Porosity measurements of interstellar ice mixtures using optical laser interference and extended effective medium approximations

Aims. This article aims to provide an alternative method of measuring the porosity of multi-phase composite ices from their refractive indices and of characterising how the abundance of a premixed contaminant (e.g., CO2) affects the porosity of water-rich ice mixtures during omni-directional deposition. Methods. We combine optical laser interference and extended effective medium approximations (EMAs) to measure the porosity of three astrophysically relevant ice mixtures: H2O:CO2=10:1, 4:1, and 2:1. Infrared spectroscopy is used as a benchmarking test of this new laboratory-based method. Results. By independently monitoring the O-H dangling modes of the different water-rich ice mixtures, we confirm the porosities predicted by the extended EMAs. We also demonstrate that CO2 premixed with water in the gas phase does not significantly affect the ice morphology during omni-directional deposition, as long as the physical conditions favourable to segregation are not reached. We propose a mechanism in which CO2 molecules diffuse on the surface of the growing ice sample prior to being incorporated into the bulk and then fill the pores partly or completely, depending on the relative abundance and the growth temperature.Comment: 9 pages, 6 figures, 1 table. Accepted for publication in A&

An analysis of interplanetary solar radio emissions associated with a coronal mass ejection

Coronal mass ejections (CMEs) are large-scale eruptions of magnetized plasma that may cause severe geomagnetic storms if Earth-directed. Here we report a rare instance with comprehensive in situ and remote sensing observa- tions of a CME combining white-light, radio, and plasma measurements from four different vantage points. For the first time, we have successfully applied a radio direction-finding technique to an interplanetary type II burst detected by two identical widely separated radio receivers. The derived locations of the type II and type III bursts are in general agreement with the white light CME recon- struction. We find that the radio emission arises from the flanks of the CME, and are most likely associated with the CME-driven shock. Our work demon- strates the complementarity between radio triangulation and 3D reconstruction techniques for space weather applications

Recurrent Primary Intrasellar Paraganglioma

We describe a case of an 81-year-old male presenting with bitemporal visual field defects and blurry vision in the right eye. The patient was found to have a recurrent primary paraganglioma in the sellar and suprasellar region requiring a repeat transsphenoidal endoscopic resection. Immunohistochemical examination confirmed paraganglioma with the classic zellballen appearance which stained positive for chromogranin, synaptophysin, and S-100 in the periphery. Paragangliomas (PGLs) in the sella turcica are a rare entity; only 19 cases have ever been reported in the literature. PGLs in the sellar region are often misdiagnosed or diagnosed in a delayed fashion. Earlier diagnosis of this locally aggressive tumor and meticulous debulking can prevent morbidity secondary to the tumor's compressive effects. This report highlights the effectiveness of surgical interventions in treatment of paragangliomas. More research is still needed to determine the need for adjuvant therapies such as radiation

No Changes in Human Immunodeficiency Virus (HIV) Suppression and Inflammatory Markers in Cerebrospinal Fluid in Patients Randomly Switched to Dolutegravir Plus Lamivudine (Spanish HIV/AIDS Research Network, PreEC/RIS 62)

A major concern of HIV dual therapy is a potential lower efficacy in viral reservoirs, especially in the central nervous system (CNS). We evaluated HIV RNA, neuronal injury and inflammatory biomarkers and dolutegravir (DTG) exposure in cerebrospinal fluid (CSF) in patients switching to DTG+lamivudine (3TC). All participants maintained viral suppression in plasma and CSF at week 48. We observed no increase in CSF markers of inflammation or neuronal injury. Median (IQR) total and unbound DTG in CSF were 7.3(5.9-8.4) ng/mL and 1.7(1.2-1.9) ng/mL, respectively. DTG+3TC may maintain viral control without changes in inflammatory/injury markers within the CNS reservoir