In vivo lifetimes of the three color-sectors in bioluminescence emissions of the firefly Luciola praeusta at different temperatures

Bioluminescence emissions from fireflies have been well-studied for over a century. From the apparent features of the emitted light, conclusions have been drawn and hypotheses put forward on the characteristics of the highly efficient light emitting system. The basic emitter oxyluciferin, being chemically unstable, is difficult to study in isolation and, therefore, its analogs have been prepared and analyzed. In this letter, the lifetimes of the excited-state emitter oxyluciferin are measured, and an inference is drawn on the chemiluminescence reaction in vivo. The light from the Indian species of firefly Luciola praeusta contains three color-sectors: green, yellow, and red, and hence three optical filters are used to study time-resolved emissions from these sectors at different temperatures. All the three color-sectors are observed to be temperature sensitive in the time domain. An exponential variation of lifetime with temperature is observed for the emissions in these three regions.     

Molecular Photoacoustic Tomography with Colloidal Nanobeacons

Spotting clots : Vascularly constrained colloidal gold nanobeacons (GNBs; see picture) can be used as exogenous photoacoustic contrast agents for the targeted detection of fibrin, a major biochemical feature of thrombus. Fibrin‐targeted GNBs provide a more than tenfold signal enhancement in photoacoustic tomography in the near‐IR wavelength window, indicating their potential for diagnostic imaging.

     

Design of a Waste Paper-Derived Chemically ‘Reactive’ and Durable Functional Material with Tailorable Mechanical Property Following an Ambient and Sustainable Chemical Approach

Controlled tailoring of mechanical property and wettability is important for designing various functional materials. The integration of these characteristics with waste materials is immensely challenging to achieve, however, it can provide sustainable solutions to combat relevant environmental pollutions and other relevant challenges. Here, the strategic conversion of discarded and valueless waste paper into functional products has been introduced following a catalyst-free chemical approach to tailor both the mechanical property and water wettability at ambient conditions for sustainable waste management and controlling the relevant environmental pollution. In the current design, the controlled and appropriate silanization of waste paper allowed to modulate both the a) porosity and b) compressive modulus of the paper-derived sponges. Further, the association of 1,4-conjugate addition reaction between amine and acrylate groups allowed to obtain an unconventional waste paper-derived chemically ‘reactive’ sponge. The appropriate covalent modification of the residual reactive acrylate groups with selected alkylamines at ambient conditions provided a facile basis to tailor the water wettability from moderate hydrophobicity, adhesive superhydrophobicity to non-adhesive superhydrophobicity. The embedded superhydrophobicity in the waste paper-derived sponge was capable of sustaining large physical deformations, severe physical abrasions, prolonged exposure to harsh aqueous conditions, etc. Further, the waste paper-derived, extremely water-repellent sponges and membranes were successfully extended for proof-of-concept demonstration of a practically relevant outdoor application, where the repetitive remediation of oil spillages has been demonstrated following both selective absorption (25 times) of oils and gravity-driven filtration-based (50 times) separation of oils from oil/water mixtures at different harsh aqueous scenarios.     

Ligand-directed nanobialys as theranostic agent for drug delivery and manganese-based magnetic resonance imaging of vascular targets

Although gadolinium has been the dominant paramagnetic metal for MR paramagnetic contrast agents, the recent association of this lanthanide with nephrogenic systemic fibrosis, an untreatable disease, has spawned renewed interest in alternative metals for MR molecular imaging. We have developed a self-assembled, manganese(III)-labeled nanobialys (1), a toroidal-shaped MR theranostic nanoparticle. In this report, Mn(III) nanobialys are characterized as MR molecular imaging agents for targeted detection of fibrin, a major biochemical feature of thrombus. A complementary ability of nanobialys to incorporate chemotherapeutic compounds with greater than 98% efficiency and to retain more than 80% of these drugs after infinite sink dissolution, point to the theranostic potential of this platform technology.     

Synthesis of NanoQ, a copper-based contrast agent for high-resolution magnetic resonance imaging characterization of human thrombus

A new site-targeted molecular imaging contrast agent based on a nanocolloidal suspension of lipid-encapsulated, organically soluble divalent copper has been developed. Concentrating a high payload of divalent copper ions per nanoparticle, this agent provides a high per-particle r1 relaxivity, allowing sensitive detection in T1-weighted magnetic resonance imaging when targeted to fibrin clots in vitro. The particle also exhibits a defined clearance and safety profile in vivo.     

Recent Advances On Direct Formylation Reactions

Aldehydes serve as the key functional group in organic synthesis and are valuable intermediates. The various advanced methods of direct formylation reactions have been reviewed in this article. Overcoming the drawbacks of the traditional methods of formylation, newer methods involving homo and heterogenous catalysts, one pot reactions, solvent free techniques are elaborated, which can be performed under mild conditions and using inexpensive resources.