Ocular manifestations in Gorlin-Goltz syndrome

Background: Gorlin-Goltz syndrome, also known as nevoid basal cell carcinoma syndrome, is a rare genetic disorder that is transmitted in an autosomal dominant manner with complete penetrance and variable expressivity. It is caused in 85% of the cases with a known etiology by pathogenic variants in the PTCH1 gene, and is characterized by a wide range of developmental abnormalities and a predisposition to multiple neoplasms. The manifestations are multiple and systemic and consist of basal cell carcinomas in various regions, odontogenic keratocistic tumors and skeletal anomalies, to name the most frequent. Despite the scarce medical literature on the topic, ocular involvement in this syndrome is frequent and at the level of various ocular structures. Our study focuses on the visual apparatus and its annexes in subjects with this syndrome, in order to better understand how this syndrome affects the ocular system, and to evaluate with greater accuracy and precision the nature of these manifestations in this group of patients. Results: Our study confirms the presence of the commonly cited ocular findings in the general literature regarding the syndrome [hypertelorism (45.5%), congenital cataract (18%), nystagmus (9%), colobomas (9%)] and highlights strabismus (63% of the patients), epiretinal membranes (36%) and myelinated optic nerve fiber layers (36%) as the most frequent ophthalmological findings in this group of patients. Conclusions: The presence of characteristic and frequent ocular signs in the Gorlin- Goltz syndrome could help with the diagnostic process in subjects suspected of having the syndrome who do not yet have a diagnosis. The ophthalmologist has a role as part of a multidisciplinary team in managing these patients. The ophthalmological follow-up that these patients require, can allow, if necessary, a timely therapy that could improve the visual prognosis of such patients

Interaction of Cd(II) and Ni(II) terpyridine complexes with model polynucleotides: a multidisciplinary approach

Two metal complexes of 2,2′:6′,2″-terpyridine (terpy), i.e. Cd(terpy)Cl2 and Ni(terpy)Cl2·3H2O, have been prepared and extensively characterized. The interaction of Cd(terpy)Cl2 with synthetic DNA models, poly(dA-dT)·poly(dA-dT) (polyAT) and poly(dG-dC)·poly(dG-dC) (polyGC), has been studied by CD, fluorescence and UV-vis electronic absorption spectroscopy at several metal/polynucleotide-phosphate ratios and for different NaCl concentrations. All the experimental results indicate an intercalative mechanism of interaction. The optimized geometry of the cadmium complex intercalated between the sixth and seventh base pairs of (AT) and (GC) dodecanucleotide duplexes, obtained by quantum mechanics/molecular mechanics (QM/MM) calculations, lends support to the proposed mechanism. The calculated models provide some additional structural details of the intercalation complex at the molecular level. To evidence the influence of the charge and geometry of the metal complex on the mechanism of interaction with polynucleotides, the nickel complex-polyAT system has been studied to some extent by means of CD and UV-vis spectroscopy, and by thermal melting experiments. The results suggest that the octahedral complex cation [Ni(terpy)(H2O)2Cl]+ interacts with polyAT by partial intercalation assisted by electrostatic interaction with the negative charges of the backbone phosphate groups

The rest-frame UV-to-optical spectroscopy of APM 08279+5255 - BAL classification and black hole mass estimates

We present the analysis of the rest-frame optical-to-UV spectrum of APM 08279+5255, a well-known lensed broad absorption line (BAL) quasar at $z = 3.911$. The spectroscopic data are taken with the optical DOLoRes and near-IR NICS instruments at TNG, and include the previously unexplored range between C III] $\lambda$1910 and [O III] $\lambda\lambda$4959,5007. We investigate the possible presence of multiple BALs by computing "balnicity" and absorption indexes (i.e. BI, BI$_0$ and AI) for the transitions Si IV $\lambda$1400, C IV $\lambda$1549, Al III $\lambda$1860 and Mg II $\lambda$2800. No clear evidence for the presence of absorption features is found in addition to the already known, prominent BAL associated to C IV, which supports a high-ionization BAL classification for APM 08279+5255. We also study the properties of the [O III], H$\beta$ and Mg II emission lines. We find that [O III] is intrinsically weak ($F_{\rm [OIII]}/F_{\rm H\beta} \lesssim 0.04$), as it is typically found in luminous quasars with a strongly blueshifted C IV emission line ($\sim$2500 km s$^{-1}$ for APM 08279+5255). We compute the single-epoch black hole mass based on Mg II and H$\beta$ broad emission lines, finding $M_{\rm BH} = (2 \div 3) \times 10^{10}\mu^{-1}$ M$_\odot$, with the magnification factor $\mu$ that can vary between 4 and 100 according to CO and rest-frame UV-to-mid-IR imaging respectively. Using a Mg II equivalent width (EW)-to-Eddington ratio relation, the EW$_{\rm MgII} \sim 27$ \AA\ measured for APM 08279+5255 translates into an Eddington ratio of $\sim$0.4, which is more consistent with $\mu=4$. This magnification factor also provides a value of $M_{\rm BH}$ that is consistent with recent reverberation-mapping measurements derived from C IV and Si IV.Comment: 10 pages, 4 figures, 4 tables, accepted for publication in A&

A revision of the X-ray absorption nature of the BALQSOs

Broad absorption line quasars (BALQSOs) are key objects for studying the structure and emission/absorption properties of AGN. However, despite their fundamental importance, the properties of BALQSOs are still not well understood. In order to investigate the X-ray nature of these sources, as well as the correlations between X-ray and rest-frame UV properties, we compile a large sample of 88 BALQSOs observed by XMM-Newton. We performed a full X-ray spectral analysis on a sample of 39 sources with higher X-ray spectral quality, and an approximate HR analysis on the remaining sources. Using available optical spectra, we calculate the BALnicity index and investigate the dependence between this optical parameter and different X-ray properties. Using the neutral absorption model, we found that 36% of our BALQSOs have NH < 5x10^21 cm^-2, lower than the expected X-ray absorption for such objects. However, when we used a physically-motivated model for the X-ray absorption in BALQSOs, i.e. ionized absorption, \sim 90% of the objects are absorbed. The absorption properties also suggest that LoBALs may be physically different objects from HiBALs. In addition, we report on a correlation between the ionized absorption column density and BAL parameters. There is evidence (at 98% level) that the amount of X-ray absorption is correlated with the strength of high-ionization UV absorption. This correlation, not previously reported, can be naturally understood in virtually all BALQSO models, as driven by the total amount of gas mass flowing towards the observer.Comment: Accepted by A&A. 12 pages, 8 figures. Added references and corrected typo

Chandra X-Ray Observations of Two Unusual BAL Quasars

We report sensitive Chandra X-ray non-detections of two unusual, luminous Iron Low-Ionization Broad Absorption Line Quasars (FeLoBALs). The observations do detect a non-BAL, wide-binary companion quasar to one of the FeLoBAL quasars. We combine X-ray-derived column density lower limits (assuming solar metallicity) with column densities measured from ultraviolet spectra and CLOUDY photoionization simulations to explore whether constant density slabs at broad line region densities can match the physical parameters of these two BAL outflows, and find that they cannot. In the "overlapping-trough" object SDSS J0300+0048, we measure the column density of the X-ray absorbing gas to be N_H >= 1.8 x 1024 cm-2. From the presence of Fe II UV78 absorption but lack of Fe II UV195/UV196 absorption, we infer the density in that part of the absorbing region to be n_e ~ 106 cm-3. We do find that a slab of gas at that density might be able to explain this object's absorption. In the Fe III-dominant object SDSS J2215-0045, the X-ray absorbing column density of N_H >= 3.4 x 1024 cm-2 is consistent with the Fe III-derived N_H >= 2 x 1022 cm-2 provided the ionization parameter is log U > 1.0 for both the n_e = 1011 cm-3 and n_e = 1012 cm-3 scenarios considered (such densities are required to produce Fe III absorption without Fe II absorption). However, the velocity width of the absorption rules out its being concentrated in a single slab at these densities. Instead, this object's spectrum can be explained by a low density, high ionization and high temperature disk wind that encounters and ablates higher density, lower ionization Fe III-emitting clumps.Comment: 18 pages, 6 figure

Theoretical and experimental study on the O(3P) + 2,5-dimethylfuran reaction in the gas phase

In this work we report a joint experimental and computational study on the 2,5-dimethylfuran oxidation reaction in the gas phase initiated by atomic oxygen O(3P). The experiments have been performed by using vacuum-ultraviolet synchrotron radiation at the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory (LBNL), at a temperature of 550 K and a pressure of 8 Torr. The experimental data were supported by quantum-chemical calculations along with a kinetic model, also taking into account the possible involvement of different magnetic states, performed in the framework of the RRKM theory. Propyne, acetaldehyde, methylglyoxal, dimethylglyoxal, 3-penten-2-one, 2,5-dimethylfuran-3(2H)-one, and 1,2-diacetyl ethylene have been identified as the main primary products arising under the conditions of the experiment. Our computational model suggests that these species can be formed at the concentration and branching ratio experimentally observed only in the presence of a non-negligible fraction of non-thermalized intermediates