1,835 research outputs found
Antioxidant activity of alkyl gallates and glycosyl alkyl gallates in fish oil in water emulsions: Relevance of their surface active properties and of the type of emulsifier
The antioxidant activity of gallic acid and a series of alkyl gallates (C4-C18) and glycosylated alkyl gallates (C4-C18) on fish oil-in-water emulsions was studied. Three types of emulsifiers, lecithin, Tween-20 and sodium dodecyl sulphate (SDS) were tested. A nonlinear behavior of the antioxidant activity of alkyl gallates when increasing alkyl chain length was observed for emulsions prepared with lecithin. Medium-size alkyl gallates (C6-C12) were the best antioxidants. In contrast, for emulsions prepared with Tween-20, the antioxidants seem to follow the polar paradox. Glucosyl alkyl gallates were shown previously to be better surfactants than alkyl gallates. Nevertheless, they exhibited a worse antioxidant capacity than their corresponding alkyl gallates, in emulsions prepared with lecithin or Tween-20, indicating the greater relevance of having three OH groups at the polar head in comparison with having improved surfactant properties but just a di-ortho phenolic structure in the antioxidant
Field Evaluation of Smart Sensor Vehicle Detectors at Railroad Grade Crossings���Volume 4: Performance in Adverse Weather Conditions
The performance of a microwave radar system for vehicle detection at a railroad grade crossing with quadrant gates was evaluated in adverse weather conditions: rain (light and torrential), snow (light and heavy), dense fog, and wind. The first part of this report compares the results of the modified system setup in adverse weather conditions with those from good weather conditions (as presented in Volume 3 of this study). Then, the results of a re-modified system setup were compared to the results for the modified system setup in good and adverse weather conditions. The re-modification was in response to increased detection errors in adverse weather conditions. With the modified setup, system performance was sensitive to the adverse weather conditions. In torrential rain, false calls increased to 24.82%–27.08% (e.g., May 28 and June 1) when there was some traffic on the crossing. However, when there was torrential rain but only one vehicle (e.g., May 31) or no traffic flow (e.g., June 10), the radar units generated 15 false calls on each of those 2 days. For all heavy snow datasets combined, missed calls by a single radar unit and by the two radar units working as a combined unit (i.e., systemwide) represented 13.51% and 11.66% of the loop calls, respectively. The most severe snow effects were found during freezing rain/ice. In dense fog, false calls increased to 11.58%, and all false calls were generated when the gates were moving or in the down position. Wind did not affect system performance, and the errors were similar to those in good weather conditions. With the re-modified setup, the frequency of errors in heavy rain and heavy snow conditions was reduced and system performance was similar to the good weather, light rain, and light snow conditions. In heavy rain, false calls in the re-modified setup were reduced to 2.6% compared with 30.5% in the modified setup. This reduction was the result of a significant decrease in the false calls generated without objects in the crossing. The re-modified setup eliminated the systemwide missed calls in heavy snow. The re-modified setup also reduced the false calls to less than 1% in good weather, light rain, and light snow conditions and practically had no missed, stuck-on, or dropped calls. Results indicate that re-modifications improved the performance of detection system.Illinois Department of Transportation, R27-095Ope
In situ detection of AE2 anion-exchanger mRNA in the human liver
Na+-independent anion exchangers, a family of membrane proteins that mediate electroneutral exchanges of chloride and bicarbonate ions across the cell membrane, are considered to be involved in intracellular pH regulation as well as in transepithelial acid/base transport. Previous immunohistochemical data have shown that anion-exchanger-2 (AE2) protein is expressed in the liver parenchyma, localizing at both the canaliculi and the luminal surfaces of intrahepatic bile ducts, where it may have a role in the biliary secretion of bicarbonate. In the present study, we have carried out in situ hybridization experiments on biopsies of human liver using three overlapping antisense anion-exchanger-2 riboprobes. Anion-exchanger-2 mRNA signals were localized mainly in the cytoplasm of terminal and interlobular bile-duct cells, whereas weaker signals were observed in bile-duct cells of larger intrahepatic ducts. Furthermore, some hepatocytes, mostly periportal, contained detectable anion-exchanger-2 mRNA signals in their cytoplasm. No hybridization signals were observed in controls with sense riboprobes, with omission of the antisense probe, or with treatment of the sections with RNase before hybridizations. Finally, intense anion-exchanger-2 hybridization signals were observed in lymphomononuclear cells in sinusoids and in portal infiltrates. Immunocytochemical data from reverse-phase sections suggest that these cells correspond to some of the CD45R+ (UCHL1+) T lymphocytes resident in the liver
Reversible Motion In a Contact Line
When a body of liquid sits on a surface, an irregular border between the wet and dry regions of the surface exists, called the contact line. Driving this contact line back and forth repeatedly can change its shape.We use a syringe pump to cyclically infuse and withdraw a predetermined volume of water, and take photos of the contact line after each cycle. Comparing these images to each other determines if the contact line is returning to the same shape. We find that below a critical value of infused volume, after many cycles the contact line reaches a steady state in which it always returns to the same shape. Above that value the shape fluctuates in the steady state. This suggests a transition similar to that seen in other systems like particle suspensions and solids
The A-Type event in the eastern Sierras Pampeanas, La Rioja and Catamarca Provinces (Argentina): geochronological and isotopic considerations
Depto. de MineralogĂa y PetrologĂaFac. de Ciencias GeolĂłgicasTRUEsubmitte
A-Type granitoids in the eastern Sierras Pampeanas (Argentina): evidence for early Carboniferous aborted rifting?
Depto. de MineralogĂa y PetrologĂaFac. de Ciencias GeolĂłgicasTRUEsubmitte
Treatment of epidermoid tumors with gamma knife radiosurgery: case series
Epidermoid tumors (ETs) are benign lesions that are treated
mainly by means of surgical resection, with overall good results. External beam
radiotherapy is an alternative treatment for those recurrent tumors, in which a
second surgery might not be the best choice for the patient. A little information
exists about the effectiveness of gamma knife radiosurgery for the treatment of
newly diagnosed and recurrent ETs. We present three cases of ETs treated with
gamma knife radiosurger
Impact of the COVID-19 pandemic on HIV care in Guatemala
Objectives: To describe the impact of the coronavirus disease 2019 (COVID-19) pandemic on the diagnosis of human immunodeficiency virus (HIV) and deaths from opportunistic infections in Guatemala. Methods: A retrospective study was conducted to investigate the impact of the COVID-19 pandemic on people with HIV at a referral clinic (Clinica Familiar Luis Angel GarcĂa, CFLAG), as well as the disruption of services at a diagnostic laboratory hub (DLH) which provides diagnosis for opportunistic infections to a network of 13 HIV healthcare facilities. Comparative analysis was undertaken using the months March-August from two different time periods: (i) pre-COVID-19 (2017-2019); and (ii) during the COVID-19 period (2020). Results: During the COVID-19 period, 7360 HIV tests were performed at Clinica Familiar Luis Angel GarcĂa, compared with an average of 16,218 tests in the pre-COVID-19 period; a reduction of 54.7% [95% confidence interval (CI) 53.8-55.4%],Deaths from opportunistic infections at 90 days were 10.7% higher in 2020 compared with 2019 (27.3% vs 16.6%; P = 0.05). Clinical samples sent to the DLH for diagnosis of opportunistic infections decreased by 43.7% in 2020 (95% CI 41.0-46.2%). Conclusion: The COVID-19 pandemic is having a substantial impact on HIV care in Guatemala. Diagnostic services for HIV have been severely affected and deaths from opportunistic infections have increased. The lessons learnt must guide the introduction of strategies to reduce the impact of the pandemic.S
Influence of curing conditions on recycled aggregate concrete
This paper presents the results of a study of permeability and its influence on the durability of recycled concrete exposed to an aggressive environment. Recycled concretes with 20%, 50% and 100% in weight ofrecycled aggregate and 24 effective w/c ratios have been exposed directly to a marine environment. Control specimens cured in a humidity chamber have been also tested in order to compare the influence of the curing environment. The durability of recycled aggregate concretes exposed to aggressive conditions decreases in terms of permeability, as the results show. However, the influence of the environment on the recycled concrete also depends on the quality of the cement paste. The differences between the control and the exposed concrete are lower for low water/cement (w/c) ratios. The lower capillarity obtained in the new cement paste of the recycled concretes with low w/c ratios isolates the porosity of the recycled aggregate, increasing the durability but with a rise in the cement content.The authors wish to thank the Spanish Ministry of the Environment for the funding of this research. The results contained herein have been achieved under the RECNHOR Project (funded by the Spanish Ministry of Environment) and under the CLEAM Project (funded by the Spanish Centre for Industrial Technology Development, CDTI), Code 3.2-358/200 5/3-B, led by the Economic InterestGrouping CLEAM-CENIT, AIE (Acciona, Dragados, Ferrovial, FCC,Sioux, OHL and Sacyr) and SMEs Informatica 68, Quilosa and Martinez Segovia and associates
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