Objectives To analyse the characteristics and predictors of death in hospitalized patients with coronavirus disease 2019 (COVID-19) in Spain. Methods A retrospective observational study was performed of the first consecutive patients hospitalized with COVID-19 confirmed by real-time PCR assay in 127 Spanish centres until 17 March 2020. The follow-up censoring date was 17 April 2020. We collected demographic, clinical, laboratory, treatment and complications data. The primary endpoint was all-cause mortality. Univariable and multivariable Cox regression analyses were performed to identify factors associated with death. Results Of the 4035 patients, male subjects accounted for 2433 (61.0%) of 3987, the median age was 70 years and 2539 (73.8%) of 3439 had one or more comorbidity. The most common symptoms were a history of fever, cough, malaise and dyspnoea. During hospitalization, 1255 (31.5%) of 3979 patients developed acute respiratory distress syndrome, 736 (18.5%) of 3988 were admitted to intensive care units and 619 (15.5%) of 3992 underwent mechanical ventilation. Virus- or host-targeted medications included lopinavir/ritonavir (2820/4005, 70.4%), hydroxychloroquine (2618/3995, 65.5%), interferon beta (1153/3950, 29.2%), corticosteroids (1109/3965, 28.0%) and tocilizumab (373/3951, 9.4%). Overall, 1131 (28%) of 4035 patients died. Mortality increased with age (85.6% occurring in older than 65 years). Seventeen factors were independently associated with an increased hazard of death, the strongest among them including advanced age, liver cirrhosis, low age-adjusted oxygen saturation, higher concentrations of C-reactive protein and lower estimated glomerular filtration rate. Conclusions Our findings provide comprehensive information about characteristics and complications of severe COVID-19, and may help clinicians identify patients at a higher risk of death.

To the extent that geography correlates with particular environmental parameters, the geographical distribution of phylogenetically related social and nonsocial organisms should shed light on the conditions that lead to sociality versus nonsociality. Social spiders are notorious for being concentrated in tropical regions of the world, occupying a set of habitats more restricted than those available to the phylogenetic lineages in which they occur. Here we document a parallel pattern involving elevation in the spider genus Anelosimus in America and describe the biology of a newly discovered social species found at what appears to be the altitudinal edge of sociality in the genus. We show that this is a cooperative permanent-social species with highly female-biased sex ratios but colonies that are one to two orders of magnitude smaller than those of a low-elevation congener of similar body size. We suggest that the absence of subsocial Anelosimus species in the lowland rain forest may be due to an increased probability of maternal death in this habitat due to greater predation and/or precipitation, while absence of a sufficient supply of large insects at high elevations or latitudes may restrict social species to low- to midelevation tropical moist forests. We refer to these as the "maternal survival" and "prey size" hypotheses, respectively, and suggest that both in combination may explain the geographical distribution of sociality in the genus.

The effects of ultrasound treatment on the mean particle size, crystal structure, crystallite dimensions and specific surface area of natural muscovite and biotite samples have been investigated. Sonication of macroscopic flakes of muscovite and biotite produced a drastic particle-size reduction. The conditions for the preparation of micron and submicron-sized muscovite and biotite particles of narrow particle-size distribution by sonochemistry are described. The effect of sonication on particle-size reduction is more significant for muscovite than for biotite. Thus, for long sonication times (100 h), submicron and micron particles are predominant in muscovite and biotite, respectively. The resulting materials are crystalline, as assayed by X-ray diffraction, only broadening of the diffraction lines due to size-reduction was observed. Nuclear magnetic resonance studies revealed that the coordination of Al and Si was not modified by the treatment. Chemical analysis showed that the composition of the sample was not affected by the sonication except for a small contamination by Ti from the tip cup of the sonication instrument.

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