24 research outputs found

    Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

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    PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

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    PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

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    This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Magnetization dynamics and magnetoimpedance effect of novel Fe-B-Si-M (M = Ta, Y) amorphous wires

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    Amorphous wires of composition Fe64Co8B 19.2Si4.8M4 (M = Ta, Y) and 140 μm of diameter were obtained by rotating-water-bath-melt-spinning technique. Saturation magnetization (Ms) and coercivity values (Hc), at room temperature, were in the range of 1 T and 31 A/m, respectively, for the Ta samples, and Ms = 1.32 T and Hc = 109 A/m, respectively, for the Y samples. The magnetic permeability as a function of frequency showed a domain wall relaxation character, with relaxation frequency, of 3.5 kHz and 9 kHz for the Ta and the Y compounds, respectively. Magnetoimpedance (MI) measurements exhibited a MI factor ΔZ/Z0 = 11% for the Ta alloys, and 41% for the Y alloys. Results are interpreted in terms of magnetoelastic coupling differences in both alloys caused by distinctive frozen-in stresses for each case during the fabrication process. Copyright © 2013 American Scientific Publishers All rights reserved.Peer Reviewe

    Low-field magnetization process and complex permeability of FeCoBSiTa wires coated with hard magnetic CoNi layer

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    Biphase wires consisting of a soft magnetic amorphous nucleus surrounded by a hard magnetic CoNi layer of variable thickness were obtained by means of rotating water-quenching method and subsequent electroplating technique. Magnetization processes for all the biphase wires were resolved in terms of reversible bulging of magnetic domains and spin rotation by means of complex permeability measurements within the frequency range of 10 Hz-13 MHz. Results are interpreted in terms of CoNi layer effect on the magnetic anisotropy of the soft core. © Indian Academy of Sciences.Acknowledges the scholarship granted by DGEP-UNAM. (IB) acknowledges the financial support from Research Grant IN106808 PAPIIT-UNAM.Peer Reviewe

    Rare earth-free hard magnetic microwires

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    [EN] Novel microwires of composition MnBi were obtained by means of quenching and drawing technique having a metallic nucleus of 50 μm diameter. Phase distribution analysis showed a composite microstructure comprising extensive zones of the ferromagnetic hexagonal MnBi phase (of up to 12 μm), interspersed within a matrix of diamagnetic Bi and some inclusions of pure Mn varying between 1 and 2 μm in length. A coercive field in excess of 4000 Oe was measured. Coercivity mechanism is described in terms of nucleation of reverse domains, for which the interface MnBi/Bi largely determines the hard magnetic response of the composite microwire.Project UNAM-PAPIIT IN103216. J. Zamora is grateful for the scholarship received from UNAM-PAPIIT IN103216 and CONACYT-Mexico. Special thanks are given to Adriana Tejeda, Omar Novelo and Josue Romero (IIM-UNAM) for their valuable technical assistance. The work has been Fig. 3. Temperature dependence for a) maximum magnetization and b) coercive field of the MnBi microwire. Fig. 4. Fitting of experimental data for Eq. (1) (R2 = 0.998). 42 I. Betancourt et al. / Scripta Materialia 153 (2018) 40–43 partly supported by the Regional Government of Madrid under Project S2013/MIT-1942850, NANOFRONTMAG-C

    High-temperature magnetic behavior of soft/soft and soft/hard Fe and Co-based biphase microwires

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    The magnetic behavior of biphase magnetic microwires has been investigated in the high-temperature range from 295 to 1200 K. Bimagnetic microwires consist of a magnetically soft amorphous core (i.e., positive, FeSiB, and negative, CoFeSiB, magnetostriction alloy) and external polycrystalline shell with soft (FeNi, Permalloy) and medium-hard (CoNi) magnetic character. The magnetic phase transitions (ferro to paramagnetic) of individual phases are first detected through the temperature dependence of magnetization where structural changes in the amorphous alloy cores are also identified. Moreover, the values of coercive field of individual and bimagnetic phase systems are analyzed in view of these magnetic and structural transitions. The study is relevant for technological applications of bimagnetic microwires in the temperature regime above room temperature

    Electrochemical synthesis and magnetic characterization of periodically modulated Co nanowires

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    The synthesis of templates with modulated pore channels by combined mild and hard anodization processes is described. The hard anodization pulses, implemented during anodization, are controlled not only in time length and amplitude, but also in shape: square and exponential signals have been applied. Electrodeposition of Co is subsequently performed to obtain uniform and modulated diameter nanowire arrays. Square and exponential modulated diameter nanowires are imaged by scanning electron microscopy and hcp hexagonal polycrystalline structure is confirmed in all Co nanowires. Magnetic behavior strongly depends on nanowire shape and is interpreted considering the modification of magnetostatic interactions between wires induced by local stray fields from magnetic charges at the ends of the wider segments in modulated wires. As a consequence, magnetization processes under parallel and perpendicular field configurations denote the contribution of both thin and wide segments. © 2014 IOP Publishing Ltd.The support of the Ministerio de Economia y Competitividad of Spain under projects MAT201002798C0501 and C0503 is acknowledged. Ignacio Mínguez Bacho thanks the Spanish National Research Council (CSIC) for a JAE-preDoc fellowship cofinanced by the European Social Fund.Peer Reviewe

    Influence of sulfur incorporation into nanoporous anodic alumina on the volume expansion and self-ordering degree

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    Self-ordering degree of anodic alumina nanopores is related to the volume expansion of the aluminum oxide. However, little is known about how the ionic species derived from electrolyte affect parameters inducing self-ordering of the nanopores. The influence of sulfur incorporation into nanoporous anodic aluminum oxide (AAO) films on volume expansion and self-ordering degree has been investigated under potentiostatic conditions (14-25 V) in different sulfuric acid electrolytes (3-20 wt %), the average current densities of each anodization being in the range of 0.1-10 mA cm. Rutherford backscattering spectroscopy (RBS) reveals that the incorporation of sulfur species into AAO, as well as the volume expansion factor (VEF), follows a logarithmic dependence on the average current density regardless of the applied voltage and sulfuric acid concentration. The relationship between volume expansion and the S/Al ratio is linear for each concentration of acid in the electrolyte. Furthermore, self-ordering regimes are also revealed for each acid concentration at VEF in the range of 1.50-1.66. We suggest that plasticity, enhanced by sulfur incorporation, counterbalances the high mechanical stress generated by volume expansion, thus inducing new self-ordering regimes. These new regimes are dependent not only on VEF but also on a subtle equilibrium between stress and plasticity of the nanoporous AAO films.Work supported by the Spanish Ministry of Science and Innovation under project MAT2010-20798-05-01 and 05-05. The authors wish to thank the support from the Ministry of Education in Singapore under the AcRF Tier 2 (MOE2014-T2-1-132). I.M.B. thanks the Spanish National Research Council (CSIC) for a JAE-preDoc fellowship cofinanced by the European Social Fund. M.H.-V. thanks financial support under project CCG08-UAM/MAT-4024
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