China has the largest afforested area in the world (∼62 million hectares in 2008), and these forests are carbon sinks. The climatic effect of these new forests depends on how radiant and turbulent ...energy fluxes over these plantations modify surface temperature. For instance, a lower albedo may cause warming, which negates the climatic benefits of carbon sequestration. Here, we used satellite measurements of land surface temperature (LST) from planted forests and adjacent grasslands or croplands in China to understand how afforestation affects LST. Afforestation is found to decrease daytime LST by about 1.1 ± 0.5 °C (mean ± 1 SD) and to increase nighttime LST by about 0.2 ± 0.5 °C, on average. The observed daytime cooling is a result of increased evapotranspiration. The nighttime warming is found to increase with latitude and decrease with average rainfall. Afforestation in dry regions therefore leads to net warming, as daytime cooling is offset by nighttime warming. Thus, it is necessary to carefully consider where to plant trees to realize potential climatic benefits in future afforestation projects.
Cell death results in tissue damage and ultimately donor graft rejection and can occur as an active molecular process through apoptotic, necrotic and newly identified receptor interacting protein 1 ...and 3 kinase (RIPK1/3)‐mediated necroptotic pathways. Necroptosis leads to the release of inflammatory molecules which can activate host immune cells. This pathway has yet to be studied in heart transplantation. We have found that necroptosis was induced in murine cardiac microvascular endothelial cell (MVEC) under anti‐apoptotic condition following tumor necrosis factor alpha treatment. Necroptotic cell death and release of the danger molecule high mobility group box 1 (HMGB1) were inhibited by the RIPK1 inhibiting molecule necrostatin‐1 and by genetic deletion of RIPK3. In addition, tissue necrosis, release of HMGB1 and graft cell infiltrate were attenuated in RIPK3 null heart allografts following transplantation. Finally, a brief sirolimus treatment markedly prolonged RIPK3 null cardiac allograft survival in allogeneic BALB/c recipients as compared to WT C57BL/6 donor grafts (95 ± 5.8 vs. 24 ± 2.6 days, p < 0.05). This study has demonstrated that RIPK1/3 contributes to MVEC death and cardiac allograft survival through necroptotic death and the release of danger molecules. Our results suggest that targeting RIPK‐mediated necroptosis may be an important therapeutic strategy in transplantation.
This study demonstrates that receptor‐interacting protein kinase 3 regulates necroptotic death, danger molecule release, and cardiac allograft survival.
Recently, a novel class of transcripts, long non-coding RNAs (lncRNAs), is being identified at a rapid pace. These RNAs have critical roles in diverse biological processes, including tumorigenesis. ...Here we report that taurine-upregulated gene 1 (TUG1), a 7.1-kb lncRNA, recruiting and binding to polycomb repressive complex 2 (PRC2), is generally downregulated in non-small cell lung carcinoma (NSCLC) tissues. In a cohort of 192 NSCLC patients, the lower expression of TUG1 was associated with a higher TNM stage and tumor size, as well as poorer overall survival (P<0.001). Univariate and multivariate analyses revealed that TUG1 expression serves as an independent predictor for overall survival (P<0.001). Further experiments revealed that TUG1 expression was induced by p53, and luciferase and chromatin immunoprecipitation (ChIP) assays confirmed that TUG1 was a direct transcriptional target of p53. TUG1 knockdown significantly promoted the proliferation in vitro and in vivo. Moreover, the lncRNA-mediated regulation of the expression of HOX genes in tumorigenesis and development has been recently receiving increased attention. Interestingly, inhibition of TUG1 could upregulate homeobox B7 (HOXB7) expression; ChIP assays demonstrated that the promoter of HOXB7 locus was bound by EZH2 (enhancer of zeste homolog 2), a key component of PRC2, and was H3K27 trimethylated. This TUG1-mediated growth regulation is in part due to specific modulation of HOXB7, thus participating in AKT and MAPK pathways. Together, these results suggest that p53-regulated TUG1 is a growth regulator, which acts in part through control of HOXB7. The p53/TUG1/PRC2/HOXB7 interaction might serve as targets for NSCLC diagnosis and therapy.
Although the concept of the Luttinger liquid (LL) describing a one-dimensional (1D) interacting fermion system1,2 collapses at higher dimensions, it has been proposed to be relevant to enigmatic ...problems in condensed matter physics including the normal state of cuprate superconductors3–5, unconventional metals6,7 and quantum criticality8,9. Here we investigate the electronic structure of quasi-2D η-Mo4O11, a charge-density wave material, using high-resolution angle-resolved photoemission spectroscopy and ab initio calculations. We show a prototypical LL behaviour originating from the crossed quasi-1D chain arrays hidden in the quasi-2D crystal structure. Our results suggest that η-Mo4O11 materializes the crossed LL phase10–12 in its normal state, where the orthogonal orbital components substantially reduce the coupling between intersecting quasi-1D chains and therefore maintain the essential properties of the LL. Our finding not only presents a realization of a 2D LL, but also provides a new angle to understand non-Fermi liquid behaviour in other 2D and 3D quantum materials.The Luttinger liquid is a theoretical concept used to describe interacting fermions in a 1D system. Now it is shown that the model also describes electron physics in η-Mo4O11, a quasi-2D material in which 1D chains cross each other.
Recent evidence indicates that long noncoding RNAs (lncRNAs) have a critical role in the regulation of cellular processes such as differentiation, proliferation, and metastasis. These lncRNAs are ...dysregulated in a variety of cancers and many function as tumor suppressors; however, the regulatory factors involved in silencing lncRNA transcription are poorly understood. In this study, we showed that epigenetic silencing of lncRNA SPRY4 intronic transcript 1 (SPRY4-IT1) occurs in non-small-cell lung cancer (NSCLC) cells through direct transcriptional repression mediated by the Polycomb group protein enhancer of zeste homolog 2 (EZH2). SPRY4-IT1 is derived from an intron within SPRY4, and is upregulated in melanoma cells; knockdown of its expression leads to cell growth arrest, invasion inhibition, and elevated rates of apoptosis. Upon depletion of EZH2 by RNA interference, SPRY4-IT1 expression was restored, and transfection of SPRY4-IT1 into NSCLC cells resulted in a significant antitumoral effect, both in culture and in xenografted nude mice. Moreover, overexpression of SPRY4-IT1 was found to have a key role in the epithelial-mesenchymal transition through the regulation of E-cadherin and vimentin expression. In EZH2-knockdown cells, which characteristically showed impaired cell proliferation and metastasis, the induction of SPRY4-IT1 depletion partially rescued the oncogenic phenotype, suggesting that SPRY4-IT1 repression has an important role in EZH2 oncogenesis. Of most relevance, translation of these findings into human NSCLC tissue samples demonstrated that patients with low levels of SPRY4-IT1 expression had a shorter overall survival time, suggesting that SPRY4-IT1 could be a biomarker for poor prognosis of NSCLC.
The mechanism of the charge density wave transition in quasi one-dimensional blue bronzes is still debated. Here, the authors report evidence of a Luttinger liquid in the normal state of blue bronzes ...and Holstein polarons below the transition temperature, revealing the important role of electron-phonon coupling in the transition.
This paper presents an experimental investigation on local buckling behavior of extruded 6000 series alloy I-shaped aluminium alloy beams. A total of 10 specimens with a wide range of ...width-to-thickness ratios (4.4–15.0 of flange, 42.9–73.1 of web) of component plates were divided into two types: one with stiffeners at mid-span, and the other without intermediate stiffeners. Failure modes, ultimate loading capacities, load-deformation responses and load-strain curves of the specimens were studied. Local buckling occurred in the top flange and web of six specimens without intermediate stiffeners, and shear local buckling occurred in the other four specimens with intermediate stiffeners though which developed a tension field. A finite element model was developed and validated against the test results, which was used for parametric analysis of 24 specimens. The investigation focused on the effects of the intermediate stiffeners and width-to-thickness ratio on the buckling strength of the aluminium alloy beams. It was found that component plates with small width-to-thickness ratios could make material function to its fullest potential; And there was a significant increase in the post-buckling strength; Eurocode 9 underestimated the loading capacity of the specimens to be safe. For the specimens with thin (width-to-thickness ratio more than 40) web, the standards should be especially enhanced. Calculation results of the finite element model consist well with the experimental results.
•Tests were conducted on extruded I-shaped 6000 series aluminium alloy beams.•Concentrated loads are subjected to the specimens.•A FE model is developed and validated for parametric analysis of 24 specimens.•The correlation between the tests and the FE model is good.•Tests results and parametric analysis results are compared with EC 9.
► A data acquisition technique is developed, capable of separating the DC and AC potentials from the recorded potential signal. ► The effect of AC current density on corrosion of 16Mn pipe steel is ...determined. ► The AC corrosion mechanism of the steel is analyzed. ► A potential method to calculate AC current density on pipelines in the field is proposed.
In this work, the alternating current (AC), 60Hz in frequency, corrosion of 16Mn pipeline steel was studied in a simulated soil solution by weight loss and polarization curve measurements, real-time AC/DC (direct current) signal data acquisition (DAQ), and surface characterization. The developed DAQ is capable of separating the DC and AC voltage components from the recorded total reading, providing mechanistic information about the steel corrosion in the presence of AC interference. The corrosion of steel is enhanced by the applied AC current density from 0 to 400A/m2. With the further increase to 600A/m2 and 800A/m2, the corrosion rate of the steel decreases, which is attributed to the formation of a compact corrosion product layer on the steel surface at sufficiently high AC current densities, and a compact film is formed on the steel surface. While AC could enhance corrosion of the steel, only a very small percentage of AC current is involved in the steel dissolution (acts as Faradaic current). The vast majority of AC either participates in the charging–discharging process (acts as non-Faradaic current) of the double-charge layer or gets involved in the redox reaction of water.
In klystron amplifiers, spurious oscillations caused by the backstreaming electrons from collector may lead to unacceptable instabilities in experiments. To facilitate the fast and accurate analysis ...of such types of self-oscillations, rather than performing time-consuming particle-in-cell (PIC) simulations, the small signal theory to predict threshold conditions of spurious oscillations in klystrons has been further developed and implemented into the klystron computer code KlyC. If spurious oscillation occurs, the frequency and Q of the oscillation mode in a small signal regime can also be predicted. The effectiveness of the proposed threshold prediction method has been demonstrated through benchmarking against PIC codes, showing great agreement with result discrepancies at the several percentage level, while numerical computation time for small signal models is significantly (at least three orders of magnitude) faster than executed in the PIC simulations.
PDF
