cess, was observed. This may be due to a side reaction during the irradiation with 254-nm light. The photodimer may produce photodimerization by another remaining double bond on prolonged irradiation. Thus, the absorption peak at 270 nm decreased gradually on continued irradiation.
ConclusionsPrevious studies in the intermolecular reactions of LB films have been limited mainly to photopolymerization and photodimerization. In this study, the intermolecular photoreversible reaction in an LB films has been found for the first time, although the photoreversible reaction of cinnamylideneacetic acid has already been known in polymer film or in low-temperature glassy matrix. Originally, one might expect that these photoreversible systems are more favorable in LB films than in polymers. However, the reversibility was still low for the LB film of 2a, similarly to the polymer film of poly(vinyl cinnamylideneacetate). This is due to the overlapping of the absorption spectra of 2a and the photodimer of 2a and also to the side reaction arising from the chromophore containing two double bonds. Therefore, further investigations are required to find other chromophores for the improvement of reversibility.(41) MS IR, and *H and 13C NMR spectra for the compounds (four acids and their methyl or ethyl esters) in this work are saved in the Spectral Data Bank System (SDBS) constructed by our laboratory (NC-LI) in the Research Information Processing System (RIPS) of Tsukuba Research Center. The spectral patterns for the compounds are available on request.
Droplet generation has been widely used in conventional two-dimensional (2D) microfluidic devices, and has recently begun to be explored for 3D-printed droplet generators. A major challenge for 3D-printed devices is preventing water-in-oil droplets from sticking to the interior surfaces of the droplet generator when the device is not made from hydrophobic materials. In this study, two approaches were investigated and shown to successfully form droplets in 3D-printed microfluidic devices. First, several printing resin candidates were tested to evaluate their suitability for droplet formation and material properties. We determined that a hexanediol diacrylate/lauryl acrylate (HDDA/LA) resin forms a solid polymer that is sufficiently hydrophobic to prevent aqueous droplets (in a continuous oil flow) from attaching to the device walls. The second approach uses a fully 3D annular channel-in-channel geometry to form microfluidic droplets that do not contact channel walls, and thus, this geometry can be used with hydrophilic resins. Stable droplets were shown to form using the channel-in-channel geometry, and the droplet size and generation frequency for this geometry were explored for various flow rates for the continuous and dispersed phases.
Heterozgyous spondyloepiphyseal dysplasia congenita (sedc/+) mice expressing a missense mutation in col2a1 exhibit a normal skeletal morphology but early-onset osteoarthritis (OA). We have recently examined knee articular cartilage obtained from homozygous (sedc/sedc) mice, which express a Stickler-like phenotype including dwarfism. We examined sedc/sedc mice at various levels to better understand the mechanistic process resulting in OA. Mutant sedc/sedc, and control (+/+) cartilages were compared at two, six and nine months of age. Tissues were fixed, decalcified, processed to paraffin sections, and stained with hematoxylin/eosin and safranin O/fast green. Samples were analyzed under the light microscope and the modified Mankin and OARSI scoring system was used to quantify the OA-like changes. Knees were stained with 1C10 antibody to detect the presence and distribution of type II collagen. Electron microscopy was used to study chondrocyte morphology and collagen fibril diameter. Compared with controls, mutant articular cartilage displayed decreased fibril diameter concomitant with increases in size of the pericellular space, Mankin and OARSI scores, cartilage thickness, chondrocyte clustering, proteoglycan staining and horizontal fissuring. In conclusion, homozygous sedc mice are subject to early-onset knee OA. We conclude that collagen in the mutant’s articular cartilage (both heterozygote and homozygote) fails to provide the normal meshwork required for matrix integrity and overall cartilage stability.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.