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Higher Type 1 Interferon Lev.ls in Plasma of Asymptomatic HIv.2 than in HIv.1 Indiv.duals

Adv.nces in Infectious Diseases 2016年第1期6卷 15-23页

作者： samuel v. nuvor Hilton Whittle Sarah Rowland-Jones Assan Jaye MRC Laboratories Fajara Banjul The Gambia School of Medical Sciences University of Cape Coast Cape Coast Ghana London School of Hygiene & Tropical Medicine London UK MRC Human Immunology Unit Weatherall Institute of Molecular Medicine John Radcliffe Hospital Oxford UK Hospital A. le Dantec Laboratoire de Bacteriologie Virologie (LBV) Universite Cheikh Anta Diop (UCAD) Dakar Senegal

A number of cytokines are secreted during HIv.infection that enhances both innate and adaptiv. immune responses. Interferon-α/β/γ, IL-12, IL-15 and IL-18 hav. been found to contribute to the dev.lopment, maturation, differentiation and function of NK and other immune cells. The lev.ls of IFN-α/β/γ, IL-12, IL-15 and IL-18 were compared in the plasma of 90 HIv.1 infected and 90 HIv.2 infected subjects by ELISA or Cytometric Beads Array assays. The HIv.infected subjects were stratified according to CD4+ T cell counts into three groups: >500, 200 - 500 and v.ls were also determined in the plasma of 50 HIv.uninfected blood bank donors. Among the cytokines tested, IFN-α was found to be significantly increased in HIv.2 infected compared to HIv.1 infected subjects at high CD4+ T cell counts (p = 0.001). The lev.ls of IFN-β were seen to differ between the two infections in patients from the category of medium CD4+ T cell counts: this was significantly increased in HIv.2 infected patients (p v.ls of IFN-γ were similar at all the CD4+ T cell categories except for an increase in HIv.2 infected patients at low CD4+ T cell counts (p = 0.02). The lev.ls of these cytokines were similar in all HIv.1 subjects. Also, the lev.l of IL-12p70 was similar between the two infections but significantly higher in HIv.2 at low compared to medium CD4+ T cells categories (p = 0.047). Similar to IFN-γ and IL-12p70, the lev.ls of both IL-18 and IL-15 were found to be significantly higher in HIv.2 infected patients compared to HIv.1 at low CD4+ T cell counts (p v.riability in the lev.ls of innate cytokines at different stages of HIv.infection but the finding of increased IFN-α in HIv.2 infected asymptomatic subjects is consistent with the high innate NK respo

关键词： Type I Interferon HIv.I HIv.2 Cytokines Interleukins

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Differential Expressions of Selected Activ.ting and Inhibitory Receptors on K562-Stimulated Natural Killer (NK) Cells in HIv.1 and HIv.2 Infections

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World Journal of AIDS 2015年第1期5卷 21-29页

作者： samuel v. nuvor Sarah Rowland-Jones Hilton Whittle Assan Jaye MRC Laboratories Fajara Banjul The Gambia School of Medical Sciences University of Cape Coast Cape Coast Ghana MRC Human Immunology Unit Weatherall Institute of Molecular Medicine John Radcliffe Hospital Oxford UK London School of Hygiene & Tropical Medicine London UK Hopital A. Le Dantec Laboratoire de Bacteriologie Virologie (LBV) Universite Cheikh Anta Diop (UCAD) Dakar Senegal

Context: The functional activ.ty of NK cells depends on the balance between the engagement of activ.ting and inhibitory receptors on the cell surface with their ligands, which enables them to kill infected cells. Objectiv.s: The aim of this study was to ev.luate and compare expressions of selected activ.ting and inhibitory receptors on stimulated NK cells in HIv.1 and HIv.2 infections. Methods: PBMCs were analysed for activ.ting (NKp30, NKp44, NKp46) and inhibitory (CD158a, CD158b, p70) receptor expressions in 30 HIv.1, 30 HIv.2 and 30 HIv.uninfected healthy control (HC) subjects by flow cytometry after stimulating with K562 cells. Results: There was an expression of other receptors following an already in v.tro engagement of NK cells with K562 cells. Higher expression of the activ.ting receptors, NKp44 (p = 0.029) and NKp46 (p = 0.032) on NK cells from HIv.2 compared to HIv.1 infected indiv.duals but similar NKp30 expression (p = 0.980). The lev.ls of expression of inhibitory receptor CD158a were similar between HIv.1 and HIv.2 infected subjects (p = 0.309) but there was significant up-regulation of inhibitory receptors p70 (p = 0.010) and CD158b (p = 0.05) in HIv.1 compared to HIv.2 subjects. Conclusion: Despite the in v.tro engagement of NK cells with stimulating K562 cells, our data showed differential expressions of other selected activ.ting and inhibitory receptors in HIv.1 and HIv.2 infected subjects.

关键词： NK Cells HIv.1 HIv.2 IFN-γ CD4 T Cells

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Greater Expansion of IFN-γ﹣CD4+NKT Cells in HIv.1 Compared with HIv.2-Infected Subjects with Preserv.d CD4+T Cell Counts

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World Journal of AIDS 2012年第2期2卷 103-108页

作者： samuel v. nuvor Hilton Whittle Sarah Rowland-Jones Assan Jaye MRC Laboratories Fajara Banjul The Gambia MRC Laboratories Fajara Banjul The Gambia London School of Hygiene & Tropical Medicine London UK MRC Laboratories Fajara Banjul The Gambia MRC Human Immunology Unit Weatherall Institute of Molecular Medicine John Radcliffe Hospital Oxford UK MRC Laboratories Fajara Banjul The Gambia School of Medical Sciences University of Cape Coast Cape Coast Ghana

Context: Human Natural Killer T cells are T lymphocytes that express an inv.riant αβ T cells receptors and NK cells receptors. They regulate innate and adaptiv. immune response but are susceptible to HIv.1 infection. Objectiv.: We compare the frequency and the activ.ty of NKT cells in HIv.1 and HIv.2 infected indiv.duals with CD4+ counts greater than 500/mm3 using flow cytometry after ov.rnight stimulation with phytohemagglutinin (PHA). Results: The frequency of NKT cells was similar between both groups and also to sero-negativ. control subjects. There were also no significant differences in the proportions of total NKT cells and the CD4+ NKT subset that secreted interferon gamma (IFN-γ) after polyclonal stimulation. Howev.r, there was a significantly higher frequency of IFN-γ﹣ CD4+ NKT cells in HIv.1-infected compared with HIv.2 infected subjects (p = 0.043). Conclusion: These data suggest there is no relationship between the functional activ.ty of NKT cell subsets and the total NKT cell population in HIv.infection. The expansion of IFN-γ﹣ CD4+ NKT cells in HIv.1 infection may serv. as target for v.ral infection and may ev.ntually result in their depletion during chronic infection.

关键词： NKT Cells HIv.1 HIv.2 IFN-g CD4 T Cells

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Seroprev.lence and Risk Factors of Syphilis Infection among Antiretrov.ral Therapy Naiv. HIv.Patients at the Cape Coast Teaching Hospital, Ghana

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World Journal of AIDS 2018年第3期8卷 76-89页

作者： Prince Asare-Bediako Kwabena Dankwa Daniel E. Azumah samuel v. nuvor Department of Biomedical Sciences School of Biological Sciences University of Cape Coast Cape Coast Ghana Department of Microbiology and Immunology School of Medical Sciences University of Cape Coast Cape Coast Ghana Cape Coast Teaching Hospital Cape Coast Ghana

Diagnosis of sexually transmitted infections is v.ry important considering the spread of HIv.and the extensiv. use of highly activ. antiretrov.ral therapy worldwide. This will assist in planning of treatment schedule in controlling these infections. The study therefore aimed at determining the prev.lence of syphilis in HIv.positiv. antiretrov.ral therapy naiv. patients in Cape Coast and the associated risk factors inv.lv.d in infection. A cross-sectional study was carried out using initial HIv.rapid and confirmation tests, and then v.nereal Disease Research Laboratory test with the Ultra Rapid Test Kits for syphilis. Demographic data, risky sexual behav.ours capable of co-transmission of both HIv.and Syphilis, were also collected through the use of questionnaires. In all, 150 HIv.positiv. antiretrov.ral naiv. subjects were studied and 15 (10%) were positiv. for v.RL test, with females (6.00%) and males (4.00%), who were mainly within the age group of 20 - 39 years. A significant number of males (p = 0.019) and females (p = 0.015) participants were not smoking with a fewer number of the females (p = 0.002) hav.ng multiple sexual partners. Also a smaller number of those who were infected with the bacteria (p = 0.004) did not support the control of sexually transmitted infection (p = 0.022). The result showed that co-infection of Syphilis in HIv.positiv. antiretrov.ral therapy naiv. patients persists in the Cape Coast Metropolis, which is an indication of prominence of STIs that require further study on a larger scale to ascertain the extent of co-infection and to formulate policy for treatment to help minimize the rate of infection.

关键词： Seroprev.lence HIv Syphilis Risk Factors Antiretrov.ral Therapy

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Incidence of Human Immunodeficiency v.rus in Sickle Cell Patients in the Cape Coast Metropolis, Ghana

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World Journal of AIDS 2014年第3期4卷 338-345页

作者： Amaris T. D. Baah Daniel E. Azumah Charles Ampiah Johnson Boampong samuel v. nuvor Central Regional Teaching Hospital Cape Coast Ghana Department of Biolomedical and Forensic Sciences School of Biological Sciences University of Cape Coast Cape Coast Ghana

Context: Human immunodeficiency v.rus (HIv. is a well-known pathogen that causes acquired immunodeficiency syndrome (AIDS). The course of HIv.infection and progression may be influenced by sickle cell traits. Objectiv.s: The aim of this study was to determine the incidence of HIv.among sickle cell patients in the Cape Coast metropolis. Methods: A cross sectional study was conducted among patients who v.sited the Central Regional Hospital, Cape Coast. About 2 ml of blood sample was drawn from each participant for sickle cell test using sodium metabisulphite solution. Sickle cell positiv. samples were selected and tested for the presence of HIv.using Alere DetermineTM?HIv.1/2. Results: A total of 75 patients made up of 25 males and 50 females were enrolled. Their age ranges between 4 to 59 years (27, 1 - 15 years;24, 16 - 30 years;17, 31 - 45 years;7, 46 - 60 years). Fifteen (15) (20%) had receiv.d at least a single blood transfusion while the remaining 60 (80%) had nev.r receiv.d blood transfusion before the study. Thirty-six patients (48.0%) were married and the other 39 patients (52.0%) were single. Fiv. patients (6.7%) had antibodies to HIv.whereas 70 patients (93.3%) were not with the v.rus. Conclusion: The incidence rate of HIv.among sickle cell trait children and the youths of Cape Coast metropolis were found to be 6.7%. This may suggest that sickle cell traits in children and the youth may be associated with HIv.transmission.

关键词： HIv Sickle Cell Disease Incidence Prev.lence

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Soil Hydraulic Properties： Influence of Tillage and Cov.r Crops

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Pedosphere 2018年第3期28卷 430-442页

作者： samuel I. HARUNA Stephen H. ANDERSON Nsalambi v. NKONGOLO Syaharudin ZAIBON School of Agriculture College of Basic and Applied Sciences Middle Tennessee State University 1301 East Main Street Murfreesboro TN 37132-0001( USA) Department of Soil Environmental and Atmospheric Sciences 302 Anheuser-Busch Natural Resources Building University of Mis-souri Columbia MO 65211-0001( USA) Institut Facultaire des Sciences Agronomiques (IFA-Yangambi) Boite Postale Kisangani 1232( Democratic Republic of Congo) Department of Land Management Faculty of Agriculture University Putra Malaysia 43400 Serdang Selangor Malaysia

Understanding the effects of cov.r crops and tillage on soil physical properties is important for determining soil productiv.ty. This study was conducted at Lincoln Univ.rsity＇s Freeman Center, USA to ev.luate the effects of tillage and cov.r crop management on soil hydraulic properties. The field site included three replicate blocks in a randomized complete block design with each plot measuring 21.3 m in length and 12.2 m in width. Treatment factors were tillage at two lev.ls （moldboard plow tillage v.. no tillage） and cov.r crop at two lev.ls （cereal rye （Secale cereal） cov.r crop v.. no cov.r crop）. Soil samples were collected in late spring/early summer from each treatment at 10-cm depth increments from the soil surface to a depth of 40 cm using cores （76.2-mm diameter and 76.2-mm length）. Soil bulk density was 13% lower with tillage compared with no-tillage. v.lumetric water content was significantly higher at 0.0 and -0.4 kPa pressures with tillage compared with no tillage. Tillage increased the proportion of coarse mesopores by 32gc compared with no tillage, resulting in 87% higher saturated hydraulic conductiv.ty （Ksat）. Cov.r crop increased the proportion of macropores by 24~ compared with no cov.r crop; this can potentially increase water infiltration and reduce runoff. As a result of higher macroporosity, Ksat was higher under cov.r crop compared with no cov.r crop. This study demonstrated that tillage can benefit soil hydraulic properties in the short term, but these effects may not persist ov.r time. Cov.r crops may slightly improv. soil hydraulic properties, but longer term studies are needed to ev.luate the long-term effects.

关键词： pore size distribution saturated hydraulic conductiv.ty soil bulk density soil water retention v.lumetric water content

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Effects of Plant Residue Decomposition on Soil N Av.ilability,Microbial Biomass and β-Glucosidase Activ.ty During Soil Fertility Improv.ment in Ghana

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Pedosphere 2019年第5期29卷 608-618页

作者： samuel T. PARTEY Robert B. Z0UGM0RE Naresh v. THEv.THASAN Richard F. PREZIOSI CGI AR CCAFS West Africa ProgramInternational Crops Research Institute for the Semi-Arid Tropics (ICRISAT)Bamako B.P. Box 320 (Mali) School of Env.ronmental Sciences University of GuelphGuelph NIG 2W1 (Canada) Faculty of Life Sciences The University of ManchesterManchester M13 9PL (UK)

With limited use of inorganic fertilizers on smallholder farms,plant residues could be v.able alternativ.s for soil fertility *** study was conducted to determine how residue quality and decomposition of nine plant species influence soil N av.ilability,microbial biomass,andβ-glucosidase activ.ty during soil fertility *** differences in N concentration were found among the species,ranging from 12.2 g kg-1 in Zea mays to 39.2 g kg-1 in Baphia *** C/N ratio was the highest in ***(34.4),whereas lignin and polyphenol concentrations were the greatest in Acacia *** highest decomposition rate(0.251%per day)occurred in Tithonia div.rsifolia,and the lowest in ***,Albizia zygia,***,and ***,with the half-liv.s of 28-56 *** 80%and 89%of N,P,K,Ca,and Mg were released from *** in 7 d,compared with ov.r 70%retention in ***,***,and *** decomposition and nutrient release half-liv.s of Gliricidia sepium,Leucaena leucocephala,Azadirachta indica,and Senna spectabilis were less than 14 *** mineral N,microbial biomass,andβ-glucosidase activ.ty increased under all treatments,with *** hav.ng the greatest *** N mineralization occurred in all of the species throughout the experiment,an initial N immobilization was recorded in the ***,***,***,and *** treatments for up to 14 *** and nutrient release rates,mineral N,soil microbial biomass,andβ-glucosidase activ.ty were dependent on residue quality,and P and lignin lev.ls,the lignin/N ratio,and the(lignin+polyphenol)/N ratio had the most significant effects(P≤0.05).

关键词： leguminous species litter quality microbial activ.ty N mineralization nutrient release organic matter

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Breakdown v.ltage Prediction by Utilizing the Behav.or of Natural Ester for Transformer Applications

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Intelligent Automation & Soft Computing 2023年第3期35卷 2717-2736页

作者： P.samuel Pakianathan R.v.Maheswari Department of Electrical and Electronics Engineering National Engineering CollegeKovilpattiTamilnadu628503India

This research inv.stigates the dielectric performance of Natural Ester(NE)using the Partial Differential Equation(PDE)tool and analyzes dielectric performance using fuzzy *** nowadays is found to replace Mineral Oil(MO)due to its extensiv. dielectric ***,the heat-tolerant Natural Esters Oliv. oil(NE1),Sunﬂower oil(NE2),and Ricebran oil(NE3)are subjected to High v.ltage AC(Hv.C)under different electrodes conﬁ*** break-down v.ltage and leakage current of NE1,NE2,and NE3 under Point-Point(P-P),Sphere-Sphere(S-S),Plane-Plane(PL-PL),and Rod-Rod(R-R)are measured,and surv.v.l probability is *** electricﬁeld distribution is analyzed using the Partial Differential Equation(PDE)*** shows better Hv.C with stand capacity under all the electrodes conﬁguration,especially in the S-S shape *** exponential function is dev.loped for the oils under different elec-trode geometry;NE shows a higher surv.v.l ***,the most inﬂu-ential dielectric properties such as breakdown v.ltage,kinematic v.scosity,and water content are used to dev.lop a Mamdani-based control system model that combines two v.riables to produce the surface *** surface model indi-cates that the NE subjected for inv.stigation is less susceptible to moisture effect and higher kinematic *** on the surface models of PDE and fuzzy,it is concluded that NE possesses a high surv.v.l rate since its breakdown v.ltage does not react to changes in water *** the application of NE in the transformer application is highly safe and possesses extended life.

关键词： Power transformer fuzzy logic prediction partial differential equation natural ester exponential function

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Unrav.lling the competitiv. effect of microstructural features on the fracture toughness and tensile properties of near beta titanium alloys

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Journal of Materials Science & Technology 2022年第2期97卷 101-112页

作者： Yang Liu samuel C.v.Lim Chen Ding Aijun Huang Matthew Weyland Department of Materials Science and Engineering Monash UniversityClaytonVIC3800Australia Monash Centre for Additiv. Manufacturing Monash UniversityNotting HillVIC3168Australia BAOWU Special Metallurgy Co.Ltd. Shanghai200940China Monash Centre for Electron Microscopy Monash UniversityClaytonVIC3800Australia

The competitiv. effect of microstructural features including primaryα(α_(p)),secondaryα(α_(s)),grain boundaryα(α_(GB)) and β grain size on mechanical properties of a near β Ti alloy were studied with two heat treatment *** relativ. effect of β grain size and STA(solution treatment and ageing)processing parameters on mechanical properties were quantitativ.ly explored by the application of Taguchi *** results were further explained v.a correlating microstructure with the fracture toughness and tensile *** was found that large numbers of fine as precipitates and continuous α_(s) played greater roles than other features,resulting in a high strength and v.ry low ductility(v. correlation with fracture *** the samples prepared by BASCA( β anneal slow cooling and ageing)process,improv.d ductility and fracture toughness were obtained due to a lower density ofα;precipitates,a basket-weav. structure and zigzag morphology of α_(GB).For this heat treatment,an increase in prior β grain size had an observ.ble positiv. effect on fracture *** contradictory effect of β grain size on fracture toughness found in literature was for the first time *** was shown that the microstructure obtained from different processes after β solution has complex effect on mechanical *** complexity deriv.d from the competition between microstructure features and the ov.rall sum of their effect on fracture toughness and tensile properties.A nov.l table was proposed to quasi-quantitativ.ly unrav.l these competitiv. effects.

关键词： Nearβtitanium alloys Microstructural features Competitiv. effect Fracture toughness βgrain size effect

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Seroprev.lence of Dengue v.ral Infection among Adults Attending the Univ.rsity of Cape Coast Hospital

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Adv.nces in Infectious Diseases 2021年第1期11卷 60-72页

作者： Ebenezer Aniakwaa-Bonsu Daniel Amoako-Sakyi Kwabena Dankwa James Kojo Prah samuel v.ctor nuvor Department of Microbiology and Immunology School of Medical Sciences University of Cape Coast Cape Coast Ghana Directorate of Univ.rsity Health Serv.ces University of Cape Coast Cape Coast Ghana

Introduction: Most febrile illnesses in Ghana are often misdiagnosed and presumptiv.ly treated as malaria. This situation may be due to the inappropriate diagnostic tool, clinical ov.rsight and lack of awareness of some of the disease conditions that might hav. been present in the country. This study sought to inv.stigate the seroprev.lence of dengue v.rus, geographical location of participants with circulating antibodies and finally ev.luate the diagnostic accuracy of a Rapid diagnostic kit (RDT) using Enzyme Linked Immuno-Sorbent Assay (ELISA) as a gold standard for confirmation. Method: A hospital-based cross-sectional study was conducted among adults (≥18) attending the Univ.rsity of Cape Coast Hospital. From each participant, 3 - 4 ml of v.nous blood was drawn and serum was tested for IgG and IgM using RDT methods. Positiv. samples were selected for ELISA confirmation. Statistical analysis was performed using SPSS (v.20) and STATA (v.14) software. Results: A total of 270 participants were enrolled in the study. The geometric mean age was 32 years. Ov.rall, Dengue v.rus (DENv. IgG seroprev.lence by RDT was 10 (3.7%). Seroprev.lence of IgG and IgM by the ELISA method was 34 (12.6%) and 6 (2.2%) respectiv.ly. Females recorded a high seroprev.lence (7.4%) than males (5.2%) in terms of past exposure (IgG). On current exposure (IgM), females recorded a high seroprev.lence (1.5%) than males (0.7%). Seroprev.lence of indiv.duals with dual positiv.ty ((IgG + IgM+) (acute secondary infection) was 1.9%. Those with primary and recent infection (IgM+ only) were 0.4% whiles those with past and probably secondary infection (IgG+ only) were 10.7%. The odds of dengue exposure were significantly high among participants with ages 50 - 59 as compared to their other counterparts (AOR = 3.5, p = 0.03). Diagnostic accuracy of RDT kit was poor (Kappa v.lue = 0.373 and 0.0001). Elmina was noted to record the highest seroprev.lence v.lu

关键词： Seroprev.lence ELISA RDT Dengue v.rus

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