BF3·Et2O-assisted synthesis of sulfinylated spiro[5.5]trienones from biaryl ynones.

Sulfinyls are valuable structural moieties used for developing synthetically new pharmaceuticals and agrochemicals. Herein, we disclose a straightforward synthesis of sulfinylated spiro[5.5]trienones proceeding via an unprecedented BF3·Et2O-promoted spirocyclization of biaryl ynones. The availability of relatively inexpensive BF3·Et2O to carry out transformations on a bulk scale along with its further application towards the synthesis of dibenzocyclohepten-5-ones delivers a unique opportunity to deploy it in various synthetic directions.

Visible Light Promoted Brominative Dearomatization of Biaryl Ynones to Spirocycles.

Bromine induced spiro cyclization of biaryl ynones facilitated the synthesis of spiro[5,5]trienones suitable for extended functionality at the C(3') position. Herein, a step-economic photo-oxidative brominative carbannulation of biaryl ynones employing ammonium bromide and riboflavin tetraacetate (RFTA) has been developed. The reactivity between distal phenyl C-H activated ortho-annulation and dearomative ipso-annulation is well exemplified. The eminent features of the methodology include metal-free, external additive free, low-loading photocatalyst (0.1 mol %), and use of a simple precursor.

Biodegradable Hybrid Nanocomposite of Chitosan/Gelatin and Green Synthesized Zinc Oxide Nanoparticles for Food Packaging.

In the context of emerging global concerns with synthetic plastic packaging, alternative natural biodegradable packaging materials are gaining increasing attention for food packaging applications. In this study, chitosan and gelatin nanocomposite hybrid films containing green synthesized zinc oxide (ZnO) nanoparticles (NPs) were developed and microstructural properties were studied. Antimicrobial activity of the developed films was evaluated using both Gram negative (Escherichia coli) and Gram positive bacteria (Staphylococcus aureus). Green synthesis protocol was used for the precipitation of ZnO NPs using fruit extract of Cassia fistula. The as-synthesized polyhedral ZnO NPs were in the range of 20-40 nm (average size ≈29 nm). Reinforcement with ZnO NPs in the hybrid films lead to improved thermal stability, elongation-at-break (EAB), and compactness properties. The developed films with 2% and 4% ZnO NPs showed a smooth, compact, and heterogeneous surface morphology compared to the control (chitosan-gelatin hybrid) films. Disc diffusion assays showed that the nanocomposite film had significant antimicrobial activity against E. coli. The developed hybrid nanocomposite films have potential to be developed as biodegradable alternative for postharvest packaging of fresh fruits and vegetables.

Early loss of primary incisors due to parafunctional tendency--case report.

Premature loss of primary teeth associated with a parafunctional habit in a 30-month-old child is reported. Report details, clinically and radiographically, these effects in a very young child and reviews diagnostic possibilities. Early detection and scrutiny by the pediatric dentist is important to determine origin and to rule out periodontal disease as a manifestation of underlying systemic disease.

Early loss of primary incisors due to parafunctional tendency. Case report.

Premature loss of primary teeth associated with a parafunctional habit in 30-month-old child is reported. Report details, clinically and radiographically, these effects in a very young child and reviews diagnostic possibilities. Early detection and scrutiny by the pediatric dentist is important to determine origin and to rule out periodontal disease as manifestation of underlying systemic disease.

Imaging intraflagellar transport in mammalian primary cilia.

The primary cilium is a specialized organelle that projects from the surface of many cell types. Unlike its motile counterpart it cannot beat but does transduce extracellular stimuli into intracellular signals and acts as a specialized subcellular compartment. The cilium is built and maintained by the transport of proteins and other biomolecules into and out of this compartment. The trafficking machinery for the cilium is referred to as IFT or intraflagellar transport. It was originally identified in the green algae Chlamydomonas and has been discovered throughout the evolutionary tree. The IFT machinery is widely conserved and acts to establish, maintain, and disassemble cilia and flagella. Understanding the role of IFT in cilium signaling and regulation requires a methodology for observing it directly. Here we describe current methods for observing the IFT process in mammalian primary cilia through the generation of fluorescent protein fusions and their expression in ciliated cell lines. The observation protocol uses high-resolution time-lapse microscopy to provide detailed quantitative measurements of IFT particle velocities in wild-type cells or in the context of genetic or other perturbations. Direct observation of IFT trafficking will provide a unique tool to dissect the processes that govern cilium regulation and signaling.