504 research outputs found
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5 S,15 S-Dihydroperoxyeicosatetraenoic Acid (5,15-diHpETE) as a Lipoxin Intermediate: Reactivity and Kinetics with Human Leukocyte 5-Lipoxygenase, Platelet 12-Lipoxygenase, and Reticulocyte 15-Lipoxygenase-1.
The reaction of 5 S,15 S-dihydroperoxyeicosatetraenoic acid (5,15-diHpETE) with human 5-lipoxygenase (LOX), human platelet 12-LOX, and human reticulocyte 15-LOX-1 was investigated to determine the reactivity and relative rates of producing lipoxins (LXs). 5-LOX does not react with 5,15-diHpETE, although it can produce LXA4 when 15-HpETE is the substrate. In contrast, both 12-LOX and 15-LOX-1 react with 5,15-diHpETE, forming specifically LXB4. For 12-LOX and 5,15-diHpETE, the kinetic parameters are kcat = 0.17 s-1 and kcat/ KM = 0.011 Ī¼M-1 s-1 [106- and 1600-fold lower than those for 12-LOX oxygenation of arachidonic acid (AA), respectively]. On the other hand, for 15-LOX-1 the equivalent parameters are kcat = 4.6 s-1 and kcat/ KM = 0.21 Ī¼M-1 s-1 (3-fold higher and similar to those for 12-HpETE formation by 15-LOX-1 from AA, respectively). This contrasts with the complete lack of reaction of 15-LOX-2 with 5,15-diHpETE [Green, A. R., et al. (2016) Biochemistry 55, 2832-2840]. Our data indicate that 12-LOX is markedly inferior to 15-LOX-1 in catalyzing the production of LXB4 from 5,15-diHpETE. Platelet aggregation was inhibited by the addition of 5,15-diHpETE, with an IC50 of 1.3 Ī¼M; however, LXB4 did not significantly inhibit collagen-mediated platelet activation up to 10 Ī¼M. In summary, LXB4 is the primary product of 12-LOX and 15-LOX-1 catalysis, if 5,15-diHpETE is the substrate, with 15-LOX-1 being 20-fold more efficient than 12-LOX. LXA4 is the primary product with 5-LOX but only if 15-HpETE is the substrate. Approximately equal proportions of LXA4 and LXB4 are produced by 12-LOX but only if LTA4 is the substrate, as described previously [Sheppard, K. A., et al. (1992) Biochim. Biophys. Acta 1133, 223-234]
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Hydraulic performance of temporary construction traffic barriers
Center for Water and the Environmen
Heliostat-field soiling predictions and cleaning resource optimization for solar tower plants
This paper presents a novel methodology for characterizing soiling losses
through experimental measurements. Soiling predictions were obtained by
calibrating a soiling model based on field measurements from a 50 MW modular
solar tower project in Mount Isa, Australia. The study found that the mean
predicted soiling rate for horizontally fixed mirrors was 0.12 percentage
points per day (pp/d) during low dust seasons and 0.22 pp/d during high
seasons. Autoregressive time series models were employed to extend two years of
onsite meteorological measurements to a 10-year period, enabling the prediction
of heliostat-field soiling rates. A fixed-frequency cleaning heuristic was
applied to optimise the cleaning resources for various operational policies by
balancing direct cleaning resource costs against the expected lost production,
which was computed by averaging multiple simulated soiling loss trajectories.
Analysis of resource usage showed that the cost of fuel and operator salaries
contributed 42 % and 35 % respectively towards the cleaning cost. In addition,
stowing heliostats in the horizontal position at night increased daily soiling
rates by 114 % and the total cleaning costs by 51 % relative to vertically
stowed heliostat-field. Under a simplified night-time-only power production
configuration, the oversized solar field effectively charged the thermal
storage during the day, despite reduced mirror reflectance due to soiling.
These findings suggest that the plant can maintain efficient operation even
with a reduced cleaning rate. Finally, it was observed that performing cleaning
operations during the day led to a 7 % increase in the total cleaning cost
compared to a night-time cleaning policy. This was primarily attributed to the
need to park operational heliostats for cleaning
Enhancing the activity of oxygen-evolution and chlorine-evolution electrocatalysts by atomic layer deposition of TiOā
We report that TiOā coatings formed via atomic layer deposition (ALD) may tune the activity of IrOā, RuOā, and FTO for the oxygen-evolution and chlorine-evolution reactions (OER and CER). Electrocatalysts exposed to ā¼3ā30 ALD cycles of TiOā exhibited overpotentials at 10 mA cmā»Ā² of geometric current density that were several hundred millivolts lower than uncoated catalysts, with correspondingly higher specific activities. For example, the deposition of TiOā onto IrOā yielded a 9-fold increase in the OER-specific activity in 1.0 M HāSOā (0.1 to 0.9 mA cm_(ECSA)ā»Ā² at 350 mV overpotential). The oxidation state of titanium and the potential of zero charge were also a function of the number of ALD cycles, indicating a correlation between oxidation state, potential of zero charge, and activity of the tuned electrocatalysts
Strategic misrepresentation in online dating: The effects of gender, self-monitoring, and personality traits
Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
Targeting fibroblast activation protein in tumor stroma with chimeric antigen receptor T cells can inhibit tumor growth and augment host immunity without severe toxicity.
The majority of chimeric antigen receptor (CAR) T-cell research has focused on attacking cancer cells. Here, we show that targeting the tumor-promoting, nontransformed stromal cells using CAR T cells may offer several advantages. We developed a retroviral CAR construct specific for the mouse fibroblast activation protein (FAP), comprising a single-chain Fv FAP [monoclonal antibody (mAb) 73.3] with the CD8Ī± hinge and transmembrane regions, and the human CD3Ī¶ and 4-1BB activation domains. The transduced muFAP-CAR mouse T cells secreted IFN-Ī³ and killed FAP-expressing 3T3 target cells specifically. Adoptively transferred 73.3-FAP-CAR mouse T cells selectively reduced FAP(hi) stromal cells and inhibited the growth of multiple types of subcutaneously transplanted tumors in wild-type, but not FAP-null immune-competent syngeneic mice. The antitumor effects could be augmented by multiple injections of the CAR T cells, by using CAR T cells with a deficiency in diacylglycerol kinase, or by combination with a vaccine. A major mechanism of action of the muFAP-CAR T cells was the augmentation of the endogenous CD8(+) T-cell antitumor responses. Off-tumor toxicity in our models was minimal following muFAP-CAR T-cell therapy. In summary, inhibiting tumor growth by targeting tumor stroma with adoptively transferred CAR T cells directed to FAP can be safe and effective, suggesting that further clinical development of anti-human FAP-CAR is warranted
Bridging the gap to mesoscale radiation materials science with transient grating spectroscopy
Direct mesoscale measurements of radiation-induced changes in the mechanical properties of bulk materials remain difficult to perform. Most widely used characterization techniques are either macro- or microscale in nature, focusing on overall properties or overly small areas for analysis. Linking the atomic structure of irradiated materials directly with their radiation-affected properties remains one of the largest unmet challenges in radiation materials science. By measuring the change in surface acoustic wave speed as a function of relative orientation on metallic single crystals, we demonstrate that transient grating (TG) spectroscopy experiments have the sensitivity necessary to detect radiation-induced material property changes. We also show that classical molecular dynamics (MD) simulations can be used to accurately simulate orientation-based changes in surface acoustic wave speed in TG experiments, by comparing with experimental measurements and theoretical predictions. The agreement between theory, simulation, and experiment gives confidence in classical MD as a predictive tool to simulate defect-based changes in elastic properties, which cannot yet be fully treated by theory. This ability is of critical importance for the informed use of TG spectroscopy to measure material property changes induced by radiation damage, which may vary by amounts formerly too small for reliable in situ detection. Finally, our MD simulation framework is used to study the effect of an imposed vacancy population on the acoustic response of several materials. The results of these studies indicate that TG experiments are well suited to the ex situ and in situ study of radiation-induced material property changes.National Science Foundation (U.S.) (Grant 1122374)National Science Foundation (U.S.) (Grant CHE-1111557)Transatomic Power (Award 023875-001)U.S. Nuclear Regulatory Commission (MIT Nuclear Education Faculty Development Program. Grant NRC-HQ- 84-15-G-0045
Socioecological Determinants of Drought Impacts and Coping Strategies for Ranching Operations in the Great Plains
In Great Plains rangelands, drought is a recurring disturbance. Ranchers in this region expect to encounter drought but may not be adequately prepared for it. Efforts to encourage drought preparednesswould benefit froma better understanding of the conditions under which managers make decisions to minimize the impacts of drought.We tested the direct andmoderating roles of the drought hazard and the social-ecological context on drought impacts and response. This study was conducted with ranchers in western and central South Dakota and Nebraska following the drought that began in 2012. We surveyed ranchers regarding the effects of the drought and their responses and used multimodel analysis to explore the relationships among measures of drought preparedness, drought response, and drought impacts. Drought severity was the primary predictor of all impacts, but specific types of impacts were varied depending on the operationās enterprisemix, resources, and management. The socioecological characteristics of the ranch system predicted drought response actions taken, by either providing the necessary resources and capacity to take action or creating sensitivity in the system that required action to be taken. We conclude with recommendations for learning from current drought experiences in order to better adapt to future drought events
āRespect the way I need to communicate with youā: Healthcare Experiences of Adults on the Autism Spectrum
Our objective was to obtain an in-depth understanding of autistic adultsā experiences with healthcare and their recommendations for improving care. Our academic-community partnership used a community based participatory research (CBPR) approach to conduct semi-structured, open-ended interviews with 39 autistic adults and 16 people who had experience supporting autistic adults in healthcare settings. Participants identified patient-level, autism-related factors that impact healthcare interactions, including verbal communication skills, sensory sensitivities, challenges with body awareness, slow processing speed, atypical non-verbal communication, and challenges with organization. However, the success of healthcare interactions largely depended on the interplay between patient- and provider-level factors, as well as on the larger context in which patients were receiving care. Provider-level factors included providersā knowledge about autism in adults, incorrect assumptions about individual patients, willingness to allow written communication, use of accessible language, openness to providing other accommodations, and skill in appropriately incorporating supporters. System-level factors included the availability of supporters, complexity of the healthcare system, accessibility of healthcare facilities, and stigma about autism. Further efforts are needed to empower patients, adequately train providers, increase the accessibility of the healthcare system, and decrease discrimination
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