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Microchannel reactive distillation for the conversion of aqueous ethanol to ethylene

Journal of Energy Chemistry 2024年第11期98卷 481-493页

作者： Johnny Saavedra-Lopez stephen d.davidson Paul H.Humble dan R.Bottenus Vanessa Lebarbier dagle Yuan Jiang Charles J.Freeman Ward E.Te Grotenhuis Robert A.dagle Pacific Northwest National Laboratory 902 Battelle Blvd.RichlandWA 99354USA

Here we demonstrate the proof-of-concept for microchannel reactive distillation for alcohol-to-jet application:combining ethanol/water separation and ethanol dehydration in one unit *** is first distilled into the vapor phase,converted to ethylene and water,and then the water co-product is condensed to shift the reaction *** intensification is achieved through rapid mass transfer-ethanol stripping from thin wicks using novel microchannel architectures-leading to lower residence time and improved separation *** savings are realized with integration of unit *** example,heat of condensing water can offset vaporizing ***,the dehydration reaction equilibrium shifts towards completion by immediate removal of the water byproduct upon formation while maintaining aqueous feedstock in the condensed *** aqueous ethanol feedstock(40%_w),71% ethanol conversion with 91% selectivity to ethylene was demonstrated at 220℃,600psig,and 0.28 h^(-1) wt hour space velocity.2.7 stages of separation were also demonstrated,under these conditions,using a device length of 8.3 *** provides a height equivalent of a theoretical plate(HETP),a measure of separation efficiency,of ^(3).3 *** comparison,conventional distillation packing provides an HETP of ^(3)0 ***,9,1 × reduction in HETP was demonstrated over conventional technology,providing a means for significant energy savings and an example of process ***,preliminary process economic analysis indicates that by using microchannel reactive distillation technology,the operating and capital costs for the ethanol separation and dehydration portion of an envisioned alcoholto-jet process could be reduced by at least 35% and 55%,respectively,relative to the incumbent technology,provided future improvements to microchannel reactive distillation design and operability are made.

关键词： Catalytic distillation Ethanol dehydration Process intensification Microchannel Alcohol-to-jet process

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Review of pharmacological inhibition of thyroid cancer metabolism

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Journal of Cancer Metastasis and Treatment 2021年第1期7卷 640-658页

作者： Cole d.davidson Frances E.Carr department of Pharmacology Larner College of MedicineBurlingtonVT 05405USA University of Vermont Cancer Center BurlingtonVT 05405USA

Thyroid cancer(TC)is the most common malignancy of the endocrine system and has been rapidly increasing in incidence over the past few *** TCs metastasize quickly and often levy poor prognoses,as they are frequently resistant to first-line treatment *** diagnosed with aggressive,dedifferentiated TC have a prognosis of under a year with the most current treatment *** many cancers,TCs also exhibit altered cell metabolism,which enhances the cell’s ability to generate energy,protect against reactive oxygen species,and synthesize macromolecules such as lipids,proteins,and nucleotides for *** and enzyme profiling of TC tissues and cell lines have uncovered several dysregulated metabolic pathways such as glycolysis,the pentose phosphate pathway,glutamine metabolism,and pyrimidine *** aberrations are most often due to overexpression of rate-limiting enzymes or metabolite *** pathways pose attractive therapeutic targets in aggressive TC and may serve to work in tandem with standard therapeutics such as kinase inhibitors depending on the genetic,metabolic,and signaling backgrounds of individual *** studies are needed to clearly delineate altered metabolic targets across TC subtypes for implementing therapeutic metabolic inhibitors that have shown success in other aggressive tumors.

关键词： Thyroid cancer tumor metabolism metabolic inhibitors Warburg effect cell signaling

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SARS-CoV-2 spike variants differ in their allosteric responses to linoleic acid

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Journal of Molecular Cell Biology 2023年第3期15卷 55-66页

作者： A.Sofia F.Oliveira deborah K.Shoemark Andrew d.davidson Imre Berger Christiane Schaffitzel Adrian J.Mulholland School of Chemistry Centre for Computational ChemistryUniversity of BristolBristol BS81TSUK School of Chemistry University of BristolBristol BS81TSUK School of Biochemistry University of BristolBristol BS81TDUK School of Cellular and Molecular Medicine University of BristolUniversity WalkBristol BS81TDUK School of Chemistry Max Planck Bristol Centre for Minimal BiologyBristol BS81TSUK

The SARS-CoV-2 spike protein contains a functionally important fatty acid(FA)binding site,which is also found in some other coronaviruses,***-CoV and *** occupancy of the FA site by linoleic acid(LA)reduces infectivity by‘locking’the spike in a less infectious ***,we use dynamical-nonequilibrium molecular dynamics(d-NEMd)simulations to compare the allosteric responses of spike variants to LA removal.d-NEMd simulations show that the FA site is coupled to other functional regions of the protein,*** receptor-binding motif(RBM),N-terminal domain(NTd),furin cleavage site,and regions surrounding the fusion peptide.d-NEMd simulations also identify the allosteric networks connecting the FA site to these functional *** comparison between the wild-type spike and four variants(Alpha,delta,delta plus,and Omicron BA.1)shows that the variants differ significantly in their responses to LA *** allosteric connections to the FA site on Alpha are generally similar to those on the wild-type protein,with the exception of the RBM and the S71–R78 region,which show a weaker link to the FA *** contrast,Omicron is the most different variant,exhibiting significant differences in the RBM,NTd,V622–L629,and furin cleavage *** differences in the allosteric modulation may be of functional relevance,potentially affecting transmissibility and *** comparison of the effects of LA on SARS-CoV-2 variants,including emerging variants,is warranted.

关键词： SARS-CoV-2 spike allosteric modulation d-NEMd simulations fatty acid binding site SARS-CoV-2 variants

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Current protective strategies in liver surgery

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World Journal of Gastroenterology 2010年第48期16卷 6098-6103页

作者： Kurinchi S Gurusamy Hector d Gonzalez Brian R davidson HPB and Liver Transplantation Royal Free CampusUniversity College London Medical SchoolRoyal Free Hospital

during liver resection surgery for cancer or liver transplantation,the liver is subject to ischaemia (reduction in blood flow) followed by reperfusion (restoration of blood flow),which results in liver injury [ischemiareperfusion (IR) or IR injury]. Modulation of IR injury can be achieved in various ways. These include hypothermia,ischaemic preconditioning (IPC) (brief cycles of ischaemia followed by reperfusion of the organ before the prolonged period of ischaemia i.e. a conditioning response),ischaemic postconditioning (conditioning after the prolonged period of ischaemia but before the reperfusion),pharmacological agents to decrease IR injury,genetic modulation of IR injury,and machine perfusion (pulsatile perfusion). Hypothermia decreases the metabolic functions and the oxygen consumption of organs. Static cold storage in University of Wisconsin solution reduces IR injury and has prolonged organ storage and improved the function of transplanted grafts. There is currently no evidence for any clinical advantage in the use of alternate solutions for static cold storage. Although experimental data from animal models suggest that IPC,ischaemic postconditioning,various pharma-cological agents,gene therapy,and machine perfusion decrease IR injury,none of these interventions can be recommended in clinical practice. This is because of the lack of randomized controlled trials assessing the safety and efficacy of ischaemic postconditioning,gene therapy,and machine perfusion. Randomized controlled trials and systematic reviews of randomized controlled trials assessing the safety and efficacy of IPC and various pharmacological agents have demonstrated biochemical or histological improvements but this has not translated to clinical benefit. Further well designed randomized controlled trials are necessary to assess the various new protective strategies in liver resection.

关键词： Liver Hepatectomy Liver transplantation Ischemia-reperfusion injury Hypothermia Ischaemic preconditioning

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Gas flow in rotary kilns

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Particuology 2010年第6期8卷 613-616页

作者： Patrick R.davies Michael J.S.Norton d.Ian Wilson John F.davidson david M.Scott department of Chemical Engineering and Biotechnology University of CambridgePembroke StreetCambridgeCB2 3RAUK

This paper describes an experimental investigation on the flow characteristics within a rotating cylinder containing a rolling bed of sand. The axis of the cylinder was horizontal and there was no axial bulk flow of particles. The velocity field of the gas flowing through the cylinder was measured by hot-wire anemometry. The measurements indicate that the velocity field is asymmetric with respect to a diameter perpendicular to the granular bed. CFd calculations confirm this finding. The gas velocity profiles are crucial in determining heat transfer from gas to solid.

关键词： Rotating cylinderVelocity profile

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玻璃和熔体包裹体中水含量的拉曼光谱定量测定方面的进展评述

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岩石学报 2007年第1期23卷 15-20页

作者： Rainer THOMAS Paul davidson GeoForschungsZentrum Potsdam Telegrafenberg B120D-14473 PotsdamGermany ARC Centre of ExceUence in Ore deposits University of TasmaniaHobart 7001Australia

This paper is focused on the progress in the determination of water in glasses and melt inclusions with Raman *** the presented'Comparator Technique'the water content of a sample is determined by simple comparison with a known standard.A calibration curve is not ***,with this technique the water concentration in silicate melt inclusions can be determined without exposing the inclusions for *** is very important for extremely water-rich melt inclusions,which would loose H_2O on exposure.

关键词：玻璃熔体包裹体水含量拉曼光谱定量测定研究进展

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An arthropod community beyond the dry limit of plant life

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Journal of Arid Land 2021年第6期13卷 629-638页

作者： Benjamin davidson Elli GRONER Arava Institute for Environmental Studies D.N.Eilot 88840Israel Vassar College PoughkeepsieNew York 12604United States of America dead Sea and Arava Science Center Mitzpe Ramon 8060000Israel Ben Gurion University Eilat 88556Israel

Water availability,which enables plant growth and animal activity,regulates dryland ecosystem *** hyper-arid ecosystems,rain cannot support vascular plant ***,hyper-arid vegetation is restricted to the lower topography,where runoff ***,food resources originating from areas of dense vegetation are dispersed across the desert floor,enabling animal life in areas lacking vascular plant ***,certain regions,such as the hyper-arid upper topography,may be devoid of plant-derived food *** present study examined arthropod activity in the upper topography of a hyper-arid desert,in comparison with arthropod activity in the lower *** traps were utilized to compare arthropod activity along unvegetated ridges with activity in parallel,vegetated ***,the study revealed dense arthropod communities in the barren upper *** collected in the upper topography represented 26%of total arthropod *** addition,the overlap between arthropod identity in the ridges and wadis(i.e.,riverbeds)was low,and certain arthropods were strongly affiliated with the *** upper topographic communities included high numbers of silverfish(Zygentoma:Lepismatidae),malachite beetles(Psiloderes),and predatory mites(Acari:Anystidae),and these arthropods were present at various life *** remains unclear how arthropod communities can persist in the unvegetated upper topography of the hyper-arid study *** results raise the possibility that other food sources,independent from vascular plants,may play a significant role in the life history of hyper-arid arthropods.

关键词： hyper-arid area spatial distribution topography silverfish Tenebrionidae desert

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Early acute kidney injury after liver transplantation: Predisposing factors and clinical implications

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World Journal of Hepatology 2017年第18期9卷 823-832页

作者： Suehana Rahman Susan V Mallett Brian R davidson Royal Free Perioperative Research Group Department of Anaesthesia Royal Free Hospital Royal Free NHS Foundation Trust department of Surgery Royal Free Hospital Royal Free NHS Foundation Trust

To investigate the additional clinical impact of hepatic ischaemia reperfusion injury (HIRI) on patients sustaining acute kidney injury (AKI) following liver transplantation. METHOdSThis was a single-centre retrospective study of consecutive adult patients undergoing orthotopic liver transplantation (OLT) between January 2013 and June 2014. Early AKI was identified by measuring serum creatinine at 24 h post OLT (> 1.5 × baseline) or by the use of continuous veno-venous haemofiltration (CVVHF) during the early post-operative period. Patients with and without AKI were compared to identify risk factors associated with this complication. Peak serum aspartate aminotransferase (AST) within 24 h post-OLT was used as a surrogate marker for HIRI and severity was classified as minor (derate (1000-5000 IU/L) or severe (> 5000 IU/L). The impact on time to extubation, intensive care length of stay, incidence of chronic renal failure and 90-d mortality were examined firstly for each of the two complications (AKI and HIRI) alone and then as a combined outcome. RESULTSOut of the 116 patients included in the study, 50% developed AKI, 24% required CVVHF and 70% sustained moderate or severe HIRI. Median peak AST levels were 1248 IU/L and 2059 IU/L in the No AKI and AKI groups respectively (P = 0.0003). Furthermore, peak serum AST was the only consistent predictor of AKI on multivariate analysis P = 0.02. AKI and HIRI were individually associated with a longer time to extubation, increased length of intensive care unit stay and reduced survival. However, the patients who sustained both AKI and moderate or severe HIRI had a longer median time to extubation (P d intensive care length of stay (P = 0.001) than those with either complication alone. Ninety-day survival in the group sustaining both AKI and moderate or severe HIRI was 89%, compared to 100% in the groups with either or neither complication (P = 0.049). CONCLUSIONHIRI has an important role in the devel

关键词： Hepatic ischaemia reperfusion injury Liver transplantation Perioperative care Acute kidney injury Marginal grafts

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Phytoestrogens and prevention of breast cancer: The contentious debate

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World Journal of Clinical Oncology 2014年第4期5卷 705-712页

作者： Iqra Bilal Avidyuti Chowdhury Juliet davidson Saffron Whitehead department of Basic Medical Sciences St George’s University of London

Phytoestrogens have multiple actions within target cells, including the epigenome, which could be beneficial to the development and progression of breast cancer. In this brief review the action of phytoestrogens on oestrogen receptors, cell signalling pathways, regulation of the cell cycle, apoptosis, steroid synthesis and epigenetic events in relation to breast cancer are discussed. Phytoestrogens can bind weakly to oestrogen receptors(ERs) and some have a preferential affinity for ERβ which can inhibit the transcriptional growthpromoting activity of ERα. However only saturating doses of phytoestrogens, stimulating both ERα and β, exert growth inhibitory effects. Such effects on growth may be through phytoestrogens inhibiting cell signalling pathways. Phytoestrogens have also been shown to inhibit cyclin d1 expression but increase the expression of cyclin-dependent kinase inhibitors(p21 and p27) and the tumour suppressor gene p53. Again these effects are only observed at high(> 10) μmol/L doses of phytoestrogens. Finally the effects of phytoestrogens on breast cancer may be mediated by their ability toinhibit local oestrogen synthesis and induce epigenetic changes. There are, though, difficulties in reconciling epidemiological and experimental data due to the fact experimental doses, both in vivo and in vitro, far exceed the circulating concentrations of "free" unbound phytoestrogens measured in women on a high phytoestrogen diet or those taking phytoestrogen supplements.

关键词： Phytoestrogens Breast cancer Cell signalling Cell cycle Epigenomics

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Surface integral analogy approaches for predicting noise from 3d high-lift low-noise wings

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Acta Mechanica Sinica 2014年第3期30卷 326-338页

作者： Hua-dong Yao Lars davidson Lars-Erik Eriksson Shia-Hui Peng Olof Grundestam Peter E.Eliasson department of Applied Mechanics Chalmers University of Technology department of Aeronautics and Systems Technology Swedish Defence Research Agency (FOI)

Three surface integral approaches of the acoustic analogies are studied to predict the noise from three concep- tual configurations of three-dimensional high-lift low-noise wings. The approaches refer to the Kirchhoff method, the Ffowcs Williams and Hawkings （FW-H） method of the permeable integral surface and the Curle method that is known as a special case of the FW-H method. The first two approaches are used to compute the noise generated by the core flow region where the energetic structures exist. The last approach is adopted to predict the noise specially from the pressure perturbation on the wall. A new way to con- struct the integral surface that encloses the core region is proposed for the first two methods. Considering the local properties of the flow around the complex object-the actual wing with high-lift devices-the integral surface based on the vorticity is constructed to follow the flow structures. The surface location is discussed for the Kirchhoff method and the FW-H method because a common surface is used for them. The noise from the core flow region is studied on the basis of the dependent integral quantities, which are indicated by the Kirchhoff formulation and by the FW-H formulation. The role of each wall component on noise contribution is analyzed using the Curle formulation. Effects of the volume integral terms of Lighthill＇s stress tensors on the noise pre-diction are then evaluated by comparing the results of the Curle method with the other two methods.

关键词： Aero-acoustics High-lift facilities Surface integral approaches of acoustic analogy

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