We report a novel approach to modify the second order nonlinear optical (NLO) susceptibility of organic nanofiber crystals by hybridization with the optical modes of microcavities in the strong coupling regime. The wavelength dependence of the SHG efficiency displays two intense peaks corresponding to the so-formed light-matter hybrid states. Our results demonstrate an enhancement of the resonant SHG efficiency of the lower polariton by 2 orders of magnitude for the collectively coupled molecules as compared to that of the same material outside the microcavity. This study is a proof of principle that opens a new direction for NLO of organic materials in subwavelength resonators.

We present in-situ observations of the epitaxial nucleation of the metastable polymorph of a steroid on specific faces of the stable form in different solutions using optical microscopy. The polar morphology of the crystals allows for the determination of the specific face where the epitaxial nucleation takes place. The observations prove that there is a different barrier for 2D epitaxial nucleation of the metastable polymorph on the opposite polar faces. In-situ Raman measurements are used to confirm the structure of the epitaxially growing crystals. The metastable zone width and the role of the solvent in this process are discussed. The relatively large lifetime of the metastable polymorph in ethanol solutions is exploited to determine the solubility curves of the bulk phases of both polymorphs. The relation between the solubility of the two polymorphs in different solvents and the polymorphic transformation rate is discussed.

NMR signal amplification by reversible exchange (SABRE) has been observed for pyridine, methyl nicotinate, N-methylnicotinamide, and nicotinamide in D 2 Ow ith the new catalyst[ Ir(Cl)(IDEG)(COD)] (IDEG = 1,3-bis(3,4,5-tris(diethyleneglycol)benzyl)imidazole-2-ylidene). During the activation and hyperpolarization steps, exclusively D 2 Ow as used, resulting in the first fully biocompatible SABRE system. Hyperpolarized 1 Hs ubstrate signals wereo bserved at 42.5 MHz upon pressurizing the solutionw ith parahydrogen at close to the Earth's magnetic field, at concentrations yielding barely detectablet hermals ignals. Moreover,4 2-, 26-, 22-, and 9-fold enhancements wereo bserved for nicotinamide, pyridine, methyl nicotinate, and N-methylnicotinamide, respectively,i nc onventional 300 MHz studies. This research opens up new opportunities in af ield in which SABRE has hitherto primarilyb een conducted in CD 3 OD.T his system uses simple hardware, leaves the substrate unaltered, and shows that SABRE is potentially suitable for clinical purposes.

The discovery of the phenomenon known as aggregation-induced emission (AIE) has opened the door to a variety of brilliant organic solid-state lightemitting materials. While AIE is well established in linear optics, the development of AIE luminogens (AIEgens) with highly efficient nonlinear optical (NLO) effects remains relatively unexplored. Particularly, second-order NLO requires the AIEgens to be organized in a non-centrosymmetric fashion, and such examples are rarely reported. Here, an AIEgen, 2,7-di([1,1′-biphenyl]-4-yl)fluorenone (4-DBpFO), is designed and synthesized by introducing a carbonyl group onto the backbone of p-hexaphenylene. The restricted rotation of the compound upon aggregation results in a dramatic enhancement of the linear optical emission when forming self-assemblies. Furthermore, introducing the carbonyl group drives the formation of hydrogen bonded molecular chains, which are attached by the zigzag CH⋅⋅⋅π interactions in a non-centrosymmetric way. As a result, the dipole of each individual molecule contributes accumulatively to a macroscopic dipole of the formed 4-DBpFO microcrystals. This leads to a highly efficient second harmonic generation with very high laser damage treshold. This AIEgen, whose optical response is greatly enhanced in both linear and nonlinear optical regimes upon the formation of well-defined self-assemblies, has potential applications in next generation photonic circuits.

Magnesium has been shown to effectively prevent vascular calcification associated with chronic kidney disease. Magnesium has been hypothesized to prevent the upregulation of osteoblastic genes that potentially drives calcification. However, extracellular effects of magnesium on hydroxyapatite formation are largely neglected. This study investigated the effects of magnesium on intracellular changes associated with transdifferentiation and extracellular crystal formation. Bovine vascular smooth muscle cells were calcified using β-glycerophosphate. Transcriptional analysis, alkaline phosphatase activity and detection of apoptosis were used to identify transdifferentiation. Using X-ray diffraction and energy dispersive spectroscopy extracellular crystal composition was investigated. Magnesium prevented calcification in vascular smooth muscle cells. β-glycerophosphate increased expression of osteopontin but no other genes related to calcification. Alkaline phosphatase activity was stable and apoptosis was only detected after calcification independent of magnesium. Blocking of the magnesium channel TRPM7 using 2-APB did not abrogate the protective effects of magnesium. Magnesium prevented the formation of hydroxyapatite, which formed extensively during β-glycerophosphate treatment. Magnesium reduced calcium and phosphate fractions of 68% and 41% extracellular crystals, respectively, without affecting the fraction of magnesium. This study demonstrates that magnesium inhibits hydroxyapatite formation in the extracellular space, thereby preventing calcification of vascular smooth muscle cells.