An Efficient and Green Synthesis of 1′Hspiro[isoindoline-1,2′-quinazoline]-3,4′(3′H)-dione Derivatives in the Presence of Nano Fe3O4–GO–SO3H

ABSTRACT

In this article a simple, rapid, green and efficient method for the synthesis of various 1′Hspiro[isoindoline-1,2′-quinazoline]-3,4′(3′H)-diones in the presence of acidic magnetic graphene oxide nanosheets (Fe₃O₄–GO–SO₃H) as catalyst is reported. Different substituted spirooxindoles have been synthesized from one-pot three component reaction of isatoic anhydride, aliphatic or aromatic primary amines and isatin in the presence of Fe₃O₄–GO–SO₃H. This reaction allowed us to prepare some new and known derivatives of substituted spirooxindoles. The worthwhile advantages of this method are high product yields, short reaction times, the possibility of using of a magnetic, reusable and non-toxic catalyst and solvent-free conditions.     

Synthesis of Prussian Blue Metal Coordination Polymer Nanocubes via Cyanoferrate Monomer Design

The effect of cyanoferrate monomers on the metal coordination polymerization of Fe³⁺ and [Fe(CN)₅L]^3?, where L = CN, NH₃, pyrazine (Pz), pyridine (Py) and 4-(dimethylamino)-pyridine (DMAP), for the synthesis of Prussian blue (PB) polymers was investigated. The polymerizations were performed in water at ambient temperature in the absence of templates and/or surfactants. The morphology and crystallinity of the resulting polymers are influenced by the nature of the ligands L associated with the monomers. When L = CN or NH₃, crystalline polymers with irregular structures were produced. The polymerization employing [Fe(CN)₅L]^3? with L = Pz, Py and DMAP led to amorphous polymers with a tendency to form individual nanoparticles depending on the choice of L. Notably, in the case of [Fe(CN)₅DMAP]^3?, amorphous PB nanocubes with a regular size distribution were produced. Based on this study, the binding forces of L to Fe(II)(CN)₅ is highlighted as an important parameter for PB metal coordination polymer nanostructure control and design.     

Novel methods to fabricate macroporous 3D carbon scaffolds and ordered surface mesopores on carbon filaments

New methods for fabrication of 3D macroporous carbon scaffolds and synthesis of mesopores on carbon surfaces are proposed. Ordered macroporous filamentary carbon structures were made by rapid prototyping using solvent-based extrusion freeforming which allows the scaffold to be designed on computer and downloaded directly to a building platform. The surface of extruded filaments was decorated with 20?C25?nm open mesopores by coating with nano-silica as a hard template followed by pyrolysis and dissolution of the silica. This left an open mesoporous surface to serve as a host for catalysts or enzymes while retaining integrity in the core for electrical and mechanical performance. The combination of these two methods could be used to make different hierarchical, multi-functional carbon structures which could be applied in fuel cells as the catalyst carrier and biofuel cell electrode.     

Electrospun polystyrene coatings with tunable wettability

Hydrophobic materials with tunable wettability were developed by electrospinning aligned polystyrene (PS) fibers onto the surface of a unimorph composite piezoelectric substrate. An electric field was used to modify the curvature of the substrate resulting in a corresponding change in the morphology of the electrospun coating. Contact angle measurements were performed on droplets deposited onto the surface before and after application of the electric field. The water droplet contact angle was observed to change in response to the applied voltage. Contact angle measurements were performed as a function of surface fiber density and suggest that the change in contact angle is caused by a transition from Wenzel to Cassie–Baxter wetting. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41592.     

Dual lanthanide role in the designed synthesis of hollow metal coordination (Prussian Blue analogue) nanocages with large internal cavity and mesoporous cage

Prussian Blue (PB) analogue metal coordination nanocages comprised of mesoporous walls (ca. 3.5 nm pore width) encapsulating a cavity approaching ca. 100 nm in diameter (surfactant free) are presented as an advance in rational metal coordination polymer nanostructure design. The synthesis employs lanthanide ions (Gd(3+) or Er(3+)) which function initially as peripheral coordination crosslinkers of metallo-surfactant templated miniemulsion droplets, and, subsequently, as promoters in the removal of the organic component of those surfactants via metal-assisted ester hydrolysis. The success of this synthetic strategy relies entirely on the periphery coordination event occurring prior to the ester hydrolysis surfactant removal step. Crucially, this one-pot sequential synthesis was achieved using a newly developed metallo-surfactant designed to have a reduced ester hydrolysis rate. Syntheses of this innovative metallo-surfactant, intermediary PB analogue coordination polymer organo-nanoshells and the subsequent conversion to hollow metal coordination nanocages are fully characterised using a wide variety of techniques, including TEM, SEM, EFTEM, EDX, TGA, WAXD, NMR, N(2) adsorption, etc., and represent the first designed synthesis of hollow metal coordination nanocages containing a large nanoscale cavity (wall of hollow nanosphere is mesoporous; hence nanocage).     

Processing of strong and highly conductive carbon foams as electrode

Porous carbons were processed by the foaming of two-part polymer precursors with pre-loaded carbon powder (graphitic or amorphous), and then resin impregnation and carbonization to control both porosity and mechanical strength of the resulting foam. Electrical conductivity of the foams was improved by nickel-catalyzed graphitization. Different levels of graphitization were obtained for varied concentrations of nickel to the amorphous carbon foams. The presence of graphitic carbon improves the electrical conductivity by a factor of 50, compared to the amorphous counterparts. Electrochemical studies showed that graphitization of the amorphous structures increased the specific electrochemical surface area and electron transfer rate of the carbon electrodes.     

Relationship between vitamin D and gestational diabetes in overweight or obese pregnant women may be mediated by adiponectin

Scope

Maternal vitamin D deficiency has been implicated in adverse pregnancy outcomes. However, the association between vitamin D and inflammation, particularly adipokines, remains unexplored in pregnancy.

Methods and results

In 102 overweight or obese pregnant women at high‐risk of gestational diabetes mellitus (GDM), we investigated relationships between maternal 25‐hydroxyvitamin D (25(OH)D) concentrations at 12–15 wk gestation (baseline) and serum lipids, inflammatory markers, novel adipokines (omentin‐1, visfatin, high molecular weight (HMW) adiponectin), and subsequent pregnancy outcomes (GDM, preeclampsia, preterm birth [PTB]). After adjustment for maternal factors (age, BMI, parity, ethnicity, and smoking status), baseline 25(OH)D concentrations were inversely associated with total cholesterol and triglycerides, and positively associated with HMW‐adiponectin. Higher baseline 25(OH)D concentrations were associated with decreased fasting and 1‐h post‐OGTT glucose and reduced risk of GDM at 26–28 wk, as well as with longer gestation and reduced risk of PTB upon additional adjustment for caesarean section. Adding HMW‐adiponectin to the multivariable models attenuated most associations, and HMW‐adiponectin was a significant predictor in the models.

Conclusion

Our findings suggest that lower maternal 25(OH)D concentrations in overweight/obese pregnant women at high‐risk of GDM are associated with increased cardiometabolic risks during pregnancy and adverse pregnancy outcomes, and that these associations may be mediated by HMW‐adiponectin.

     

Design of biocompatible polylactic acid–polyethylene glycol combination for manufacturing biodegradable staplers

For the development of an effective and faster wound closure method, it is necessary to overcome current techniques' limitations. As compared to other methods, biodegradable staples provide superior mechanical properties, reduce scarring, and promote healing faster. Here, polylactic acid (PLA) and polyethylene glycol (PEG) composite staplers produced by solvent casting are presented as a suggestion for rapidly and easily closing wounds. The resulting samples were tested for mechanical properties, contact angle, and degradation properties over 21–90 days in the engineering phase. Selected formulations were moved to the biological phase for in vitro cytotoxicity by MTT assay and the in vivo biocompatibility assessment by transplantation of the samples into rats' back muscle. The tissue samples were collected and evaluated using hematoxylin and eosin and trichrome staining 1, 6, and 12 weeks after transplantation. When considering the maximum force tolerance range for PLA–PEG at around 20–58 N and comparing it with comparable commercial products, as well as their degradation rate and hydrophilicity, it was concluded that this combination maintains wound edges together. Cell viability tests demonstrated no cytotoxicity in the samples after 48 and 72 h. Morphological observations indicated some condensations of collagen fibers and no remarkable infiltration of inflammatory cells around the transplanted samples. In conclusion, the combination of PLA and PEG showed suitable mechanical properties, superior hydrophilicity, high biocompatibility and is suitable for medical staplers, and is innovative.     

An aligned fibrous and thermosensitive hyaluronic acid-puramatrix interpenetrating polymer network hydrogel with mechanical properties adjusted for neural tissue

Journal of Materials Science - Central nervous system (CNS) injuries such as stroke or trauma can lead to long-lasting disability, and there is no currently accepted treatment to regenerate...