5,492 research outputs found
3,3′-Dimethyl-1,1′-[2,2′-bipyridine-5,5′-diylbis(methylÂene)]diimidazol-3-ium bisÂ(hexaÂfluoroÂphosphate)
The title compound, C20H22N6
2+·2PF6
−, was prepared by the reaction of 5,5′-bisÂ(bromoÂmethÂyl)-2,2′-bipyridine with 1-methylÂimidazole. The main molÂecule lies on an inversion center located at the mid-point of the C—C bond joining the two pyridine rings. The asymmetric unit therefore contains one half-molÂecule and one hexaÂfluoroÂphosphate anion. The dihedral angle between the pyridine and imidazole rings is 76.93 (7)°. In the crystal, weak interÂmolecular C—H⋯F hydrogen bonds contribute to the stabilization of the packing
Bis[μ-N-(pyridin-2-ylmethÂyl)pyridin-2-amine-κ2 N:N′]disilver(I) bis(trifluoroÂmethaneÂsulfonate)
In the binuclear title compound, [Ag2(C11H11N3)2](CF3O3S)2, the complex cation is centrosymmetric, with the unique Ag+ cation coordinated by two pyridine N atoms from two symmetry-related N-(pyridin-2-ylmethÂyl)pyridin-2-amine ligands in a geometry slightly distorted from linear [N—Ag—N 161.02 (7)°]. This set-up leads to the formation of a 14-membered cyclic dimer. The two pyridine rings coordinated to the Ag+ cation are tilted by 80.19 (7)° with respect to each other. InterÂmolecular N—H⋯O hydrogen-bonding interÂactions between the cyclic dimer and the anion exist. A two-dimensional network parallel to the ac plane is constructed by three weak Ag⋯(O,N) interÂactions as well as an F⋯F contact of 2.890 (4) Å
Extract of Allium tuberosum Rottler ex Spreng
Allium tuberosum Rottler ex Spreng (ATRES) has been used as a traditional medicine for the treatment of abdominal pain, diarrhea, and asthma. In this study, we investigated the hair growth promoting activities of ATRES on telogenic C57BL6/N mice. Hair growth was significantly increased in the dorsal skin of ethanol extract of ATRES treated mouse group compared with the control mouse group. To enrich the hair promoting activity, an ethanol-insoluble fraction was further extracted in sequence with n-hexane, dichloromethane, ethyl acetate, n-butanol, and distilled water. Interestingly, we found that extraction with n-butanol is most efficient in producing the hair promoting activity. In addition, the soluble fraction of the n-butanol extract was further separated by silica gel chromatography and thin layer chromatography (TLC) resulting in isolating four single fractions which have hair growth regeneration potential. Furthermore, administration of ATRES extracts to dorsal skin area increased the number of hair follicles compared with control mouse group. Interestingly, administration of ATRES extract stimulated the expression of insulin-like growth factor-1 (IGF-1) but not of keratin growth factor (KGF) or vascular endothelial growth factor (VEGF). Taken together, these results suggest that ATRES possesses strong hair growth promoting potential which controls the expression of IGF-1
Perception-Oriented Single Image Super-Resolution using Optimal Objective Estimation
Single-image super-resolution (SISR) networks trained with perceptual and
adversarial losses provide high-contrast outputs compared to those of networks
trained with distortion-oriented losses, such as L1 or L2. However, it has been
shown that using a single perceptual loss is insufficient for accurately
restoring locally varying diverse shapes in images, often generating
undesirable artifacts or unnatural details. For this reason, combinations of
various losses, such as perceptual, adversarial, and distortion losses, have
been attempted, yet it remains challenging to find optimal combinations. Hence,
in this paper, we propose a new SISR framework that applies optimal objectives
for each region to generate plausible results in overall areas of
high-resolution outputs. Specifically, the framework comprises two models: a
predictive model that infers an optimal objective map for a given
low-resolution (LR) input and a generative model that applies a target
objective map to produce the corresponding SR output. The generative model is
trained over our proposed objective trajectory representing a set of essential
objectives, which enables the single network to learn various SR results
corresponding to combined losses on the trajectory. The predictive model is
trained using pairs of LR images and corresponding optimal objective maps
searched from the objective trajectory. Experimental results on five benchmarks
show that the proposed method outperforms state-of-the-art perception-driven SR
methods in LPIPS, DISTS, PSNR, and SSIM metrics. The visual results also
demonstrate the superiority of our method in perception-oriented
reconstruction. The code and models are available at
https://github.com/seungho-snu/SROOE.Comment: Code and trained models will be available at
https://github.com/seungho-snu/SROO
OPTIMAL CONGESTION CHARGES IN GENERAL EQUILIBRIUM
This paper deals with pricing and investment decision problems of multi-route and multi-period highway systems in which the congestion is a significant factor in the assessment of system costs. This study approaches this congestion pricing scheme with two different social welfare maximization problems, both of which search for the optimal solutions through general equilibrium analysis. These two optimization problems have an identical structure except financial constraints that reflect different decision environments. One welfare maximization problem involves estimating the first-best social optimal solution. This problem yields the optimal solution for the implementation scheme to impose the differentiated congestion charge for each trip alternative in terms of travel route and trip period. The optimal congestion charge for this problem has the expression similar to that derived in previous studies dealing with congestion pricing. Another maximization problem involves characterizing the second-best optimal solution. In this problem, it is assumed to impose the congestion toll only on a single highway link. This problem yields the second-best congestion toll different from the first-best one. This second-best optimal congestion toll has the structure to reflect its impact on other highway links exempt from the congestion charge program.
Document type: Articl
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