SOMATIC CELL COUNTS IN RAW MILK CONTAMINATED WITH ANTIBIOTIC RESIDUES

El presente estudio tuvo como objetivo evaluar el recuento de células somáticas (RCS) en muestras de leche fresca contaminadas por antibióticos en la cuenca de Arequipa. Se recolectó 1814 muestras de leche en la estación de verano del año 2009, de las cuales 59 resultaron contaminadas con antibióticos. Los valores de RCS de las muestras contaminadas se clasificaron en cinco rangos de acuerdo a condiciones fisiológicas y requisitos de calidad de la leche fresca. El promedio del RCS fue de 1520 ± 1173 x 103 células/ml, habiendo diferencias significativas entre rangos (p< 0.01).The objective of the present study was to evaluate the somatic cell count (SCC) inraw milk samples contaminated with antibiotics in Arequipa milkshed. A total of 1814 werecollected in summer 2009, and 59 of them resulted contaminated with antibiotics. SCCvalues from contaminated samples were stratified in five levels according to physiologicalstatus and milk quality requirements. The average SCC was 1520 ± 1173 x 10 3 cel/ml.Significant differences were found between levels of SCC (p<0.01)

Differential changes in myocardial performance index and its time intervals in donors and recipients of twin-to-twin transfusion syndrome before and after laser therapy.

OBJECTIVE: To evaluate left myocardial performance index (MPI) and time intervals in fetuses with twin-to-twin transfusion syndrome (TTTS) before and after laser surgery. METHODS: Fifty-one fetal pairs with TTTS and 47 uncomplicated monochorionic twin pairs were included. Left ventricular isovolumetric contraction time (ICT), ejection time (ET), and isovolumetric relaxation time (IRT) were measured using conventional Doppler. RESULTS: Recipients showed prolonged ICT (46 ± 12 vs. 31 ± 8 vs. 30 ± 5 ms; p < 0.001) and IRT (51 ± 9 vs. 43 ± 8 vs. 43 ± 5 ms; p < 0.001) and higher MPI (0.57 ± 0.12 vs. 0.47 ± 0.09 vs. 0.44 ± 0.05; p < 0.001) than donors and controls. Donors showed shorter ET than recipients and controls (157 ± 12 vs. 169 ± 10 vs. 168 ± 10 ms; p < 0.001) and higher MPI than controls (0.47 ± 0.09 vs. 0.44 ± 0.05; p = 0.006). Preoperative MPI changes were observed in all TTTS stages. Time intervals partially improved after surgery. CONCLUSION: Donor and recipient twins had higher MPI due to different changes in the time intervals, possibly reflecting the state of hypovolemia in the donor and hypervolemia and pressure overload in the recipient

Pressure-induced amorphization of YVO4:Eu3+ nanoboxes

This is an author-created, un-copyedited version of an article published in Nanotechnology. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at http://dx.doi.org/10.1088/0957-4484/27/2/025701A structural transformation from the zircon-type structure to an amorphous phase has been found in YVO4:Eu3+ nanoboxes at high pressures above 12.7 GPa by means of x-ray diffraction measurements. However, the pair distribution function of the high-pressure phase shows that the local structure of the amorphous phase is similar to the scheelite-type YVO4. These results are confirmed both by Raman spectroscopy and Eu3+ photoluminescence which detect the phase transition to a scheelite-type structure at 10.1 and 9.1 GPa, respectively. The irreversibility of the phase transition is observed with the three techniques after a maximum pressure in the upstroke of around 20 GPa. The existence of two D-5(0)-> F-7(0) photoluminescence peaks confirms the existence of two local environments for Eu3+, at least for the low-pressure phase. One environment is the expected for substituting Y3+ and the other is likely a disordered environment possibly found at the surface of the nanoboxes.This work has been performed under financial support from Spanish MINECO under the National Program of Materials (MAT2013-46649-C4-1/2/3/4-P) and the Consolider-Ingenio 2010 Program (MALTA CSD2007-00045). Funding by the Fundacion Caja Canarias (ENER-01) and the EU-FEDER funds is also acknowledged. JR-F thanks the Alexander von Humboldt Foundation for a postdoctoral fellowship and NS thanks the German Research Foundation (DFG) for financial support (Project RA2585/1-1). We acknowledge Diamond Light Source for time on beamline I15 under proposals EE3652 and EE6517. Parts of this research were carried out at the light source PETRA III at DESY (Hamburg), a member of the Helmholtz Association (HFG). We would like to thank H-P Liermann and W Morgenroth for assistance in using beamline P02.2.Ruiz Fuertes, J.; Gomis, O.; León Luis, SF.; Schrodt, N.; Manjón Herrera, FJ.; Ray, S.; Santamaría Pérez, D.... (2016). Pressure-induced amorphization of YVO4:Eu3+ nanoboxes. Nanotechnology. 27(2):025701-1-025701-8. https://doi.org/10.1088/0957-4484/27/2/025701S025701-1025701-8272Piot, L., Le Floch, S., Cornier, T., Daniele, S., & Machon, D. (2013). Amorphization in Nanoparticles. The Journal of Physical Chemistry C, 117(21), 11133-11140. doi:10.1021/jp401121cZhang, F. X., Wang, J. W., Lang, M., Zhang, J. M., Ewing, R. C., & Boatner, L. A. (2009). High-pressure phase transitions ofScPO4andYPO4. Physical Review B, 80(18). doi:10.1103/physrevb.80.184114Lacomba-Perales, R., Errandonea, D., Meng, Y., & Bettinelli, M. (2010). High-pressure stability and compressibility ofAPO4(A=La, Nd, Eu, Gd, Er, and Y) orthophosphates: An x-ray diffraction study using synchrotron radiation. Physical Review B, 81(6). doi:10.1103/physrevb.81.064113Yuan, H., Wang, K., Li, S., Tan, X., Li, Q., Yan, T., … Zou., B. (2012). Direct Zircon-to-Scheelite Structural Transformation in YPO4 and YPO4:Eu3+ Nanoparticles Under High Pressure. The Journal of Physical Chemistry C, 116(46), 24837-24844. doi:10.1021/jp3088995Mishra, A. K., Garg, N., Pandey, K. K., Shanavas, K. V., Tyagi, A. K., & Sharma, S. M. (2010). Zircon-monoclinic-scheelite transformation in nanocrystalline chromates. Physical Review B, 81(10). doi:10.1103/physrevb.81.104109Wang, L., Yang, W., Ding, Y., Ren, Y., Xiao, S., Liu, B., … Mao, H. (2010). Size-Dependent Amorphization of NanoscaleY2O3at High Pressure. Physical Review Letters, 105(9). doi:10.1103/physrevlett.105.095701Mukherjee, S., Kim, K., & Nair, S. (2007). Short, Highly Ordered, Single-Walled Mixed-Oxide Nanotubes Assemble from Amorphous Nanoparticles. Journal of the American Chemical Society, 129(21), 6820-6826. doi:10.1021/ja070124cŞopu, D., Albe, K., Ritter, Y., & Gleiter, H. (2009). From nanoglasses to bulk massive glasses. Applied Physics Letters, 94(19), 191911. doi:10.1063/1.3130209Ozawa, L., & Itoh, M. (2003). Cathode Ray Tube Phosphors. Chemical Reviews, 103(10), 3835-3856. doi:10.1021/cr0203490Zhu, Y., Xu, W., Zhang, H., Wang, W., Tong, L., Xu, S., … Song, H. (2012). Highly modified spontaneous emissions in YVO4:Eu3+ inverse opal and refractive index sensing application. Applied Physics Letters, 100(8), 081104. doi:10.1063/1.3688167Khan, A. F., Haranath, D., Yadav, R., Singh, S., Chawla, S., & Dutta, V. (2008). Controlled surface distribution and luminescence of YVO4:Eu3+ nanophosphor layers. Applied Physics Letters, 93(7), 073103. doi:10.1063/1.2973163Cho, Y.-S., & Huh, Y.-D. (2011). Preparation of Transparent Red-Emitting YVO4:Eu Nanophosphor Suspensions. Bulletin of the Korean Chemical Society, 32(1), 335-337. doi:10.5012/bkcs.2011.32.1.335Jayaraman, A., Kourouklis, G. A., Espinosa, G. P., Cooper, A. S., & Van Uitert, L. G. (1987). A high-pressure Raman study of yttrium vanadate (YVO4) and the pressure-induced transition from the zircon-type to the scheelite-type structure. Journal of Physics and Chemistry of Solids, 48(8), 755-759. doi:10.1016/0022-3697(87)90072-2Wang, X., Loa, I., Syassen, K., Hanfland, M., & Ferrand, B. (2004). Structural properties of the zircon- and scheelite-type phases ofYVO4at high pressure. Physical Review B, 70(6). doi:10.1103/physrevb.70.064109Manjón, F. J., Rodríguez-Hernández, P., Muñoz, A., Romero, A. H., Errandonea, D., & Syassen, K. (2010). Lattice dynamics ofYVO4at high pressures. Physical Review B, 81(7). doi:10.1103/physrevb.81.075202Boehler, R. (2006). New diamond cell for single-crystal x-ray diffraction. Review of Scientific Instruments, 77(11), 115103. doi:10.1063/1.2372734Mao, H. K., Xu, J., & Bell, P. M. (1986). Calibration of the ruby pressure gauge to 800 kbar under quasi-hydrostatic conditions. Journal of Geophysical Research, 91(B5), 4673. doi:10.1029/jb091ib05p04673Hammersley, A. P., Svensson, S. O., Hanfland, M., Fitch, A. N., & Hausermann, D. (1996). Two-dimensional detector software: From real detector to idealised image or two-theta scan. High Pressure Research, 14(4-6), 235-248. doi:10.1080/08957959608201408Holland, T. J. B., & Redfern, S. A. T. (1997). Unit cell refinement from powder diffraction data: the use of regression diagnostics. Mineralogical Magazine, 61(404), 65-77. doi:10.1180/minmag.1997.061.404.07Kraus, W., & Nolze, G. (1996). POWDER CELL – a program for the representation and manipulation of crystal structures and calculation of the resulting X-ray powder patterns. Journal of Applied Crystallography, 29(3), 301-303. doi:10.1107/s0021889895014920Toby, B. H. (2001). EXPGUI, a graphical user interface forGSAS. Journal of Applied Crystallography, 34(2), 210-213. doi:10.1107/s0021889801002242Qiu, X., Thompson, J. W., & Billinge, S. J. L. (2004). PDFgetX2: a GUI-driven program to obtain the pair distribution function from X-ray powder diffraction data. Journal of Applied Crystallography, 37(4), 678-678. doi:10.1107/s0021889804011744Chupas, P. J., Qiu, X., Hanson, J. C., Lee, P. L., Grey, C. P., & Billinge, S. J. L. (2003). Rapid-acquisition pair distribution function (RA-PDF) analysis. Journal of Applied Crystallography, 36(6), 1342-1347. doi:10.1107/s0021889803017564Farrow, C. L., Juhas, P., Liu, J. W., Bryndin, D., Božin, E. S., Bloch, J., … Billinge, S. J. L. (2007). PDFfit2 and PDFgui: computer programs for studying nanostructure in crystals. Journal of Physics: Condensed Matter, 19(33), 335219. doi:10.1088/0953-8984/19/33/335219Trenque, I., Mornet, S., Duguet, E., & Gaudon, M. (2013). New Insights into Crystallite Size and Cell Parameters Correlation for ZnO Nanoparticles Obtained from Polyol-Mediated Synthesis. Inorganic Chemistry, 52(21), 12811-12817. doi:10.1021/ic402152fLangford, J. I., & Wilson, A. J. C. (1978). Scherrer after sixty years: A survey and some new results in the determination of crystallite size. Journal of Applied Crystallography, 11(2), 102-113. doi:10.1107/s0021889878012844Klotz, S., Chervin, J.-C., Munsch, P., & Le Marchand, G. (2009). Hydrostatic limits of 11 pressure transmitting media. Journal of Physics D: Applied Physics, 42(7), 075413. doi:10.1088/0022-3727/42/7/075413Jeong, I.-K., Proffen, T., Mohiuddin-Jacobs, F., & Billinge, S. J. L. (1999). Measuring Correlated Atomic Motion Using X-ray Diffraction. The Journal of Physical Chemistry A, 103(7), 921-924. doi:10.1021/jp9836978Frogley, M. D., Sly, J. L., & Dunstan, D. J. (1998). Pressure dependence of the direct band gap in tetrahedral semiconductors. Physical Review B, 58(19), 12579-12582. doi:10.1103/physrevb.58.12579Birch, F. (1978). Finite strain isotherm and velocities for single-crystal and polycrystalline NaCl at high pressures and 300°K. Journal of Geophysical Research, 83(B3), 1257. doi:10.1029/jb083ib03p01257Popescu, C., Sans, J. A., Errandonea, D., Segura, A., Villanueva, R., & Sapiña, F. (2014). Compressibility and Structural Stability of Nanocrystalline TiO2 Anatase Synthesized from Freeze-Dried Precursors. Inorganic Chemistry, 53(21), 11598-11603. doi:10.1021/ic501571uChen, G., Stump, N. A., Haire, R. G., Peterson, J. R., & Abraham, M. M. (1992). Pressure-induced phase transition in YVO4:Eu3+: A luminescence study at high pressure. Journal of Physics and Chemistry of Solids, 53(10), 1253-1257. doi:10.1016/0022-3697(92)90241-5Rivera-López, F., Martín, I. R., Da Silva, I., González-Silgo, C., Rodríguez-Mendoza, U. R., Lavín, V., … Fernández-Urban, J. (2006). Analysis of the Eu3+emission in a SrWO4laser matrix under pressure. High Pressure Research, 26(4), 355-359. doi:10.1080/08957950601105085Dieke, G. H., & Crosswhite, H. M. (1963). The Spectra of the Doubly and Triply Ionized Rare Earths. Applied Optics, 2(7), 675. doi:10.1364/ao.2.000675Lavı́n, V., Babu, P., Jayasankar, C. K., Martı́n, I. R., & Rodrı́guez, V. D. (2001). On the local structure of Eu3+ ions in oxyfluoride glasses. Comparison with fluoride and oxide glasses. The Journal of Chemical Physics, 115(23), 10935-10944. doi:10.1063/1.1420731Peacock, R. D. (s. f.). The intensities of lanthanide f ↔ f transitions. Rare Earths, 83-122. doi:10.1007/bfb0116556Oomen, E. W. J. L., & van Dongen, A. M. A. (1989). Europium (III) in oxide glasses. Journal of Non-Crystalline Solids, 111(2-3), 205-213. doi:10.1016/0022-3093(89)90282-2Song, H., Chen, B., Peng, H., & Zhang, J. (2002). Light-induced change of charge transfer band in nanocrystalline Y2O3:Eu3+. Applied Physics Letters, 81(10), 1776-1778. doi:10.1063/1.1501441Ray, S., León-Luis, S. F., Manjón, F. J., Mollar, M. A., Gomis, Ó., Rodríguez-Mendoza, U. R., … Lavín, V. (2014). Broadband, site selective and time resolved photoluminescence spectroscopic studies of finely size-modulated Y2O3:Eu3+ phosphors synthesized by a complex based precursor solution method. Current Applied Physics, 14(1), 72-81. doi:10.1016/j.cap.2013.07.02

Interleukin-10 polymorphisms in Spanish IgA deficiency patients: a case-control and family study

BACKGROUND: IgA deficiency (IgAD) is the most common primary immunodeficiency in Caucasians. Genetic and environmental factors are suspected to be involved in the development of the disease. Interleukin-10 (IL-10) is a cytokine with stimulatory activity on immunoglobulin production and it may be an important regulator in IgAD pathogenesis. The IL-10 gene contains several single nucleotide polymorphisms (SNPs) and two polymorphic microsatellites located in the 5'-flanking region. Our aim was to ascertain if any of these polymorphic markers are associated or linked to IgAD in Spanish patients. METHODS: We genotyped 278 patients with IgAD and 573 ethnically matched controls for the microsatellites IL-10R and IL-10G and for three single nucleotide polymorphisms at positions -1082, -819 and -592 in the proximal promoter of the gene. We also included in this study the parents of 194 patients in order to study the IL-10 haplotypes transmitted and not transmitted to the affected offspring. RESULTS: The only allele where a significant difference was observed in the comparison between IgA deficiency patients and controls was the IL-10G12 allele (OR = 1.58 and p = 0.021). However, this p value could not withstand a Bonferroni correction. None of the IL-10R or promoter SNP alleles was found at a different frequency when patients were compared with controls. CONCLUSION: Our data do not show any significant difference in IL-10 polymorphism frequencies between control and IgAD patient samples. Their haplotype distribution among patients and controls was also equivalent and therefore these microsatellites and SNPs do not seem to influence IgAD susceptibility

Compressibility systematics of calcite-type borates : An experimental and theoretical structural study on ABO3 (A = Al, Sc, Fe and In)

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry C , copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/jp4124259The structural properties of calcite-type orthoborates ABO(3) (A = Al, Fe, Sc, and In) have been investigated at high pressures up to 32 GPa. They were studied experimentally using synchrotron powder X-ray diffraction and theoretically by means of ab initio total-energy calculations. We found that the calcite-type structure remains stable up to the highest pressure explored in the four studied compounds. Experimental and calculated static geometries (unit-cell parameters and internal coordinates), bulk moduli, and their pressure derivatives are in good agreement. The compressibility along the c axis is roughly three times that along the a axis. Our data clearly indicate that the compressibility of borates is dominated by that of the [AO(6)] octahedral group and depends on the size of the trivalent A cations. An analysis of the relationship between isomorphic borates and carbonates is also presented, which points to the potentiality of considering borates as chemical analogues of the carbonate mineral family.This study was supported by the Spanish government MEC under Grant Nos.: MAT2010-21270-C04-01/03/04 and CTQ2009-14596-C02-01, by MALTA Consolider Ingenio 2010 Project (CSD2007-00045), by Generalitat Valenciana (GVA-ACOMP-2013-1012), and by the Vicerrectorado de Investigacion y Desarrollo of the Universidad Politecnica de Valencia (UPV2011-0914 PAID-05-11 and UPV2011-0966 PAID-06-11). We thank ALBA and Diamond synchrotrons for providing beamtime for the XRD experiments. A.M. and P.R-H. acknowledge computing time provided by Red Espanola de Supercomputacion (RES) and MALTA-Cluster. J.A.S. and B.G.-D. acknowledge Juan de la Cierva fellowship and FPI programs for financial support. We are gratefully indebted to Dr. Capponi and Dr. Diehl for supplying us single crystals of AlBO3 and FeBO3, respectively.Santamaría Pérez, D.; Gomis Hilario, O.; Sans, JÁ.; Ortiz, HM.; Vegas, Á.; Errandonea, D.; Ruiz-Fuertes, J.... (2014). Compressibility systematics of calcite-type borates : An experimental and theoretical structural study on ABO3 (A = Al, Sc, Fe and In). Journal of Physical Chemistry C. 118(8):4354-4361. https://doi.org/10.1021/jp4124259S43544361118

Smokers with CT detected emphysema and no airway obstruction have decreased plasma levels of EGF, IL-15, IL-8 and IL-1ra

Current or former smokers expressing a well-defined disease characteristic such as emphysema, has a specific plasma cytokine profile. This includes a decrease of cytokines mainly implicated in activation of apoptosis or decrease of immunosurveillance. This information should be taken into account when evaluated patients with tobacco respiratory diseases

La Ingeniería Automotriz clave para el desarrollo sostenible de Ecuador

El presente texto es una contribución al desarrollo de la sostenibilidad ecuatoriana y mantiene el debate sobre temas del estudio de la Ingeniería Automotriz. El mérito del libro radica en una triple condición: alimenta la investigación académica ecuatoriana, contribuye a llenar el vacío de producción científica automotriz direccionada a las necesidades del Ecuador y reconoce el esfuerzo de los investigadores que se dedican a la producción académica técnica. La Universidad Politécnica Salesiana —en su sede Guayaquil— realizó en 2018, las Segundas Jornadas Científicas de Ingeniería Automotriz; este texto es el producto final de ese evento académico, cuyas memorias técnicas son constituidas por ocho resultados de investigaciones en Ingeniería Automotriz que aportarán desarrollo sostenible al Ecuador en áreas como: el diseño, el control de contaminación, la eficiencia energética y la movilidad. Este recorrido por varias ramas de la Ingeniería Automotriz muestra al lector múltiples aplicaciones y cambios de paradigmas en la industria; no somos solamente consumidores de tecnología, somos también productores de la misma. Este texto da cuenta del desarrollo de la industria automotriz ecuatoriana. Ing. Renato Fierro J. MSc

Zinc Phthalocyanine−Graphene Hybrid Material for Energy Conversion: Synthesis, Characterization, Photophysics and Photoelectrochemical Cell Preparation

Graphene exfoliation upon tip sonication in o-­‐DCB was accomplished. Then, covalent grafting of (2-­‐ aminoethoxy)(tri-­‐tert-­‐butyl) zinc phthalocyanine (ZnPc), to exfoliated graphene sheets was achieved. The newly formed ZnPc-­‐graphene hybrid material was found soluble in common organic solvents without any precipitation for several weeks. Application of diverse spectroscopic techniques verified the successful formation of ZnPc-­‐graphene hybrid materi-­‐ al, while thermogravimetric analysis revealed the amount of ZnPc loading onto graphene. Microscopy analysis based on AFM and TEM was applied to probe the morphological characteristics and to investigate the exfoliation of graphene sheets. Efficient fluorescence quenching of ZnPc in the ZnPc-­‐graphene hybrid material suggested that photoinduced events occur from the photoexcited ZnPc to exfoliated graphene. The dynamics of the photoinduced electron transfer was evaluated by femtosecond transient absorption spectroscopy, thus, revealing the formation of transient species such as ZnPc+ yielding the charge-­‐separated state ZnPc•+–graphene•–. Finally, the ZnPc-­‐graphene hybrid material was integrated into a photoactive electrode of an optical transparent electrode (OTE) cast with nanostructured SnO2 films (OTE/SnO2), which exhibited sta le and reproducible photocurrent responses and the incident photon-­‐to-­‐current conversion efficien-­‐ cy was determine

Association between convalescent plasma treatment and mortality in COVID-19: a collaborative systematic review and meta-analysis of randomized clinical trials.

Funder: laura and john arnold foundationBACKGROUND: Convalescent plasma has been widely used to treat COVID-19 and is under investigation in numerous randomized clinical trials, but results are publicly available only for a small number of trials. The objective of this study was to assess the benefits of convalescent plasma treatment compared to placebo or no treatment and all-cause mortality in patients with COVID-19, using data from all available randomized clinical trials, including unpublished and ongoing trials (Open Science Framework, https://doi.org/10.17605/OSF.IO/GEHFX ). METHODS: In this collaborative systematic review and meta-analysis, clinical trial registries (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform), the Cochrane COVID-19 register, the LOVE database, and PubMed were searched until April 8, 2021. Investigators of trials registered by March 1, 2021, without published results were contacted via email. Eligible were ongoing, discontinued and completed randomized clinical trials that compared convalescent plasma with placebo or no treatment in COVID-19 patients, regardless of setting or treatment schedule. Aggregated mortality data were extracted from publications or provided by investigators of unpublished trials and combined using the Hartung-Knapp-Sidik-Jonkman random effects model. We investigated the contribution of unpublished trials to the overall evidence. RESULTS: A total of 16,477 patients were included in 33 trials (20 unpublished with 3190 patients, 13 published with 13,287 patients). 32 trials enrolled only hospitalized patients (including 3 with only intensive care unit patients). Risk of bias was low for 29/33 trials. Of 8495 patients who received convalescent plasma, 1997 died (23%), and of 7982 control patients, 1952 died (24%). The combined risk ratio for all-cause mortality was 0.97 (95% confidence interval: 0.92; 1.02) with between-study heterogeneity not beyond chance (I2 = 0%). The RECOVERY trial had 69.8% and the unpublished evidence 25.3% of the weight in the meta-analysis. CONCLUSIONS: Convalescent plasma treatment of patients with COVID-19 did not reduce all-cause mortality. These results provide strong evidence that convalescent plasma treatment for patients with COVID-19 should not be used outside of randomized trials. Evidence synthesis from collaborations among trial investigators can inform both evidence generation and evidence application in patient care

Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study

Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe