Chitosan is a desirable material for several reasons, including its biocompatibility, biodegradability, non-toxicity, and excellent absorption. Rapid progress in material science has resulted in the development and widespread use of chitosan in the textile industry primarily because it is polycationic and can inhibit microorganism activity. However, high electrostatic, poor mechanical properties, and the polycationic property of chitosan materials, which are the main reason for the electro-static generation of chitosan fibers, have a negative impact on the spinning process and lower the quality of chitosan yarns. Therefore, there is a critical need to reduce production losses and improve the poor spinnability. A new spinning approach exploits triboelectric electrostatic theory to efficiently remove the electric charge and to promote yarn formation under optimum conditions precisely and controllably, thereby minimizing waste and achieving a high utilization ratio of the chitosan fibers. Lagrange interpolation is used to systematically analyze the basic mechanical properties of the developed materials. The results show that the tenacity of chitosan/PAN blended yarns is superior to that of chitosan/cotton blended yarns because of the complementary effect of positive and negative charges; and the novel application of static theory can be used to effectively resolve the high static and reduce material cost problems in the yarn production process. This new approach is expected to promote the usage of chitosan fibers in the textile industry and in medical applications.

Marine plastic pollution is emerging as a potential hazard to global ecosystems and human health. Micro-fibers derived from synthetic textiles contribute a considerable proportion of plastic debris. Bio-polymers/bio-plastics have been proposed for the application of apparel products, yet their degradability, fate, durability and related environmental parameters are still elusive and need further exploration. Herein, we report the degradation behavior of poly(lactide acid)/poly(hydroxybutyrate) (PLA/PHB) fabrics, made from PLA/PHB multi-filament yarns, in subtropics marine seawater. The degradation experiments were performed under various parallel conditions including static seawater, aerobic seawater in dark box, aerobic seawater under sunlight, static seawater under ultra-violet light and aerobic seawater under ultra-violet light. Continuous mass loss of PLA/PHB fabrics as the immersion time in the seawater increased was confirmed. The hydrolysis rate of PLA/PHB fabrics accelerated in the presence of UV light and dissolved oxygen in the seawater. Moreover, the tensile strength of the PLA/PHB yarns dropped rapidly by 38.54–68.70% in spite of the mass loss percentage being from 9.57% to 14.48% after 2 weeks’ immersion. All the PLA/PHB fabrics after two weeks’ immersion exhibited similar ATR-IR spectra. Therefore, the degradability of PLA/PHB fabrics, in the marine surface water under the synergistic destructive effect of seawater, UV and dissolved oxygen, provides a pathway for more sustainable textile fibers and apparel products.

Hairiness is a prominent property of staple yarns, but the existing evaluation parameters mainly describe the fiber ends already protruding out of yarn bodies. The potential fiber ends in yarns also play a crucial role in the performance of yarns in the subsequent processes and the resultant fabric quality. In our previous studies, maximum hairiness and its theoretical model have been proposed, which indicate the maximum fiber ends of a staple yarn having the potential to protrude out of yarn bodies and become hairy. On this basis, the relative hairiness index (RHI) is developed in this study to evaluate the fiber end tucking and securities of yarns. This index is treated as a ratio of the measured hairiness of sample yarns and the maximum hairiness of ring yarns in the same twist level and yarn count. A lower RHI indicates more fiber ends being tucked into yarn bodies, and a slower increment of the RHI with the increasing winding times represents more stable securities of fiber ends in yarns. The experimental results demonstrate that the RHI can directly reveal the effectiveness of different spinning parameters and methods in tucking and securing fiber ends; also, the changes of the RHI with increasing winding times visually present the stableness of fiber ends in various yarns experiencing abrasion, as well as predict the possibility of the potential fiber ends being pulled out to form hairiness during successive processes. The proposed RHI, therefore, provides a significant reference for the spinning process design and yarn quality control.

Background: Neuroimaging research has determined deficits in the dopaminergic circuit of major depressive disorder (MDD) during adolescence. This study investigated how emotional contexts modulate the temporal dynamics of reward anticipation and feedback in adolescents. Methods: EEG data from 35 MDD and 37 healthy adolescents were recorded when they conducted a gambling task after being presented with emotional pictures. Results: The results demonstrated that both MDD and healthy adolescents exhibited the largest late positive component (LPC) in positive contexts at the frontal sites and the largest LPC in negative contexts at the central sites; however, MDD adolescents exhibited anticipatory LPC hypoactivation than healthy adolescents. However, MDD adolescents exhibited smaller gain feedback negativity (FN) than healthy adolescents independent of emotional contexts, positively correlating with the trait anhedonia according to the consummatory aspect of the Temporal Experience of Pleasure Scale. In contrast, MDD adolescents exhibited greater FN loss in positive and neutral contexts than healthy adolescents while no difference in FN loss was found between the two groups in negative contexts. Moreover, the FN loss amplitudes negatively correlated with hedonic tone according to the Snaith-Hamilton Pleasure Scale over the past week. Conclusions: These findings suggest that MDD adolescents exhibited dissociable deficits in reward anticipation and gain or loss feedback that are distinctly modulated by emotional contexts, and they deepen our understanding of the modulation of emotional contexts on the temporal dynamic reorganization of the reward circuit in MDD adolescents.

This article presents a systematic investigation of the knitted fabrics made from various blends of intrinsically antimicrobial poly (hydroxybutyrate-co-hydroxyvalerate)/polylactide acid filaments and cotton staple fibers. The effects of blend yarn, fabric structures, and distributions of fibers on antimicrobial properties of resultant yarns and knitted fabrics were studied. The relationships among fiber distribution, blend ratio, and anti-microbial properties were experimentally determined for three blend yarns made by sirofil, wrap-spun, and core-spun spinning technologies. The fabrics made from the sirofil-spun and wrap-spun yarns show better anti-microbial effects against Staphylococcus aureus, Klebsiella pneumoniae, and Candida albicans than those of the core-spun yarns, according to the standard AATCC100-2012 Antibacterial Finishes on Textile Materials (American Association of Textile Chemists and Colorists, 2012). An alternative blending method of co-knitting of the pure poly (hydroxybutyrate-co-hydroxyvalerate)/polylactide acid yarns and cotton yarns achieved excellent antimicrobial effects. Furthermore, a wearing trial of underwear made from the blended knitted fabrics was conducted in a nursing home. The wearing comfort of the garments, low-stress mechanical and surface properties of fabrics were evaluated objectively by the Kawabata Evaluation System of Fabric (KESF) system and subjectively by a questionnaire survey to users.