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Quantitative characterization of polyacrylamide–shale interaction under various saline conditions

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Petroleum Science 2017年第3期14卷 586-596页

作者： Samyukta Koteeswaran Jack c.Pashin Josh D.Ramsey peter E.clark School of chemical Engineering Oklahoma State UniversityStillwater OK 74078 USA Boone Pickens School of Geology Oklahoma State University Stillwater OK 74078 USA

Interaction of polymer-containing injected fluids with shale is a widely studied phenomenon, but much is still unknown about the interaction of charged polyacrylamides such as anionic and cationic polyacrylamides with shale. The nature of interaction of charged polyacrylamides with shale is not well understood, especially from the perspective of assessing the potential for polyacrylamides to cause formation damage. Zeta potential and rheological measurements were made for chattanooga and Pride Mountain shales suspended in polyacrylamide solutions with and without inorganic salts and tetramethyl ammonium chloride（TMAc）. The change in zeta potential and viscosity with time was recorded. The magnitude of decrease in the absolute value of zeta potential with time is indicative of adsorption of polymer on the surface of shale and serves as a measure of the extent of polymer interaction with shale. The salts that were used in this study are potassium chloride（Kcl）, sodium chloride（Na cl）. This study quantified the interaction of anionic and cationic polyacrylamide with different North American *** the experimental results, it was determined that the polyacrylamides can interact strongly with shale, particularly the cationic polyacrylamide. The objective of this study was to determine the extent of interaction of anionic and cationic polyacrylamide with each shale sample in the presence of additives such as salts.

关键词： Anionic and cationic polyacrylamides chattanooga shale Pride Mountain shale Zeta potentialSlurry rheology

Helicobacter pylori upregulates prion protein expression in gastric mucosa: A possible link to prion disease

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World Journal of Gastroenterology 2005年第48期11卷 7651-7656页

作者： peter c Konturek Karolina Bazela Vitally Kukharskyy Michael Bauer Eckhart G Hahn Detlef Schuppan Department of Medicine

AIM： Pathological prion protein （PrP^sc） is responsible for the development of transmissible spongiform encephalopathies （TSE）. While PrPc enters the organism via the oral route, less data is available to know about its uptake and the role of gastrointestinal inflammation on the expression of priori precursor PrPc, which is constitutively expressed in the gastric ***： We studied PrPc expression in the gastric mucosa of 10 Helicobacter pylori-positive patients before and after successful H pylori eradication compared to non-infected controls using RT-PcR and Western blotting. The effect of central mediators of gastric inflammation, i.e., gastrin, prostaglandin E2 （PGE2）, tumor necrosis factor alpha （TNF-α） and interleukin 1 beta （IL-1β） on PrPc expression was analyzed in gastric cell ***： PrPc expression was increased in H pyloriinfection compared with non-infected controls and decreased to normal after successful eradication. Gastrin, PGE2, and IL-1β dose-dependently upregulated PrPc in gastric cells, while TNF-α had no ***： H pylori infection leads to the upregulation of gastric PrPc expression. This can be linked to H pylori induced hypergastrinemia and increased mucosal PGE2 and IL-1β synthesis. H pylori creates a milieu for enhanced propagation of prions in the gastrointestinal tract.

关键词： Prions Helicobacter pylori, Gastrin Proinflammatory cytokines

Solvent Extraction Developments in Southern Africa

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Tsinghua Science and Technology 2006年第2期11卷 153-159页

作者： peter M. cole Kathryn c. Sole Angus M. Feather Matomo Projects (Pty) Ltd. Johannesburg South Africa Anglo American Research Laboratories Johannesburg South Africa cognis corporation Johannesburg South Africa

The largest solvent-extraction plant in the world at the time, the Nchanga copper Operation, was in Zambia. The first commercial process using solvent extraction for the refining of the platinum-group metals was in South Africa. More recently, the Southern African region has seen the implementation of solvent extraction for other base metals, precious metals, and specialty metals. These include the world firsts of primary production of zinc at Skorpion Zinc in Namibia and the large-scale refining of gold by Harmony Gold in South Africa. Several other flowsheets that use solvent-extraction technology are currently under commissioning, development, or feasibility study for implementation in this part of the world, including those for the recovery of copper, cobalt, nickel, tantalum, and niobium.

关键词： solvent extraction zinc recovery gold refining copper cobalt nickel

Geomorphic predictors of riparian vegetation in small mountain watersheds

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Journal of Plant Ecology 2015年第6期8卷 593-604页

作者： Blake M.Engelhardt Jeanne c.chambers peter J.Weisberg Department of Natural Resources and Environmental Science University of NevadaMS 1861664 Virginia StreetRenoNV 89557USA USDA Forest Service Rocky Mountain Research Station920 Valley RoadRenoNV 89512USA

Aims Hydrogeomorphic processes operating at watershed,process zone and site scales influence the distribution of riparian ***,most studies examining the relationships between hydrogeomorphic processes and riparian vegetation are conducted at site *** quantified the relative importance of watershed,process zone and site geomorphic characteristics for predicting riparian plant community types and plant species abundances in four small mountain watersheds in central Nevada,*** We mapped riparian vegetation types and identified process zones(based on dominant geomorphic process and valley fill material)within the *** sampled sites in each combination of veg-etation type and process zone(n=184 sites)and collected data on watershed scale factors,valley and stream geomorphic characteristics and on plant cover of each geomorphic *** community types were defined by cluster and indicator species analyses of plant cover data,and related to geomorphic variables using ordination analysis(nonmetric multidimensional scaling).linear mixed effects models were used to predict abundances of indicator *** Findings Variables describing position in the watershed(elevation,contrib-uting area)that are related to gradients of temperature,moisture and stream discharge were of primary importance in predicting plant community *** describing local geomorphic setting(valley width,stream gradient,channel sediments,geomor-phic surface height)were of secondary importance,but accurately described the geomorphic setting of indicator *** process zone classification did not include position in the watershed or channel characteristics and only predicted plant community types with unique geomorphic *** small mountain watersheds,predicting riparian vegetation distribution requires explicit consid-eration of scale and geomorphic context within and among water-sheds in addition to site variables.

关键词： great basin multiscale plant community analysis process zone riparian

Endovascular thrombectomy for stroke: current best practice and future goals

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Stroke & Vascular Neurology 2016年第1期1卷 16-22页

作者： Bruce c V campbell Geoffrey A Donnan peter J Mitchell Stephen M Davis Department of Medicine and Neurology Melbourne Brain Centre at the Royal Melbourne HospitalUniversity of MelbourneParkvilleVictoriaAustralia The Florey Institute of Neuroscience and Mental Health University of MelbourneParkvilleVictoriaAustralia Department of Radiology Royal Melbourne HospitalUniversity of MelbourneParkvilleVictoriaAustralia

Endovascular thrombectomy for large vessel ischaemic stroke substantially reduces disability,with recent positive randomised trials leading to guideline changes *** review discusses in detail the evidence provided by recent randomised trials and metaanalyses,the remaining areas of uncertainty and the future directions for *** data from existing trials have demonstrated the robust benefit of endovascular thrombectomy for internal carotid and proximal middle cerebral artery *** remains for more distal occlusions where the efficacy of alteplase is greater,less tissue is at risk and the safety of endovascular procedures is less *** artery occlusion was excluded from the trials,but with a dire natural history and proof of principle that rapid reperfusion is effective,it seems reasonable to continue treating these patients pending ongoing trial *** has been no evidence of heterogeneity in treatment effect in clinically defined subgroups by age,indeed,those aged>80 years have at least as great an overall reduction in disability and reduced *** there was no heterogeneity across the range of baseline stroke severities included in the *** that routine use of general anaesthesia reduces the benefit of endovascular thrombectomy is increasing and conscious sedation is generally preferred unless severe agitation or airway compromise is *** impact of time delays has become clearer with description of onset to imaging and imaging to reperfusion *** in the onset to imaging reduce the proportion of patients with salvageable brain ***,in the presence of favourable imaging,rapid treatment appears beneficial regardless of the onset to imaging time *** to reperfusion delays lead to decay in the clinical benefit achieved,particularly in those with less robust collateral *** brain imaging options to assess prognosis have various advantages and disadvan

关键词： routine epoch benefit

Statin, testosterone and phosphodiesterase 5-inhibitor treatments and age related mortality in diabetes

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World Journal of Diabetes 2017年第3期8卷 104-111页

作者： Geoffrey Hackett peter W Jones Richard c Strange Sudarshan Ramachandran Department of Urology University of Bed-fordshire Department of Urology Heart of England NHS Foundation Trust Metabolic Research Group Institute of Science and Technology in Medicine Keele University Department of clinical Biochemistry Heart of England NHS Foundation Trust Department of clinical Biochemistry University Hospitals of North Midlands/Faculty of Health Sciences Staffordshire University

AIMTo determine how statins, testosterone (T) replacement therapy (TRT) and phosphodiesterase 5-inhibitors (PDE5I) influence age related mortality in diabetic *** studied 857 diabetic men screened for the BLAST study, stratifying them (mean follow-up = 3.8 years) into: (1) Normal T levels/untreated (total T > 12 nmol/L and free T > 0.25 nmol/L), Low T/untreated and Low T/treated; (2) PDE5I/untreated and PDE5I/treated; and (3) statin/untreated and statin/treated groups. The relationship between age and mortality, alone and with T/TRT, statin and PDE5I treatment was studied using logistic regression. Mortality probability and 95%cI were calculated from the above models for each *** was associated with mortality (logistic regression, OR = 1.10, 95%cI: 1.08-1.13, P ctors included, age (OR = 1.08, 95%cI: 1.06-1.11, P cI: 0.15-0.92, P = 0.033), PDE5I/treated (OR = 0.17, 95%cI: 0.053-0.56, P = 0.004) and statin/treated (OR = 0.59, 95%cI: 0.36-0.97, P = 0.038) were associated with lower mortality. Age related mortality was as described by Gompertz, r2 = 0.881 when Ln (mortality) was plotted against age. The probability of mortality and 95%cI (from logistic regression) of individuals, treated/untreated with the drugs, alone and in combination was plotted against age. Overlap of 95%cI lines was evident with statins and TRT. No overlap was evident with PDE5I alone and with statins and TRT, this suggesting a change in the relationship between age and *** show that statins, PDE5I and TRT reduce mortality in diabetes. PDE5I, alone and with the other treatments significantly alter age related mortality in diabetic men.

关键词： Type 2 diabetes Mortality Gompertz-Makeham equation Phosphodiesterase 5 inhibitors Male hypogonadism Statins Testosterone replacement therapy

Esports players,got muscle?competitive video game players’physical activity,body fat,bone mineral content,and muscle mass in comparison to matched controls

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Journal of Sport and Health Science 2022年第6期11卷 725-730页

作者： Joanne DiFrancisco-Donoghue William G.Werner peter c.Douris Hallie Zwibel Department of Osteopathic Medicine New York Institute of Technology College of Osteopathic Medicine(NYIT-COM)Old WestburyNY 11568USA center for Sports Medicine NYIT-COMOld WestburyNY 11568USA Department of Physical Therapy NYITOld WestburyNY 11568USA Department of Family Medicine NYIT-COMOld WestburyNY 11568USA

Background:Esports players,like traditional athletes,practice for long hours and,thus,are vulnerable to the negative health effects of prolonged *** is a lack of research on the physical activity and the health ramifications of prolonged sitting by competitive *** purpose of this study was to investigate activity levels,body mass index(BMI),and body composition in collegiate esports players as compared to agematched ***:Twenty-four male collegiate esports players and non-esports players between 18 and 25 years of age signed a written consent to *** activity was examined using daily activity(step count)with a wrist-worn activity tracker.A questionnaire assessing physical activity was also *** outcomes included body-fat percentage,lean-body mass,BMI,and bone mineral content measured using dual X-ray ***:The step count in the esports players was significantly lower than the age-matched controls(6040.2±3028.6 vs.12843.8±5661.1;p=0.004).Esports players exhibited greater body-fat percentage(p=0.05),less lean body mass(p=0.003),and less bone mineral content(p=0.03),despite no difference in BMI between the esports and non-esports ***:As compared to non-esports players,collegiate esports players were significantly less active and had a higher body-fat percentage,with lower lean body mass and bone mineral *** BMIs showed no difference between the 2 *** athletes displayed significantly less activity and poor body composition,which are all correlated with potential health issues and risk of *** did not capture this difference and should not be considered as an accurate measure of health in competitive esports players.

关键词： Body composition Body mass index Gaming

The Voisey's Bay Ni-cu-co Sulfide Deposit, Labrador, canada: Emplacement of Silicate and Sulfide-Laden Magmas into Spaces created within a Structural corridor

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西北地质 2012年第4期45卷 17-38页

作者： peter c.Lightfoot Dawn Evans-Lamswood Robert Wheeler Vale ExplorationHighway 17 WestSudburyOntarioP0M 1N0Canada Vale Newfoundland and Labrador Limited Bally Rou Place280Torbay RoadSuite W200St.John'sNewfoundlandA1A 3W8Canada

The Voisey's Bay Ni-cu-co sulfide deposit is hosted in a 1.34 Ga mafic intrusion that is part of the Nain Plutonic Suite in Labrador, *** Ni-cu-co sulfide mineralization is associated with magmatic breccias that are typically contained in weakly mineralized olivine gabbros, troctolites and ferrogabbros, but also occur as veins in adjacent *** mineralization is associated with a dyke-like body which is termed the feeder *** dyke connects the shallow differentiated Eastern Deeps chamber in the east to a deeper intrusion in the west termed the Western Deeps *** the conduit is connected to the Eastern Deeps Intrusion, the Eastern Deeps Deposit is developed at the entry line of the dyke along the steep north wall of the Eastern Deeps *** Eastern Deeps Deposit is surrounded by a halo of moderately to weakly mineralized Variable-Textured Troctolite (VTT) that reaches a maximum thickness above the ENE-WSW axis of the Eastern Deeps Deposit. At depth to the west, the conduit is adjacent to the south side of the Western Deeps Intrusion, where the dyke and intrusion contain disseminated magmatic sulfide *** Reid Brook Zone plunges to the east within the dyke, and both the dyke and adjacent paragneiss are *** Ovoid Deposit comprises a bowl-shaped body of massive sulfide where the dyke widens near to the present-day *** is not clear whether this deposit was developed as a widened-zone within the conduit or at the entry point into a chamber that is now lost to erosion. The massive sulfides and breccia sulfides of the Eastern Deeps are petrologically and chemically different when compared to the disseminated sulfides in the VTT; there is a marked break in Ni tenor (Ni content in 100% sulfide, abbreviated to [Ni]100) and Ni/co of sulfide between the *** boundary of the sulfide types is often marked by strong sub-horizontal alignment of heavily digested and metamorphosed paragneiss fragments, developm

关键词： Voisey’s Bay Ni-cu-co sulfide deposit Labrador canada

changes in Air Temperatures and Atmosphere circulation in High Mountainous Parts of Bulgaria for the Period 1941-2008

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Journal of Mountain Science 2012年第2期9卷 185-200页

作者： peter NOJAROV National Institute of Geophysics Geodesy and GeographyBulgarian Academy of Sciences

changes of air temperatures and atmosphere circulation at three high mountainous stations in Bulgaria are investigated for the period of *** three stations are located on peaks Musala,cherni vrah and Botev,where air temperature data have good *** missing data were recovered using the method of differences. A significant mean annual air temperature rise happened in high mountainous parts of Bulgaria- the warming is in the order of 0.7°c for the entire *** increase is very prominent particularly in the last 30 *** contributors to this overall tendency are summer months-June,July and *** some degree,January also could be included in this *** trend shows temperature rise at the beginning of the investigated *** of the causes for such a tendency is atmosphere circulation in respective *** also shows signs of considerable reorganization in both winter and *** is an increase of the cases of warm atmosphere patterns typical for winter, summer and autumn seasons in *** circulation has essential significance for air temperatures during the cold half of the *** January and June atmosphere circulation has a substantial influence on the thermal regime of air in high mountains of *** July,August and November this influence is *** are no cycles in air temperatures for the investigated period.

关键词： Air temperature Trends Atmosphere circulation Bulgaria Mountains