RÉSUMÉ
Lasers play a significant role in optical communication, medical, and scientific research, owing to their high brightness and high coherence. However, the high spatial coherence will lead to specific challenges, such as speckle noise in imaging and wavefront distortion during propagation through scattering media. Here, a continuous-wave (cw) degenerate cavity laser (DCL) with low spatial coherence is demonstrated with efficient suppression of the thermal lensing effect from the gain crystal. Experimentally, a cw degenerate laser output with about 2000 transverse modes corresponding to a speckle contrast of about 0.0224 is achieved. This laser can be used for speckle reduction and is robust against atmospheric turbulence, which may find applications in the field of laser imaging technology and illumination.
RÉSUMÉ
Two quinoline-malononitrile-based NIR fluorescent probes with good water-solubility have been developed for detecting and imaging of Aß aggregates in Alzheimer's disease. In vitro studies demonstrated that both probes exhibited high affinity to Aß aggregates with an increase of fluorescence intensity due to the intramolecular charge transfer effect. Moreover, the probes could particularly image Aß plaques in brain sections of triple transgenic AD mice.
Sujet(s)
Maladie d'Alzheimer/diagnostic , Peptides bêta-amyloïdes/composition chimique , Colorants fluorescents/composition chimique , Eau/composition chimique , Animaux , Rayons infrarouges , Souris , Souris transgéniques , Structure moléculaire , Taille de particule , Agrégats de protéines , Théorie quantique , Solubilité , Propriétés de surfaceRÉSUMÉ
Self-assembled nanostructures of amphiphilic peptides have a wide range of applications in bioimaging and delivery systems. In this study, we design and synthesize a biocompatible amphiphilic peptide (C-3) consisting of an RVRRFFF sequence and a nitrobenzoxadiazole fluorophore that can self-assemble into stable micelles for specifically detecting furin, a kind of proprotein convertase with promoting tumor progression. The self-assembly of C-3 with a ß-sheet nanostructure is capable of a rapid and specific response to furin in only 5 min in aqueous solution because of the existence of the RVRR motif in the C-3 molecule. The C-3 nanostructures thus can selectively distinguish high furin-expressing cancer cells, like MDA-MB-231 cells, a kind of human breast cancer cells, from normal cells. Furthermore, the C-3 self-assembly can stay in living cells for a long time and are capable of durable detection of intracellular furin, being good for tracer analysis. To our knowledge, this is the first example of self-assembly of a soluble amphiphilic peptide that can selectively detect furin in high furin-expressing live cells.