Recent trends in fountain solution are summarized as follows:

① Nitrate-free: Technology to replace nitrate has been developed.

② VOC reduction: In Japan, the introduction of volatile organic compound (VOC) alerts has begun; Europe has shifted to NonVOC.

③ Elimination of isothiazoline (CMIT/MIT) preservatives: In Europe, isothiazoline preservatives can no longer be added to fountain solutions.

④ Expansion of high-sensitivity UV printing: Fountain solutions need to maintain a low pH and not form poorly soluble calcium salts.

⑤ Spread of lithographic processless plates: Fountain solutions that can easily penetrate into the photosensitive layer and are difficult to emulsify are considered better.

Freestanding thin films have been used for various purposes such as for separation and wound dressing as well as applications in sensors, catalysts, supercapacitors, and artificial organs. Most of the freestanding thin films used in these applications are fabricated via the peeling-off of films that have been formed on solid substrates. In this review, we discuss possible methods and advantages of the direct formation of thin films on liquid surfaces without peeling-off processes; these methods are denominated as “printing on liquid surfaces.”

Microbubbles are tiny bubbles of less than 50 μm in diameter; these shrink underwater because of the rapid dissolution of their interior gas. It has been recognized that surface charge is an important factor in understanding the properties of microbubbles. In an electrophoresis cell, the surface charge of each microbubble can be determined from the speed and direction of its movement in the presence of an electrical potential; in addition, it can be evaluated by its zeta potential value. Adsorbed protons and hydroxide ions are crucial in influencing the gas-water interface charge; electrolyte ions are attracted to the interface by the electrostatic force and generate an electrical double layer. The accelerative increase of the zeta potential of a microbubble suggests the extreme accumulation of ions during the final stage of the collapse process. Moreover, the extinction of the gas-water interface might cause a drastic environmental change for the ions originally concentrated at the bubble surface. Therefore, the instantaneous high density of ions at the site of the collapsed microbubble could potentially describe the phenomenon of free-radical generation. This manuscript also shows the fundamental properties of nanobubbles generated by the accumulation of counter ions around the shrinking gas-water interface; this manuscript introduces our cutting-edge efforts to develop novel related technology in various technical fields.

The state of water droplets rolling up like a lotus leaf that repels water very well is called ultra-water-repellency. The lotus leaf has a multilevel structure on its surface, which is the origin of ultra-water-repellency. If a surface resembling the surface of this lotus leaf is artificially produced, an ultra-water-repellent surface can be obtained. The application of ultra-water-repellent surface is wide and expected in various industrial fields. The preparation method using plama and application of transparent ultra-water-repellent films and the preparation of ultra-water-repellent paper using self-assembled monolayers (SAMs) are described.

Roots of land plants apply both gravitropism and hydrotropism in response to gravity and moisture gradients, respectively, in controlling their growth orientation. Both responses enable efficient water acquisition by plants. In the gravitropic response of seedling roots, columella cells in the root cap perceive gravity and re-localize the auxin-efflux carrier PIN3 so that the plant hormone auxin can move downward to the lateral root cap. Then, PIN2 plays a role in transporting the auxin from the lateral root cap to the elongation zone along the lower side of the re-oriented roots. Thus, auxin is redistributed with a greater accumulation on the bottom side, leading differential growth to bend downwards. In hydrotropism, however, the root cap is dispensable; as such, instead of auxin abscisic acid (ABA) and MIZ1 play positive roles in inducing a hydrotropic response of Arabidopsis roots. It was found that both MIZ1 and ABA function in the cortex of the elongation zone for the induction of hydrotropism. In addition, the overexpression of MIZ1 results in the enhancement of the hydrotropic response, which in turn results in a greater tolerance to drought stress. These results imply that a molecular mechanism unique to hydrotropism exists, and that the manipulation of hydrotropic ability is useful for improving plant production under various conditions.