Copper stearate as a catalyst for improving the oxidation performance of heavy oil in in-situ combustion process

© 2018 Elsevier B.V. Copper stearate was applied as a catalyst for the oxidation of heavy oils. The catalytic effect was investigated by high-pressure differential scanning calorimetry (HP-DSC) and accelerating rate calorimetry (ARC). The results showed that copper stearate significantly improved the oxidation performance including decreasing activation energies, enhancing combustion efficiency of coke, and reducing induction time and ignition temperature. CuO nanoparticles were in-situ formed due to the decomposition of copper stearate. To understand the catalytic mechanism, the catalytic effect of copper stearate was compared with nickel stearate, iron stearate and CuO. Furthermore, the existed form and transition of copper stearate during the oxidation process of crude oil were investigated using thermogravimetric analyser coupled with FTIR-spectrometer (TG-FTIR), HP-DSC, X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results indicated that copper stearate and in-situ formed CuO nanoparticles played their catalytic roles as a homogeneous and heterogenous catalyst in low and high-temperature ranges, respectively. It was believed that the high catalytic activity of CuO can be not only attributed to those well-known catalytic mechanisms, but also benefits from the well-distribution of both copper stearate and in-situ formed CuO nanoparticles

Characteristics of post hoc subgroup analyses of oncology clinical trials: A systematic review

BACKGROUND: Subgroup analyses in clinical trials assess intervention effects on specific patient subgroups, ensuring generalizability. However, they are usually only able to generate hypotheses rather than definitive conclusions. This study examined the prevalence and characteristics of post hoc subgroup analysis in oncology. METHODS: We systematically reviewed published subgroup analyses from 2000 to 2022. We included articles presenting secondary, post hoc, or subgroup analyses of interventional clinical trials in oncology, cancer survivorship, or cancer screening, published separately from the original clinical trial publication. We collected cancer type, year of publication, where and how subgroup analyses were reported, and funding. RESULTS: Out of 16 487 screened publications, 1612 studies were included, primarily subgroup analyses of treatment trials for solid tumors (82%). Medical writers contributed to 31% of articles, and 58% of articles reported conflicts of interest. Subgroup analyses increased significantly over time, with 695 published between 2019 and 2022, compared to 384 from 2000 to 2014. Gastrointestinal tumors (25%) and lymphoid lineage tumors (39%) were the most frequently studied solid and hematological malignancies, respectively. Industry funding and reporting of conflicts of interest increased over time. Subgroup analyses often neglected to indicate their secondary nature in the title. Most authors were from high-income countries, most commonly North America (45%). CONCLUSIONS: This study demonstrates the rapidly growing use of post hoc subgroup analysis of oncology clinical trials, revealing that the majority are supported by pharmaceutical companies, and they frequently fail to indicate their secondary nature in the title. Given the known methodological limitations of subgroup analyses, caution is recommended among authors, readers, and reviewers when conducting and interpreting these studies

Ethical issues in human genomics research in developing countries

<p>Abstract</p> <p>Background</p> <p>Genome-wide association studies (GWAS) provide a powerful means of identifying genetic variants that play a role in common diseases. Such studies present important ethical challenges. An increasing number of GWAS is taking place in lower income countries and there is a pressing need to identify the particular ethical challenges arising in such contexts. In this paper, we draw upon the experiences of the MalariaGEN Consortium to identify specific ethical issues raised by such research in Africa, Asia and Oceania.</p> <p>Discussion</p> <p>We explore ethical issues in three key areas: protecting the interests of research participants, regulation of international collaborative genomics research and protecting the interests of scientists in low income countries. With regard to participants, important challenges are raised about community consultation and consent. Genomics research raises ethical and governance issues about sample export and ownership, about the use of archived samples and about the complexity of reviewing such large international projects. In the context of protecting the interests of researchers in low income countries, we discuss aspects of data sharing and capacity building that need to be considered for sustainable and mutually beneficial collaborations.</p> <p>Summary</p> <p>Many ethical issues are raised when genomics research is conducted on populations that are characterised by lower average income and literacy levels, such as the populations included in MalariaGEN. It is important that such issues are appropriately addressed in such research. Our experience suggests that the ethical issues in genomics research can best be identified, analysed and addressed where ethics is embedded in the design and implementation of such research projects.</p

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

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

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

Upgrading of “domanik” shale oil by supercritical water

© 2019, International Multidisciplinary Scientific Geoconference. All rights reserved. The purpose of this research is the treatment of Domanik shale oil (DSO) by supercritical water conditions. The experiments were carried out at 400oC and with different residence times at 140, 300 and 480 min. The DSO is powdered and mixed with distilled water then loaded in the batch reactor and they were heated until reach the desired conditions at 400 °C and of 265.9 bars. The results reveal a great dependence of the product yield and quality at the residence time. Similarly, the obtained products were analyzed, and it is proved that as time increases, the rate of yield of liquid product (synthetic oil) increases, and the formation of coke was not observed during this work. Regarding the coke formation, two products yield of 140 and 300 min the coke was not observed except the product of 480 min which the yield of coke is 7.02%. At 140 min of residence time, the conversion rate reached 7.45% of the synthetic oil; at 300 min the yield continues to increase up to 8.16% and the liquid yield continue to increase until reach 9.00% at 480 min. The supercritical water treatment of Domanik shale oil at 400oC shown a positive effect in this work, and the only factor in the process is the temperature and residence time and also the water density

Comparison of upgrading of heavy oil and vacuum distillation residues by supercritical water

© Published under licence by IOP Publishing Ltd. The purpose of this work is to test the upgrading technology by supercritical water of two different raw materials heavy oil and vacuum distillation residue. The experiments were carried out under the same conditions (temperature 400°C, pressure 236 bar). The products obtained after upgrading were analyzed. Density, viscosity, SARA-composition, elemental composition and composition of saturates fraction were determined. The results revealed that after upgrading at 400°C during 60 minutes raw materials heavy oil and vacuum residues yielded light oil 85.6 % and 64.7 %, coke at level of 11.3 % and 13.7 % and gaseous products 3.1 % and 21.6 %

Effect of tripoli of pervomaysky field on the heavy crude oil combustion by hp-dsc

© 2019, International Multidisciplinary Scientific Geoconference. All rights reserved. In situ combustion (ISC) method is considered as a relatively inexpensive and effective method for enhanced oil recovery (EOR). It can achieve a very high oil recovery factor due to a significant increase of pressure and temperature during the combustion process of crude oil. Over the last ten years, high pressure differential scanning calorimetry (HP-DSC) has been widely used for understanding the oxidation process of heavy oil. In this paper, HP-DSC experiments were carried out to investigate the alteration of combustion behavior of Iraq heavy oil by addition of Pervomaysky tripoli. In general, for the oxidation process two obvious exothermic reaction intervals were observed for Iraq pure oil and for the mixture: low-temperature oxidation (LTO) and high-temperature oxidation (HTO). It can be seen that the addition of Pervomaysky tripoli shifted both LTO and HTO peaks into lower temperatures to 255 ˚C and 398 ˚C from 263 and 437 ˚C, respectively. Especially, it showed a stronger promotion on the HTO, which means that the presence of Pervomaysky tripoli might promote the formation of fuel and its combustion in high-temperature range. This implies that Pervomaysky tripoli is favorable for the stability of combustion front in an ISC process

Effect of tripoli of pervomaysky field on the heavy crude oil combustion by hp-dsc

© 2019, International Multidisciplinary Scientific Geoconference. All rights reserved. In situ combustion (ISC) method is considered as a relatively inexpensive and effective method for enhanced oil recovery (EOR). It can achieve a very high oil recovery factor due to a significant increase of pressure and temperature during the combustion process of crude oil. Over the last ten years, high pressure differential scanning calorimetry (HP-DSC) has been widely used for understanding the oxidation process of heavy oil. In this paper, HP-DSC experiments were carried out to investigate the alteration of combustion behavior of Iraq heavy oil by addition of Pervomaysky tripoli. In general, for the oxidation process two obvious exothermic reaction intervals were observed for Iraq pure oil and for the mixture: low-temperature oxidation (LTO) and high-temperature oxidation (HTO). It can be seen that the addition of Pervomaysky tripoli shifted both LTO and HTO peaks into lower temperatures to 255 ˚C and 398 ˚C from 263 and 437 ˚C, respectively. Especially, it showed a stronger promotion on the HTO, which means that the presence of Pervomaysky tripoli might promote the formation of fuel and its combustion in high-temperature range. This implies that Pervomaysky tripoli is favorable for the stability of combustion front in an ISC process