Search

Background: Chemoresistance is a major factor contributing to the poor prognosis of patients with pancreatic cancer, and cancer stemness is one of the most crucial factors associated with chemoresistance and a very promising direction for cancer treatment. However, the exact molecular mechanisms of cancer stemness have not been completely elucidated. Methods: m6A-RNA immunoprecipitation and sequencing were used to screen m6A-related mRNAs and lncRNAs. qRT-PCR and FISH were utilized to analyse DDIT4-AS1 expression. Spheroid formation, colony formation, Western blot and flow cytometry assays were performed to analyse the cancer stemness and chemosensitivity of PDAC cells. Xenograft experiments were conducted to analyse the tumour formation ratio and growth in vivo. RNA sequencing, Western blot and bioinformatics analyses were used to identify the downstream pathway of DDIT4-AS1. IP, RIP and RNA pulldown assays were performed to test the interaction between DDIT4-AS1, DDIT4 and UPF1. Patient-derived xenograft (PDX) mouse models were generated to evaluate chemosensitivities to GEM. Results: DDIT4-AS1 was identified as one of the downstream targets of ALKBH5, and recruitment of HuR onto m6A-modified sites is essential for DDIT4-AS1 stabilization. DDIT4-AS1 was upregulated in PDAC and positively correlated with a poor prognosis. DDIT4-AS1 silencing inhibited stemness and enhanced chemosensitivity to GEM (Gemcitabine). Mechanistically, DDIT4-AS1 promoted the phosphorylation of UPF1 by preventing the binding of SMG5 and PP2A to UPF1, which decreased the stability of the DDIT4 mRNA and activated the mTOR pathway. Furthermore, suppression of DDIT4-AS1 in a PDX-derived model enhanced the antitumour effects of GEM on PDAC. Conclusions: The ALKBH5-mediated m6A modification led to DDIT4-AS1 overexpression in PDAC, and DDIT-AS1 increased cancer stemness and suppressed chemosensitivity to GEM by destabilizing DDIT4 and activating the mTOR pathway. Approaches targeting DDIT4-AS1 and its pathway may be an effective strategy for the treatment of chemoresistance in PDAC. [ABSTRACT FROM AUTHOR]

This type of fly ash is difficult to float even at a higher concentration of collector due to less dispersion of the collector molecules on the surface. Emulsification of kerosene in the presence of Sodium Dodecyl Sulfate (SDS) dramatically reduces the size of the kerosene droplets. The results showed that much less collector was required to achieve a good separation of carbon from fly ash when SDS was employed in conjunction with the collector. In this paper, the influence of the concentration of emulsifier on flotation was discussed. The emulsifier concentration of 0.2 kg/t produced the superior performance of LOI of 54.5% and the corresponding CR of 93.1%. The contact angle and attachment efficiency of CFA after pretreatment were found to be increased. The results of XRD and SEM demonstrate that a complete separation of unburned carbon from CFA could be achieved by using the emulsifier. [ABSTRACT FROM AUTHOR]

MoS2 is considered a potential electrode material for lithium-ion batteries because of its high energy density. However, it has not been commercialized owing to its poor cycle stability. To explore the reasons for its poor cycle stability, in situ X-ray diffraction, in situ transmission electron microscopy, and other characterization methods were used to explore the lithium storage mechanism and the phase transitions of MoS2 during lithium storage. Because MoS2 forms an amorphous structure during cycling, these physical methods have difficulty distinguishing between the various electrochemical stages of the reaction in detail. In this work, in situ electrochemical impedance spectroscopy (EIS) was adopted to record the change in the impedance of the MoS2 electrode during the discharging and charging processes. The results show that the first discharging and charging process of MoS2 can be further divided into six stages and five stages, respectively. In addition, a program based on Python was used to batch-process EIS data, which promotes the further application of in situ EIS. This study can help researchers analyze the lithium storage process of MoS2 in more detail than was previously possible, and this method can also be applied to mechanistic research on other electrode materials. [ABSTRACT FROM AUTHOR]

Highlights 3D printing of continuous carbon fiber reinforced thermoplastic (C‐CFRTP) composites is a promising fabricating process to achieve complex lightweight structures within a short time; nevertheless, low mechanical performance between printed layers is always a limitation. Adding short carbon fibers during C‐CFRTP fabrication could achieve short‐continuous carbon fiber reinforced thermoplastic (S/C‐CFRTP) composites with enhanced mechanical properties. However, the underlying reinforcement mechanism is not well understood, which hinders the optimization of 3D printing process for S/C‐CFRTP. This paper investigates reinforcing behavior of short carbon fibers and impregnation behavior of the matrix (short carbon fiber reinforced PA6) under various 3D printing conditions. The results indicate that promoting both reinforcing and impregnation behaviors during S/C‐CFRTP 3D printing can improve mechanical performance. As short carbon fiber content increases, the mechanical performance initially experiences enhancement caused by the reinforcing behavior of short fibers, followed by a decline attributed to the insufficient impregnation of the molten matrix. Higher nozzle temperatures facilitate the impregnation behavior of the molten matrix, resulting in superior mechanical performance. Moreover, by leveraging the reinforcement mechanism, the optimal parameter combination is proposed to improve tensile, flexural, and interlaminar shear strengths of the 3D‐printed S/C‐CFRTP to approximately 368.27, 319.80, and 20.09 MPa, respectively. Reinforcement mechanism is revealed by reinforcing and impregnation behaviors. Short carbon fiber content affects both reinforcing and impregnation behaviors. Beyond 15 wt%, short carbon fiber content shows adverse effects on performance. High nozzle temperature promotes impregnation behavior to improve performance. Optimal parameters raise 19.8% tensile, 39.9% flexural and 161.2% shear strength. [ABSTRACT FROM AUTHOR]