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By the use of a high-speed collection drum, poly(vinylidene fluoride) (PVDF) was electrospun into aligned ultrafine fibrous membranes from its solutions in a mixture of N, N-dimethylformamide and acetone (9:1, v/v), and a continuous hot-press post-treatment was performed on the membranes to improve their mechanical properties. Anisotropic tensile results and rupture behaviors of the hot-pressed PVDF membranes with higher fiber alignments in both revolving direction (RD) and cross direction were obtained. It was found that, due to the true fracture of electrospun fibers and improvement of the interfiber compaction by hot-press, the tensile strength and modulus of the hot-pressed membranes in RD reached the highest values at 58.12 ± 4.46 MPa and 519.9 ± 34.1 MPa, respectively when the collection speed was 10.42 m/s. The decrease of porosity and liquid absorption also represented the compaction improvement of the electrospun fibrous membranes. The combination of fiber alignments and hot-press could provide a novel method to fabricate high strength of electrospun membranes which have highly potential applications in filtration or battery separators. POLYM. ENG. SCI., 49:1291-1298, 2009. [C]2009 Society of Plastics Engineers, INTRODUCTION The electrospinning process has been studied as a useful method to produce ultrafine fibrous membranes from polymer solutions or melts under a high electric voltage for several years (1-5). [...]

Poly(vinylidene fluoride) (PVDF) was electrospun into ultrafine fibrous membranes from its solutions in a mixture of N,N-dimethylformamide and acetone (9:1, v/v). The electrospun membranes were subsequently treated by continuous hot-press at elevated temperatures up to 155°C. Changes of morphology, crystallinity, porosity, liquid absorption, and mechanical properties of the membranes after hot-press were investigated. Results of scanning electron microscopy showed that there were no significant changes in fibrous membrane morphology when the hot-press temperature varied from room temperature to 130°C, but larger pores were formed because of fibers melting and bonding under higher temperatures. Analyses of X-ray diffraction and differential scanning calorimeter exhibited that the crystalline form of PVDF could transfer from β-type to α-type during hot-press at temperatures higher than 65°C. Tensile tests suggested that the mechanical properties of the electrospun PVDF membranes were remarkably enhanced from 25 to 130°C, whereas the porosity and the liquid absorption decreased. The hot-press at 130°C was optimal for the electrospun PVDF membranes. The continuous hot-press post-treatment could be a feasible method to produce electrospun membranes, not limited to PVDF, with suitable mechanical properties as well as good porosity and liquid absorption for their applications in high-quality filtrations or battery separators. POLYM. ENG. SCI., 48:934-940, 2008. © 2008 Society of Plastics Engineers, INTRODUCTION The electrospinning is a straightforward way to produce ultrafine fibrous membranes from polymer solutions or melts under a high electric voltage [1-5]. Because of the tiny diameter in several [...]

RNA-binding protein Lin28A is frequently over-expressed in human malignant tumors and is associated with tumor advance and poor prognosis. However, the expression pattern and functions of Lin28A in colon cancer are unknown. In this study, we detected the expression of Lin28A in colon cancer patients and tested the effect of Lin28A on the chemotherapeutic sensitivity of colon cancer cells to 5-fluorouracil (5-FU). As expected, we showed that Lin28A is up-regulated in 73.3 % of colon cancer patients. However, to our surprise, we found that oncogenic protein Lin28A-enforced expression in colon cancer cells enhanced the chemosensitivity of cancer cells to 5-FU via promoting the cell apoptosis. Further mechanisms study revealed that the effect of Lin28A increasing chemosensitivity of cancer cells is in a let-7 independent manner, but which is associated with decreasing the expression of DNA damage repair protein H2AX. Conclusively, here we reported an unexpected function of Lin28A, which may shed lights on fully understanding the physiological and pathological roles of this oncogene. [ABSTRACT FROM AUTHOR]

MicroRNAs encoded by the miR-15b/16-2 cluster act as tumor suppressors. Aberrant regulation of miR-15b in human malignant tumors is reportedly involved in cancer development, contributing to cell death, reduced proliferation, angiogenesis and metastasis resistance, metabolism reprogramming, genome instability, and tumor-associated inflammation. In this review, we summarize the mechanisms involved in regulating miR-15b expression in mammalian tumors and discuss the effects of miR-15b dysregulation on the hallmarks of cancer and highlight its role as a potentially valuable target for future cancer therapeutic strategies. [ABSTRACT FROM AUTHOR]

Road transport is the primary source of greenhouse gas emissions in China's transportation field. As an important means to achieve the "double carbon" goal in the transportation field, the new energy automobile industry will face a large number of power battery scrapping in the future. In order to quantitatively assess the carbon emission reduction benefits generated by the spent ternary lithium-ion battery waste recycling industry, the carbon footprint accounting model of spent ternary lithium-ion battery waste recycling and utilization was constructed from the life cycle perspective. By optimizing the power structure and transportation structure, the carbon emission reduction potential of spent ternary lithium-ion battery waste recycling was predicted and evaluated. In addition, the uncertainty analysis was conducted using the propagation of uncertainty equation to ensure the reliability and effectiveness of the carbon footprint results. The results showed that the current carbon footprint of Chinese enterprises using wet technology to recover 1 kg waste lithium batteries was -2 760.90 g (directional recycling process) and -3 752.78 g (recycling process), and the uncertainty of the carbon footprint was 16 % (directional recycling process) and 15 % (recycling process), respectively. From the analysis of carbon emission contribution, the regenerated product stage was the primary source of carbon reduction in the wet recycling and utilization of waste ternary lithium batteries, whereas the battery acquisition, disassembly, and end treatment stages were the main sources of carbon increase. Compared to optimizing the transportation structure, optimizing the power structure could effectively achieve greater carbon emission reduction potential. Under the collaborative optimization scenario, compared to that before optimization, 14 %-19 % carbon emission reduction could be achieved. Compared with native products, the directional circulation process and recycling process could achieve 9 % and 11 % emission reduction potential, respectively.

The steel industry is one of the most carbon-intensive industries in China. To analyze the carbon emission and carbon reduction potential of the steel industry in the life cycle, a carbon emission accounting model was built from the perspective of the life cycle. Taking the year 2020 as an example, an empirical analysis was carried out to predict and evaluate the carbon reduction potential of the steel industry in the life cycle by optimizing four variables, namely, scrap usage, fossil fuel combustion, electric power carbon footprint factor, and clean transportation proportion. At the same time, sensitivity analysis was used to determine the key degree of factors affecting carbon emission reduction in the life cycle of steel. The results showed that in 2020, the total life cycle CO 2 emissions of the steel industry in China was approximately 2.404 billion tons, of which the acquisition and processing of raw materials were the key links in the carbon emissions of the steel industry, accounting for more than 98% of the total life cycle CO 2 emissions of the steel industry. From the analysis of CO 2 emission source categories, fossil fuel savings and outsourcing power cleaning were the top priorities of carbon reduction in the steel industry. By 2025, the steel industry could achieve 20%, 6%, 5%, and 1% carbon emission reduction potential by respectively promoting low-carbon technology, optimizing the power structure, increasing the number of steel scraps, and increasing the proportion of clean transportation. The fossil fuel combustion had the most significant impact on the life cycle CO 2 emissions of the steel industry, followed by the electric power carbon footprint factor and scrap steelmaking usage. With regard to low-carbon technologies in the steel industry, in the short term, the promotion of low-carbon technologies in the steel rolling process and blast furnace ironmaking process should be the main focus. Later, with the gradual increase in the proportion of electric furnace steelmaking, the promotion of low-carbon technologies in the electric furnace steelmaking process will significantly improve the carbon emission reduction potential of the steel industry throughout its life cycle.

Aim: Arginase-1 (Arg-1) metabolizes l-arginine to l-ornithine and urea. It has been documented to have a role in various malignancies. However, the relationship between Arg-1 expression and clinicopathological characteristics of colorectal cancer (CRC) patients remains to be elucidated. The present study aimed to analyze the expression and prognostic value of Arg-1 in patients with CRC., Material and Methods: The mRNA and protein expressions of Arg-1 in fresh colorectal cancer tissue specimens and the corresponding noncancerous tissue specimens were examined by RT-qPCR (n = 24) and western blot analysis (n = 17). Arg-1 expression levels were determined in paraffin-embedded CRC tissue specimens (n = 236) by immunohistochemistry. The associations of Arg-1 expression and clinicopathological features and clinical prognosis in 236 CRC patients were analyzed., Results: The expression levels of Arg-1 were significantly higher in the CRC tissues compared with the matched noncancerous tissues, and elevated Arg-1 expression was remarkably associated with stage III-IV tumors (P = 0.007), lymph node metastasis (P = 0.019) and a plasma albumin concentration <35 g/l (P = 0.022). Kaplan-Meier analysis indicated that Arg-1 overexpression was associated with adverse prognoses for overall survival (OS) (P < 0.001) and disease-free survival (DFS) (P < 0.001) in all cases. Further analysis revealed that the patients with high Arg-1 expression had significantly shorter OS and DFS at the advanced stages (III + IV) (P = 0.032 for OS, and P = 0.012 for DFS) but not at the early stages (I + II) (P = 0.194 for OS, and P = 0.065 for DFS). Multivariate analysis revealed that Arg-1 overexpression was an independent prognostic factor for OS (P = 0.002) and DFS (P < 0.001) in patients with CRC., Conclusion: The data indicated that Arg-1 overexpression in CRC may be a marker that can discriminate subgroups of patients with a poor prognosis., (Copyright © 2019 Elsevier GmbH. All rights reserved.)

RNA-binding protein Lin28A is frequently over-expressed in human malignant tumors and is associated with tumor advance and poor prognosis. However, the expression pattern and functions of Lin28A in colon cancer are unknown. In this study, we detected the expression of Lin28A in colon cancer patients and tested the effect of Lin28A on the chemotherapeutic sensitivity of colon cancer cells to 5-fluorouracil (5-FU). As expected, we showed that Lin28A is up-regulated in 73.3 % of colon cancer patients. However, to our surprise, we found that oncogenic protein Lin28A-enforced expression in colon cancer cells enhanced the chemosensitivity of cancer cells to 5-FU via promoting the cell apoptosis. Further mechanisms study revealed that the effect of Lin28A increasing chemosensitivity of cancer cells is in a let-7 independent manner, but which is associated with decreasing the expression of DNA damage repair protein H2AX. Conclusively, here we reported an unexpected function of Lin28A, which may shed lights on fully understanding the physiological and pathological roles of this oncogene.

MicroRNAs encoded by the miR-15b/16-2 cluster act as tumor suppressors. Aberrant regulation of miR-15b in human malignant tumors is reportedly involved in cancer development, contributing to cell death, reduced proliferation, angiogenesis and metastasis resistance, metabolism reprogramming, genome instability, and tumor-associated inflammation. In this review, we summarize the mechanisms involved in regulating miR-15b expression in mammalian tumors and discuss the effects of miR-15b dysregulation on the hallmarks of cancer and highlight its role as a potentially valuable target for future cancer therapeutic strategies.