A series of amphiphilic platinum(II) complexes with tridentate N-donor ligands has been synthesized and characterized. Different supramolecular architectures are constructed using the amphiphilic molecules as the building blocks through the formation of Pt•••Pt and π−π stacking interactions in aqueous media. The aggregation−deaggregation−aggregation self-assembly behavior together with obvious spectroscopic changes could be fine-tuned by the addition of THF in aqueous media. More interestingly, one of the complexes is found to show fast response and high selectivity toward alcohol and water vapors with good reversibility, leading to drastic color and luminescence changes, and hence unique dual switching behavior, with the water molecules readily displaced by the alcohol vapor. Rapid writing and erasure have been realized via the control of a jet or a stream of alcohol vapor flow. In addition, it has been employed as active materials in the fabrication of small-molecule solution-processable resistive memory devices, exhibiting stable and promising binary memory performance with threshold voltages of ca. 3.4 V, high ON/OFF ratios of up to 10 5 and long retention times of over 10 4 s. The vapochromic and vapoluminescent materials are demonstrated to have potential applications in chemosensing, logic gates, VOC monitoring, and memory functions.

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The capacity of anode materials plays a critical role in the performance of lithium-ion batteries. Using the nanocrystals of oxygen-free metal-organic framework ZIF-67 as precursor, a one-step calcination approach toward the controlled synthesis of CoO nanoparticle cookies with excellent anodic performances is developed in this work. The CoO nanoparticle cookies feature highly porous structure composed of small CoO nanoparticles (≈12 nm in diameter) and nitrogen-rich graphitic carbon matrix (≈18 at% in nitrogen content). Benefiting from such unique structure, the CoO nanoparticle cookies are capable of delivering superior specific capacity and cycling stability (1383 mA h g(-1) after 200 runs at 100 mA g(-1) ) over those of CoO and graphite.

MiRNAs play crucial roles in many aspects of plant development and the response to the environment. The miR172 family has been shown to participate in the control of flowering time and the response to abiotic stress. This family regulates the expression of APETALA2 (AP2)-like transcription factors in Arabidopsis. In the present study, soybean (Glycine max L. Merr.) miR172c, a member of the miR172 family, and its target gene were investigated for abiotic stress responses in transgenic Arabidopsis. gma-miR172c was induced by abscisic acid (ABA) treatments and abiotic stresses, including salt and water deficit. 5'-RACE (5'-rapid amplification of cDNA ends) assays indicated that miR172c directed Glyma01g39520 mRNA cleavage in soybeans. Overexpression of gma-miR172c in Arabidopsis resulted in reduced leaf water loss and increased survival rate under stress conditions. Meanwhile, the root length, germination rate, and cotyledon greening of transgenic plants were improved during both high salt and water deficit conditions. In addition, transgenic plants exhibited hypersensitivity to ABA during both the seed germination and post-germination seedling growth stages. Stress-related physiological indicators and the expression of stress/ABA-responsive genes were affected by abiotic treatments. The overexpression of gma-miR172c in Arabidopsis promoted earlier flowering compared with the wild type through modulation of the expression of flowering genes, such as FT and LFY during long days, especially under drought conditions. Glyma01g39520 weakened ABA sensitivity and reduced the tolerance to drought stress in the snz mutant of Arabidopsis by reducing the expression of ABI3 and ABI5. Overall, the present results demonstrate that gma-miR172c confers water deficit and salt tolerance but increased ABA sensitivity by regulating Glyma01g39520, which also accelerates flowering under abiotic stresses.

The leaves of dark-grown bean (Phaseolus vulgaris L.) seedlings accumulate considerably lower quantities of xanthophylls and carotenes than do leaves of light-grown seedlings, but they synthesize at least comparable amounts of abscisic acid (ABA) and its metabolites when water stressed. We observed a 1:1 relationship on a molar basis between the reduction in levels of violaxanthin, 9'-cis-neoxanthin, and 9-cis-violaxanthin and the accumulation of ABA, phaseic acid, and dihydrophaseic acid, when leaves from dark-grown plants were (10,12,15,20 one atom of 180 into the carboxyl group of ABA. One explanation for these latter results is that a preformed xanthophyll was cleaved by a dioxygenase to form an aldehyde that was converted to ABA by dehydrogenases. Li and Walton (12) suggested that at least a portion of ABA was derived from violaxanthin in water-stressed bean leaves based on studies in which the violaxanthin epoxide oxygens were labeled in situ with 180 via the xanthophyll cycle.One of the difficulties in demonstrating a precursor role for a major leaf xanthophyll is that these compounds are present at high levels in green leaves compared with the levels to which ABA and its metabolites accumulate even under water stress. Small differences in xanthophyll levels between leaf samples, either real or due to experimental error, can obscure any reductions that might result from ABA synthesis. Resynthesis of the precursors could also mask any reductions. Gamble and Mullet (7) stressed dark-grown fluridone-treated barley leaves which contained considerably lower xanthophyll levels than were present in untreated green leaves. They observed that ABA production was still 25% of normal, even when xanthophyll levels had been reduced by 99%. They also reported that violaxanthin, neoxanthin, and antheraxanthin levels were reduced during the stress period. Their results were confounded, however, by the fact that xanthophyll levels were also reduced, albeit to a lesser extent, when leaves were detached but not stressed. Thus, they were unable to conclude what the stoichiometry was between xanthophyll reduction and total ABA synthesis. We report on the results we have obtained with bean leaves stressed after detachment from dark-grown bean seedlings. In this system, only leaves that have been stressed show significant changes in xanthophyll content, the levels of ABA produced are at least comparable to those in light-grown plants, and the total amount of ABA produced is closely matched by reductions in the levels of several xanthophylls. These results enable us to draw inferences about the origin of ABA. MATERIALS AND METHODS Plant MaterialsPhaseolus vulgaris L. cv Blue Lake seeds were surfacesterilized with a 10% Clorox solution for 30 min and then imbibed in sterile water for 7 h. The seeds were planted in flats in a soil:vermiculite mixture (1:1) and grown in complete darkness at about 23°C for 8 or 9 d. Unless otherwise indicated, plants were sprayed with fluridone (13 mg L-') twice daily from d 4 to the end o...