Search

Geothermal pavements can be used with ground-source heat pump systems to sustainably provide energy for heating and cooling by incorporating ground heat exchanger elements underneath pavement surfaces. This work investigates the suitability of geothermal pavements at scale, adopting the city of Cardiff, UK, as a case-study. A two-scale modelling framework, combining detailed small-scale with holistic large-scale approaches, is presented, incorporating the accuracy of the former with the continuity of the latter. The results show that between 184 kWh and 345 kWh of thermal energy per metre length of pavement can be supplied annually, depending on soil profile. Moreover, geothermal operation can reduce anthropogenic heat flux into the ground from heated basements, and its associated negative impacts, by about 390 MWh/year. A city-scale analysis using population-consistent geographic areas called LSOAs, estimates that geothermal pavements can supply about 23% of the entire city residential heat demand, or up to 75% with heat sharing between LSOAs. The suitability of geothermal pavements for larger LSOAs is highlighted, supplying up to 100% of the annual domestic heat demand. Investigating the carbon emissions of heating and cooling technologies shows potential reductions of up to 75% when replacing gas boilers and resistance heating with geothermal pavement systems. • Two-scale modelling is used to assess city-scale geothermal pavement potential. • Depending on ground conditions, 184–345 kWh annually/m road of heat can be provided. • Geothermal pavements can reduce anthropogenic heat flux into the ground by ∼ 390 MWh/a. • In low population density areas 100% residential demand can be fulfilled, overall 23%. • Replacing traditional systems can reduce carbon emission by ∼ 75%. [ABSTRACT FROM AUTHOR]

Background and Aims: Dyslipidemia has been identified as a major risk factor for cardiovascular disease. We aimed to identify metabolites and metabolite modules showing novel association with lipids among Bogalusa Heart Study (BHS) participants using untargeted metabolomics.Methods and Results: Untargeted ultrahigh performance liquid chromatography-tandem mass spectroscopy was used to quantify serum metabolites of 1 243 BHS participants (816 whites and 427 African-Americans). The association of single metabolites with lipids was assessed using multiple linear regression models to adjust for covariables. Weighted correlation network analysis was utilized to identify modules of co-abundant metabolites and examine their covariable adjusted correlations with lipids. All analyses were conducted according to race and using Bonferroni-corrected α-thresholds to determine statistical significance. Thirteen metabolites with known biochemical identities showing novel association achieved Bonferroni-significance, p < 1.04 × 10-5, and showed consistent effect directions in both whites and African-Americans. Twelve were from lipid sub-pathways including fatty acid metabolism (arachidonoylcholine, dihomo-linolenoyl-choline, docosahexaenoylcholine, linoleoylcholine, oleoylcholine, palmitoylcholine, and stearoylcholine), monohydroxy fatty acids (2-hydroxybehenate, 2-hydroxypalmitate, and 2-hydroxystearate), and lysoplasmalogens [1-(1-enyl-oleoyl)-GPE (P-18:1) and 1-(1-enyl-stearoyl)-GPE (P-18:0)]. The gamma-glutamylglutamine, peptide from the gamma-glutamyl amino acid sub-pathway, were also identified. In addition, four metabolite modules achieved Bonferroni-significance, p < 1.39 × 10-3, in both whites and African-Americans. These four modules were largely comprised of metabolites from lipid sub-pathways, with one module comprised of metabolites which were not identified in the single metabolite analyses.Conclusion: The current study identified 13 metabolites and 4 metabolite modules showing novel association with lipids, providing new insights into the physiological mechanisms regulating lipid levels. [ABSTRACT FROM AUTHOR]

• Long-term exposure to PM 2.5 are associated with large- and small- airway function. • Organic matter and nitrate show stronger associations with lung function than PM 2.5. • Exposure to PM 2.5 constituents might be more important in impairing lung function. The associations of long-term exposure to various constituents of fine particulate matter (≤2.5 μm in aerodynamic diameter, PM 2.5) air pollution with lung function were not clearly elucidated in developing countries. The aim was to evaluate the associations of long-term exposure to main constituents of PM 2.5 with lung function in China. This is a nationwide, cross-sectional analysis among 50,991 study participants from the China Pulmonary Health study. Multivariable linear regression models were used to obtain differences of forced expiratory volume in 1 s (FEV 1), forced vital capacity (FVC), FEV 1 /FVC, peak expiratory flow (PEF), and forced expiratory flow at 25–75% of exhaled FVC (FEF 25-75%) associated with an interquartile range (IQR) change of PM 2.5 or its constituents. Residential annual PM 2.5 levels varied from 26 μg/m3 to 92 μg/m3 (average: 53 μg/m3). An IQR increase of PM 2.5 concentrations was associated with lower FEV 1 (19.82 mL, 95% CI: 11.30–28.33), FVC (17.45 mL, 95% CI: 7.16–27.74), PEF (86.64 mL/s, 95% CI: 59.77–113.52), and FEF 25-75% (31.93 mL/s, 95% CI: 16.64–47.22). Black carbon, organic matter, ammonium, sulfate, and nitrate were negatively associated with most lung function indicators, with organic matter and nitrate showing consistently larger magnitude of associations than PM 2.5 mass. This large-scale study provides first-hand epidemiological evidence that long-term exposure to ambient PM 2.5 and some constituents, especially organic matter and nitrate, were associated with lower large- and small- airway function. [ABSTRACT FROM AUTHOR]

Herein, we proposed a new strategy to enhance compatibility and flame retardancy of the immiscible and flammable polylactic acid (PLLA)/polypropylene (PP) blend materials simultaneously. It is found that the boehmite nanorods are located at the PLLA-PP interface by in-situ reactions and the compatibility between phases is greatly improved, resulting in significant enhancement of mechanical properties and flame retardancy: tensile strength and elongation at break of the blends with 7 wt% reactive nanorods are 163% and 601% higher than that without nanorods, respectively. Meanwhile, the peak heat release rate (PHRR) decreases 51.4% and limiting oxygen index (LOI) increases 22.6%. The synergetic improvements are directly attributed to the strengthened interface and the interface takes the role of the flame retarding belt. The research opens a new avenue to fabricate non-halogen flame retardant multicomponent polymer materials with simultaneously enhanced mechanical properties. [Display omitted] •Ternary Poly(L-lactic acid)/Polypropylene/boehmite nanorods nanocomposites were prepared. •Epoxide groups modified boehmite nanorods are thermodynamically located at the PLLA/PP blend interface by the in-situ reactions. •The interfacially located nanorods improve the mechanical properties and flame retardancy of the PLLA/PP blends simultaneously. [ABSTRACT FROM AUTHOR]

At present, anti-angiogenic drugs (AADs) are widely used in the systemic treatment of hepatocellular carcinoma (HCC) or other types of cancer, and have achieved good anti-cancer effect, whereas treatment-related proteinuria can affect the routine use of AADs, which in turn abates the overall efficacy. Currently, most clinicians prescribe angiotensin-converting enzyme inhibitors (ACEIs) to alleviate proteinuria according to diabetic nephropathy guidelines or expert recommendations. However, the efficacy of ACEIs in reducing AAD-related proteinuria and its effect on the anticancer effect of AADs is unknown. Our clinical data showed that some HCC patients experienced tumor progression by ACEIs administration for the treatment of proteinuria caused by AADs. Here, we confirmed that in different tumor-bearing mouse models, ACEIs did not delay the appearance of proteinuria or alleviate proteinuria caused by AADs but compromised the anticancer efficacy of AADs. This effect is unrelated to the change in the VEGF signaling pathway. Our data showed that the combination of ACEIs and AADs flared the production of kidney-derived erythropoietin (EPO). In turn, EPO compromises the anti-angiogenic effects of AADs and decreases antitumor activity. In conclusion, for the treatment of proteinuria caused by AADs, ACEIs have no efficacy while also promoting AADs resistance. This finding is of great significance to guide clinical standardized management of side effects of anti-angiogenic therapy for cancer patients. • ACEIs cannot reduce or delay proteinuria caused by AADs. • ACEIs alone do not promote tumor growth of liver cancer subcutaneous tumor. • High doses of AADs easily induce stable proteinuria, but the anticancer effect is better. • Proteinuria caused by AADs is reversible after withdrawal. • ACEIs promotes the production of kidney-derived EPO and reduces the anticancer efficacy of AADs. [ABSTRACT FROM AUTHOR]

Reactive polymer processing is an effective and environmentally-friendly means of preparing new materials based on combining components with various properties. Numerous investigations have been carried out to explore the reaction processes that occur during the melt blending of polymers. However, reactive processing is far from fully understood because it involves a complicated combination of shear and extensional flows as well as high temperatures and pressures. In this work, a two-step compatibilizing strategy (called reactive splicing compatibilization) has been used to compatibilize immiscible Poly(lactic acid) (PLLA)/Poly(butylene adipate- co -terephthalate) (PBAT) blends with two different PBAT molecular weights (termed H-PBAT and L-PBAT, respectively), using styrene- co -glycidyl methacrylate (SG) as the grafting counterpart. Reactive compatibilizers with various architectures were prepared by pre-grafting either PLLA or PBAT (or both) onto the SG main chains. The remaining unreacted epoxide groups of the pregrafted SG underwent in situ reactions to form double grafted copolymers as compatibilizers for the final blends. The reactivity of SG with these polymers was found to decrease in the order of L-PBAT > PLLA > H-PBAT. Reactive compatibilizers having various architectures were applied to PLLA/PBAT blends with compositions ranging from 90/10 to 10/90 (w/w). The most efficient pre-grafted reactive compatibilizer was determined for the blends with certain composition. A higher proportion of H-PBAT had to be pre-grafted onto the SG to achieve the best compatibilization efficiency when increasing the PLLA content in PLLA/H-PBAT blends. In the case of PLLA/L-PBAT blends, PLLA chains had to be pre-grafted onto the SG for the best compatibilization when L-PBAT was the primary component of the blend. These results provide a better understanding of the reactive processing mechanism. Evidently, the dynamic shear applied during melt processing continuously renews the interface between the different phases to provide sites for reactions between the blend components. These reactions are affected by both the reactivity of the components and the contact time, which in turn is determined by the blend composition. The compatibilizers located at the blend interface were found to have very similar symmetrical binary grafted structures for blends with different compositions. Image 1 • A two-step compatibilizing strategy (called reactive splicing compatibilization) has been used to compatibilize the immiscible Poly(lactic acid) (PLLA)/Poly(butylene adipate- co -terephthalate) (PBAT) blends with two different PBAT molecular weights, using styrene-co-glycidyl methacrylate (SG) as the grafting counterpart. • More than 100 compatibilized blends have been prepared and compared the compatibilization effects of the different compatibilizers. • This work demonstrates the locations of the various reactions and the factors affecting the reactive processing. • The work is very important for better understanding the reactive processing, especially the functions of the dynamic shearing, the reactivity and the composition effects. [ABSTRACT FROM AUTHOR]

Use of corticosteroids is common in the treatment of coronavirus disease 2019, but clinical effectiveness is controversial. We aimed to investigate the association of corticosteroids therapy with clinical outcomes of hospitalized COVID-19 patients. In this single-centre, retrospective cohort study, adult patients with confirmed coronavirus disease 2019 and dead or discharged between 29 December 2019 and 15 February 2020 were studied; 1:1 propensity score matchings were performed between patients with or without corticosteroid treatment. A multivariable COX proportional hazards model was used to estimate the association between corticosteroid treatment and in-hospital mortality by taking corticosteroids as a time-varying covariate. Among 646 patients, the in-hospital death rate was higher in 158 patients with corticosteroid administration (72/158, 45.6% vs. 56/488, 11.5%, p < 0.0001). After propensity score matching analysis, no significant differences were observed in in-hospital death between patients with and without corticosteroid treatment (47/124, 37.9% vs. 47/124, 37.9%, p 1.000). When patients received corticosteroids before they required nasal high-flow oxygen therapy or mechanical ventilation, the in-hospital death rate was lower than that in patients who were not administered corticosteroids (17/86, 19.8% vs. 26/86, 30.2%, log rank p 0.0102), whereas the time from admission to clinical improvement was longer (13 (IQR 10–17) days vs. 10 (IQR 8–13) days; p < 0.001). Using the Cox proportional hazards regression model accounting for time varying exposures in matched pairs, corticosteroid therapy was not associated with mortality difference (HR 0.98, 95% CI 0.93–1.03, p 0.4694). Corticosteroids use in COVID-19 patients may not be associated with in-hospital mortality. [ABSTRACT FROM AUTHOR]

At present, anti-angiogenic drugs (AADs) are widely used in the systemic treatment of hepatocellular carcinoma (HCC) or other types of cancer, and have achieved good anti-cancer effect, whereas treatment-related proteinuria can affect the routine use of AADs, which in turn abates the overall efficacy. Currently, most clinicians prescribe angiotensin-converting enzyme inhibitors (ACEIs) to alleviate proteinuria according to diabetic nephropathy guidelines or expert recommendations. However, the efficacy of ACEIs in reducing AAD-related proteinuria and its effect on the anticancer effect of AADs is unknown. Our clinical data showed that some HCC patients experienced tumor progression by ACEIs administration for the treatment of proteinuria caused by AADs. Here, we confirmed that in different tumor-bearing mouse models, ACEIs did not delay the appearance of proteinuria or alleviate proteinuria caused by AADs but compromised the anticancer efficacy of AADs. This effect is unrelated to the change in the VEGF signaling pathway. Our data showed that the combination of ACEIs and AADs flared the production of kidney-derived erythropoietin (EPO). In turn, EPO compromises the anti-angiogenic effects of AADs and decreases antitumor activity. In conclusion, for the treatment of proteinuria caused by AADs, ACEIs have no efficacy while also promoting AADs resistance. This finding is of great significance to guide clinical standardized management of side effects of anti-angiogenic therapy for cancer patients. [ABSTRACT FROM AUTHOR]

Polymer blend nanocomposites with the nanoparticles exclusively located at the interface have attracted significant attention while the compatibilization functions of such nanoparticles in the blends are still controversial. Herein, the pristine boehmite nanorods (p-BNRs) and epoxide group modified boehmite nanorods (m-BNRs) have been synthesized and incorporated in the immiscible Poly(l -lactide)/Poly(1,4-butylene succinate) (PLLA/PBSU) blends. It is found that both p-BNRs and m-BNRs are thermodynamically located at the interface and the phase morphologies of the two nanocomposites are very similar at the same nanofiller loadings. However, the two nanocomposites exhibit different mechanical properties. The PLLA/PBSU blend nanocomposites with m-BNRs show increased elongation at break, enhanced notched impact strength and improved yield strength, as compared with the binary PLLA/PBSU blends. In contrast, p-BNRs lead to drastically deteriorating mechanical properties of the PLLA/PBSU blends even with all p-BNRs located at the interface. The investigation indicates that p-BNRs at the interface have barren surface and are lack of specific interactions with the polymers in the neighboring phases. In contrast, the epoxide groups on m-BNRs reacted with the end carboxylic acid groups of both PLLA and PBSU and the polymer chains were chemically bonded onto the surface of nanorods. The chemically bonded polymer chains on the nanorods at the interface can entangle with the molecular chains of the two polymers to enhance the interfacial adhesion. This paper demonstrates the significance of molecular chain entanglements of the compatibilizing nanoparticles and paves a new possibility to fabricate new materials with simultaneously enhanced strength and toughness. Image 1 • Ternary Poly(l -lactide)/Poly(1,4-butylene succinate)/boehmite nanorods nanocomposites were prepared. • Both pristine boehmite nanorods and epoxide groups modified boehmite nanorods are thermodynamically located at the interface of PLLA/PBSU. • Barren nanorods deteriorate the mechanical properties of PLLA/PBSU blends, but surface grafted nanorods enhance the mechanical properties drastically. • Molecular entanglements of the grafted nanorods are the prerequisite for the compatibilization of immiscible polymer blends. [ABSTRACT FROM AUTHOR]

Reactive compatibilization is an effective method to improve the compatibility of immiscible polymer blends. The in-situ-formed graft/block copolymers should be thermodynamically located at the interface to bridge the neighboring phases. Unfortunately, they are often pulled out of the interface because of the asymmetric molecular structures. Here, we propose a new strategy to compatibilize immiscible polymer blends called reactive splicing compatibilization. Poly (styrene- co -glycidyl methacrylate) (SG) with high glycidyl methacrylate (GMA) content is used as the reactive backbone chain. Both poly (l -lactic acid) (PLLA) and poly (butylene adipate-co-terephthalate) (PBAT) molecular chains can be easily grafted onto the SG main backbone by the reaction of the terminal carboxylic acid groups with the epoxide groups in the melt. Direct melt blending SG with PLLA and/or PBAT leads to reactive compatibilizers with various molecular architectures, which are used for subsequent compatibilization of PLLA/PBAT blends. It was found that the compatibilizer architecture significantly affects the compatibilization efficiency. The best compatibilization occurs with a reactive compatibilizer of SG-g-PBAT with the SG to PBAT weight ratio of 1:2. The compatibilized PLLA/PBAT (50/50 w/w) blend has precise co-continuous phase morphology with very few micelles. The blend exhibits extremely high Charpy notched impact strength of 90.2 kJ/m2 and tensile strength of 33.3 MPa. The principle of the facile splicing compatibilization strategy is highly applicable to many other immiscible blends with both components containing reactive groups. We report the splicing compatibilization strategy for immiscible polymer blends. The compatibilizer architecture effects on the compatiblization efficiency were investigated. Image 1 • New compatibilization strategy called reactive splicing compatibilization was proposed. • Reactive comb compatibilizers with various architectures were synthesized by melt blending. • Molecular architecture effects on compatibilization of PBAT/PLLA blends were investigated. • PLLA/PBAT blends with superior toughness and high tensile strength were prepared. [ABSTRACT FROM AUTHOR]