Identification of a fibronectin-binding protein signature associated with idiopathic pulmonary fibrosis.

The extracellular matrix (ECM) is a critical component of tissue where it provides structural and signaling support to cells. Its dysregulation and accumulation lead to fibrosis, a major clinical challenge underlying many diseases that currently has little effective treatment. An understanding of the key molecular initiators of fibrosis would be both diagnostically useful and provide potential targets for therapeutics.

Ultrafast hole extraction from photoexcited colloidal CdSe quantum dots coupled to nitroxide free radicals.

Organic free radicals related to the 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radical are known as photoluminescence-quenchers when coupled to group II-chalcogenide colloidal quantum dots (QDs), but the mechanism responsible for this phenomenon has so far remained unresolved. Using a combination of time-resolved photoluminescence and transient absorption spectroscopies, we demonstrate that photoexcited colloidal CdSe QDs coupled to 4-amino-TEMPO undergo highly efficient reductive quenching, that is, hole transfer from the valence band of the quantum dot to the organic paramagnetic species. Interestingly, the process is shown to occur on a subpicosecond time scale for bound 4AT; such a large rate constant for the extraction of holes from photoexcited CdSe QD by a molecular species is rare and underlines the potential that TEMPO derivatives can play in mediating efficient redox processes involving colloidal CdSe QDs.

Insights into the Structural Complexity of Colloidal CdSe Nanocrystal Surfaces: Correlating the Efficiency of Nonradiative Excited-State Processes to Specific Defects.

II-VI colloidal semiconductor nanocrystals (NCs), such as CdSe NCs, are often plagued by efficient nonradiative recombination processes that severely limit their use in energy-conversion schemes. While these processes are now well-known to occur at the surface, a full understanding of the exact nature of surface defects and of their role in deactivating the excited states of NCs has yet to be established, which is partly due to challenges associated with the direct probing of the complex and dynamic surface of colloidal NCs. Here, we report a detailed study of the surface of cadmium-rich zinc-blende CdSe NCs.