Two-Photon Absorption and Multiphoton Excited Fluorescence of Acetamide-Chalcone Derivatives: The Role of Dimethylamine Group on the Nonlinear Optical and Photophysical Properties.

This work studied the effect of different electron-withdrawing and electron-donating groups on the linear and nonlinear optical properties of acetamide-chalcone derivatives. The results showed that the addition of the dimethylamine group led to a large fluorescence emission (71% of fluorescence quantum yield in DMSO solution) that can be triggered by two and three-photon excitations, which is essential for biological applications. Furthermore, dimethylamine also red-shifts the lower energy state by approximately 90 nm, increasing the two-photon absorption cross-section of the lower energy band by more than 100% compared with the other studied compounds.

Frequency-resolved microscopic second-order hyperpolarizability of azochromophores: a study on nonlinear all-optical switching applications.

Azochromophores present interesting optical properties for application in all-optical switches (AOSs), such as ultrafast photoisomerization and considerable nonlinear optical response. However, determining the frequency-resolved microscopic second-order hyperpolarizability (real and imaginary parts) related to the pure electronic effects of molecules in solution is a challenging task. In this context, we have used femtosecond-laser induced nonlinear ellipse rotation (NER) measurements to obtain the electronic nonlinear refraction (()) and two-photon absorption spectra (()) of four azochromophores dissolved in methanol and acetone.

Heart failure as an adverse effect of infliximab for Crohn's disease: A case report and review of the literature.

Background: Anti-tumor necrosis factor agents were the first biologic therapy approved for the management of Crohn's disease (CD). Heart failure (HF) is a rare but potential adverse effect of these medications. The objective of this report is to describe a patient with CD who developed HF after the use of infliximab.

Small Intestinal Hemangioma: A Case Report.

BACKGROUND Hemangiomas are benign vascular neoplasms that originate from fast-growing embryonic mesodermal tissue and have a proliferation of endothelial cells, which manifest themselves in different forms, locations, and dimensions. Owing to its rarity and similarity of symptoms with other chronic bowel diseases, intestinal hemangioma is a differential diagnosis to be considered in patients presenting with symptoms such as abdominal pain and anemia. CASE REPORT A 46-year-old woman with a history of diffuse abdominal pain and abdominal distension for 20 years presented with a worsening of symptoms in the past year.

Intramolecular Cooperative and Anti-Cooperative Effect on the Two-Photon Absorption Cross Section in Triphenylamine Derivatives.

The intramolecular cooperative effect in branched molecules is a consequence of the interaction and extent of electronic coupling among the different axes of charge transfer. Such an effect is the key to obtain remarkable nonlinear optical response in molecular systems. Here we show that triphenylamine derivative molecules containing only two branches present the strongest electronic interaction between them at the excited state, generating exponential enhancement of the 2PA cross section.