In this study, the intrinsic properties of recycled coarse aggregates (RC), associated with bonded mortar, were modified with two different pretreatment techniques viz-a-viz HCl pretreatment and ...Na2SO4 pretreatment, while maintaining a fixed aggregate-to-solution ratio of 1:4.5. The residual bonded mortar was quantified to evaluate the potential of both techniques. HCl pretreatment yielded greater removal of bonded mortar content (BMC), almost twice as high as achieved by Na2SO4 pretreatment. Subsequently, the concretes were developed (termed as recycled aggregate concrete; RAC) by incorporating HCl treated coarse aggregates (HTC) and Na2SO4 treated coarse aggregates (STC). Both natural and recycled (untreated) fine aggregates (NF and RF, respectively) were used. Control specimens with natural coarse aggregates (NC) were prepared for comparative assessment. The resulting properties showed significantly influenced by bonded mortar content (BMC). About 14% higher compressive strength was achieved by using HTC in comparison with untreated RC, while a mere corresponding decline of 5% was seen when compared with NC. Likewise, the carbonation resistance and the resistance to chloride ion penetration showed better performance for HTC and STC incorporated concretes. Such superior performance is attributed to the denser interface (between the aggregate and paste matrix) with reduced pores/voids, as assessed from the optical and scanning electron microscopy. Further, the determined properties were used to develop regression models for the prediction of RAC properties. The prediction equations thus obtained showed remarked precision with the experimentally determined results, and as such these can be used for strength and durability prediction.
•Properties of recycled coarse aggregates (RC) were improved by pre-treating with HCl and Na2SO4.•HCl pretreatment was demonstrated twice as beneficial as Na2SO4 pretreatment.•Concretes incorporating treated RC showed remarkable properties enhancement.•Recycled aggregate concrete properties were also modeled (by regression) based on bonded mortar content.
Although COVID-19 is considered to be primarily a respiratory disease, SARS-CoV-2 affects multiple organ systems including the central nervous system (CNS). Yet, there is no consensus on the ...consequences of CNS infections. Here, we used three independent approaches to probe the capacity of SARS-CoV-2 to infect the brain. First, using human brain organoids, we observed clear evidence of infection with accompanying metabolic changes in infected and neighboring neurons. However, no evidence for type I interferon responses was detected. We demonstrate that neuronal infection can be prevented by blocking ACE2 with antibodies or by administering cerebrospinal fluid from a COVID-19 patient. Second, using mice overexpressing human ACE2, we demonstrate SARS-CoV-2 neuroinvasion in vivo. Finally, in autopsies from patients who died of COVID-19, we detect SARS-CoV-2 in cortical neurons and note pathological features associated with infection with minimal immune cell infiltrates. These results provide evidence for the neuroinvasive capacity of SARS-CoV-2 and an unexpected consequence of direct infection of neurons by SARS-CoV-2.
China is considered to account for nearly a third of all plastic waste discharging from land to the ocean. To overall assess microplastic pollution status in Chinese coastal and marginal seas, this ...study summarized the abundance and characteristics of microplastics in the seawater, sediments and marine organisms. The results showed that the abundance of microplastics in the seawater of four major seas of China was 0.13–545 items/m³, and microplastic abundance in the sediments from the estuaries was 20–7900 items/kg, which are at middle level or even lower than those detected in other countries. By contrast, severe microplastic pollution was recorded in the estuaries, suggesting that plastic waste and microplastic interception measures should be conducted on the rivers to prevent the input of microplastics. In addition, microplastics were widely detected in marine fishes, mollusks, zooplankton, mammals and birds, which highlights the potential impacts of microplastic pollution on the whole marine ecosystem. Compared to the dry season, higher microplastic abundance was found in the rainy season, revealing that plastic waste recycling should be strengthened before the onset of rainy season. We suggest that all countries respond actively to the ubiquitous microplastic pollution through practical policies and measures to prevent microplastics from further damaging the marine ecosystem.
•Microplastic abundance in seawaters of Chinese coastal seas was 0.13–545 items/m³.•Microplastic abundance in the sediments from the estuaries was 20–7900 items/kg.•High microplastic pollution was found in the estuaries, especially in rainy season.•Microplastic level in Chinese seas was moderate or lower compared to other countries.
•Incorporation of waste materials in manufacturing of clay bricks was investigated.•Mechanical and durability properties of bricks incorporating RHA and SBA was studied.•Addition of RHA and SBA in ...brick manufacturing can lead towards sustainable and economical construction.
Burnt clay brick is one of the major and widely used building unit in masonry construction around the globe. The manufacturing of burnt clay bricks using waste materials can minimize the environmental overburden caused by waste deposition on open landfills and would also improve the brick performance at low production cost leading to more sustainable construction. This study aims to evaluate the effect of the waste addition produced from two major crops: sugarcane and rice in clay bricks manufacturing. In this study, sugarcane bagasse ash (SBA) and rice husk ash (RHA) were collected locally from a sugar mill and bull’s trench kiln, respectively. Brick specimens were manufactured at an industrial brick kiln plant using various dosages (5%, 10% and 15% by clay weight) of SBA and RHA. Mechanical and durability properties of these bricks were studied. It was observed that clay bricks incorporating SBA and RHA exhibited lower compressive strength compared to that of clay bricks without SBA and RHA. However, compressive strength of bricks with 5% of SBA and RHA satisfied the Pakistan Building Code requirements (i.e. >5MPa). Scanning electron microscopy (SEM) analysis confirms the porous microstructure of the brick specimens incorporating SBA and RHA, which resulted into lesser unit weight leading to lighter and economical structures. Furthermore, resistance against efflorescence was improved in all the tested bricks incorporating SBA and RHA. Based on this study, it can be concluded that the brick specimens incorporating lower dosage of SBA and RHA (i.e. 5% by clay weight) will not only relieve the environmental burden but also result into a more sustainable and economical construction.
Perfusion and diffusion magnetic resonance imaging (MRI) provide important biomarkers for brain tumor analysis. Our aim was to investigate if regions of increased perfusion or tumor with restricted ...diffusion on the immediate post-operative MRI examination would be predictive of time to tumor progression in patients with high-grade gliomas.
Twenty-three patients with high-grade gliomas were retrospectively analyzed. We measured the perfusion at the resection area and evaluated the presence or absence of the restricted diffusion in residual tumor masses. The associations of the perfusion, diffusion and contrast enhancement (delayed static enhancement (DSE)) characteristics with time to tumor progression were statistically calculated. We also evaluated if the location of the tumor progression was concordant to the areas of the elevated perfusion, tumor type restricted diffusion and enhancement.
Patients with >200 days to progression are more likely to have no elevated relative cerebral blood volume (rCBV) ratio (p = 0.0004), no tumor restriction (p = 0.024), and no DSE (p = 0.052). The elevated mean rCBV ratio (p<0.001) and tumor type restricted diffusion (p = 0.002) were significantly associated with a higher risk of progression. All cases with rCBV ratio of >1.5 progressed in 275 days or earlier. Tumors tended to progress at the area where patients with post-operative MRIs showed elevated perfusion (p = 0.006), tumor-type restricted diffusion (p = 0.005) and DSE (p = 0.008).
Post-operative analysis of rCBV, tumor type restricted diffusion and enhancement characteristics are predictive of time to progression, risk of progression and where tumor progression is likely to occur.
•Effect of RHA in mitigating the ASR expansion was investigated.•SEM and EDS analysis were conducted to study the micro-structural behavior due to ASR.•Incorporating RHA as a pozzolan can be helpful ...for mitigating the ASR expansion.
Alkali-silica reaction (ASR) in concrete structures is very common problem around the globe. In this study, the potential of rice husk ash (RHA) in mitigating the ASR expansion was investigated. For this purpose, aggregates from reactive source were selected. RHA was acquired from local industry. Mortar bar specimens were prepared with various RHA proportions (10%, 20%, 30% and 40% by cement weight) to evaluate the ASR expansion in accordance with ASTM C1260. The pozzolanic reactivity of RHA was also evaluated using strength activity index and thermal analysis. Results showed satisfactory level of pozzolanic reactivity when cement was partially replaced with RHA. Mortar bars expansion results showed 23% and 50% decrease in expansion for specimen incorporating 10% and 40% of RHA, respectively. Scanning electron microscopy (SEM) also showed cracking due to ASR in control specimens; however, no cracks were observed in mortar bar specimens incorporating RHA. Moreover, energy disperse X-ray spectroscopy (EDS) analysis of mortar bars incorporating RHA showed low calcium to silica ratio with higher amount of alumina which may resulted into alkali reduction due to alkali absorption and dilution process leading to reduce the ASR expansion. Therefore, the incorporation of RHA as a pozzolanic material can be helpful in binding alkalies and mitigating the ASR expansion.
Studies have evaluated the application of perfusion MR for predicting survival in patients with astrocytic brain tumors, but few of them statistically adjust their results to reflect the impact of ...the variability of treatment administered in the patients. Our aim was to analyze the association between the perfusion values and overall survival time, with adjustment for various clinical factors, including initial treatments and follow-up treatments.
This study consisted of 51 patients with astrocytic brain tumors who underwent perfusion-weighted MRI with MultiHance® at a dose of 0.1 mmol/kg prior to initial surgery. We measured the mean rCBV, the 5% & 10% maximum rCBV, and the variation of rCBV in the tumors. Comparisons were made between patients with and without 2-year survival using two-sample t-test or Wilcoxon rank-sum test for the continuous data, or chi-square and Fisher exact tests for categorical data. The multivariate cox-proportional hazard regression was fit to evaluate the association between rCBV and overall survival time, with adjustment for clinical factors.
Patients who survived less than 2 years after diagnosis had a higher mean and maximum rCBV and a larger variation of rCBV. After adjusting for clinical factors including therapeutic measures, we found no significant association of overall survival time within 2 years with any of these rCBV values.
Although patients who survived less than 2 years had a higher mean and maximum rCBV and a larger variation of rCBV, rCBV itself may not be used independently for predicting 2-year survival of patients with astrocytic brain tumors.
The study aims to identify and prioritize the criteria and sub-criteria dimensions essentials for green strategic sourcing. Data were taken from the experts working in the automobile industry. By ...applying the novel Grey-DEMATEL-ANP (GDANP) approach, we identified the technology and environmental management system as the key sub-criteria dimensions to be considered while selecting the supplier. Besides, we also found quality and delivery time as the important factors to be considered while selecting a supplier for green supply chain management (GSCM). To present the useful application of our findings, we conducted an empirical study by taking the automobile industry of an emerging market as the case. The major contribution of the study is the application of variant D-ANP in identifying the important dimensions of supplier selection.
•Green supply chain management is captivating attention of the scholars and practitioners around the globe.•Development of Green Strategic Sourcing (GSS) criteria is essential for GSCM.•The environmental management system and technology are the two influential aspects of green supplier selection.•The findings highlight the role of supplier’s quality and delivery time in improving green supply chain management.•Firms in the automobile sector should give greater attention to the environmental management system for GSCM.
•Study proposed an integrated decision-making framework for techno-economic and sustainability assessment in the context of SDG-7 and SDG-13.•LCOE, NPC, and renewable diversity injection (R.Divinj) ...are the objective functions. In addition to environmental analysis, forests absorbing emission is also conducted.•PV coupled with hydro provides the most feasible results with average LCOE from 0.0359 $/kWh to 0.1185 $/kWh.•Northern zone remains most feasible zone for standalone electrification experiencing an average LCOE of 0.1026 $/kWh.•Comparative and sensitivity analyses are also performed for performance and behaviors evaluation of proposed systems.
Renewable energy is considered a viable solution for addressing the energy crisis and environmental issues sustainably. However, instead of huge available renewable potential in especially Northern region of Pakistan, its potential undermining imposes a utilization of traditional energy resources, which poses a lot of sustainability and economic challenges. Focusing on almost 100% renewable fraction and solving the sustainable energy access issues of almost 0.439091 million energy consumers, this study proposes an integrative decision-making framework to carry techno-economic-environmental sustainability and optimal sizing of renewable dominated hybrid autonomous microgrids for 19 independent sites of Khyber Pakhtunkhwa with the aims of minimizing the Levelized cost of energy (LCOE) and life cycle cost (LCC). A comparative analysis based on LCOE with already carried literature, dispatch strategies, and hydrogen storage-based system is also performed. In addition, environmental evaluation is performed along with required forests absorbing carbon analysis. At last, sensitivity analyses are performed for various uncertain variables. Optimization results showed that the PV system coupled with hydro remains the most feasible configuration with an average LCOE of 0.0359 $/kWh to 0.1185 $/kWh. Due to having a significant potential for hydel, Northern zone remains the most feasible zone for investing in standalone electrification infrastructure experiencing an average LCOE of 0.1026 $/kWh. A system with a 100% renewable fraction more specifically a combination of PV and wind proved the most environment-friendly configuration. In contrast, MG-08 experiences the highest GHG emission i.e., 5748.75 tonnes, thus requiring the largest forest area i.e., 523.15 ha to absorb carbon emissions. Developed model can provide a reference pathway for U.N.-SDGs as well as to government and private investors for decision-making and policy optimization.
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