Converting low-grade thermal energy into electrical energy is crucial for the development of modern smart wearable energy technologies. The free-standing films of PEDOT@Bi2Te3 prepared by tape-casting hold promise for flexible thermoelectric technology in self-powered sensing applications. Bi2Te3 nanosheets fabricated by the solvothermal method are tightly connected with flat-arranged PEODT molecules, forming an S-Bi bonded interface in the composite materials, and the bandgap is reduced to 1.63 eV. Compared with the PEDOT film, the mobility and carrier concentration of the composite are significantly increased at room temperature, and the conductivity reaches 684 S/cm. Meanwhile, the carrier concentration decreased sharply at 360 K indicating the creation of defect energy levels during the interfacial reaction of the composites, which increased the Seebeck coefficient. The power factor was improved by 68.9% compared to PEDOT. In addition, the introduction of Bi2Te3 nanosheets generated defects and multidimensional interfaces in the composite film, which resulted in weak phonon scattering in the conducting polymer with interfacial scattering. The thermal conductivity of the film is decreased and the ZT value reaches 0.1. The composite film undergoes 1500 bending cycles with a 14% decrease in conductivity and has good flexibility. This self-supporting flexible thermoelectric composite film has provided a research basis for low-grade thermal energy applications.
Forests not only are an essential resource for human society but also have a significant impact on the climate. With the development of remote sensing technology, some progress has been made in forest change monitoring. However, relatively little research has been conducted on historical forest dynamics. Estimating forest loss and its drivers during historical time periods remains a scientific pursuit. In this study, we reconstructed forest loss and its dominant drivers across China based on long time-series socioeconomic and environmental data using LightGBM classification and regression models. The models showed good performance in both 10-fold cross-validation and comparison with other datasets. The results indicate that from 1900 to 2000, forest loss mainly occurred in southern China, with a total loss area of 34.4 × 104 km2. Additionally, there was significant spatial heterogeneity, showing a decreasing trend from east to west and from south to north. The forest loss in China can be divided into two stages: (1) the stable stage from 1900 to 1949; and (2) the fluctuating stage from 1950 to 1999. In the first stage, most of the forest loss was attributed to forestry (>80%), followed by commodity-driven deforestation. In the early stage of the development of the People’s Republic of China, forest loss showed an increasing trend. In the 1960s, the forest loss area decreased by 12.9% due to the stagnation of the economy. With the adoption of the reform and opening-up policy, the total forest loss area in China reached its peak value (6.4 × 104 km2) during 1980–1989. The models also accurately captured the impact of urbanization and government policy in this period. This study not only provides an in-depth understanding of historical forest change in China, but also offers data and methodological references for the further study of human–nature interactions over the long term.
Abstract Background: Existing literatures demonstrated that meteorological factors could be of importance in affecting the spread patterns of the respiratory infectious diseases. However, how ambient temperature may influence the transmissibility of COVID-19 remains unclear. Objectives: We explore the association between ambient temperature and transmissibility of COVID-19 in different regions across China. Methods: The surveillance data on COVID-19 and meteorological factors were collected from 28 provincial level regions in China, and estimated the instantaneous reproductive number ( R t ). The generalized additive model was used to assess the relationship between mean temperature and R t . Results: There were 12745 COVID-19 cases collected in the study areas. We report the effect of temperature on R t is not of statistical significance, which holds for most of included regions except for those in North China. Conclusions: We found little statistical evidence for that the higher temperature may reduce the transmissibility of COVID-19.
Dendritic cells (DCs) as professional antigen presenting cells, are important in the initiation of the primary immune response. The present study compared the morphology, phenotypes and function between monocyte‑derived human DCs produced from a conventional culturing system containing granulocyte‑macrophage colony‑stimulating factor (GM‑CSF) and IL‑4 (IL‑4‑DC) and DCs generated by the stimulation of GM‑CSF and interferon (IFN)‑α (IFN‑DC). When compared with IL‑4‑DC in morphology, IFN‑DC contained more organelles, including endoplasmic reticulum and myelin figures, whereas mature (m)IL‑4‑DC contained more vacuoles in the cells. The spikes of IFN‑DC were shorter and thicker. The expression of phenotypes between immature IFN‑DC and IL‑4‑DC were diverse. Following maturation with tumor necrosis factor‑α, IFN‑DC and IL‑4‑DC upregulated the expression of cluster of differentiation (CD) 11c and CD83. Conversely, immature IFN‑DC and IL‑4‑DC secreted few inflammatory cytokines including interleukin (IL)‑18, IL‑23, IL‑12p70, IL‑1β and anti‑inflammatory IL‑10. Following maturation, large amounts of the cytokines were secreted by these two DCs and mIFN‑DC secreted more cytokines compared with mIL‑4‑DC in general. Furthermore, immature IFN‑DC and IL‑4‑DC loaded with cytomegalovirus (CMV)‑pp65 protein were unable to induce the priming of T cells, as evaluated by the intracellular staining with IFN‑γ. Notably, mature DCs exhibited the ability to present CMV‑pp65 protein and activate T cells. The mIFN‑DC activated a greater proportion of autologous CD4+ T cells (0.91 vs. 0.31%, P<0.001) and CD8+ T cells (0.90 vs. 0.48%, P<0.001) to secret IFN‑γ compared with mIL‑4‑DC. The results suggested that the morphology, phenotypes and cytokine secretion of IFN‑DC and IL‑4‑DC were diverse. The mIFN‑DC were more effective in priming and cross‑priming T cells when compared with IL‑4‑DC.
6-Phosphogluconate dehydrogenase (6PGD) is a key enzyme that converts 6-phosphogluconate into ribulose-5-phosphate with NADP+ as cofactor in the pentose phosphate pathway (PPP). 6PGD is commonly upregulated and plays important roles in many human cancers, while the mechanism underlying such roles of 6PGD remains elusive. Here we show that upon EGFR activation, 6PGD is phosphorylated at tyrosine (Y) 481 by Src family kinase Fyn. This phosphorylation enhances 6PGD activity by increasing its binding affinity to NADP+ and therefore activates the PPP for NADPH and ribose-5-phosphate, which consequently detoxifies intracellular reactive oxygen species (ROS) and accelerates DNA synthesis. Abrogating 6PGD Y481 phosphorylation (pY481) dramatically attenuates EGF-promoted glioma cell proliferation, tumor growth and resistance to ionizing radiation. In addition, 6PGD pY481 is associated with Fyn expression, the malignancy and prognosis of human glioblastoma. These findings establish a critical role of Fyn-dependent 6PGD phosphorylation in EGF-promoted tumor growth and radiation resistance.
Many types of human tumour cells overexpress the dual-specificity phosphatase Cdc25A. Cdc25A dephosphorylates cyclin-dependent kinase and regulates the cell cycle, but other substrates of Cdc25A and their relevant cellular functions have yet to be identified. We demonstrate here that EGFR activation results in c-Src-mediated Cdc25A phosphorylation at Y59, which interacts with nuclear pyruvate kinase M2 (PKM2). Cdc25A dephosphorylates PKM2 at S37, and promotes PKM2-dependent β-catenin transactivation and c-Myc-upregulated expression of the glycolytic genes GLUT1, PKM2 and LDHA, and of CDC25A; thus, Cdc25A upregulates itself in a positive feedback loop. Cdc25A-mediated PKM2 dephosphorylation promotes the Warburg effect, cell proliferation and brain tumorigenesis. In addition, we identify positive correlations among Cdc25A Y59 phosphorylation, Cdc25A and PKM2 in human glioblastoma specimens. Furthermore, levels of Cdc25A Y59 phosphorylation correlate with grades of glioma malignancy and prognosis. These findings reveal an instrumental function of Cdc25A in controlling cell metabolism, which is essential for EGFR-promoted tumorigenesis.
Platinum-based chemotherapy is the the cornerstone of treatment of many cancers. Combinations of platinum drugs with other agents are still the mainstream therapies for non-small cell lung cancer,showing significant effectiveness in an early phase. Along with the treatment,the tumor cells can become resistant to chemotherapy drugs,which affect the efficacy and prognosis. The mechanisms of drug resistance are complicated,including abnormal expressions of membrane proteins,enhanced DNA repair functions,abnormal regulation mechanisms of apoptosis,and enhanced cellular detoxification function. In this article we summarize some of the main mechanisms of platinum resistance in lung cancer cells,with an attempt to identify new potential target analogues or inhibitors and improve the efficacies of the combined use of platinum-based drugs.
Mold spoilage and nutrition enrichment are major concerns of Chinese steamed bread, and using functional lactic acid bacteria as starter to play the role of in-situ preservation and nutritional fortification was a promising alternative. Hence, Lactiplantibacillus plantarum P10 capable of inhibiting spoilage microorganisms and producing GABA (380 mg/L) was screened from Chinese pickle. Metabolomics analysis showed that P10 produced key antimicrobial metabolites mainly including ten organic acids, aldehyde, alkaloid. Besides, P10 might exhibit health beneficial effects such as degrading cholesterol, lowering blood glucose and reducing uric acid due to the production of deoxycholic acid and Ile-Pro-Ile, and the degradation of purine. Finally, the promising application potential of P10 was evidenced in steamed bread with extended shelf life, excellent anti-aging effect, and 24.5-fold enrichment of GABA. Conclusively, this investigation could provide scientific basis for the application of P10 as a functional starter in steamed bread.
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