University of Alcalá

About: University of Alcalá is a education organization based out in Alcalá de Henares, Spain. It is known for research contribution in the topics: Population & Context (language use). The organization has 10795 authors who have published 20718 publications receiving 410089 citations. The organization is also known as: University of Alcala & University of Alcala de Henares.

Thermal state of permafrost and active-layer monitoring in the Antarctic: advances during the International Polar Year 2007-2009

Abstract: Results obtained during the International Polar Year (IPY) on the thermal state of permafrost and the active layer in the Antarctic are presented, forming part of ANTPAS (‘Antarctic Permafrost and ...

Micromotor-Based High-Yielding Fast Oxidative Detoxification of Chemical Threats

Abstract: Rapid field conversion of chemical weapons into non-toxic products is one of the most challenging tasks in weapons of mass destruction (WMD) science. This is particularly the case for eliminating stockpiles of chemical warfare agents (CWAs) in remote storage field locations, where the use of large quantities of decontaminating reagents, long reaction times, and controlled mechanical agitation is impossible or undesired. New efficient “clean” technologies and (bio)chemical processes are thus sought for detoxifying stored agents, counteracting nerve-agent attacks, and decommissioning chemical weapons. Environmentally friendly solutions of hydrogen peroxide, combined with suitable activators (e.g., bicarbonate), have been shown to be extremely useful for decontaminating a broad spectrum of CWAs to yield nontoxic products. These peroxide-based systems, which rely on the in situ generation of OOH nucleophiles, have recently replaced chlorine-based bleaching processes, which produce undesirable products, and have thus led to effective decontamination of the chemical agents GB (Sarin, isopropyl methylphosphonofluoridate), VX ((S)-[2-(diisopropylamino)ethyl] O-ethyl methylphosphonothioate), GD (Soman, pinacolyl methylphosphonofluoridate), and HD (sulfur mustard). Yet, such an oxidative treatment commonly requires high peroxide concentrations (20–30%; approaching a stoichiometry of 1:50), along with prolonged operation and/or mechanical agitation. Such reaction conditions are not suitable or not desired for eliminating stockpiles of CWAs in remote field settings or hostile storage locations, as large quantities of the reagents may not be transportable on military aircrafts and require special packaging and handling. The efficient elimination of chemical-weapon stockpiles in field locations thus remains a major challenge to the chemistry and defense communities. Herein, we describe a powerful strategy that is based on self-propelled micromotors, for a high-yielding accelerated oxidative decontamination of chemical threats using low peroxide levels and no external agitation. Functionalized synthetic micromotors have recently demonstrated remarkable capabilities in terms of isolation and transport for diverse biomedical and environmental applications, but not in connection to increasing the yield and speed of chemical reactions. The new motor-based method relies on the use of peroxide-driven microtubular engines for the efficient selfmixing of a remediation solution, which dramatically accelerates the decontamination process. Fluid mixing is extremely important for enhancing the yield and speed of a wide range of chemical processes, including decontamination reactions, where quiescent conditions lead to low reaction efficiency and long operations. The observed mixing, which is induced by the peroxide-driven micromotor, is analogous to that reported for the motility of E. coli bacteria, where a large-scale collective motion has been shown to enhance diffusion processes. Enhanced diffusion of passive tracers has also been observed in the presence of catalytic nanowire motors. Although the new micromotor strategy presented herein was applied to the accelerated, high-yielding, and simplified decontamination of organophosphate (OP) nerve agents, the concept could have broad implications for enhancing the efficiency and speed of a wide range of chemical processes in the absence of external agitation. The concept of the micromotor/peroxide-based decontamination of chemical threats is illustrated in Figure 1. This new strategy relies on micromotors without mechanical stirring (Figure 1A). A known number of micromotors were placed in a nerve-agent-contaminated solution, along with hydrogen peroxide (used as the oxidizing agent as well as the micromotor fuel), the peroxide activator (NaHCO3 or NaOH), and the surfactant sodium cholate (NaCh), which was essential for bubble generation. The oxidative conversion of the OP nerve agent into para-nitrophenol (p-NP) was achieved under mild quiescent conditions that involve the in situ generation of OOH nucleophiles with no external stirring (Figure 1B). The decrease in concentration of the OP [*] Dr. J. Orozco, G. Cheng, D. Vilela, Dr. S. Sattayasamitsathit, Prof. R. Vazquez-Duhalt, Dr. G. Vald s-Ram rez, Dr. O. S. Pak, Prof. J. Wang Departments of Nanoengineering and Mechanical Engineering University of California San Diego La Jolla, CA 92093 (USA) E-mail: josephwang@ucsd.edu G. Cheng, Prof. C. Kan Tsinghua University, Beijing, 100084 (China) D. Vilela, Prof. A. Escarpa University of Alcal 28871 Alcal de Henares (Spain)

Longitudinal and radial dependence of solar energetic particle peak intensities: stereo, ace, soho, goes, and messenger observations

Abstract: Simultaneous measurements of solar energetic particle (SEP) events by two or more of the spacecraft located near 1 AU during the rising phase of solar cycle 24 (i.e., STEREO-A, STEREO-B, and near-Earth spacecraft such as ACE, SOHO, and GOES) are used to determine the longitudinal dependence of 71-112 keV electron, 0.7-3 MeV electron, 15-40 MeV proton, and 25-53 MeV proton peak intensities measured in the prompt component of SEP events. Distributions of the peak intensities for the selected 35 events with identifiable solar origin are approximated by the form exp [ – ( – 0)2/2σ2], where is the longitudinal separation between the parent active region and the footpoint of the nominal interplanetary magnetic field (IMF) line connecting each spacecraft with the Sun, 0 is the distribution centroid, and σ determines the longitudinal gradient. The MESSENGER spacecraft, at helioradii R 3. These two cases correspond to SEP events occurring in a complex interplanetary medium that favored the enhancement of peak intensities near Mercury but hindered the SEP transport to 1 AU.

Thermal tolerance patterns across latitude and elevation.

Abstract: Linking variation in species' traits to large-scale environmental gradients can lend insight into the evolutionary processes that have shaped functional diversity and future responses to environmental change. Here, we ask how heat and cold tolerance vary as a function of latitude, elevation and climate extremes, using an extensive global dataset of ectotherm and endotherm thermal tolerance limits, while accounting for methodological variation in acclimation temperature, ramping rate and duration of exposure among studies. We show that previously reported relationships between thermal limits and latitude in ectotherms are robust to variation in methods. Heat tolerance of terrestrial ectotherms declined marginally towards higher latitudes and did not vary with elevation, whereas heat tolerance of freshwater and marine ectotherms declined more steeply with latitude. By contrast, cold tolerance limits declined steeply with latitude in marine, intertidal, freshwater and terrestrial ectotherms, and towards higher elevations on land. In all realms, both upper and lower thermal tolerance limits increased with extreme daily temperature, suggesting that different experienced climate extremes across realms explain the patterns, as predicted under the Climate Extremes Hypothesis. Statistically accounting for methodological variation in acclimation temperature, ramping rate and exposure duration improved model fits, and increased slopes with extreme ambient temperature. Our results suggest that fundamentally different patterns of thermal limits found among the earth's realms may be largely explained by differences in episodic thermal extremes among realms, updating global macrophysiological 'rules'. This article is part of the theme issue 'Physiological diversity, biodiversity patterns and global climate change: testing key hypotheses involving temperature and oxygen'.

Impact of hematologic malignancy and type of cancer therapy on COVID-19 severity and mortality: lessons from a large population-based registry study.

Abstract: Patients with cancer have been shown to have a higher risk of clinical severity and mortality compared to non-cancer patients with COVID-19. Patients with hematologic malignancies typically are known to have higher levels of immunosuppression and may develop more severe respiratory viral infections than patients with solid tumors. Data on COVID-19 in patients with hematologic malignancies are limited. Here we characterize disease severity and mortality and evaluate potential prognostic factors for mortality. In this population-based registry study, we collected de-identified data on clinical characteristics, treatment and outcomes in adult patients with hematologic malignancies and confirmed severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection within the Madrid region of Spain. Our case series included all patients admitted to 22 regional health service hospitals and 5 private healthcare centers between February 28 and May 25, 2020. The primary study outcome was all-cause mortality. We assessed the association between mortality and potential prognostic factors using Cox regression analyses adjusted for age, sex, comorbidities, hematologic malignancy and recent active cancer therapy. Of 833 patients reported, 697 were included in the analyses. Median age was 72 years (IQR 60–79), 413 (60%) patients were male and 479 (69%) and 218 (31%) had lymphoid and myeloid malignancies, respectively. Clinical severity of COVID-19 was severe/critical in 429 (62%) patients. At data cutoff, 230 (33%) patients had died. Age ≥ 60 years (hazard ratios 3.17–10.1 vs 2 comorbidities (1.41 vs ≤ 2), acute myeloid leukemia (2.22 vs non-Hodgkin lymphoma) and active antineoplastic treatment with monoclonal antibodies (2·02) were associated with increased mortality; conventional chemotherapy showed borderline significance (1.50 vs no active therapy). Conversely, Ph-negative myeloproliferative neoplasms (0.33) and active treatment with hypomethylating agents (0.47) were associated with lower mortality. Overall, 574 (82%) patients received antiviral therapy. Mortality with severe/critical COVID-19 was higher with no therapy vs any antiviral combination therapy (2.20). In this series of patients with hematologic malignancies and COVID-19, mortality was associated with higher age, more comorbidities, type of hematological malignancy and type of antineoplastic therapy. Further studies and long-term follow-up are required to validate these criteria for risk stratification.