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Chiral supramolecular assemblies with helical structures (e. g. proteins with α‐helix, DNA with double helix, collagen with triple‐helix) as the central structure motifs in biological systems play a crucial role in various physiological activities of living organisms. Variations in chiral structure can cause many abnormal physiological activities. To gain insight into the construction, structural transition, and related physiological functions of these complex helix in natural systems, it is necessary to fabricate artificial supramolecular assemblies with controllable helix orientation as research platform. This review discusses recent advances in chiral supramolecular assembly, including the precise construction and regulation of assembled chiral nanostructures with tunable chirality. Chiral structure‐dependent biological activities, including cell proliferation, cell differentiation, antibacterial activity and tissue regeneration, are also discussed. This review not only contributes to further understanding of the importance of chirality in the physiological environment, but also plays an important role in the development of chiral biomedical materials for the treatment of diseases (e. g. tissue engineering regeneration, stem cell transplantation therapy). [ABSTRACT FROM AUTHOR]

Electromagnetic shielding (EMS) clothing is an important product to protect human body from electromagnetic damage, but the change law and influencing factors of its protective effect have not been clarified so far. In this paper, an important phenomenon is found that the shielding effectiveness (SE) value of the EMS clothing is abnormally reduced to 0 or even less than 0 under certain conditions, which is named failure phenomenon. A semi anechoic chamber is selected to build a testing system to carry out the experiments. The occurring rule and mechanism of the failure phenomenon is explored when the emission source parameters and the test positions are different. The projection method is proposed to obtain the equivalent hole and equivalent seam of the clothing. According to the electromagnetic theory, the estimation method of whether the failure phenomenon appears is established. The results show that the failure phenomenon of the EMS clothing is a serious hidden danger to human health, and the parameters of the emission source and test location have an important impact on the generation of the failure phenomenon. Its essence is determined by the distribution and characteristics of the leakage area and the normal area of the clothing area incident by electromagnetic wave. The estimation method of the failure phenomenon and the design principle of the clothing can prevent the occurrence of the failure phenomenon. This paper can provide reference for the design, production, test and evaluation of the EMS clothing and related scientific research, and has great significance for really protection of human health by the EMS clothing. [ABSTRACT FROM AUTHOR]

Being able to precisely manipulate both the morphology and chiroptical signals of supramolecular assemblies will help to better understand the natural biological self‐assembly mechanism. Two simple l/d‐phenylalanine‐based derivatives (L/DPFM) have been designed, and their solvent‐dependent morphology evolutions are illustrated. It was found that, as the content of H2O in aqueous ethanol solutions was increased, LPFM self‐assembles first into right‐handed nanofibers, then flat fibrous structures, and finally inversed left‐handed nanofibers. Assemblies in ethanol and H2O exhibit opposite conformations and circular dichroism (CD) signals even though they are constructed from the same molecules. Thus, the morphology‐dependent cell adhesion and proliferation behaviors are further characterized. Left‐handed nanofibers are found to be more favorable for cell adhesion than right‐handed nanostructures. Quantitative AFM analysis showed that the L929 cell adhesion force on left‐handed LPFM fibers is much higher than that on structures with inversed handedness. Moreover, the value of cell Young's modulus is lower for left‐handed nanofibrous films, which indicates better flexibility. The difference in cell‐substrate interactions might lead to different effects on cell behavior. [ABSTRACT FROM AUTHOR]

Knitted electromagnetic shielding fabric is widely used for its excellent extensibility and permeability. However, the influence law and mechanism of the effect of needle loops on the shielding effectiveness of fabrics is still unclear. In this paper, we designed five kinds of knitted fabrics. They are plain single jersey, '1 × 1' rib knitted fabric, '2 × 2' rib knitted fabric, interlock knitted fabric, and full Milano structure. The shielding effectiveness adopts the flange coaxial test. Based on the electromagnetic theory principle, the influence law and mechanism of needle loop arrangement form, needle loop length, metal material, and metal amount on the shielding effectiveness of knitted fabrics were analyzed. Therefore, it can be concluded that the arrangement of needle loops dramatically influences the frequency band and shielding performance of knitted fabrics. When there is fewer intermeshing points of needle loops, the less is the shielding effectiveness of the fabric. The needle loop's length mainly affects the shielding effectiveness of knitted fabric. The small needle loop length has great shielding effectiveness on knitted fabric. Metallic yarns with high amounts and low -resistance are beneficial for improving the shielding effect of the clothing. It provides a reference for the design, production, and related research of electromagnetic shielding knitted fabrics. [ABSTRACT FROM AUTHOR]

Single‐entity collisional electrochemistry (SECE) can capture physicochemical information at the single entity level. In the present work, we systematically studied in‐situ generation and detection of single anionic ionosomes via SECE combined with a miniaturized interface between two immiscible electrolyte solutions (ITIES). Ionosome is an ionic‐bilayer encapsulated nanoscopic water cluster/droplet that carries a net charge. Discrete spiky ionic currents were observed upon collisions/fusions of individual F− or Cl−‐ionosomes with a positively polarized micro‐ITIES. This fusion process was proved to follow the bulk electrolysis model. With this method, some essential factors such as concentration and charge density of the hydrated anions, and the interfacial area, were revealed. It demonstrates that anionic ionosomes share a common theoretical framework with their counterparts (i. e. cationic ionosomes, like Li+‐ionosomes). This work will spur the advancements in a myriad of fields, including such as the colloid and interface science, micro‐ and/or nanoscale electrochemistry, and electrophysiology and brain sciences. [ABSTRACT FROM AUTHOR]

Electromagnetic shielding (EMS) fabrics have the bottlenecks of the difficulty to improve the shielding effectiveness (SE) and the lacking of absorbing properties. Finishing fabrics with Ti3C2Tx are expected to be a fast and effective way to solve these problems. In this paper, two kinds of main EMS fabrics of the stainless steel blending and copper–nickel coating are selected. Ti3AlC2 is etched using hydrochloric acid and lithium fluoride in situ to generate hydrofluoric acid to prepare multilayer Ti3C2Tx. The finishing experiments of the fabric with Ti3C2Tx impregnation are designed. The influence of multilayer Ti3C2Tx on the shielding and absorbing properties of the EMS fabric are studied. The results show that the multilayer Ti3C2Tx can be prepared and dispersed as the treatment by the proposed method. For the blended fabric, the Ti3C2Tx micro-media are absorbed or are infiltrated into the fibers in most cases. For the coated fabric, the Ti3C2Tx micro-media are on the surface of the fabric. The SE of the blended fabric in a frequency range of 6.57–18 GHz and the copper plated nickel fabric in a frequency range of 6.57–16 GHz are enhanced. At the same time, the absorbing performances of the two types of fabrics in a high frequency band above 11.97 GHz are improved. This paper can provide a new efficient and low-cost method to improve the performance of the EMS fabric and provide a reference for the design, production and evaluation of new absorbing EMS fabrics. [ABSTRACT FROM AUTHOR]

Blended electromagnetic shielding (EMS) fabrics of cotton/stainless steel/polyester have been widely applied. The porous structure of the fabric is the guarantee of its good comfort performance, but it also hinders the improvement of shielding efficiency and the endowing of wave absorption performance. To solve the above problems, this paper proposes a mixed resistance field based on fabric pores by the construction of multi-layer MXenes. Ti3AlC2 is etched by hydrochloric acid and lithium fluoride to generate hydrofluoric acid in situ to prepare multi-layer Ti3C2T x. The finishing experiments are designed to finish the fabric around the pores with Ti3C2T x impregnation. The enhancement effect and mechanism of the mixed resistance field on the shielding effectiveness and wave absorbing properties of the fabric are analyzed. The result shows that the multi-layer Ti3C2T x for textile finishing is prepared quickly and effectively using the proposed method. The micro media of the Ti3C2T x in the dispersion are adsorbed on the surface of various fibers, most of which are cotton fibers. The shielding effectiveness of the finished EMS fabric is improved significantly in the frequency ranges of 6.57–14 GHz and 11.97–18 GHz. The wave absorbing performances in the frequency range of 11.97–18 GHz are excellent. It is proved that the effect of the mixed resistance field of the pores was satisfactory. This paper provides a new way for the application of Ti3C2T x in EMS fabric, solves the disadvantages caused by pores, and can provide a reference for the design and production of wave absorbing EMS fabric. [ABSTRACT FROM AUTHOR]

2,5-Bis(9H-fluoren-9-ylidene)-2,5-dihydrothiophene (ThBF) was potentially important for utilization as an organic semiconductor material. However, the study of the structure–property relationship for this compound was very limited due to its harsh synthesis. Here, we reported the synthesis of a series of ThBF derivatives B1–B9 using a two-step synthetic route involving a Lewis acid-promoted Friedel–Crafts reaction followed by an oxidation process. Compared to conventional methods, the promoted synthetic route was much milder, providing the feasibility for the introduction of halogen atoms. Subsequently, the substituent effects on their thermal, opto-physical, and electro-chemical properties as well as the structure and energy information of ThBFs were systematically explored by experimental and theoretical studies. [ABSTRACT FROM AUTHOR]