Spectroscopic identification of r-process nucleosynthesis in a double neutron-star merger.

The merger of two neutron stars is predicted to give rise to three major detectable phenomena: a short burst of γ-rays, a gravitational-wave signal, and a transient optical-near-infrared source powered by the synthesis of large amounts of very heavy elements via rapid neutron capture (the r-process). Such transients, named 'macronovae' or 'kilonovae', are believed to be centres of production of rare elements such as gold and platinum. The most compelling evidence so far for a kilonova was a very faint near-infrared rebrightening in the afterglow of a short γ-ray burst at redshift z = 0.356, although findings indicating bluer events have been reported. Here we report the spectral identification and describe the physical properties of a bright kilonova associated with the gravitational-wave source GW170817 and γ-ray burst GRB 170817A associated with a galaxy at a distance of 40 megaparsecs from Earth. Using a series of spectra from ground-based observatories covering the wavelength range from the ultraviolet to the near-infrared, we find that the kilonova is characterized by rapidly expanding ejecta with spectral features similar to those predicted by current models. The ejecta is optically thick early on, with a velocity of about 0.2 times light speed, and reaches a radius of about 50 astronomical units in only 1.5 days. As the ejecta expands, broad absorption-like lines appear on the spectral continuum, indicating atomic species produced by nucleosynthesis that occurs in the post-merger fast-moving dynamical ejecta and in two slower (0.05 times light speed) wind regions. Comparison with spectral models suggests that the merger ejected 0.03 to 0.05 solar masses of material, including high-opacity lanthanides.

Minimally invasive repair of Morgagni hernia - A multicenter case series.

Children may benefit from minimally invasive surgery (MIS) in the correction of Morgagni hernia (MH). The present study aims to evaluate the outcome of MIS through a multicenter study. National institutions that use MIS in the treatment of MH were included. Demographic, clinical and operative data were analyzed. Thirteen patients with MH (6 males) were operated using similar MIS technique (percutaneous stitches) at a mean age of 22.2±18.3 months. Six patients had chromosomopathies (46%), five with Down syndrome (39%). Respiratory complaints were the most common presentation (54%). Surgery lasted 95±23min. In none of the patients was the hernia sac removed; prosthesis was never used. In the immediate post-operative period, 4 patients (36%) were admitted to intensive care unit (all with Down syndrome); all patients started enteral feeds within the first 24h. With a mean follow-up of 56±16.6 months, there were two recurrences (18%) at the same institution, one of which was repaired with an absorbable suture; both with Down syndrome. The application of MIS in the MH repair is effective even in the presence of comorbidities such as Down syndrome; the latter influences the immediate postoperative recovery and possibly the recurrence rate. Removal of hernia sac does not seem necessary. Non-absorbable sutures may be more appropriate.

Groundwater geochemistry and microbial community structure in the aquifer transition from volcanic to alluvial areas.

Groundwaters may act as sinks or sources of organic and inorganic solutes, depending on the relative magnitude of biochemical mobilizing processes and groundwater-surface water exchanges. The objective of this study was to link the lithological and hydrogeological gradients to the aquatic microbial community structure in the transition from aquifer recharge (volcanic formations) to discharge areas (alluvial deposits). A field-scale analysis was performed along a water table aquifer in which volcanic products decreased in thickness and areal extension, while alluvial deposits became increasingly important. We measured the main groundwater physical parameters and the concentrations of major and trace elements. In addition, the microbial community structure was assessed by estimating the occurrence of total coliforms and Escherichia coli, the prokaryotic abundance, the cytometric and phylogenetic community composition. The overall biogeochemical asset differed along the aquifer flow path. The concentration of total and live prokaryotic cells significantly increased in alluvial waters, together with the percentages of Beta- and Delta-Proteobacteria. The microbial propagation over a theoretical groundwater travel time allowed for the identification of microbial groups shifting significantly in the transition between the two different hydrogeochemical facies. The microbial community structure was intimately associated with geochemical changes, thus it should be further considered in view of a better understanding of groundwater ecology and sustainable management strategies.

[Pediatric Crohn's disease complications]. / Doença de Crohn complicada em idade pediátrica.

This case report describes our experience in treatment of a child with Crohn's disease involvement of ileocecal and sigmoid regions complicated with a severe abdominal wall abscess. A combined therapeutic approach of the acute episode was based on intestinal diversion, abscess drainage, antibiotherapy, nutritional support and post-operative immunosuppression with azathioprine. The definitive treatment of the ileocolonic involvement occurred 6 months after the acute episode and consisted of limited resection, multiple strictureplasties, primar" closure of ileosigmod fistula and undiversion. This operative procedure was followed by a short period of total parenteral nutrition and progressive re-establishment ofenteric nutritional support and immunosuppression. At 18 months follow-up, under low dose azathioprine revealed, a normal growth with a 20 Kg weight gain and 10 cm height gain, no evidence of fistula recurrence or restenosis and suggests the safety of strictureplasty in paediatric patients as a way to conserve as much small bowel as possible.

HIV infection among foreign people involved in HIV-related risk activities and attending an HIV reference centre in Rome: the possible role of counselling in reducing risk behaviour.

Between September 1993 and December 1995, 528 foreign individuals at risk of HIV infection attended the drug treatment centre located in the Santo Spirito Hospital in Rome, undergoing medical examination, HIV testing and counselling. The geographic distribution showed that the majority of the participants were from South America (40.0%), most of whom were transsexual sex workers (from Brazil or Columbia), and from North Africa (37.5%); all the individuals coming from Western and Eastern Europe and the USA were heroin users. The overall HIV prevalence was high (21.6%), though it varied by nationality, ranging from 5.1% among North Africans to 68.3% among Brazilian transsexuals. During the study period, 170 of the individuals returned for at least one follow-up visit. Three seroconversions occurred among the 118 initially HIV-negative immigrants who were retested, all three among the 26 HIV-negative Columbian transsexuals; the seroconversion rate within this group was 10.1 per 100 persons/years. During follow-up, there was no reduction observed in drug-related practices associated with HIV infection, yet a general increase in regular condom use was reported. The increasing number of foreign persons contacting our programme emphasizes the need for easy access to care and treatment for marginalized populations possibly engaging in behaviour at risk for HIV infection. Counselling strategies seem to be relatively effective in promoting safer sex among these population groups.

Nosocomial outbreak of Aspergillus fumigatus infection among patients in a renal unit?

Aspergillus fumigatus is present in the environment worldwide and it is only able to infect debilitated or immunodepressed subjects. Nosocomial outbreaks of A. fumigatus infection have been associated with hospital reconstruction. Spores are released into the environment and are inhaled by immunodepressed patients housed in nearby Medical Units. Specific clinical syndromes are allergic bronchopulmonary aspergillosis and invasive pulmonary aspergillosis with characteristic radiological features. Invasive A. fumigatus infection is commonly fatal, even if promptly diagnosed and treated. Three consecutive cases of A. fumigatus infection occurred in debilitated patients housed in our Renal Unit while building renovation near the Unit was being performed. Two of these patients died and pulmonary and diffuse aspergillosis was found on postmortem examination. The third patient, highly suspected to be infected with Aspergillus, was aggressively and successfully treated with liposomal amphotericin B. Our experience suggests that fungal infections have gained increasing prominence in clinical medicine and they must be considered in chronic debilitated patients including dialysis patients, and that liposomal amphotericin B represents an important advance in the treatment of aspergillosis.

[Identification of staphylococci of clinical importance: evaluation of available commercial kits and technical notes on the reduction of response time and cost of performance]. / Identificazione degli stafilococchi di interesse clinico: valutazione di kits disponibili in commercio e note di tecnica sulla riduzione dei tempi di risposta e costi di esecuzione.

A study was carried out on 150 strains of staphylococci of human origin in order to evaluate the possibility of achieving identification that is accurate, swift and perhaps economical, with the following aims in mind: a) the testing of fast systems for the detection of coagulase of Staphyslide and Sero Stat compared with classical coagulase in a test tube with EDTA and citrate; b) the evaluation of the API Staph system by comparing identification obtained through subculturing the strains in agar P, as suggested by manufacturers, with those that have been streaked directly with material on triptose agar. All the experiments were carried out in both laboratories and in double blindness. The strains of Staphylococcus aureus were 88, 90 and 98% respectively, identified by the Staphyslide, Sero Stat and coagulase in a test tube. The same results were obtained by greatly reducing the amount of the kits reactive substance. The facts show that system can take place in the microbiological laboratory to improve screening processes. The API Staph system identified 96% of all the strains and 89% of negative coagulase. The methods used to identify through primary culture in triptose are mirrored with subculture from agar P. Using this medium to streak urine, one can expect to prepare the recognition of the isolated strains the day before.

[Polycenter evaluation of the break-point system]. / Valutazione policentrica del sistema break-point.

Several research center have been set up to evaluate the system that deals with sensitivity to microbes under Sensititre break-point. The study has been broken down as follows: the break-point system was compared with the agar diffusion according to Bauer et al., using 1180 strains of fast-growing Gram-negative bacteria; a limited number of strains (176) have been used to compare the Sensititre break-point and the Sensititre MIC; results have been obtained testing 448 strains processed by break-point with correct inoculum and with simplified inoculum, from a colony; an investigation has been carried out on the time and cost of the break-point functioning. Having taken the Bauer system and others are compared them with the break-point, it was seen that their total agreement was 90.3% with 2% of major disagreement. The total major disagreement between Sensititre MIC and Sensititre break-point was 2.7%. The total major disagreement of the latter was largely the result of cephalotin (21%) on the Escherichia coli strains. An initial research centre has been formed to try to trow light upon the origins of such disagreements and we are now pleased to report back their initial findings. The preparation and reading of a test with the Bauer system and others takes about 18 minutes and costs 5600 Lit; a break-point test takes 10 minutes and costs 4500 Lit.