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With the increasing volume of synthetic fiber waste, interest in plastic reuse technologies has grown. To address this issue, physical and chemical recycling techniques for polyamide, a major component of textile waste, have been developed. This study investigates the remelting and reforming properties of four types of pristine and recycled polyamide 6, focusing on how the microstructural arrangement of recycled polyamides affects polymer fiber formation. DSC and FT-IR were used to determine the thermal properties and chemical composition of the reformed thin films. Differences in the elongation behavior of molten fibers during the spinning process were also observed, and the morphology of the resulting fibers was examined via SEM. Birefringence analysis revealed that the uniformity of the molecular structure greatly influenced differences in the re-fiberization process, suggesting that chemically recycled polyamide is the most suitable material for re-fiberization with its high structural similarity to pristine polyamide. [ABSTRACT FROM AUTHOR]

In this study, we analyzed the laser cutting characteristics of pulse transverse electrical discharge in gas at atmospheric pressure (TEA) CO2 and ultraviolet (UV) pulse laser processing in a multilayer display panels. First, the numerical calculation for was performed to confirm the thermal characteristics of each materials and optical field distribution at the interface of different material layers. Also, processing characteristics were experimentally confirmed by measuring cutting profile and adhesion characteristics of layer interface. Experimental results show that the characteristics of multi layers polymer cutting have different trend from those in a single‐layer because of the optical and thermal properties of each layer. In particular, the interface of layers had a substantial affect due to optical field distributions and thermal characteristic difference. Also, the optical absorbance of layers affect adhesion at the interface. The result suggests proper processing condition to enhance the laser ablation processing quality of multilayer display panel. In conclusion, understanding the characteristics of multilayer laser cutting processing is important for determining the optimal conditions for display panel micromachining and enhancing the quality of laser cutting for the cutting edge technology. [ABSTRACT FROM AUTHOR]

G-protein coupled receptors (GPCRs) and ion channels serve as key molecular switches through which extracellular stimuli are transformed into intracellular effects, and it has long been postulated that ion channels are direct effector molecules of the alpha subunit of G-proteins (Gα). However, no complete structural evidence supporting the direct interaction between Gα and ion channels is available. Here, we present the cryo-electron microscopy structures of the human transient receptor potential canonical 5 (TRPC5)-Gαi3 complexes with a 4:4 stoichiometry in lipid nanodiscs. Remarkably, Gαi3 binds to the ankyrin repeat edge of TRPC5 ~ 50 Å away from the cell membrane. Electrophysiological analysis shows that Gαi3 increases the sensitivity of TRPC5 to phosphatidylinositol 4,5-bisphosphate (PIP2), thereby rendering TRPC5 more easily opened in the cell membrane, where the concentration of PIP2 is physiologically regulated. Our results demonstrate that ion channels are one of the direct effector molecules of Gα proteins triggered by GPCR activation–providing a structural framework for unraveling the crosstalk between two major classes of transmembrane proteins: GPCRs and ion channels. Ion channels could be directly regulated by the alpha subunit of heterotrimeric G-proteins. Here, authors present the cryo-EM structure of an ion channel-Gα complex, TRPC5-Gαi3, and present functional insights into their direct interaction. [ABSTRACT FROM AUTHOR]

PKD1 regulates a number of cellular processes through the formation of complexes with the PKD2 ion channel or transient receptor potential classical (TRPC) 4 in the endothelial cells. Although Ca 2+ modulation by polycystins has been reported between PKD1 and TRPC4 channel or TRPC1 and PKD2, the function with TRPC subfamily regulated by PKD2 has remained elusive. We confirmed TRPC4 or TRPC5 channel activation via PKD1 by modulating G-protein signaling without change in TRPC4/C5 translocation. The activation of TRPC4/C5 channels by intracellular 0.2 mM GTPγS was not significantly different regardless of the presence or absence of PKD1. Furthermore, the C-terminal fragment (CTF) of PKD1 did not affect TRPC4/C5 activity, likely due to the loss of the N-terminus that contains the G-protein coupled receptor proteolytic site (GPS). We also investigated whether TRPC1/C4/C5 can form a heterodimeric channel with PKD2, despite PKD2 being primarily retained in the endoplasmic reticulum (ER). Our findings show that PKD2 is targeted to the plasma membrane, particularly by TRPC5, but not by TRPC1. However, PKD2 did not coimmunoprecipitate with TRPC5 as well as with TRPC1. PKD2 decreased both basal and La 3+ -induced TRPC5 currents but increased M 3 R-mediated TRPC5 currents. Interestingly, PKD2 increased STAT3 phosphorylation with TRPC5 and decreased STAT1 phosphorylation with TRPC1. To be specific, PKD2 and TRPC1 compete to bind with TRPC5 to modulate intracellular Ca 2+ signaling and reach the plasma membrane. This interaction suggests a new therapeutic target in TRPC5 channels for improving vascular endothelial function in polycystic kidney disease.

Traditionally prescribed for mood disorders, tricyclic antidepressants (TCAs) have shown promising therapeutic effects on chronic neuralgia and irritable bowel syndrome. However, the mechanism by which these atypical effects manifest is unclear. Among the proposed mechanisms is the well-known pain-related inhibitory G-protein coupled receptor, namely the opioid receptor (OR). Here, we confirmed that TCA indeed stimulates OR and regulates the gating of TRPC4, a downstream signaling of the G i -pathway. In an ELISA to quantify the amount of intracellular cAMP, a downstream product of OR/G i -pathway, treatment with amitriptyline (AMI) showed a decrease in [cAMP] i similar to that of the μOR agonist. Next, we explored the binding site of TCA by modeling the previously revealed ligand-bound structure of μOR. A conserved aspartate residue of ORs was predicted to participate in salt bridge interaction with the amine group of TCAs, and in aspartate-to-arginine mutation, AMI did not decrease the FRET-based binding efficiency between the ORs and Gα i2 . As an alternative way to monitor the downstream signaling of G i -pathway, we evaluated the functional activity of TRPC4 channel, as it is well known to be activated by Gα i . TCAs increased the TRPC4 current through ORs, and TCA-evoked TRPC4 activation was abolished by an inhibitor of Gα i2 or its dominant-negative mutant. As expected, TCA-evoked activation of TRPC4 was not observed in the aspartate mutants of OR. Taken together, OR could be proclaimed as a promising target among numerous binding partners of TCA, and TCA-evoked TRPC4 activation may help to explain the nonopioid analgesic effect of TCA. NEW & NOTEWORTHY Endogenous opioid systems modulate pain perception, but concerns about opioid-related substance misuse limit their use. This study has raised TRPC4 channel as a candidate target for alternative analgesics, tricyclic antidepressants (TCAs). TCAs have been shown to bind to and activate opioid receptors (ORs), leading to downstream signaling pathways involving TRPC4. The functional selectivity and biased agonism of TCA towards TRPC4 in dependence on OR may provide a better understanding of its efficacy or side effects.