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Evaluation of formation susceptibility and sand production potential in an offshore field,Niger Delta Basin,Nigeria

Energy Geoscience 2024年第1期5卷 1-11页

作者： david O.Ubuara Yinka A.Olayinka Godwin O.Emujakporue Geoffrey c.Soronnadi-Ononiwu Department of Geology University of Port HarcourtNigeria Mease Energy Nigeria Limited Port HarcourtNigeria Department of Geology University of IbadanNigeria Department of Physics University of Port HarcourtNigeria

Wellbore instability and sand production are all common challenges in the Niger Delta oil province,resulting in high drilling and production cost as well as damage to oil *** vulnerability of lithologic formations to wellbore instability and resultant sand production is investigated in the four delineated reservoirs of the“Areo”field,western part of Niger Delta *** foundation for establishing the geomechanical properties in this study was a 1-dimensional mechanical earth model,using gamma ray(GR),density(RHOB),compressional slowness(DTc),and shear slowness(DTS)*** the Areo oil field,two wells(well 001 and well 002)were *** evaluated formations are still primarily composed of compacted shale and unconsolidated sandstone,with reservoir sand units exhibiting lower elastic and rock strength properties than shale *** compressibility and porosity make sand more brittle,while low compressibility and porosity make shale stiffer due to high *** maximum force that can be applied to a shale unit without causing it to fail is 17.23 MPa,which is the maximum average rock strength of the *** means that shale requires more vertical stress or pressure than sand does in order to deform it(15.06 MPa).The three sand prediction approaches used in the analysis of sand production predictions have cut-off values that are higher than the average values of the *** Schlumberger sand production index method(S/I)indicates that the reservoir has potential for sand influx in the two wells,with the average of the four reservoirs studied in wells 001 and 002 being 1.551012 psi and 1.141012 psi ***,when a formation's sand production index is less than 1.241012 psi,as it is in this study,the formation is likely to produce *** findings support the notion that the defined sandstone units are highly unconsolidated and have a high potential for producing sands;therefore,sand control techniques must be factored in

关键词： Wireline log Stress Geo-mechanicanical characterization Sand prediction Niger delta

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An in vitro investigation of photodynamic efficacy of FosPeg■ on human colon cancer cells

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Journal of Innovative Optical Health Sciences 2015年第5期8卷 86-93页

作者： Ricky W.K.Wu Ellie S.M.chu Zheng Huang Malini c.Olivo david c.W.Ip christine M.N.Yow Medical Laboratory Science Department of Health Technology&Informatics Hong Kong Polytechnic UniversityHKSARChina Department of Medical Science Tung Wah CollegeHKSARChina college of Photonic&Electronic Engineering Fujian Normal University Fuzhou China University of colorado Denver cancer center COUSA Department of Pharmacy National University of SingaporeSingapore

Photodynamic therapy(PDT)is a novel therapeutic approach for combating various *** involves the administration of a photosensitizer which generates singlet oxygen after light ***■ is the liposomal formulation of *** this in vitro study,the photodynamic efficacy of FosPeg■ on a human colon cancer cell line(HT29)was investigated via studying the cellular uptake of FosPeg■,FosPeg■ PDT mediated photocytotoxicity and the cell death mechanism were ***■ PDT demonstrated its antitumor effect in a drug and light dose-dependent manner in HT-29 *** dose(LD50)was achieved with 0.4g/mL of drug and 3 J/cm^(2) of light ***■ PDT triggered apoptotic cell death via activating caspase cascade and regulating cell cycle *** conclusion,FosPegr-PDT is an effective measure to combat human colon cancer cells.

关键词： FosPeg■ HT-29 apoptosis caspase-3

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Atlas of precipitation extremes for South America and Africa based on depth-duration-frequency relationships in a stochastic weather generator dataset

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International Soil and Water conservation Research 2023年第4期11卷 726-742页

作者： Andrew Fullhart david c.Goodrich Menberu B.Meles Paulo Tarso S.Oliveira cristiano das Neves Almeida Joséc.de Araújo Shea Burns Southwest Watershed Research center USDA-ARS 2000 E.Allen Rd.TucsonAZ85719United States Sustainable Agricultural Water Systems Unit USDA-ARS 239 Hopkins RoadDavisCA95616United States Faculty of Engineering Architecture and Urbanism and GeographyUniversidade Federal de Mato Grosso do SulCampo GrandeMS79070-900Brazil Water Resources and Environmental Engineering Laboratory Universidade Federal da ParaíbaJoao PessoaPB58051-900Brazil Department of Agricultural Engineering campus do Pici Fortaleza Universidade Federal do CearáFortaleza60020-181Brazil

Information about extreme rainfall is lacking in regions of South America and *** study attempts to fill this scientific gap by use of a gridded parameterization for the stochastic weather generator,cLIGEN,to map depth-duration-frequency(DDF)*** of 500-year point-scale precipitation time series generated at each grid point allowed maps of return period precipitation to be produced for a se-lection of sixteen durations ranging from 10-min to 1-year and for nine return periods from 2 to 500 *** generalized extreme value(GEV)probability distribution was fitted for all durations,and given GEV quantiles,an interpolation method was applied to produce maps at 0.1° resolution that better resolve small-scale spatial climate *** addition to uncertainties related to GEV fitting,this study quantifies prediction intervals based on ground *** validation was important for identifying biases in cLIGEN,although uncertainties were not always satisfactorily defined due to sampling design and other *** daily/multi-day durations,100 stations with daily observations and ≥50-year records were selected for validation against the 0.1° cLIGEN map series,resulting in a median and average absolute error of 13%and 16%,*** sub-daily durations,prediction errors were larger *** analogy using available *** established the degree of bias in cUGEN for sub-daily durations,and three records in Brazil with high temporal resolutions were used to confirm that applied bias adjustments resulted in error ranges similar to the daily/multi-day *** atlas is freely available for study of extreme precipitation.

关键词： Africa Depth-duration-frequency Extreme precipitation South America

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Biliary Mucinous cystadenoma: A Review of the Literature

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Journal of clinical and Translational Hepatology 2019年第2期7卷 149-153页

作者： Leon D.Averbukh david c.Wu Woo cheal cho George Y.Wu Department of Medicine Division of Gastroenterology-HepatologyUniversity of Connecticut Health CenterFarmingtonCTUSA Department of Pathology Hartford HospitalHartfordCTUSA

Biliary mucinous cystadenomas are cystic neoplasms commonly mistaken for simple *** are rare and generally benign tumors,often incidentally found on imaging and during unrelated surgical *** tend to be slow growing though may reach symptomatic *** of biliary mucinous cystadenomas may have serious consequences secondary to their potential for malignant transformation into biliary mucinous ***,we review the epidemiology,etiology,pathology,diagnostic modalities,histology,and available treatment methods for mucinous cystadenomas reported in current literature.

关键词： Biliarymucinous cystadenoma Biliary mucinous cystadenocarcinoma cystic neoplasm

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collatz Sequences and characteristic Zero-One Strings: Progress on the 3<i>x</i>+ 1 Problem

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American Journal of computational Mathematics 2021年第3期11卷 226-239页

作者： david c. Kay Asheville USA

The unsolved number theory problem known as the 3x + 1 problem involves sequences of positive integers generated more or less at random that seem to always converge to 1. Here the connection between the first integer (n) and the last (m) of a 3x + 1 sequence is analyzed by means of characteristic zero-one strings. This method is used to achieve some progress on the 3x + 1 problem. In particular, the long-standing conjecture that nontrivial cycles do not exist is virtually proved using probability theory.

关键词： Generator Resultant 3x + 1 cycle

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Short mucin 1 alleles are associated with low virulent H pylori strains infection

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World Journal of Gastroenterology 2007年第12期13卷 1885-1886页

作者： Bárbara Peleteiro Nuno Lunet Filipe Santos-Silva Leonor david céu Figueiredo Henrique Barros Department of Hygiene and Epidemiology Medical Faculty University of Porto Portugal Institute of Molecular Pathology and Immunology of the University of Porto Portugal

TO THE EDITORWe read with interest the article published by Nguyen et al in the World Journal of Gastroenterology, showing an association between short MUc6 alleles and H pjloff infection. These results, together with previous observations by Vinall et al, reinforce the role of mucin genes （MUc6 and MUc1） VNTR polymorphisms for the variability in individual susceptibility to H pylori infection that cannot be explained by differences in environmental factors.

关键词： H pylori MUc1 Polymorphism cagA vacA

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A Solution to the 3x + 1 Problem

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American Journal of computational Mathematics 2023年第2期13卷 371-377页

作者： david c. Kay Weaverville NC USA

The author makes the claim to have a solution for the famous 3x + 1 problem. The key to its solution is a special proof that the term (3 + ε)r is a non-integer, as well as the use of properties of extremal points of ... 详细信息

关键词： collatz Sequences Extreme Points Pre-Extreme Sequence

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Sorption and Leaching Potential of Isoproturon and Atrazine in Low Organic carbon Soil of Pakistan Under a Wheat-Maize Rotation

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Pedosphere 2016年第5期26卷 687-698页

作者： Muhammad TAHIR Anwar Ul HASSAN Saliha MAQBOOL Brian BARBER William c.KOSKINEN PENG Xinhua david J.MULLA State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008(China) Institute of Soil&Environmental Sciences University of Agriculture FaisalabadPunjab 38000(Pakistan) Soil and Water Management Research Laboratory St.Paul MN 55108-6089(USA) Department of Soil Water&ClimateUniversity of MinnesotaTwin Cities MN 55108-6089(USA)

Pesticide leaching is a great threat in low organic carbon soils when subjected to improper irrigation *** data are available on the sorption and leaching potential of pesticides in agricultural soils of Pakistan with low soil organic carbon(SOc).Lysimeter and field studies were conducted with and without manure application at two irrigation levels in a wheat-fallowmaize rotation in Faisalabad,Punjab,*** was applied to wheat 55 d after sowing at 1 kg active ingredient(a.i.)ha^(-1),while atrazine was sprayed on maize 30 d after sowing at 0.774 kg ***^(-1).Soil was sampled from three depths(0-35,35-70,and 70-110 cm) for the field study and four depths(0-35,35-70,70-115,and 115-160 cm) for the lysimeter study,280 and 65 d after application of isoproturon and atrazine,*** soil-water partition coefficients(K_d) of isoproturon and atrazine ranged from 0.3 to 1.2 and 0.4 to 1.5 L kg^(-1),respectively,and increased linearly with increase in SOc *** organic carbon-normalized soil-water partition coefficient(K_(oc)) of isoproturon and atrazine averaged 246.1 and 184.9 L kg^(-1),respectively,being higher with low spiking *** residues measured 280 d after application ranged from 2.1% to 3.6% of the applied mass in the lysimeter study and from 1.5% to 3.1% under field *** residues 65 d after application ranged from only 0.62% to 0.78% and from 0.88% to 0.82% in the lysimeter and field studies,*** lowest levels of residues for both pesticides were observed with frequent irrigation applied to manure-amended soil.A pesticide leaching risk screening tool,the ground water ubiquity score(GUS),indicated that in the absence of manure under both irrigation levels,isoproturon has a leaching potential(GUS = 2.8),while with the application of manure it has a very low leaching *** GUS ranged from 1.7 to 1.9,indicating a very low risk of leaching.

关键词： concentration dependent sorption irrigation manure leaching risk assessment pesticide

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Validation of the Rockall scoring system for outcomes from non-variceal upper gastrointestinal bleeding in a canadian setting

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World Journal of Gastroenterology 2006年第48期12卷 7779-7785页

作者： Robert A Enns Yves M Gagnon Alan N Barkun david Armstrong Jamie c Gregor Richard N Fedorak RUGBE Investigators Group Division of Gastroenterology University of British Columbia Vancouver Canada Occam Research & consulting Inc. VancouverCanada Department of Medicine Division of Gastroenterology McGill University and the McGill UniversityHealth Center Montreal Canada Division of Gastroenterology McMaster University Medical Centre Hamilton Canada Division of Gastroenterology University of Western Ontario London Canada Division of Gastroenterology University of Alberta Edmonton Canada 不详

AIM: To validate the Rockall scoring system for predicting outcomes of rebleeding, and the need for a surgical procedure and death. METHODS: We used data extracted from the Registry of Upper Gastrointestinal Bleeding and Endoscopy including information of 1869 patients with non-variceal upper gastrointestinal bleeding treated in canadian hospitals. Risk scores were calculated and used to classify patients based on outcomes. For each outcome, we used χ2 goodness-of-fit tests to assess the degree of calibration, and built receiver operating characteristic curves and calculated the area under the curve (AUc) to evaluate the discriminative ability of the scoring system. RESULTS: For rebleeding, the χ2 goodness-of-fit test indicated an acceptable fit for the model [χ2 (8) = 12.83, P = 0.12]. For surgical procedures [χ2 (8) = 5.3, P = 0.73] and death [χ2 (8) = 3.78, P = 0.88], the tests showed solid correspondence between observed proportions and predicted probabilities. The AUc was 0.59 (95% cI: 0.55-0.62) for the outcome of rebleeding and 0.60 (95% cI: 0.54-0.67) for surgical procedures, representing apoor discriminative ability of the scoring system. For the outcome of death, the AUc was 0.73 (95% cI: 0.69-0.78), indicating an acceptable discriminative ability. cONcLUSION: The Rockall scoring system provides an acceptable tool to predict death, but performs poorly for endpoints of rebleeding and surgical procedures.

关键词： Upper gastrointestinal bleeding Nonvariceal Predictors Rockall Outcomes

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Proton therapy for hepatocellular carcinoma

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chinese Journal of cancer Research 2012年第4期24卷 361-367页

作者： Ted c.Ling Joseph I.Kang david A.Bush Jerry D.Slater Gary Y.Yang Department of Radiation Medicine Loma Linda University Medical Center

Proton radiotherapy has seen an increasing role in the treatment of hepatocellular carcinoma （Hcc）. Historically, external beam radiotherapy has played a very limited role in Hcc due to a high incidence of toxicity to surrounding normal structures. The ability to deliver a high dose of radiation to the tumor is a key factor in improving outcomes in Hcc. Advances in photon radiotherapy have improved dose conformity and allowed dose escalation to the tumor. However, despite these advances there is still a large volume of normal liver that receives a considerable radiation dose during treatment. Proton beams do not have an exit dose along the beam path once they enter the body. The inherent physical attributes of proton radiotherapy offer a way to maximize tumor control via dose escalation while avoiding excessive radiation to the remaining liver, thus increasing biological effectiveness. In this review we discuss the physical attributes and rationale for proton radiotherapy in Hcc. We also review recent literature regarding clinical outcomes of using proton radiotherapy for the treatment of I-Icc.

关键词： Proton radiotherapy hepatocellular carcinoma (Hcc)

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