| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
- Axfors, Cathrine, et al.
(författare)
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Association between convalescent plasma treatment and mortality in COVID-19 : a collaborative systematic review and meta-analysis of randomized clinical trials
- 2021
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Ingår i: BMC Infectious Diseases. - : BioMed Central (BMC). - 1471-2334. ; 21:1
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Forskningsöversikt (refereegranskat)abstract
- Background: Convalescent plasma has been widely used to treat COVID-19 and is under investigation in numerous randomized clinical trials, but results are publicly available only for a small number of trials. The objective of this study was to assess the benefits of convalescent plasma treatment compared to placebo or no treatment and all-cause mortality in patients with COVID-19, using data from all available randomized clinical trials, including unpublished and ongoing trials (Open Science Framework, ). Methods: In this collaborative systematic review and meta-analysis, clinical trial registries (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform), the Cochrane COVID-19 register, the LOVE database, and PubMed were searched until April 8, 2021. Investigators of trials registered by March 1, 2021, without published results were contacted via email. Eligible were ongoing, discontinued and completed randomized clinical trials that compared convalescent plasma with placebo or no treatment in COVID-19 patients, regardless of setting or treatment schedule. Aggregated mortality data were extracted from publications or provided by investigators of unpublished trials and combined using the Hartung-Knapp-Sidik-Jonkman random effects model. We investigated the contribution of unpublished trials to the overall evidence. Results: A total of 16,477 patients were included in 33 trials (20 unpublished with 3190 patients, 13 published with 13,287 patients). 32 trials enrolled only hospitalized patients (including 3 with only intensive care unit patients). Risk of bias was low for 29/33 trials. Of 8495 patients who received convalescent plasma, 1997 died (23%), and of 7982 control patients, 1952 died (24%). The combined risk ratio for all-cause mortality was 0.97 (95% confidence interval: 0.92; 1.02) with between-study heterogeneity not beyond chance (I-2 = 0%). The RECOVERY trial had 69.8% and the unpublished evidence 25.3% of the weight in the meta-analysis. Conclusions: Convalescent plasma treatment of patients with COVID-19 did not reduce all-cause mortality. These results provide strong evidence that convalescent plasma treatment for patients with COVID-19 should not be used outside of randomized trials. Evidence synthesis from collaborations among trial investigators can inform both evidence generation and evidence application in patient care.
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| 3. |
- de Castro Araujo Moreira, Andrea Cristina, et al.
(författare)
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The first Brazilian Field Lab fully dedicated to CO2 MMV experiments : from the start-up to the initial results
- 2014
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Ingår i: 12th International Conference on Greenhouse Gas Control Technologies, GHGT-12. - : Elsevier. ; , s. 6227-6238
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Konferensbidrag (refereegranskat)abstract
- Currently one of the main challenges in CO2 storage research is the development, testing and validation of accurate and efficient Measuring, Monitoring and Verification (MMV) techniques to be deployed at geological sequestration sites that are cost effective yet help minimize risk. This perspective motivated PETROBRAS, the National Oil Major in Brazil, through its R&D investments portfolio to prioritize research projects that would contribute to decreasing the technological gap in the area. The Company's periodic surveys indicated the lack of infrastructure, as well as expertise in CO2 MMV, as two of the most critical issues at the national level. In order to bridge that gap, initial steps were taken in 2010 for the start-up and development of the first CO2 MMV Field Lab in Brazil, fully sponsored by PETROBRAS, with a long term goal of enabling the ranking of the best, most cost-effective MMV technology alternatives to be deployed at commercial large scale CCGS sites scheduled to be installed in the country. In addition to providing basic infrastructure to carry out the CO2 injection and controlled release experiments, the facility was designed for the simultaneous testing of multiple measuring methodologies. Additional benefits of the initiative are the creation of expertise and the acceleration of the know-how in MMV in Brazil, as well as the development of a deeper and more practical knowledge of CO2 dynamics and impacts in a real world, open air scenario. Under the full support of the PETROBRAS R&D Center (CENPES), through its Climate Change Mitigation Technological Program (PROCLIMA), the Brazilian Pilot CO2 MMV Lab was made possible through a joint 4-year research Project, conceived and carried out by PETROBRAS and local academia in Brazil, in close cooperation with international experts. An overview of the Project and the multiple research areas encompassed will be presented, together with the preliminary results of the first CO2 injection campaign, which took place in 2013. (c) 2014 The Authors. Published by Elsevier
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| 4. |
- Frias Martinez, Maria Alejandra, et al.
(författare)
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Surface roughness of titanium disks influences the adhesion, proliferation and differentiation of osteogenic properties derived from human
- 2020
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Ingår i: International Journal of Implant Dentistry. - : Springer. - 2198-4034. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- Purpose The aim of this study was to investigate the response of osteogenic cell lineage and gingival fibroblastic cells to different surface treatments of grade IV commercially pure Titanium (cpTi) disks. Material and methods Grade IV cpTi disks with different surfaces were produced: machined (M), sandblasting (B), sandblasting and acid subtraction (NP), and hydrophilic treatment (ACQ). Surface microtopography characteristics and chemical composition were investigated by scanning electron microscopy (SEM) and energy dispersive x-ray spectrometry (EDS). Adhesion and proliferation of SC-EHAD (human surgically-created early healing alveolar defects) and HGF-1 (human gingival fibroblasts) on Ti disks were investigated at 24 and 48 h, and osteogenic differentiation and mineralization were evaluated by assessing alkaline phosphatase (ALP) activity and alizarin red staining, respectively. Results No significant differences were found among the various surface treatments for all surface roughness parameters, except for skewness of the assessed profile (Rsk) favoring M (p= 0.035 ANOVA). M disks showed a slightly higher (p> 0.05; Kruskal-Wallis/Dunn) adhesion of HGF-1 (89.43 +/- 9.13%) than SC-EHAD cells (57.11 +/- 17.72%). ACQ showed a significantly higher percentage of SC-EHAD (100%) than HGF-1 (69.67 +/- 13.97%) cells adhered at 24 h. SC-EHAD cells expressed increased ALP activity in osteogenic medium at M (213%) and NP (235.04%) surfaces, but higher mineralization activity on ACQ (54.94 +/- 4.80%) at 14 days. Conclusion These findings suggest that surface treatment influences the chemical composition and the adhesion and differentiation of osteogenic cells in vitro.
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| 5. |
- Hu, Yannan, et al.
(författare)
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Trends in socioeconomic inequalities in self-assessed health in 17 European countries between 1990 and 2010
- 2016
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Ingår i: Journal of Epidemiology and Community Health. - : BMJ. - 0143-005X .- 1470-2738. ; 70:7, s. 644-652
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Between the 1990s and 2000s, relative inequalities in all-cause mortality increased, whereas absolute inequalities decreased in many European countries. Whether similar trends can be observed for inequalities in other health outcomes is unknown. This paper aims to provide a comprehensive overview of trends in socioeconomic inequalities in self-assessed health (SAH) in Europe between 1990 and 2010.METHODS: Data were obtained from nationally representative surveys from 17 European countries for the various years between 1990 and 2010. The age-standardised prevalence of less-than-good SAH was analysed by education and occupation among men and women aged 30-79 years. Socioeconomic inequalities were measured by means of absolute rate differences and relative rate ratios. Meta-analysis with random-effects models was used to examine the trends of inequalities.RESULTS: We observed declining trends in the prevalence of less-than-good SAH in many countries, particularly in Southern and Eastern Europe and the Baltic states. In all countries, less-than-good SAH was more prevalent in lower educational and manual groups. For all countries together, absolute inequalities in SAH were mostly constant, whereas relative inequalities increased. Almost no country consistently experienced a significant decline in either absolute or relative inequalities.CONCLUSIONS: Trends in inequalities in SAH in Europe were generally less favourable than those found for inequalities in mortality, and there was generally no correspondence between the two when we compared the trends within countries. In order to develop policies or interventions that effectively reduce inequalities in SAH, a better understanding of the causes of these inequalities is needed.
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| 6. |
- Oliva, Andresa, et al.
(författare)
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A comparison of three methods for monitoring CO2 migration in soil and shallow subsurface in the Ressacada Pilot site, Southern Brazil
- 2014
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Ingår i: 12th International Conference on Greenhouse Gas Control Technologies, GHGT-12. - : Elsevier. ; , s. 3992-4002
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Konferensbidrag (refereegranskat)abstract
- In a joint R&D project under the full sponsorship of PETROBRAS, the Brazilian National Oil Company, the first CO2 monitoring field lab was started-up in Brazil in 2011. The site chosen, the Ressacada Farm, in the Southern region of the country, offered an excellent opportunity to run controlled CO2 release experiments in soil and shallow subsurface (< 3 m depth). This paper focuses on the presentation and comparison of the results obtained using electrical imaging, CO2 flux measurements and geochemical analysis of the groundwater to monitor CO2 migration in both saturated and unsaturated sand-rich sediments and soil. In 2013 a controlled release campaign was run, covering an area of approximately 6,300 m(2). Commercial food-grade gaseous carbon dioxide was continuously injected at 3 m depth for 12 days. The average injection rate was 90 g/day, totaling ca. 32kg of gas being released. The low injection rate avoided fracturing of the unconsolidated sediments composing the bulk of the local soil matrix. Monitoring techniques deployed during 30 consecutive days, including background characterization, injection and post-injection periods, were: (1) 3D electrical imaging using a Wenner array, (2) soil CO2 flux measurements using accumulation chambers, (3) water sampling and analysis, (4) 3D (tridimensional) and 4D (time-lapsed) electrical imaging covering depth levels to approximately 10 m below the surface. Water geochemical monitoring consisted of the analyses of several chemical parameters, as well as acidity and electrical conductivity in five multi-level wells (2m; 4m and 6 m depth) installed in the vicinity of the CO2 injection well. Comparison of pre- and post-injection electrical imaging shows changes in resistivity values consistent with CO(2)migration pathways. A pronounced increase in resistivity values occurred, from 1,500 ohm. m to 2,000 ohm. m, in the vicinity of the injection well. The accumulation chamber assessment show significant changes in the CO2 flux during the release experiment: maximum values detected were ca. 270 mmol/m(2)/s(during injection) as compared to background values of c.a. 34mmol/m(2)/s. The pH showed variations after CO2 injection in two monitoring wells at 2m, 4m and 6m depth. After the CO2 injection ceased, the lowest pH measured was 4.1, which represents a decrease of 0.5 relative to the background values. Slight variations in the oxidation-reduction potential (Eh) were observed near the CO2 injection well. There was a decreasing trend of this potential, especially in a monitoring well at 6m depth, ranging from 308mV to 229mV, between the background and the injection scenarios. Ppb level increments were detected in the measurements carried out for the major cations (Ca, Mg, Na, and P) and trace elements (Ag, Al, As, B, Ba, Cd, Pb, Cu, Cr, Ni, Mn, S, V, and Zn). Electrical conductivity and alkalinity, however, remained constant throughout the experiment, with values around 40 mu S.cm(-1) and 2.5 mgCaCO(3).L-1, respectively. The response to CO2 injection was not uniformly observed by the different methods deployed on site. The highest percentage change in resistivity values near the injection well occurred 5 days after the injection had started. However the highest percentage changes in the CO2 flux values occurred 9 days after the injection, 4 days after the observed changes in resistivity values. This delay is probably due to the migration time of the gas from 0.5m depth to the surface. (C) 2014 Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/). Peer-review under responsibility of the Organizing Committee of GHGT-12
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| 7. |
- Schwandt, Hannes, et al.
(författare)
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Inequality in mortality between Black and White Americans by age, place, and cause and in comparison to Europe, 1990 to 2018
- 2021
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Ingår i: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 118:40
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Tidskriftsartikel (refereegranskat)abstract
- Although there is a large gap between Black and White American life expectancies, the gap fell 48.9% between 1990 and 2018, mainly due to mortality declines among Black Americans. We examine age-specific mortality trends and racial gaps in life expectancy in high- and low-income US areas and with reference to six European countries. Inequalities in life expectancy are starker in the United States than in Europe. In 1990, White Americans and Europeans in high-income areas had similar overall life expectancy, while life expectancy for White Americans in low-income areas was lower. However, since then, even high-income White Americans have lost ground relative to Europeans. Meanwhile, the gap in life expectancy between Black Americans and Europeans decreased by 8.3%. Black American life expectancy increased more than White American life expectancy in all US areas, but improvements in lower-income areas had the greatest impact on the racial life expectancy gap. The causes that contributed the most to Black Americans’ mortality reductions included cancer, homicide, HIV, and causes originating in the fetal or infant period. Life expectancy for both Black and White Americans plateaued or slightly declined after 2012, but this stalling was most evident among Black Americans even prior to the COVID-19 pandemic. If improvements had continued at the 1990 to 2012 rate, the racial gap in life expectancy would have closed by 2036. European life expectancy also stalled after 2014. Still, the comparison with Europe suggests that mortality rates of both Black and White Americans could fall much further across all ages and in both high-income and low-income areas.
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| 8. |
- Travassos, Maria, et al.
(författare)
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Does Caffeine Consumption Modify Cerebrospinal Fluid Amyloid-β Levels in Patients with Alzheimer's Disease?
- 2015
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Ingår i: Journal of Alzheimer's disease : JAD. - 1875-8908. ; 47:4, s. 1069-78
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Tidskriftsartikel (refereegranskat)abstract
- Caffeine may be protective against Alzheimer's disease (AD) by modulating amyloid-β (Aβ) metabolic pathways. The present work aimed to study a possible association of caffeine consumption with the cerebrospinal fluid (CSF) biomarkers, particularly Aβ. The study included 88 patients with AD or mild cognitive impairment. The consumption of caffeine and theobromine was evaluated using a validated food questionnaire. Quantification of caffeine and main active metabolites was performed with liquid chromatography coupled to tandem mass spectrometry. The levels of A(1-42), total tau, and phosphorylated tau in the CSF were determined using sandwich ELISA methods and other Aβ species, Aβ(X-38), Aβ(X-40), and Aβ(X-42), with the MSD Aβ Triplex assay. The concentration of caffeine was 0.79±1.15 μg/mL in the CSF and 1.20±1.88 μg/mL in the plasma. No correlation was found between caffeine consumption and Aβ42 in the CSF. However, a significant positive correlation was found between the concentrations of theobromine, both in the CSF and in the plasma, with Aβ42 in the CSF. Theobromine in the CSF was positively correlated with the levels of other xanthines in the CSF, but not in the plasma, suggesting that it may be formed by central metabolic pathways. In conclusion, caffeine consumption does not modify the levels of CSF biomarkers, and does not require to be controlled for when measuring CSF biomarkers in a clinical setting. Since theobromine is associated with a favorable Aβ profile in the CSF, the possibility that it might have a protective role in AD should be further investigated.
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