Photodegradation Diuron herbicide with TiO2-Al2O3 catalysts supported on graphene nanoplatelets

Objective: To photodegrade Diuron with TiO2-Al2O3 nanomaterials supported on graphene nanoplatelets (GnPs) Design/methodology/approach: The synthesis of the materials was carried out by the sol-gel method under mild conditions. Subsequently, the obtained materials were subjected to thermal processing for structural stabilization and pulverized. Synthesized nanomaterials were then characterized by nitrogen adsorption/desorption, X-ray diffraction, scanning electron microscopy, and Uv-Vis spectroscopy. Results: The adsorption/desorption results indicated that the ternary TiO2-Al2O3/GnPs nanomaterials were found to have complex porosity, which suggested that TiO2-Al2O3 was formed on agglomerated GnPs. X-ray diffraction data revealed that the anatase phase of TiO2 and the g-Al2O3 phase coexist with the crystalline phase of graphene. The morphology of the materials indicates that the nanoplatelets were randomly dispersed in a continuous mixed oxide phase. About the UV analysis, the presence of GnPs at 1 wt % concentration reduces the band gap by 6%. Limitations on study/implications: The physical and chemical properties of GnPs make the material an excellent candidate for the degradation of pollutants by photocatalysis. Findings/conclusions: The addition of GnPs improved the Diuron degradation, probably by forming a nanostructured interface or heterojunction.  Objective: To photodegrade Diuron with TiO2-Al2O3 nanomaterials supported on graphene nanoplatelets (GnPs) Design/methodology/approach: The synthesis of the materials was carried out by the sol-gel method under mild conditions. Subsequently, the obtained materials were subjected to thermal processing for structural stabilization and pulverized. Synthesized nanomaterials were then characterized by nitrogen adsorption/desorption, X-ray diffraction, scanning electron microscopy, and Uv-Vis spectroscopy. Results: The adsorption/desorption results indicated that the ternary TiO2-Al2O3/GnPs nanomaterials were found to have complex porosity, which suggested that TiO2-Al2O3 was formed on agglomerated GnPs. X-ray diffraction data revealed that the anatase phase of TiO2 and the g-Al2O3 phase coexist with the crystalline phase of graphene. The morphology of the materials indicates that the nanoplatelets were randomly dispersed in a continuous mixed oxide phase. About the UV analysis, the presence of GnPs at 1 wt % concentration reduces the band gap by 6%. Limitations on study/implications: The physical and chemical properties of GnPs make the material an excellent candidate for the degradation of pollutants by photocatalysis. Findings/conclusions: The addition of GnPs improved the Diuron degradation, probably by forming a nanostructured interface or heterojunctio

Risk of COVID-19 after natural infection or vaccinationResearch in context

Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health

Risk of COVID-19 after natural infection or vaccinationResearch in context

Summary: Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health

Effects of pre-operative isolation on postoperative pulmonary complications after elective surgery: an international prospective cohort study an international prospective cohort study

We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05–1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4–7 days or ≥ 8 days of 1.25 (1.04–1.48), p = 0.015 and 1.31 (1.11–1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care. We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05–1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4–7 days or ≥ 8 days of 1.25 (1.04–1.48), p = 0.015 and 1.31 (1.11–1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care

Measurement of the integrated and differential ttˉt \bar t production cross sections for high-pTp_T top quarks in pppp collisions at s=\sqrt s = 8 TeV

The cross section for pair production of top quarks $(t\bar{t})$ with high transverse momenta is measured in pp collisions, collected with the CMS detector at the LHC with $\sqrt{s} =$ 8 TeV in data corresponding to an integrated luminosity of 19.7 fb$^{-1}$. The measurement is performed using lepton+jets events, where one top quark decays semileptonically, while the second top quark decays to a hadronic final state. The hadronic decay is reconstructed as a single, large-radius jet, and identified as a top quark candidate using jet substructure techniques. The integrated cross section and the differential cross sections as a function of top quark $p_T$ and rapidity are measured at particle level within a fiducial region related to the detector-level requirements and at parton level. The particle-level integrated cross section is found to be $\sigma_{t\bar{t}} =$ 0.499 $\pm$ 0.035 (stat+syst) $\pm$ 0.095 (theory) $\pm$ 0.013 (lumi) pb for top quark $p_T$ > 400 GeV. The parton-level measurement is $\sigma_{t\bar{t}} =$ 1.44 $\pm$ 0.10 (stat+syst) $\pm$ 0.29 (theory) $\pm$ 0.04 (lumi) pb. The integrated and differential cross section results are compared to predictions from several event generators