36 research outputs found
Investigating the Impact of Non-Hydrodynamically Connected Descaling Parameters in the Removal of Different Stages of Paraffin Deposits Using Multiple Nozzles in Petroleum Production Tubing
Despite the continued research efforts in understanding the erosional behaviors of multiple flat fan nozzles in the removal of different types of scale deposits from petroleum production tubing. The non-hydrodynamically connected descaling parameters such as stand-off distance, nozzle arrangement and chamber pressure have not been duly considered up to date. This research utilizes 3-flat fan high-pressure nozzles at a high injection pressure of 10 MPa to remove paraffin deposits at different growth stages from petroleum production tubing to evaluate the effects of the descaling parameters on scale removal. A stand-off distance of 25 mm, 50 mm and 75 mm; nozzle arrangement in novel orientations (triangle, diagonal & right-angle) involving 7-nozzles header and chamber pressures (in compression ā 0.2 MPa and vacuum -8.0 x10-3 MPa) were utilized as the varying non-hydrodynamically connected parameters. Generally, the selection of both nozzle arrangement and chamber air concentration was found to be governed by the type and shape of the deposit in question while the scale removal capability was found to be reduced with an increase in stand-off distance due to poor jet contact. An average hollow shaped paraffin removal of 276 g, 259 g and 226 g were recorded at ambient condition across the respective stand-off distance of the three respective nozzles arrangements. While the introduction of 0.2 MPa compressed air significantly increased the respective removal of the early stage paraffin deposition to 342 g, 299 g and 277 g respectively. Also, more hollow shaped removal improvement of 366 g, 320 g and 288 g were achieved after suctioning the chamber by -0.008 MPa, while simultaneously pumping water at 10 MPa. The case of solid shaped paraffin signifying complete tubing blockage was not effective at ambient condition, with average paraffin removal of 99 g, 126 g and 112 g respectively. However, the introduction of compressed chamber air registered the best solid paraffin removal results of 235 g, 286 g and 256 g respectively. Whereas the suction operation recorded an average removal of 229 g, 270 g and 250 g of paraffin across the respective jet positions and nozzle configurations. This result provides a practical approach to the removal of organic scales deposits at varying descaling conditions of injection pressure, standoff distance and nozzle arrangement
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Explaining Adherence Success in Sub-Saharan Africa: An Ethnographic Study
Background: Individuals living with HIV/AIDS in sub-Saharan Africa generally take more than 90% of prescribed doses of antiretroviral therapy (ART). This number exceeds the levels of adherence observed in North America and dispels early scale-up concerns that adherence would be inadequate in settings of extreme poverty. This paper offers an explanation and theoretical model of ART adherence success based on the results of an ethnographic study in three sub-Saharan African countries. Methods and Findings: Determinants of ART adherence for HIV-infected persons in sub-Saharan Africa were examined with ethnographic research methods. 414 in-person interviews were carried out with 252 persons taking ART, their treatment partners, and health care professionals at HIV treatment sites in Jos, Nigeria; Dar es Salaam, Tanzania; and Mbarara, Uganda. 136 field observations of clinic activities were also conducted. Data were examined using category construction and interpretive approaches to analysis. Findings indicate that individuals taking ART routinely overcome economic obstacles to ART adherence through a number of deliberate strategies aimed at prioritizing adherence: borrowing and ābeggingā transport funds, making āimpossible choicesā to allocate resources in favor of treatment, and ādoing without.ā Prioritization of adherence is accomplished through resources and help made available by treatment partners, other family members and friends, and health care providers. Helpers expect adherence and make their expectations known, creating a responsibility on the part of patients to adhere. Patients adhere to promote good will on the part of helpers, thereby ensuring help will be available when future needs arise. Conclusion: Adherence success in sub-Saharan Africa can be explained as a means of fulfilling social responsibilities and thus preserving social capital in essential relationships
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Treatment Outcomes in a Decentralized Antiretroviral Therapy Program: A Comparison of Two Levels of Care in North Central Nigeria
Background. Decentralization of antiretroviral therapy (ART) services is a key strategy to achieving universal access to treatment for people living with HIV/AIDS. Our objective was to assess clinical and laboratory outcomes within a decentralized program in Nigeria. Methods. Using a tiered hub-and-spoke model to decentralize services, a tertiary hospital scaled down services to 13 secondary-level hospitals using national and program guidelines. We obtained sociodemographic, clinical, and immunovirologic data on previously antiretroviral drug naĆÆve patients aged ā„15 years that received HAART for at least 6 months and compared treatment outcomes between the prime and satellite sites. Results. Out of 7,747 patients, 3729 (48.1%) were enrolled at the satellites while on HAART, prime site patients achieved better immune reconstitution based on CD4+ cell counts at 12 (P < 0.001) and 24 weeks (P < 0.001) with similar responses at 48 weeks (P = 0.11) and higher rates of viral suppression (<400 c/mL) at 12 (P < 0.001) and 48 weeks (P = 0.03), but similar responses at 24 weeks (P = 0.21). Mortality was 2.3% versus 5.0% (P < 0.001) at prime and satellite sites, while transfer rate was 8.7% versus 5.5% (P = 0.001) at prime and satellites. Conclusion. ART decentralization is feasible in resource-limited settings, but efforts have to be intensified to maintain good quality of care
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High-risk human papilloma virus and cervical abnormalities in HIV-infected women with normal cervical cytology
Background: The prevalence of High-Risk Human papilloma virus (HR-HPV), a necessary cause of invasive cervical cancer (ICC) is relatively high in HIV infected women. Gaps exist in our knowledge of the optimal approaches for managing women who have HR-HPV with normal cervical cytology (NCC) particularly in settings of HIV infection. Methods: Between May 2012 and June 2013 we conducted a colposcopic assessment of HIV-infected women with prior (NCC) and known HR-HPV status to compare cervical abnormalities in women with and without HR-HPV. Colposcopic examinations were done at the Operation Stop Cervical Cancer (OSCC) unit of the Jos University Teaching Hospital (JUTH), Jos, Nigeria. Abnormal colposcopic finding (ACF) was defined as areas of aceto-white epithelium involving the squamo-coulumnar junction, areas of punctation, mosaic pattern or atypical vessels. We compared proportions of ACF as well as histologic grades of cervical intra-epithelial neoplasia (CIN) in women with or without HR-HPV. Statistical analysis was done on STATA. Results: We conducted colposcopic examinations in 78 out of 89 (86.5%) eligible women. The mean age of the cohort was 32.4 years (SD Ā±4.6) with a median 32 years (IQR 29ā36). After a mean follow up time of 20.1 months from the initial cervical pap cytology and HR-HPV testing, we found 12 of 78 (15.4%) women with ACF. The odds for an ACF was statistically higher [OR = 4.0 (95% CI: 1.1-14.7)] in women with HR-HPV compared to those without. Of the twelve women with ACF, subsequent histologic examination of colposcopically directed cervical biopsies confirmed CIN 1 in 4 cases (33.3%), CIN 2 in 1 case (8.3%), CIN 3 in 2 cases (16.7%), carcinoma-in-situ (CIS) in 2 cases (16.7%), and normal cervix in 3 (25.0%). Overall, the proportion of women detected with any grade of CIN was 11.5% (9/78) and 6.4% (5/78) were CIN 2 or greater lesion (CIN2+). Conclusion: HIV-infected women with NCC and HR-HPV had a four-fold higher likelihood for an ACF. The practice of early colposcopic examination of HIV-infected women with prior NCC and HR-HPV may increase early detection of higher grade CIN and CIS cancer stages in our setting
Immunogenicity and safety of 13-valent pneumococcal conjugate vaccine (PCV13) formulated with 2-phenoxyethanol in multidose vials given with routine vaccination in healthy infants: An open-label randomized controlled trial.
BACKGROUND: This open-label randomized controlled trial in infants compared safety, tolerability, and immunogenicity of the 13-valent pneumococcal conjugate vaccine (PCV13) formulated with the preservative 2-phenoxyethanol (2-PE) in a multidose vial (MDV) to the current PCV13 without 2-PE in a single-dose syringe (SDS). METHODS: Gambian infants were randomized 1:1 to receive PCV13 as either MDV or SDS at ages 2, 3, and 4months. Serotype-specific antipneumococcal antibody responses and opsonophagocytic activity ([OPA]; subset) were measured at age 5months. Noninferiority was declared if the lower bound of the 97.5% CI for the difference (MDV-SDS) in proportions of subjects achieving IgG concentrations ā„0.35Ī¼g/mL (primary endpoint) was greater than -10%. IgG geometric mean concentrations (GMCs) were noninferior if the lower limit of the two-sided 97.5% CI of the geometric mean ratio (MDV vs SDS) was greater than 0.5. Reactogenicity and other adverse events were collected. RESULTS: 500 participants were randomized and vaccinated; 489 (MDV: n=245; SDS: n=244) completed the trial. Noninferiority of MDV was demonstrated for all serotypes as measured by percentage of subjects achieving antibody responses above ā„0.35Ī¼g/mL. IgG GMCs (coprimary endpoint) also demonstrated noninferiority of MDV; OPA results supported these findings. Safety and tolerability were comparable between groups. CONCLUSIONS: PCV13 in MDV was safe and immunogenic when administered according to the routine schedule to infants. MDV was noninferior to SDS for all 13 pneumococcal serotypes. Comparable immunogenicity and safety profiles of PCV13 MDV and SDS suggest PCV13 MDV can help optimize vaccination in resource-limited settings. ClinicalTrials.gov NCT01964716 https://clinicaltrials.gov/ct2/show/NCT01964716
Human Immunodeficiency Virus and Risk of Type 2 Diabetes in a Large Adult Cohort in Jos, Nigeria
BACKGROUND
HIV infection and the use of anti-retroviral therapy (ART) may increase the risk of type 2 diabetes mellitus (T2DM). However, data from regions with a high burden of HIV/AIDS is limited. We determined the prevalence of T2DM at the time of presentation to a large HIV Clinic in Nigeria, as well as the incidence of diabetes 12 months following ART initiation.
METHODS
Data from patients enrolled for ART from 2011 to 2013 was analyzed, including 2632 patients on enrollment and 2452 re-evaluated after 12 months of ART commencement. The presence of diabetes, demographic, clinical and biochemical data were retrieved from standardized databases. CD4+, HIV viral load, and hepatitis C virus (HCV) status were noted. Bivariate and logistic regressions were used to identify risk factors for T2DM.
RESULTS
Baseline T2DM prevalence was 2.3% (95%CI: 1.8% - 2.9%), and age, but not body mass index (BMI) was a risk factor for diabetes. After 12 months of ART, a further 5.3% had developed T2DM. Newly developed diabetes was not associated with age, but was associated with BMI. There were no significant associations between prevalent or incident diabetes and CD4+, viral load or type of ART.
CONCLUSIONS
Diabetes is not uncommon in HIV infected individuals at the time of presentation to HIV services. Patients initiating ART then have a high risk of developing diabetes in the first year of ART. Incident diabetes was associated with a BMIā„25.0, and excessive weight gain should be avoided
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Treatment Outcomes Among Older Human Immunodeficiency Virus-Infected Adults in Nigeria
Abstract Background. Older age at initiation of combination antiretroviral therapy (cART) has been associated with poorer clinical outcomes. Our objectives were to compare outcomes between older and younger patients in our clinical cohort in Jos, Nigeria. Methods. This retrospective cohort study evaluated patients enrolled on cART at the Jos University Teaching Hospital, Nigeria between 2004 and 2012. We compared baseline and treatment differences between older (ā„50 years) and younger (15ā49 years) patients. Kaplan-Meier analysis and Cox proportional hazard models estimated survival and loss to follow-up (LTFU) and determined factors associated with these outcomes at 24 months. Results. Of 8352 patients, 643 (7.7%) were aged ā„50 years. The median change in CD4 count from baseline was 151 vs 132 (P = .0005) at 12 months and 185 vs 151 cells/mm3 (P = .03) at 24 months for younger and older patients, respectively. A total of 68.9% vs 71.6% (P = .13) and 69.6% vs 74.8% (P = .005) of younger and older patients achieved viral suppression at 12 and 24 months, with similar incidence of mortality and LTFU. In adjusted hazard models, factors associated with increased risk of mortality were male sex, World Health Organization (WHO) stage III/IV, and having a gap in care, whereas being fully suppressed was protective. The risk of being LTFU was lower for older patients, those fully suppressed virologically and with adherence rates >95%. Male sex, lack of education, WHO stage III/IV, body mass index <18.5 kg/m2, and having a gap in care independently predicted LTFU. Conclusions. Older patients achieved better viral suppression, and older age was not associated with increased mortality or LTFU in this study
Association of HIV-induced immunosuppression and clinical malaria in Nigerian adults
Background: Despite the growing body of evidence on the interaction between HIV and malaria in sub-Saharan Africa, there is a dearth of data on clinical malaria in HIV-infected patients in Nigeria. We determined the burden of clinical malaria in HIV-infected adult Nigerians and further investigated the association between their immunological status and the rates of clinical malaria.
Methods: Ninety seven antiretroviral treatment-naĆÆve HIV-infected adults were enrolled in a cross-sectional study from August to December, 2009. The participants had a complete clinical evaluation, thick and thin blood films for malaria parasites and CD4 cell count quantification. Clinical malaria was defined as having fever (temperature ā„ 37.5oC or history of fever within 48 hours) and a malaria parasite density above the median value obtained for subjects with co-existing fever and parasitaemia.
Results: Clinical malaria was diagnosed in 10 out of 97 patients (10.3%). Lower CD4 cell counts were associated with increasing rates of clinical malaria which was 0% at CD4 cell count of ā„ 500, 2.6% at 200-499 and 30% a
Explaining Adherence Success in Sub-Saharan Africa: An Ethnographic Study
Using ethnographic data from Nigeria, Tanzania, and Uganda, Norma Ware and colleagues examine why levels of adherence to HIV/AIDS drugs are so much higher in sub-Saharan Africa than in North America
Hepatitis B Co-Infection is Associated with Poorer Survival of HIV-Infected Patients on Highly Active Antiretroviral Therapy in West Africa
Background: Hepatitis B has been reported to be high in HIV-infected African populations. However, the impact of this co-infection on the survival of HIV-infected Africans on long-term highly active antiretroviral therapy (HAART) remains poorly characterised. We investigated the impact of HBV/HIV co-infection on survival of HIV infected patients undergoing antiretroviral therapy in a West African population. Methods: This was a clinic-based cohort study of HIV-infected adults enrolled in Nigeria, West Africa. Study subjects (9,758) were screened for hepatitis B and hepatitis C at HAART initiation. Kaplan-Meier survival and Cox proportional hazards models were used to estimate probability of survival and to identify predictors of mortality respectively, based on hepatitis B surface antigen status. All patients had signed an informed written consent before enrolment into the study; and we additionally obtained permission for secondary use of data from the Harvard institutional review board. Results: Patients were followed up for a median of 41 months (interquartile range: 30ā62 months) during which, 181 (1.9%) patients died. Most of the deaths; 143 (79.0%) occurred prior to availability of Tenofovir. Among those that were on antiretroviral therapy, hepatitis B co-infected patients experienced a significantly lower survival than HIV mono-infected patients at 74 months of follow up (94% vs. 97%; p=0.0097). Generally, hepatitis B co-infection: HBsAg-positive/HIV-positive (Hazards Rate [HR]; 1.5: 95% CI 1.09ā2.11), co-morbid tuberculosis (HR; 2.2: 95% CI 1.57ā2.96) and male gender (HR; 1.5: 95% CI 1.08ā2.00) were significantly predictive of mortality. Categorising the patients based on use of Tenofovir, HBV infection failed to become a predictor of mortality among those on Tenofovir-containing HAART. Conclusions: HBsAg-positive status was associated with reduced survival and was an independent predictor of mortality in this African HIV cohort on HAART. However, Tenofovir annulled the impact of HBV on mortality of HIV patients in the present study cohort