239 research outputs found
Long-Term Outcome of an HIV-Treatment Programme in Rural Africa: Viral Suppression despite Early Mortality
Objective. To define the long-term (2–4 years) clinical and virological outcome of an antiretroviral treatment (ART) programme in rural South Africa.
Methods. We performed a retrospective observational cohort study, including 735 patients who initiated ART. Biannual monitoring, including HIV-RNA testing, was performed. Primary endpoint was patient retention; virological suppression (HIV-RNA < 50 copies/mL) and failure (HIV-RNA > 1000 copies/mL) were secondary endpoints. Moreover, possible predictors of treatment failure were analyzed.
Results. 63% of patients (466/735) have a fully suppressed HIV-RNA, a median of three years after treatment initiation. Early mortality was high: 14% died within 3 months after treatment start. 16% of patients experienced virological failure, but only 4% was switched to second-line ART. Male gender and a low performance score were associated with treatment failure; immunological failure was a poor predictor of virological failure.
Conclusions. An “all or nothing” phenomenon was observed in this rural South African ART programme: high early attrition, but good virological control in those remaining in care. Continued efforts are needed to enrol patients earlier. Furthermore, the observed viro-immunological dissociation emphasises the need to make HIV-RNA testing more widely available
N-Hexane induced swelling of thin PDMS films under non-equilibrium nanofiltration permeation conditions, resolved by spectroscopic ellipsometry
A nondestructive technique is presented for in-situ analysis of solvent induced membrane swelling. The technique is based on spectroscopic ellipsometry (SE) and allows simultaneous measurement of membrane film thickness and solvent sorption. The attainable experimental conditions are only limited by the test cell (≤473.15 K, ≤20 MPa) and by far exceed those encountered in typical solvent resistant nanofiltration (SRNF) applications. The influence of cross-linker concentration on swelling of thin films and bulk samples of poly(dimethyl siloxane) (PDMS) is resolved and interaction parameters according to Flory-Huggins and Flory-Rehner theories are calculated. It is found that due to confinement on the support for the thin supported films a correction for elastic deformation of the network is necessary. In the pressurized swollen film the thickness and refractive index are found to be independent of pressure in the range of 0.1-10 MPa suggesting that the molar volumes of the penetrant in the liquid and sorbed phases are not significantly different. When a pressure difference over the membrane is applied and the solvent is allowed to permeate, a progressing reduction in thickness of the membrane is observed with increasing upstream pressure. The derived concentrations of n-hexane at the interface between thin film and support, at the permeate side, are in excellent agreement with values calculated using the solution-diffusion model. This implies that in-situ spectroscopic ellipsometry allows quantification of the contribution of solution-diffusion to mixed mode transport, for instance occurring simultaneously with pore-flow and transport through defects, in composite membranes.</p
Теоретичні та практичні аспекти приватизації в Україні
Цели статьи заключаются в изучении спроса покупателей на объекты приватизации и анализе финансового состояния предприятий к принятию решения
об их приватизации (на основе данных за I квартал 2006 года), раскрытии основных критериев целесообразности принятия решения о приватизации объектов ведения хозяйства.Цілі статті полягають у вивченні попиту покупців на об'єкти приватизації та
аналізі фінансового стану підприємств до прийняття рішення про їх приватизацію (на основі даних за I квартал 2006 року), розкритті основних критеріїв
доцільності прийняття рішення про приватизацію об'єктів господарювання
Gene expression profiling in hepatic tissue of newly weaned pigs fed pharmacological zinc and phytase supplemented diets
<p>Abstract</p> <p>Background</p> <p>Zinc (Zn) is an essential trace element. However, Zn bioavailability from commonly consumed plants may be reduced due to phytic acid. Zn supplementation has been used to treat diarrheal disease in children, and in the U.S. swine industry at pharmacological levels to promote growth and fecal consistency, but underlying mechanisms explaining these beneficial effects remain unknown. Moreover, adding supplemental phytase improves Zn bioavailability. Thus, we hypothesized that benefits of pharmacological Zn supplementation result from changes in gene expression that could be further affected by supplemental phytase. The goal of this study was to investigate the effects of feeding newly weaned pigs dietary Zn (150, 1,000, or 2,000 mg Zn/kg) as Zn oxide with or without phytase [500 phytase units (FTU)/kg] for 14 d on hepatic gene expression. Liver RNA from pigs fed 150, 1,000, or 2,000 mg Zn/kg, or 1,000 mg Zn/kg with phytase (n = 4 per treatment) was reverse transcribed and examined using the differential display reverse transcription polymerase chain reaction technique. Liver RNA from pigs fed 150 or 2,000 mg Zn/kg (n = 4 per treatment) was also evaluated using a 70-mer oligonucleotide microarray.</p> <p>Results</p> <p>Expressed sequence tags for 61 putatively differentially expressed transcripts were cloned and sequenced. In addition, interrogation of a 13,297 element oligonucleotide microarray revealed 650 annotated transcripts (FDR ≤ 0.05) affected by pharmacological Zn supplementation. Seven transcripts exhibiting differential expression in pigs fed pharmacological Zn with sequence similarities to genes encoding <it>GLO1</it>, <it>PRDX4</it>, <it>ACY1</it>, <it>ORM1</it>, <it>CPB2</it>, <it>GSTM4</it>, and <it>HSP70.2 </it>were selected for confirmation. Relative hepatic <it>GLO1 </it>(<it>P </it>< 0.0007), <it>PRDX4 </it>(<it>P </it>< 0.009) and <it>ACY1 </it>(<it>P </it>< 0.01) mRNA abundances were confirmed to be greater in pigs fed 1,000 (n = 8) and 2,000 (n = 8) mg Zn/kg than in pigs fed 150 (n = 7) mg Zn/kg. Relative hepatic <it>HSP70.2 </it>(P < 0.002) mRNA abundance was confirmed to be lower in pigs fed 2,000 mg Zn/kg than in pigs fed 150 or 1,000 mg Zn/kg.</p> <p>Conclusion</p> <p>Results suggest that feeding pharmacological Zn (1,000 or 2,000 mg Zn/kg) affects genes involved in reducing oxidative stress and in amino acid metabolism, which are essential for cell detoxification and proper cell function.</p
MicroarrayDesigner: an online search tool and repository for near-optimal microarray experimental designs
<p>Abstract</p> <p>Background</p> <p>Dual-channel microarray experiments are commonly employed for inference of differential gene expressions across varying organisms and experimental conditions. The design of dual-channel microarray experiments that can help minimize the errors in the resulting inferences has recently received increasing attention. However, a general and scalable search tool and a corresponding database of optimal designs were still missing.</p> <p>Description</p> <p>An efficient and scalable search method for finding near-optimal dual-channel microarray designs, based on a greedy hill-climbing optimization strategy, has been developed. It is empirically shown that this method can successfully and efficiently find near-optimal designs. Additionally, an improved interwoven loop design construction algorithm has been developed to provide an easily computable general class of near-optimal designs. Finally, in order to make the best results readily available to biologists, a continuously evolving catalog of near-optimal designs is provided.</p> <p>Conclusion</p> <p>A new search algorithm and database for near-optimal microarray designs have been developed. The search tool and the database are accessible via the World Wide Web at <url>http://db.cse.ohio-state.edu/MicroarrayDesigner</url>. Source code and binary distributions are available for academic use upon request.</p
One-pot synthesis of nano-crystalline MCM-22
[EN] Nano-crystalline MCM-22 zeolite was synthesized in a one-pot procedure by the use of an organosilane (dimethyl-octadecyl-(3-trimethoxysilylpropyl)-ammonium chloride, TPOAC) in the zeolite synthesis gel. This crystal growth inhibition procedure introduced mesopores in the MCM-22 crystallites. The lower mechanical stability of the nano-crystalline MCM-22 zeolite compared with bulk MCM-22 can be countered to some extent by pillaring. The increased external surface of the microporous zeolite domains resulted in increased accessibility of the Bronsted acid sites, as followed from the better performance in liquid-phase benzene alkylation with propylene as compared with bulk MCM-22. The increased accessibility of the internal acid sites in Mo-loaded hierarchical MCM-22 was also evident from the improved benzene selectivity during methane aromatization. Silylation of hierarchical Mo/MCM-22 was detrimental for the catalytic performance in MDA. The nano-crystalline MCM-22 has physico-chemical and catalytic properties intermediate between those of MCM-22 and ITQ-2 with the benefit over ITQ-2 that it can be synthesized in a single step. (C) 2015 Elsevier Inc. All rights reserved.Funding from the 7th Framework Program of the European Commission through the Collaborative Project Next-GTL (agreement no 229183) and financial support by the Spanish Government-MINECO through "Severo Ochoa" (SEV 2012-0267), Consolider Ingenio 2010-Multicat (CSD2009-00050) and MAT2012-31657 are acknowledged. Marta E. Martinez Armero thanks MINECO for economical support through pre-doctoral fellowship for doctors training (BES-2013-066800). The authors thank B. Esparcia for technical assistance.Tempelman, CHL.; Portilla Ovejero, MT.; Martínez Armero, ME.; Mezari, B.; De Caluwe, NGR.; Martínez, C.; Hensen, EJM. (2016). One-pot synthesis of nano-crystalline MCM-22. Microporous and Mesoporous Materials. 220:28-38. https://doi.org/10.1016/j.micromeso.2015.08.018S283822
Trends in body mass index in the pre-dolutegravir period in South Africa
Background: Antiretroviral therapy (ART) is associated with weight gain, but this has been shown to be more marked with dolutegravir and other integrase strand transfer inhibitors.
Objectives: We studied weight gain in people living with HIV (PLWH) on ART compared to the general population in the period before dolutegravir was introduced in a rural South African cohort.
Method: Longitudinal analysis of the Ndlovu Cohort Study including 36–48 months’ follow-up data. From 2014 to 2019, data were collected annually in Limpopo, rural South Africa. Linear mixed models using HIV status, demographics, ART use and cardiovascular risk factors were used to estimate trends in body mass index (BMI) over time.
Results: In total, 1518 adult, non-pregnant participants were included, of whom 518 were PLWH on ART (79.8%), 135 PLWH not yet on ART (20.2%) and 865 HIV-negative. HIV-negative participants had significantly higher BMIs than PLWH on ART at all study visits. There was a significant increase in BMI in all subgroups after 36 months (PLWH on ART, BMI +1.2 kg/m2, P 0.001; PLWH not on ART, BMI +1.8 kg/m2, P 0.001 and HIV-negative, BMI +1.3 kg/m2, P 0.001).
Conclusion: The increase in BMI in PLWH and HIV-negative participants is a serious warning signal as obesity results in morbidity and mortality
Novel genetic parameters for genetic residual feed intake in dairy cattle using time series data from multiple parities and countries in North America and Europe.
Residual feed intake is viewed as an important trait in breeding programs that could be used to enhance genetic progress in feed efficiency. In particular, improving feed efficiency could improve both economic and environmental sustainability in the dairy cattle industry. However, data remain sparse, limiting the development of reliable genomic evaluations across lactation and parity for residual feed intake. Here, we estimated novel genetic parameters for genetic residual feed intake (gRFI) across the first, second, and third parity, using a random regression model. Research data on the measured feed intake, milk production, and body weight of 7,379 cows (271,080 records) from 6 countries in 2 continents were shared through the Horizon 2020 project GenTORE and Resilient Dairy Genome Project. The countries included Canada (1,053 cows with 47,130 weekly records), Denmark (1,045 cows with 72,760 weekly records), France (329 cows with 16,888 weekly records), Germany (938 cows with 32,614 weekly records), the Netherlands (2,051 cows with 57,830 weekly records), and United States (1,963 cows with 43,858 weekly records). Each trait had variance components estimated from first to third parity, using a random regression model across countries. Genetic residual feed intake was found to be heritable in all 3 parities, with first parity being predominant (range: 22-34%). Genetic residual feed intake was highly correlated across parities for mid- to late lactation; however, genetic correlation across parities was lower during early lactation, especially when comparing first and third parity. We estimated a genetic correlation of 0.77 ± 0.37 between North America and Europe for dry matter intake at first parity. Published literature on genetic correlations between high input countries/continents for dry matter intake support a high genetic correlation for dry matter intake. In conclusion, our results demonstrate the feasibility of estimating variance components for gRFI across parities, and the value of sharing data on scarce phenotypes across countries. These results can potentially be implemented in genetic evaluations for gRFI in dairy cattle
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