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Organoids are derived from stem cells or organ-specific progenitors. They display structures and functions consistent with organs in vivo. Multiple types of organoids, including lung organoids, can be generated. Organoids are applied widely in development, disease modelling, regenerative medicine, and other multiple aspects. Various human pulmonary diseases caused by several factors can be induced and lead to different degrees of lung epithelial injury. Epithelial repair involves the participation of multiple cells and signalling pathways. Lung organoids provide an excellent platform to model injury to and repair of lungs. Here, we review the recent methods of cultivating lung organoids, applications of lung organoids in epithelial repair after injury, and understanding the mechanisms of epithelial repair investigated using lung organoids. By using lung organoids, we can discover the regulatory mechanisms related to the repair of lung epithelia. This strategy could provide new insights for more effective management of lung diseases and the development of new drugs.

Molecular aggregates formed by polymethine dyes in solutions, at surfaces, and in crystals can be used to modulate the intensity and wavelength of light absorption. 1 The applications for such dye aggregates are manifold: photography, xerography, photovoltaic, molecular photonic, and microelectronic devices. 2 The internal structure of such aggregates is widely perceived as arrays of tightly packed molecules with their molecular planes stacked against each other. Several packing models have been proposed based on the epitaxy match between dye crystalline layers and the lattice of a mica substrate: staircase, brickwork, and ladder structure. 3 A special case of the staircase packing in single crystals of polymethine dye 1,7-bis(dimethylamino)heptamethine perchlorate or BDH + ClO 4is illustrated in Figure 1. The aggregate structure has been quantitatively linked to its spectroscopic properties. 4 The strong coupling of molecular transition dipoles generates excitonic states 4 whose absorption energy is significantly shifted to shorter (Haggregates) or to longer (J-aggregates) wavelength with respect to the nonaggregated state. When there are two molecular orientations in the unit cell, the molecular transition dipoles, M 1 and M 2 , couple with each other as vectors, which results in two excitonic transitions: the Davydov sum, m + , and difference m -. These two components are perpendicular to each other. 5 In BDH + ClO 4crystals, the m + component parallels [201] and absorbs light at 639 nm, and the mcomponent parallels [010] and exhibits an absorption maximum at 592 nm. 6 Both transitions are red-shifted from the monomer absorption at 510 nm. In addition to the exciton propagation, the absorption behavior of three-dimensional dye arrays is also altered by polaritons. 7 The polaritons are generated by the coupling of the light wave with the polarization of the medium and lead to a splitting in the longitudinal and transverse exciton energy. The absorption wavelength of the dye crystal varies within the two energy boundaries according to the angle, , between the transition dipole moment and the crystal face normal. It is conceivable that the color of a transparent thin film of threedimensionally oriented J-aggregates can be tuned precisely if one finds a way to rotate the molecular axis in such thin films.A method called the thin layer aggregation (TLA) was recently developed to prepare dye films with various color patterns. 8 The TLA method exploits the aggregation of polymethine dyes in strongly undercooled amorphous layers. While the macroscopic properties of the dye layers have been investigated by the UV/vis spectroscopy and thermal analysis, almost nothing is known about the dye thin film surface coverage, roughness, morphology, and molecular packing at the nanoscale. Atomic force microscopy (AFM) 9 has been widely used to study the lattice structure of ordered self-assembled and Langmuir-Blodgett thin films as well as the microstructure of amorphous films and has recently been used to study J-aggregate st...

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A recently developed method of spherulitic crystallization was used for the preparation of highly ordered 80 nm thin films of the dye 1.7-bis(dimethylamino)heptamethinium perchlorate (BDH+ClO4 -). Depending on the crystallization temperature, the film color and surface topography varied widely, while the crystal structure and film thickness remained the same. At low undercooling, two homogeneous regions were obtained. One showed in-plane symmetrical and the other asymmetrical growth behaviors. At high undercooling, a banded spherulitic structure with rainbow-like colors developed, whose formation is attributed to the out-of-plane asymmetrical growth. The spherulitic growth kinetics, microstructure, and optical properties were investigated by optical microscopy, atomic force, and scanning tunneling microscopy in static and real time mode. A molecular mechanism is proposed which originates from different directions of macroscopic growth and microscopic molecular attachment dictated by the three-dimensional crystal lattice. This mechanism is consistent with the optical spectra and surface topography observed. This mechanism explains the exposure of different crystal faces, asymmetrical molecular attachment, fluctuation in growth rate, film thickness, and viscosity in the amorphous phase. Understanding the molecular origins of J-aggregation in thin dye films allows one to control and manipulate the film color almost in the whole visible wavelength range.

An enrichment culture which completely degraded fenoxaprop-ethyl (FE) was acquired by using FE as sole carbon source. An efficient FE-degrading strain T1 was isolated from the enrichment culture and identified as Rhodococcus sp. Strain T1 could degrade 94% of 100 mg L(-1) FE within 24 h and the metabolite fenoxaprop acid (FA) was identified by HPLC/MS analysis. This strain converted FE by cleavage of the ester bond, but could not further degrade FA. Strain T1 could also efficiently degrade haloxyfop-R-methyl, quizalofop-p-ethyl, cyhalofop-butyl and clodinafop-propargyl. FE hydrolase capable of hydrolysing FE to FA was found in the cell-free extract of strain T1 by zymogram analysis. A novel gene feh encoding FE hydrolase was cloned by shotgun library construction and successfully expressed in Escherichia coli.

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