Quasi-exact-solution of the Generalized Exe Jahn-Teller Hamiltonian

We consider the solution of a generalized Exe Jahn-Teller Hamiltonian in the context of quasi-exactly solvable spectral problems. This Hamiltonian is expressed in terms of the generators of the osp(2,2) Lie algebra. Analytical expressions are obtained for eigenstates and eigenvalues. The solutions lead to a number of earlier results discussed in the literature. However, our approach renders a new understanding of ``exact isolated'' solutions

Realization of the Radiance Scale Using Transfer Function of the Laser-Based Optical System

This work aims to determine the radiance responsivity to be used in the calibration of polychromatic radiation sources with low uncertainty. To realize the radiance, Ar-ion, He-Ne, and Nd-YAG lasers as well as an integrating sphere with a 0.15 m diameter are used to obtain radiation sources having Lambertian distributions. Then, a silicon photodiode-based reflection-type trap detector with calibrated precision aperture, which is traceable to a liquid helium cooled laser-based cryogenic radiometer, is used to measure the photocurrent corresponding to each wavelength and thereby to obtain radiance. The proposed system, which measures the spectral current response of this laser-based radiance, is a double-grating monochromator with a 2 × 300 mm focal length and triple gratings in each of its turrets. First, the radiance of the laser beam that emerged from the integrating sphere is calculated, and then the radiance responsivity of the system is obtained by measuring the photocurrent outputted from the exit slit of the monochromator at each laser wavelength. Finally, the spectral radiance values of the polychromatic lamps are obtained using the radiance responsivity of the system. Consequently, the study aims to develop the derivation and better understand traceability of the other radiometric and photometric quantities with low uncertainty from the fundamental radiometric radiance unit. Measurement results obtained in the expanded measurement uncertainty scale are determined using both classical and Monte Carlo methods

The etiology and clinical features of non-CAH gonadotropin-independent precocious puberty: A multicenter study

PubMed ID: 26964727Aim: The causes of gonadotropin-independent precocious puberty are diverse, and often have overlapping clinical and biochemical features. With the exception of congenital adrenal hyperplasia (CAH), disorders that cause gonadotropin-independent precocious puberty (GIPP) are uncommon. The literature is devoid of any large-scale studies on the etiologic distribution of GIPP. The aim of this study was to determine the frequency of each etiology in a cohort of patients with GIPP (excluding those with CAH), and to evaluate the clinical and laboratory features of these patients. Materials and Methods: This multicenter, nationwide web-based study collected data on patients who presented with non-CAH GIPP in Turkey. Results: Data were collected for 129 patients (102 girls and 27 boys) from 29 centers. Based on the data collected, the estimated prevalence of non-CAH GIPP in the studied population was 14 in 1 000 000 children. Functional ovarian cyst was the most common etiology, accounting for 37% of all cases, followed by McCune-Albright syndrome (MAS) (26%). Among the patients with MAS, 11.7% had fibrous dysplasia, 32.3% had café-au-lait spots, and 52.9% had both. Human chorionic gonadotrophin-secreting tumors included choriocarcinoma of the liver, hepatoblastoma, and germ cell tumors of the sellar-suprasellar region and mediastinum. Patients with adrenocortical tumors presented at an earlier age than those with other etiologies. Ovarian tumors included mature cystic teratoma, dysgerminoma, juvenile granulosa tumor, and steroid cell tumor. Despite overlapping features, it was possible to identify some unique clinical and laboratory features associated with each etiology. Conclusion: This largest cohort of patients with non-CAH GIPP to date yielded an estimation of the frequency of non-CAH GIPP in the general pediatric population and showed that girls were affected at a rate 4-fold greater than that of boys owing to functional ovarian cysts and MAS, which were the two most common etiologies. The data collected also provided some unique characteristics associated with each etiology. Copyright © 2016 by the Endocrine Society