Tracking the 2022 Hunga Tonga-Hunga Ha'apai Aerosol Cloud in the Upper and Middle Stratosphere Using Space-Based Observations.

On 15 January 2022, the submarine Hunga Tonga volcanic eruption lofted materials high into the upper stratosphere, reaching a record-breaking altitude of ∼58 km, unprecedented in the satellite observations era. Within two weeks, the bulk of the injected material circulated the globe between 20-30 km altitude, as observed by satellite instruments. We estimate that the stratospheric aerosol optical depth (sAOD) is the largest since the Pinatubo eruption and is at least twice as great as the sAOD after the 2015 Calbubo eruption despite the similar SO2 injection from that eruption. We use space-based observations to monitor the Hunga-Tonga volcanic plume evolution and transport at different altitudes as it circulates the globe. While the main aerosol layer remains trapped in the tropical pipe, small parts have already made it to both the northern and southern hemisphere poles by April, which is almost certain to influence this year's ozone hole.

A method for measuring macroscopic cross-sections for thermal neutrons.

A method was proposed for measuring macroscopic absorption and scattering cross-sections for thermal neutrons. It is based on a Pu-Be neutron source and He-3 neutron detectors assembly. A beam of neutrons was obtained from the source imbedded in a water tank. The He-3 detectors oriented inside the sample and at 180° and 0° with respect to the incident neutron beam were used to register neutrons after interaction with the samples. Neutron count rates (detectors responses) were obtained for large (5.5l) as well as small (1.3l) volumes of standard samples. Sensitivities of the results obtained for the large and small samples were compared. A semi-empirical model was proposed to fit the results. It describes the relative detector responses in terms of a dimensionless variable which depends on the geometrical parameters and cross section of the standard samples used. The model successfully fits the results obtained. Advantages and limitations of the method were discussed.

Ground-based assessment of the bias and long-term stability of fourteen limb and occultation ozone profile data records.

The ozone profile records of a large number of limb and occultation satellite instruments are widely used to address several key questions in ozone research. Further progress in some domains depends on a more detailed understanding of these data sets, especially of their long-term stability and their mutual consistency. To this end, we made a systematic assessment of fourteen limb and occultation sounders that, together, provide more than three decades of global ozone profile measurements. In particular, we considered the latest operational Level-2 records by SAGE II, SAGE III, HALOE, UARS MLS, Aura MLS, POAM II, POAM III, OSIRIS, SMR, GOMOS, MIPAS, SCIAMACHY, ACE-FTS and MAESTRO. Central to our work is a consistent and robust analysis of the comparisons against the ground-based ozonesonde and stratospheric ozone lidar networks. It allowed us to investigate, from the troposphere up to the stratopause, the following main aspects of satellite data quality: long-term stability, overall bias, and short-term variability, together with their dependence on geophysical parameters and profile representation. In addition, it permitted us to quantify the overall consistency between the ozone profilers. Generally, we found that between 20-40 km the satellite ozone measurement biases are smaller than ±5 %, the short-term variabilities are less than 5-12% and the drifts are at most ±5% decade-1 (or even ±3 % decade-1 for a few records). The agreement with ground-based data degrades somewhat towards the stratopause and especially towards the tropopause where natural variability and low ozone abundances impede a more precise analysis. In part of the stratosphere a few records deviate from the preceding general conclusions; we identified biases of 10% and more (POAM II and SCIAMACHY), markedly higher single-profile variability (SMR and SCIAMACHY), and significant long-term drifts (SCIAMACHY, OSIRIS, HALOE, and possibly GOMOS and SMR as well). Furthermore, we reflected on the repercussions of our findings for the construction, analysis and interpretation of merged data records. Most notably, the discrepancies between several recent ozone profile trend assessments can be mostly explained by instrumental drift. This clearly demonstrates the need for systematic comprehensive multi-instrument comparison analyses.

(R)-methanandamide: a chiral novel anandamide possessing higher potency and metabolic stability.

Four chiral congeners of arachidonylethanolamide (anandamide) have been synthesized and evaluated for (a) their ability to bind to the cannabinoid receptor in rat forebrain membranes and (b) their pharmacological potency as measured by the compounds' ability to inhibit electrically-evoked contractions of the mouse vas deferens. The lead analog was also tested for its potency in vivo. Of the analogs tested, (R)-(+)-arachidonyl-1'-hydroxy-2'-propylamide [(R)-methanandamide] exhibited the highest affinity for the cannabinoid receptor with a Ki of 20 +/- 1.6 nM, 4-fold lower than that of anandamide (Ki = 78 +/- 2 nM). Moreover, determination of the cannabinoid binding affinity in the presence and absence of the protease inhibitor phenylmethanesulfonyl fluoride (PMSF) revealed that (R)-methanandamide possesses a remarkable stability to aminopeptidase hydrolysis. Pharmacological studies on mouse isolated vasa deferentia demonstrated that all four analogs produce concentration-related inhibition of the twitch response and the order of potency is the same as the rank order of the affinities of these agonists for cannabinoid binding sites. Furthermore, experiments with mice have demonstrated that (R)-methanandamide also possesses cannabimimetric properties in vivo, as established by the four tests of hypothermia, hypokinesia, ring immobility, and antinociception.

Head group analogs of arachidonylethanolamide, the endogenous cannabinoid ligand.

Several analogs of an endogenous cannabimimetic, arachidonylethanolamide (anandamide), were synthesized to study the structural requirements of the ethanolamide head group. CB1 receptor affinities of the analogs were evaluated by a standard receptor binding assay using tritiated CP-55,940 as the radioligand and compared to anandamide which was shown to have a Ki of 78 nM. Replacement of the amide carbonyl oxygen by a sulfur atom had a detrimental effect on the CB1 affinity. The thio analogs of both anandamide and (R)-methanandamide showed very weak affinity for CB1. The secondary nature of the amidic nitrogen was also shown to be important for affinity, indicating a possible hydrogen-bonding interaction between the amide NH and the receptor. Introduction of a phenolic moiety in the head group resulted in the loss of receptor affinity except when a methylene spacer was introduced between the amidic nitrogen and the phenol. A select group of analogs were also tested for their affinity for the CB2 receptor using a mouse spleen preparation and were found to possess low affinities for the CB2 sites. Notably, anandamide and (R)-methanandamide demonstrated high selectivity for the CB1 receptor. Overall, the data presented here show that structural requirements of the head group of anandamide are rather stringent.

Descending necrotizing mediastinitis.

Descending necrotizing mediastinitis (DNM) is a rare but severe life threatening complication of oropharyngeal infections. We report a young lady who had severe pharyngitis complicated by anterior neck infection that descended to the mediastinum causing necrotizing mediastinitis. The course of her illness was complicated with septic shock, acute kidney injury, tracheo-esophageal fistula, and critical illness polyneuropathy. There was considerable delay in her diagnosis; however, she survived after aggressive surgical intervention, wide spectrum antibiotics, and appropriate intensive care management. Early and repeated chest imaging using computed tomography was vital for the detection and follow up of this case. There is a need to increase physicians' awareness of this condition that can complicate odontogentic or pharyngeal infection, procedures, or trauma.

Un análisis bibliométrico de los trabajos libres de psiquiatría presentados a congresos de la Sociedad Chilena de neurología, psiquiatría y neurocirugía entre 2000 y 2009 / A bibliometric analysis of free submissions presented to the psychiatry section of the congresses of the Sociedad Chilena de neurología, psiquiatría y neurocirugía, 2000-2009

Introduction: Bibliometry is the discipline that measures the bibliographic production in a given scientific area; in Chile there are few studies documenting the themes and trends in Mental health research. Method: A quantitative analysis is performed of the 992 papers published in the Abstracts Book in the SONEPSYN meetings between 2000 and 2009. The most productive groups are mentioned, and a classification of main research themes according to the index of the Tratado de Psiquiatría edited by Heerlein et al. Results: The most frequent themes were Affective Disorders, (14,3 percent), Liaison and General Hospital Psychiatry (8,6 percent), Epidemiology and Classification (6,6 percent), Validation and use of diagnostic and psychometric scales (5,6 percent), followed by antidepressant use and teaching with 1,2 percent each. Most presentations were prepared in university settings (48 percent) or in hospitals (35 percent), with a strong concentration in the Metropolitan Region (80,4 percent) and the VIII Region (8,3 percent). Conclusions: There is an increasing number of psychiatric papers presented from 2000 to 2009, with the Metropolitan Region of Santiago the area that present the higher number of research work (76,31 percent).There is a low number of collaborative research: 88,3 percent of the works were presented by a single institution. 9,6 percent (this is 59 papers) were presented by two, and 2,1 percent (13 papers) by three. Affective disorders were the most researched area; followed by use of antipsychotics and liaision, community, and child and adolescent psychiatry.

Introducción: La bibliometría es la disciplina que mide la producción bibliográfica en un área científica determinada y en Chile hay pocos estudios que documenten los temas y tendencias de la producción en Salud Mental. Método: Se hace un análisis cuantitativo de los 992 trabajos publicados en los libros de resúmenes de los Congresos entre los años 2000y 2009. Se describen los grupos más productivos, así como se clasifican los temas de acuerdo a los títulos de los trabajos, al índice del Tratado de Psiquiatría editado por Heerlein y Cols. Resultados: Los temas más frecuentes eran los del trastornos del ánimo (14,3 por ciento), psiquiatría de enlace y hospital general (8,6 por ciento), epidemiología y clasificación (6,6 por ciento), validación y aplicación de instrumentos diagnósticos y de medición psicológica (5,6 por ciento), y los menos frecuentes antidepresivos y docencia con 1,2 por ciento cada uno. La mayoría de las presentaciones correspondieron a centros universitarios (48 por ciento) u hospitalarios (35 por ciento), con una importante concentración en la Región Metropolitana (80,4 por ciento) y la VIII Región (8,3 por ciento). Conclusiones: Se observa un número creciente de presentaciones desde el año 2000 hasta el 2009, siendo la RM quien presenta el mayor número de investigaciones con un 76,31 por ciento, llama la atención la baja asociatividad en las presentaciones: un 88,3 por ciento de los trabajos fueron presentados por una sola institucion. 9,6 por ciento (o sea 59 trabajos) fueron presentados por dos, y 2,1 por ciento (13 trabajos) por tres instituciones.Los trastornos del ánimo son el sub-tema más analizado, seguido por antipsicóticos y psiquiatría de enlace, comunitaria e infanto-juvenil.