LUF 6283

Ultrasound characteristics of experimentally induced luteinized unruptured follicles (LUF) and naturally occurring hemorrhagic anovulatory follicles (HAF) in the mare.[Pubmed:21958645]

Theriogenology. 2012 Feb;77(3):514-24.

The development of hemorrhagic anovulatory follicles (HAF) involves luteinization and hemorrhage of the follicle. This is observed on ultrasound as an increase in the echogenicity of the granulosa layer and formation of echoic particles in the antrum. The inhibition of prostaglandin synthesis with flunixin meglumine (FM) during the periovulatory period induces ovulatory failure with development of luteinized unruptured follicles (LUF). These two types of anovulatory follicles appear to share similar ultrasound features but they have not been compared critically. The following endpoints: follicle diameter, follicular contents score, interval from hCG administration to beginning of follicular hemorrhage, interval from hemorrhage to organization of follicular contents, and cycle length were studied and compared in mares with HAF (n = 11) and LUF (n = 13). The objective of this study was to elucidate whether these two unruptured follicles have a consistent clinical pattern of development and therefore can be considered as part of the same anovulatory syndrome. None of the endpoints analyzed differed significantly between HAF and LUF. However, there was a greater individual variation in HAF as compared with LUF in regards to interval from hCG to hemorrhage, follicular diameter at the administration of hCG, and beginning of hemorrhage. In conclusion, HAF share a similar cascade of ultrasound characteristics with the experimentally induced LUF. This finding may provide new insights in elucidating the pathogenesis of HAF.

LuF[SeO3]: the structural chameleon of lanthanoid fluoride oxoselenates(IV).[Pubmed:24024560]

Inorg Chem. 2013 Oct 7;52(19):10788-94.

LuF[SeO3] is a compound that can easily be obtained by a solid-state reaction of Lu2O3, LuF3, and SeO2 with CsBr as the fluxing agent. The outstanding property of LuF[SeO3] is the appearance of two phase transitions within a range of less than 200 K. With an increase in the coordination number for Lu(3+) from 7 to 8, the triclinic room-temperature modification changes at temperatures below -40 degrees C to the monoclinic low-temperature or high-pressure phase of LuF[SeO3]. At the same time, room-temperature modification retains the structure but gains higher symmetry at the second phase transition of around +110 degrees C. This second transition can even be observed under a microscope using polarized light to see twinning lamellae disappear and reappear during this reversible process.

Solvothermal synthesis and upconversion properties of about 10 nm orthorhombic LuF(3): Yb(3)(+), Er(3)(+) rectangular nanocrystals.[Pubmed:26298284]

J Colloid Interface Sci. 2015 Dec 1;459:224-229.

The Yb(3+) and Er(3+) codoped orthorhombic LuF3 rectangular nanocrystals (NCs) with the size of about 10nm were synthesized by a facile and effective solvothermal process. X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), upconversion (UC) luminescence spectra and decay curves were used to characterize the resulting samples. Compared with YF3 and alpha-NaYF4 NCs, owning the similar size and the same doping levels of Yb(3+) ions and Er(3+) ions as LuF3 NCs, the green UC emission of LuF3 NCs is 18.7 times and 5.1 times stronger than that of YF3 and alpha-NaYF4 NCs respectively; the red UC emission of LuF3 NCs is 13.2 times and 0.6 times stronger than that of YF3 and alpha-NaYF4 NCs respectively. Under 980 nm wavelength excitation, the decay curves of both (4)S3/2-->(4)I15/2 transition and (4)F9/2-->(4)I15/2 transition exhibit a single exponential function, resulting from the fast energy migrations among Yb(3+) ions caused by the high concentration of Yb(3+) ions (20 mol%). Meanwhile, at relatively low power density, the slopes of the linear plots between log(I) and log(P) for green UC and red UC are 1.7 and 1.9 respectively, which are less than 2 due to the quenching of the thermal effect, indicating a two-photon process for them. At high power density, the slopes are decreased caused by the saturation effect. In addition, we proved the existence of the thermal effect by the pump power dependence of the intensity ratio of (2)H11/2-->(4)I15/2 transition to (4)S3/2-->(4)I15/2 transition.

Low valency in lanthanides: a theoretical study of NdF and LuF.[Pubmed:24929395]

J Chem Phys. 2014 Jun 14;140(22):224314.

The ground and low-lying excited state potential energy curves of neodymium monofluoride were calculated using multireference (CASSCF) and single reference (EOM-CR-CCSD(T)) methods. Optimized bond lengths were obtained and accurate bond dissociation energies were computed. The EOM-CR-CCSD(T) method was used to determine the bond dissociation energy of lutetium monofluoride, and it is shown that core correlation is required to produce bond dissociation energies in agreement with experiment.