Pushing the Boundary of Covalency in Lanthanoid-Tellurium Bonds: Insights from the Synthesis, Molecular and Electronic Structures of Low-Coordinate, Monomeric Europium(II) and Ytterbium(II) Tellurolates

Owing to the strict hard/soft dichotomy between the lanthanoids and tellurium atoms, and the strong affinity of lanthanoid ions for high coordination numbers, low-coordinate, monomeric lanthanoid tellurolate complexes have remained elusive as compared to the lanthanoid complexes with lighter group 16 elements (O, S, and Se). This makes the development of suitable ligand systems for low-coordinate, monomeric lanthanoid tellurolate complexes an appealing endeavor. In a first report, a series of low-coordinate, monomeric lanthanoid (Yb, Eu) tellurolate complexes were synthesized by utilizing hybrid organotellurolate ligands containing N-donor pendant arms. The reaction of bis[2-((dimethylamino)methyl)phenyl] ditelluride, 1 and 8,8′diquinolinyl ditelluride, 2 with Ln0 metals (Ln=Eu, Yb) resulted in the formation of monomeric complexes [LnII(TeR)2(Solv)2] [R=C6H4-2-CH2NMe2] [3: Ln=Eu, Solv=tetrahydrofuran; 4: Ln=Eu, Solv=acetonitrile; 5: Ln=Yb, Solv=tetrahydrofuran; 6: Ln=Yb, Solv=pyridine] and [EuII(TeNC9H6)2(Solv)n] (7: Solv=tetrahydrofuran, n=3; 8: Solv=1,2-dimethoxyethane, n=2), respectively. Complexes 3–4 and 7–8 represent the first sets of examples of monomeric europium tellurolate complexes. The molecular structures of complexes 3–8 are validated by single–crystal X-ray diffraction studies. The electronic structures of these complexes were investigated using Density Functional Theory (DFT) calculations, which revealed appreciable covalency between the tellurolate ligands and lanthanoids

Carcinosarcoma of the vulva: a rare case report

Carcinosarcomas are rare and clinically aggressive neoplasms with poor outcome. A very few cases has been reported in the literature. We present a case of a 54 yrs woman with bleeding per vagina for 1.5 months. On per vaginal examination, a lump of size 3×2 cm was found over the left anterior region of vulva. CECT abdomen revealed a well-defined heterogeneously enhancing lesion with calcific foci involving both labia minora. MRI pelvis reveals carcinoma left vulva with involvement of lower 3rd of vaginal wall. Histopathological examination showed features suggestive of carcinosarcoma of the vulva. This was further confirmed by immunohistochemistry which showed positivity for CK, SMA, caldesmon and negative for S100, CD34, desmin, CD31, ERG and MyoD1. Because it is a very rare tumor with severe prognosis, we presented this case as this case report can be a useful addition to the literature.

Oral squamous cell carcinoma with clear cell change: a rare case report

Clear-cell variant of oral squamous cell carcinoma is an extremely rare entity. Clear-cell change can be seen in any of the neoplasms, but as pure form variant, it is difficult to find in head-and-neck SCC. We hereby present a case report of 71-year-old male who presented with a growth with erythematous patches on the lateral pharyngeal wall for the past 3 months. Histopathologic examination showed nests, islands and sheets of malignant squamous cells with vesicular nuclei and abundant clear cytoplasm. Neoplastic cells constituting majority of nests exhibited clear cell changes. Special stain was performed to identify the nature of clear cells. periodic acid Schiff-diastase (PAS-D) showed positivity in the clear cells. Immunohistochemical study using antibody for pan-cytokeratin revealed diffuse positivity in the tumor cells

Effect of Freezing Rate on Quality of Cryopreserved Goat Spermatozoa Using a Programmable Freezer

Abstract: A total of 45 ejaculates from nine Beetal bucks collected by artificial vagina, washed and extended i

Cryo-capacitation changes during cryopreservation of swamp buffalo spermatozoa

Cryopreservation of sperm cells induces cryo-capacitation like changes. These changes are associated with reduced survival of sperm cells in the female reproductive tract that ultimately associate with poor fertility. The present study was designed with the objective to investigate the cryo-capacitation changes in relation to acrosomal status, transaminases activities, sperm membrane protein and cholesterol content in swamp buffalo spermatozoa. Results revealed that the total mean incidences of acrosome reacted spermatozoa and the mean activity of ALT and AST were significantly higher after equilibration and freezing. The mean level of sperm membrane protein and cholesterol was significantly lower after equilibration and freezing. It may be concluded from the present study that cryopreservation induces capacitation-like changes in swamp buffalo spermatozoa

Fractal Inspired Models of Quark and Gluon Distributions and Longitudinal Structure Function FL(x, Q2) at small x

In recent years, Fractal Inspired Models of quark and gluon densities at small x have been proposed. In this paper, we investigate longitudinal structure function F-L (x, Q2) within this approach. We make predictions using the QCD based approximate relation between the longitudinal structure function and the gluon density. As the Altarelli-Martinelli equation for the longitudinal structure function cannot be applied to Model I due to the presence of a singularity in the Bjorken x-space we consider Model II only. The qualitative feature of the prediction of Model II is found to be compatible with the QCD expectation.Comment: 11 pages, 4 figures, Accepted for publication on 10-07-2010 in Indian Journal of Physic

Laser Performance Of Cr4+-Y2Sio5

Laser action in Cr4+ doped yttrium-orthosilicate Cr4+:Y2SiO5 cooled to 77 K was demonstrated for the first time with 1064 and 532 nm pumping from a pulsed Nd:YAG laser and broad band (@ 840 nm) pumping from a Q-switched Cr:LiSAF laser