Effects of recycled asphalt shingle on the rheological and molecular composition properties of asphalt cement

Recycling of asphalt shingles in flexible pavements has received interests in recent years due to economic, environmental, and social reasons. The objective of this study is to introduce a new approach to recycle asphalt shingles in asphalt paving construction in which RAS is ground to ultra-fine sizes and blended with asphalt binder through a wet process. In this method, the ground recycled material is blended with the binder at high temperature prior to mixing with the aggregates. Two unmodified binders that are classified as PG64-22 and PG52-28 were blended with two contrasting sources of RAS, originating from tear-off and manufacturer wastes, at a modification content ranging from 10 to 40% by weight of the binder. The use of RAS modification through the proposed wet process was successful. The use of RAS modification through the proposed wet process would generally improve or not influence the high temperature grade of the binder but it may reduce the low temperature grade of the binder. An optimum shingle content may be identified that will improve the high temperature grade without influencing the low temperature grade of the binder. Using Confocal Laser-Scanning Microscopy, wax crystals were detected. However, wax crystals were not detected in the RAS-modified binder, which may indicate that the wax molecules are absorbed by the RAS material. Results of HP-GPC showed that the proposed wet method of modification caused a slight increase of the High Molecular Weight (HMW) content in the prepared blends especially at high content of RAS modification. Use of RAS resulted in an increase in viscosity ranging from 3 to 130%. The increase in viscosity was proportional to the RAS content with greater increase at RAS content of 30% and in blends prepared with RAS from tear-off. The temperature susceptibility of the binder in the range from 95 to 135°C decreased with the use of RAS. Thixotropy and shear thinning were observed concurrently in the asphalt binder blends at 25°C. In addition, RAS-modified asphalt binders showed greater susceptibility to thixotropy than the base binder. Thixotropy increased with higher RAS content

Lumbar Spondylolysis and Spondylolytic Spondylolisthesis: Who Should Be Have Surgery? An Algorithmic Approach

Lumbar spondylolysis and spondylolisthesis are common spinal disorders that most of the times are incidental findings or respond favorably to conservative treatment. In a small percentage of the patients, surgical intervention becomes necessary. Because too much attention has been paid to novel surgical techniques and new modern spinal implants, some of fundamental concepts have been forgotten. Identifying that small but important number of patients with lumbar spondylolysis or spondylolisthesis who would really benefit from lumbar surgery is one of those forgotten concepts. In this paper, we have developed an algorithmic approach to determine who is a good candidate for surgery due to lumbar spondylolysis or spondylolisthesis

The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019

Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe

Identification and characterization of human mevalonate kinase inhibitors

The mevalonate pathway is responsible for the synthesis of isoprenoids, which are essential for various biological activities, such as cell signaling and membrane function. Mevalonate kinase (MK) is a critical enzyme in this pathway, converting mevalonic acid (MVA) to mevalonate-5- phosphate (M-5-P) with ATP as a phosphoryl donor. Mutations in the MVK gene, which encodes MK, can cause mevalonate kinase deficiency, an inborn error of metabolism characterized by severe, recurrent inflammation. Previous research has shown that farnesyl pyrophosphate (FPP), a downstream metabolite of the mevalonate pathway, inhibits MK by blocking its ATP binding site. Interestingly, FPP also inhibits FPP synthase, the enzyme that produces FPP. These observations provide evidence for multilayered regulation of the mevalonate pathway, where the single feedback inhibitor FPP targets multiple enzymatic steps. In this thesis, I verified the hypothesis that analogs of FPP that can inhibit FPP synthase could also inhibit MK. Using an enzyme-coupled spectrophotometric assay, I identified several phosphonate compounds that can inhibit MK with nanomolar potency. Further analysis revealed features of these compounds that correlate with their inhibitory activity. The mode of inhibition was also determined for representative compounds. To better understand how MK interacts with its ligands, I have commenced X-ray crystallography studies. The inhibitor compounds identified in this study may serve as a useful tool for future research, for example, in evaluating MK as a new therapeutic target and advancing our understanding of mevalonate pathway regulation

Feasibility and Performance of Low-Volume Roadway Mixture Design [Tech Summary]

State Project No. DOTLT1000329During specification meetings between the Louisiana Department of Transportation and Development (DOTD) and asphalt contractors around the state, a concern was raised regarding the payment methods for low-volume roadways. At the time, DOTD was using the \u201cpercent within limits\u201d (PWL) model to determine payment for all roadways

Evaluation of Saturates/Aromatics/Resins/Asphaltenes (SARA) Fractionation of Asphalt Binders in Louisiana: Research Project Capsule [22-1B]

TT-Fed/TT-Reg-5The objective of this research is to evaluate the characterization of asphalt binder through TLC/FID testing and SARA grouping. The results will be further analyzed and compared with the available GPC results and other available characterizations of the asphalt binders. Furthermore, the results will be correlated with performance

New approach to recycling asphalt shingles in hot-mix asphalt

The objective of this study is to introduce a new approach to recycling asphalt shingles in asphalt paving construction in which recycled asphalt shingles (RAS) are ground to ultrafine particle sizes and blended with asphalt binder through a wet process. In the proposed wet process, the ground recycled material is blended with the binder at a high temperature prior to mixing with the aggregates. Two unmodified binders that are classified as PG 64-22 and PG 52-28 were blended with two contrasting sources of RAS at a modification content ranging from 10-40%by weight of the binder. The use of RAS modification through the proposed wet process was successful in the laboratory. Based on the results of the experimental program, the use of RAS modification through the proposed wet process would generally improve or not influence the high temperature grade of the binder, but it may reduce the low temperature grade of the binder. As demonstrated in this study, an optimum shingle content may be identified that will improve the high temperature grade without influencing the low temperature grade of the binder. Using confocal laser-scanning microscopy (CLSM), wax crystals ranging from 4-8 μm in size were successfully detected. However, wax crystals were not detected in the RAS-modified binder, which may indicate that the wax molecules are absorbed by the RAS material. Results of high-pressure gel permeation chromatography (HP-GPC) showed that the proposed wet method of modification produced a slight increase in the high molecular weight (HMW) (\u3e3; 000 daltons) content in the prepared blends at higher RAS contents, suggesting that a fraction of the RAS binder contributes to the blend properties. © 2012 American Society of Civil Engineers

The global burden of cancer attributable to risk factors, 2010-19: a systematic analysis for the Global Burden of Disease Study 2019

Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% 47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% 32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% 27.9-42.8] and 33.3% 25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license