote angiogenesis and cardioprotection after myocardial infarction. The mechanisms involve activation of PTEN/PI3K/Akt signaling pathway.
Bacterial small RNAs (sRNAs) have been implicated in various aspects of post-transcriptional gene regulation. Here, we demonstrate that sRNAs also act at the level of transcription termination. We ...use the rpoS gene, which encodes a general stress sigma factor σS, as a model system, and show that sRNAs DsrA, ArcZ, and RprA bind the rpoS 5′UTR to suppress premature Rho-dependent transcription termination, both in vitro and in vivo. sRNA-mediated antitermination markedly stimulates transcription of rpoS during the transition to the stationary phase of growth, thereby facilitating a rapid adjustment of bacteria to global metabolic changes. Next generation RNA sequencing and bioinformatic analysis indicate that Rho functions as a global “attenuator” of transcription, acting at the 5′UTR of hundreds of bacterial genes, and that its suppression by sRNAs is a widespread mode of bacterial gene regulation.
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•Rho termination factor acts within 5′UTRs of many bacterial genes•Rho functions as a global attenuator of gene expression•Small RNAs interfere with Rho-mediated termination by base-paring within 5′UTRs•sRNA-mediated antitermination is a widespread mode of bacterial gene regulation
Bacterial small RNAs balance the Rho-dependent termination pathway to prevent premature transcription termination, extending the role of these RNA regulators beyond post-transcriptional control.
Accurate, long-term, full-coverage carbon dioxide (CO
) data in units of prefecture-level cities are necessary for evaluations of CO
emission reductions in China, which has become one of the world's ...largest carbon-emitting countries. This study develops a novel method to match satellite-based Defense Meteorological Satellite Program's Operational Landscan System (DMSP/OLS) and Suomi National Polar-orbiting Partnership's Visible Infrared Imaging Radiometer Suite (NPP/VIIRS) nighttime light data, and estimates the CO
emissions of 334 prefecture-level cities in China from 1992 to 2017. Results indicated that the eastern and coastal regions had higher carbon emissions, but their carbon intensity decreased more rapidly than other regions. Compared to previous studies, we provide the most extensive and long-term CO
dataset to date, and these data will be of great value for further socioeconomic research. Specifically, this dataset provides a foundational data source for China's future CO
research and emission reduction strategies. Additionally, the methodology can be applied to other regions around the world.
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