Lateral cavity photonic crystal surface-emitting laser with ultralow threshold

A lateral cavity photonic crystal (PhC) surface-emitting laser is realized on a commercial epitaxial waveguide wafer without a distributed Bragg reflector first. Energy is coupled from the lateral resonance to surface-emitting light through the Γ band edge of the PhC with a square lattice. Electrically driven 1553.8?nm surface-emitting lasing action is observed at room temperature. The threshold current density of 667?A/cm2 is ultralow for the surface-emitting laser.     

Durable antimicrobial cotton fabric fabricated by carboxymethyl chitosan and quaternary ammonium salts

Cellulose - In this article, carboxymethyl chitosan (CMC) and (3-carboxypropyl) trimethylammonium chloride (CPTC) were used as raw materials to prepare an antibacterial cotton fabric with excellent...     

Remarkable durability of the antibacterial function achieved via a coordination effect of Cu(II) ion and chitosan grafted on cotton fibers

Cellulose - We report here a simple and effective method applying a combination of chitosan (Cs) and Cu(II) ion to fabricate antibacterial cotton fabric with a remarkable durability against...     

A lipid coating on cotton fibers with enhanced adsorption capability for fabric functionalization

Cellulose - Cotton is often modified to minimize its disadvantages during textile processing. However, most finishing methods suffer from difficulties in finding finishing reagents and chemical...     

Fabrication of Hollow Materials by Fast Pyrolysis of Cellulose Composite Fibers with Heterogeneous Structures

A facile method for the fabrication of inorganic hollow materials from cuprammonium cellulose composite filaments based on fast pyrolysis has been developed. Unlike Ostwald ripening, approaches based on the Kirkendall effect, and other template methods, this process yielded hollow materials within 100 s. The heterogeneous structure of the cellulose composite fibers and the gradient distribution of the metal oxides are the main reasons for the formation of the hollow structure. The diameter, wall thickness, and length of the hollow microfibers could be conveniently controlled. With their perfect morphology, these hollow structural materials have great potential for use in various fields.     

Quality fluctuation detection of an herbal injection based on biological fingerprint combined with chemical fingerprint

Herbal injection is one of the most important preparations of traditional Chinese medicine. More than 130 types of herbal injections are used clinically for 400 million patients annually with total sales of over four billion US dollars per year. However, the current quality control (QC) methods relying mainly on chemical fingerprints (CF) can hardly ensure quality and safety of the herbal injections with complex chemical composition and have resulted in an increase in serious adverse drug reactions. In this study, a comprehensive approach for the QC of a controversial herbal injection Shuang-Huang-Lian lyophilized powder (SHL) was established based on the quality fluctuation detection by a combination of CF and biological fingerprint (BF). High-performance liquid chromatography and the impedance-based xCELLigence system were applied to establish the CF and BF, respectively. In addition, multivariate analysis was performed to evaluate the discriminant ability of the two methods. The results showed that being subjected to environmental influence like oxygen/air, high temperature, and extreme illumination could lead to quality fluctuation of SHL. The combination of chemical and biological fingerprint method is a more powerful tool for the QC of SHL because it can clearly discriminate different groups of abnormal samples. This method can be used for the detection of quality fluctuation of SHL and can provide reference for the quality control of other herbal injections.     

Interfacial assembly of ZnO–cellulose nanocomposite films via a solution process: a one-step biomimetic approach and excellent photocatalytic properties

A bioinspired mineralization route to directly prepare ZnO–cellulose nanocomposite (ZCN) films from a cellulose–NaOH/urea/zincate solution was demonstrated in this study. By adding non-acid coagulants, an inclusion complex consisting of NaOH, urea and zincate, which was bound to the cellulose molecules, was broken. As a result, the cellulose aggregates occurred, which simultaneously aided the mineralization of ZnO nanostructures at room temperature. The structure and properties of the ZCN films were characterized using FE-SEM, TEM, XRD, UV–Vis spectra, XPS, TG, tensile testing and photocatalytic activity tests. Through changing different coagulants, the content and mean size of ZnO in the ZCN films varied in the range of 10.8–14.9 wt% and 56.8–146.8 nm, respectively. Owing to good interfacial interaction, the ZCN films displayed good mechanical and excellent photocatalytic properties. The mechanical strength and elongation at break of the ZCN films attained 46.7 MPa and 6.4 %, respectively. The degradation efficiency of rhodamine B reached 99.3 % within 50 min under UV light and only showed a slight decrease after three cycles. The cellulose-mediated bioinspired approach was expected to introduce a method for preparing functional cellulose-based materials under mild conditions for various niche applications.     

Structure and properties of the regenerated cellulose membranes prepared from cellulose carbamate in NaOH/ZnO aqueous solution

Regenerated cellulose (RC) membranes were prepared from cellulose carbamate—NaOH/ZnO aqueous solutions by coagulating with H₂SO₄ solution. Structure, morphology and properties of the membranes were investigated by using scanning electron micrograph (SEM), X-ray diffraction, Fourier transform infrared spectroscopy, flow rate method, and tensile testing. The results from SEM and water permeability revealed that the pore size and water permeability of the membranes in wet state changed drastically as a function of the concentration of H₂SO₄ and coagulation temperature, whereas they hardly changed with the coagulation time. RC membranes coagulated with the relatively dilute H₂SO₄ solution at relatively low temperature exhibited better mechanical properties. This work provided a promising way to prepare cellulose membranes with different pore sizes and good physical properties.     

Preorganized bis-zinc phosphodiester cleavage catalysts possessing natural ligands: a lesson pertinent to bimetallic artificial enzymes

Two preorganized bis-zinc receptors (2 and 3) were synthesized wherein the metals were ligated with ligands present in natural phosphodiesterases: imidazoles and carboxylates. The intrametallic distance is near 4.5 A, that found in natural nucleases and other successful artificial nucleases. With only two imidazoles (2), the zinc binding affinities were not high enough to achieve cooperativity. Yet, with a third ligand, a carboxylate (3), cooperativity was found in the cleavage of HPNPP. The preorganization of 3 was achieved using a "steric gearing" strategy. The enhancement was 80-fold for cooperation between the two metals relative to a mono-metallic analogue (5). However, there was no observable enhancement in the hydrolysis of RNA using 3 relative to 5. Therefore, we conclude that placing two zinc atoms that are ligated with natural ligands at the appropriate distance for catalysis is not sufficient to enhance the cleavage of RNA, but is successful for activated RNA substrate mimics.