Relevant changes in the properties of Co(Ni)Mo/Al2O3 HDS catalysts modified by small amounts of SiO2

The changes in hydrodesulfurization activity, selectivity, dispersion, sulfidation, and extent of promotion of Co(Ni)Mo catalysts were investigated when the alumina support surface is modified by grafting 4 wt% silica. Adding SiO2 eliminates the most reactive hydroxyl groups on the alumina surface (IR band at 3775 cm 1) decreasing the possibility of generating tetrahedral Mo species difficult to sulfide in favor of octahedral ones capable of contributing to the sulfided active phase. The catalysts were evaluated in the hydrodesulfurization of 4,6-dimethyldibenzothiophene. Incorporating SiO2 to alumina increases the hydrogenation rate constant and therefore the global hydrodesulfurization rate of 4,6-dimethyldibenzothiophene and enhances the promotion of Mo by Co (or Ni). The global sulfidation of Ni is not affected by the addition of silica but the sulfidation of cobalt is significantly improved. The extent of promotion of the NiMo/Al2O3 and NiMo/SiO2/ Al2O3 catalysts was greater than the one achieved in their Co-promoted counterpartsCB-168827, beca posdoctoral otorgada por CONACyT al Dr. Adolfo Romero Galarza from DGAPA-UNAM, project PAPIIT-IN-113015. We thank Mariela Bravo-Sanchez (Universidad de Guadalajara) for her discussion about the XPS results, Ivan Puente for the TEM work, and Alberto Herrera-Gómez (CINVESTAV-Unidad Querétaro, Mexico) for providing computer program AANALYZER version 1.2

Quantification of the sulfidation extent of Mo in CoMo HDS catalyst through XPS

Background removal in X-ray photoelectron spectroscopy (XPS) spectra was carried out in Co–Mo hydrodesulfurization (HDS) catalysts supported alumina using traditional and recent methods. The sulfidation extent, expressed by the XPS area ratio AMo3d-MoS2/AMo3d-Total, which is a fundamental parameter in the performance of a hydrodesulfurization catalyst, was obtained using different methodologies. The methods include the use of the background active approach, in which the background is optimized during peak-fitting. The method allows for the use of several types of backgrounds, which proved crucial for fitting the Mo 3d-S 2s and the S 2p–Si 2p regions. Both regions contain two overlapped elements, making fundamental a distinction between them. In these cases, a slope background subtraction was used in conjunction with the Shirley-Vegh-Salvi-Castle (SVSC) method to have a clear distinction between the different strengths of backgrounds arising from the overlapped peaks Mo 3d-S 2s and S 2p–Si 2p. From the resulting fitting, the relative percentage (% rel.) of each species present in Mo and S in the catalyst CoMoAl was obtained. The results were compared with those obtained using the static (traditional) approach. With these results, the sulfidation extent, an important parameter in the performance of the HDS catalyst was determined.Adolfo-Romero Galarza thanks Consejo Nacional de Ciencia y Tecnologia (CONACyT), Mexico for their postdoctoral fellowship (ID. 1908/2010C ) . We acknowledge financial support from Direccion General de Asuntos del Personal Academico ( DGAPA) Mexico, UNAM , project PAPIIT-IN-113015 . The authors appreciate the support provided by Gustavo Gomez-Sosa (CINVESTAV-Qro.) for the acquisition of the XPS data and Alberto Herrera-Gómez (CINVESTAV-Unidad Queretaro, Mexico) for engaging in useful discussion regarding the spectra fitting and for providing computer program AANALYZER version 1.2

Relevant changes in the properties of Co(Ni)Mo/Al2O3 HDS catalysts modified by small amounts of SiO2

The changes in hydrodesulfurization activity, selectivity, dispersion, sulfidation, and extent of promotion of Co(Ni)Mo catalysts were investigated when the alumina support surface is modified by grafting 4 wt% silica. Adding SiO2 eliminates the most reactive hydroxyl groups on the alumina surface (IR band at 3775 cm 1) decreasing the possibility of generating tetrahedral Mo species difficult to sulfide in favor of octahedral ones capable of contributing to the sulfided active phase. The catalysts were evaluated in the hydrodesulfurization of 4,6-dimethyldibenzothiophene. Incorporating SiO2 to alumina increases the hydrogenation rate constant and therefore the global hydrodesulfurization rate of 4,6-dimethyldibenzothiophene and enhances the promotion of Mo by Co (or Ni). The global sulfidation of Ni is not affected by the addition of silica but the sulfidation of cobalt is significantly improved. The extent of promotion of the NiMo/Al2O3 and NiMo/SiO2/ Al2O3 catalysts was greater than the one achieved in their Co-promoted counterpartsCB-168827, beca posdoctoral otorgada por CONACyT al Dr. Adolfo Romero Galarza from DGAPA-UNAM, project PAPIIT-IN-113015. We thank Mariela Bravo-Sanchez (Universidad de Guadalajara) for her discussion about the XPS results, Ivan Puente for the TEM work, and Alberto Herrera-Gómez (CINVESTAV-Unidad Querétaro, Mexico) for providing computer program AANALYZER version 1.2

HDS of 4,6-DMDBT over NiMoP/(x)Ti-SBA-15 catalysts prepared with H3PMo12O40

International audienceHDS of 4,6-DMDBT over NiMoP/SBA-15 and NiMoP/(x)TiSBA-15 catalysts prepared using an heteropolyacid (H3PMo12O40) and nickel citrate (C12H10N13O14) as Mo and Ni precursors was studied. To analyze the effect of. calcination temperature on HDS activity, catalysts noncalcined and calcined at 773 K were prepared. The performance of the different catalysts during the hydrodesulfurization of 4,6-dimethyldibenzothiophene was compared with that of a reference catalyst prepared by impregnation with a solution containing ammonium heptamolybdate and nickel nitrate. Kinetic parameters for the HDS of 4,6-DMDBT were estimated using a simplified kinetic model. The catalysts were characterized by N-2 physisorption, X-ray diffraction, Raman, and IR of adsorbed CO at similar to 100 K. The results show that for catalysts supported on pure SBA-15 the noncalcined catalyst prepared with H3PMo12O40 (NiMoP(H-nc)/SBA-15) presents the highest number of active sites, the higher apparent reaction rate constant for the hydrogenation route, and therefore the best 4,6-DMDBT HDS activity. In contrast, for Ti-modified catalysts, NiMoP/(x)Ti-SBA-15, the highest HDS activity was found when 15% of TiO2 was incorporated to SBA-15 and the catalyst was calcined at 773 K. This catalyst presented the highest TOF

Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries

© 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 licenseBackground: 80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality. Methods: This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with ClinicalTrials.gov, NCT03471494. Findings: Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70–8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39–8·80) and upper-middle-income countries (2·06, 1·11–3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26–11·59) and upper-middle-income countries (3·89, 2·08–7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications. Interpretation: Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications. Funding: National Institute for Health Research Global Health Research Unit

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

© 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licenseBackground: Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide. Methods: A multimethods analysis was performed as part of the GlobalSurg 3 study—a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital. Findings: Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3·85 [95% CI 2·58–5·75]; p<0·0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63·0% vs 82·7%; OR 0·35 [0·23–0·53]; p<0·0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer. Interpretation: Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised. Funding: National Institute for Health and Care Research