•Co-pyrolysis of biomass with plastics and coal, for the production of bio-oils is reviewed.•The progress of catalytic co-pyrolysis on upgrading of biomass-derived bio-oils is introduced.•The ...reaction mechanism between biomass and plastic in catalytic co-pyrolysis is described.•The functions of various acidic catalysts towards enhancement of bio-oil are addressed.
Co-pyrolysis of biomass with abundantly available materials could be an economical method for production of bio-fuels. However, elimination of oxygenated compounds poses a considerable challenge. Catalytic co-pyrolysis is another potential technique for upgrading bio-oils for application as liquid fuels in standard engines. This technique promotes the production of high-quality bio-oil through acid catalyzed reduction of oxygenated compounds and mutagenic polyaromatic hydrocarbons. This work aims to review and summarize research progress on co-pyrolysis and catalytic co-pyrolysis, as well as their benefits on enhancement of bio-oils derived from biomass. This review focuses on the potential of plastic wastes and coal materials as co-feed in co-pyrolysis to produce valuable liquid fuel. This paper also proposes future directions for using this technique to obtain high yields of bio-oils.
Of the three generations of biodiesel feedstocks described in this paper, food crops, non-food crops and microalgae-derived biodiesel, it was found that the third generation, microalgae, is the only ...source that can be sustainably developed in the future. Microalgae can be converted directly into energy, such as biodiesel, and therefore appear to be a promising source of renewable energy. This paper presents a comparison between the use of microalgae and palm oil as biodiesel feedstocks. It was found that microalgae are the more sustainable source of biodiesel in terms of food security and environmental impact compared to palm oil. The inefficiency and unsustainability of the use of food crops as a biodiesel source have increased interest in the development of microalgae species to be used as a renewable energy source. In this paper, the main advantages of using microalgae for biodiesel production are described in comparison with other available feedstocks, primarily palm oil.
Co-pyrolysis of sugarcane bagasse (SCB) with waste high-density polyethylene (HDPE) was performed in a fixed-bed reactor under different temperatures (400–700 °C) and blending ratios (0–100%). ...Product yields and chemical compositions were compared with those from the pyrolysis of individual components to ascertain the synergistic effect between SCB and HDPE. The synergistic effect of SCB and HDPE produced higher liquid yield than the theoretical value. The effect was strongest at 600 °C and 60:40 HDPE:SCB ratio, with the maximum difference of 6.02 wt%. The positive synergistic effects on the production of high-value organic compounds (alcohol, hydrocarbons, and aromatics) and inhibition of oxygenated compounds were most prominent at 600 °C and 40:60 HDPE:SCB ratio. SCB-derived hydroxyl radicals favored the secondary cracking of HDPE primary volatiles, thereby promoting the formation of aliphatic compounds with lower carbon numbers. Co-pyrolysis of SCB and HDPE also produced oil with higher carbon (34% higher) and hydrogen (47% higher) contents, and with lower oxygen content (70% lower) than those of SCB pyrolysis oil. It also achieved a high calorific value of 42.41 MJ/kg, which is comparable to those of commercial diesel fuels.
•Co-pyrolysis of sugarcane bagasse and high-density polyethylene was investigated.•Synergistic effect during co-pyrolysis were quantified.•Co-pyrolysis enhanced the liquid yield and production of alcohol and hydrocarbon.•The oxygenated compounds in the pyrolysis oil were decreased.•Decarbonylation, decarboxylation and H transfer promoted the deoxygenation.
Reactor experiment for neutrino oscillation (RENO) began data-taking from August 2011. It successfully observed reactor antineutrino disappearance in April 2012 to measure the smallest mixing angle ...of θ13. Two identical detectors, one at near location and the other at far location, are constructed at the Yonggwang nuclear power plant in South Korea, to compare the observed reactor neutrino fluxes. Each RENO detector is filled with 16 mass tons of Gadolinium loaded liquid scintillator (GdLS) in the neutrino target region, and with 28 mass tons of unloaded liquid scintillator (LS) in the γ-catcher region surrounding the target. LS was developed to satisfy chemical, physical, optical properties, and safety requirements. Linear alkyl benzene (LAB) was chosen as a solvent because of its high flash-point, sufficient light yield, and being environmentally friendly. GdLS is carefully developed to keep a long attenuation length and high light yield for a long time period. In this paper, we report the characteristics and mass production of the RENO LS and GdLS.
High tumor mutation burden (TMB-H) has been proposed as a predictive biomarker for response to immune checkpoint blockade (ICB), largely due to the potential for tumor mutations to generate ...immunogenic neoantigens. Despite recent pan-cancer approval of ICB treatment for any TMB-H tumor, as assessed by the targeted FoundationOne CDx assay in nine tumor types, the utility of this biomarker has not been fully demonstrated across all cancers.
Data from over 10 000 patient tumors included in The Cancer Genome Atlas were used to compare approaches to determine TMB and identify the correlation between predicted neoantigen load and CD8 T cells. Association of TMB with ICB treatment outcomes was analyzed by both objective response rates (ORRs, N = 1551) and overall survival (OS, N = 1936).
In cancer types where CD8 T-cell levels positively correlated with neoantigen load, such as melanoma, lung, and bladder cancers, TMB-H tumors exhibited a 39.8% ORR to ICB 95% confidence interval (CI) 34.9-44.8, which was significantly higher than that observed in low TMB (TMB-L) tumors odds ratio (OR) = 4.1, 95% CI 2.9-5.8, P < 2 × 10−16. In cancer types that showed no relationship between CD8 T-cell levels and neoantigen load, such as breast cancer, prostate cancer, and glioma, TMB-H tumors failed to achieve a 20% ORR (ORR = 15.3%, 95% CI 9.2-23.4, P = 0.95), and exhibited a significantly lower ORR relative to TMB-L tumors (OR = 0.46, 95% CI 0.24-0.88, P = 0.02). Bulk ORRs were not significantly different between the two categories of tumors (P = 0.10) for patient cohorts assessed. Equivalent results were obtained by analyzing OS and by treating TMB as a continuous variable.
Our analysis failed to support application of TMB-H as a biomarker for treatment with ICB in all solid cancer types. Further tumor type-specific studies are warranted.
•TMB-H failed to predict improved or clinically relevant response to ICB in all cancer types.•Cancer types where TMB-H does not predict response generally show no relationship between tumor neoantigen load and CD8 T-cell infiltration.•Further studies should be carried out before application of TMB-H as a biomarker for ICB in all cancer types.
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•Catalytic co-pyrolysis of sugarcane bagasse with waste plastic was investigated.•Mesoporous faujasite-type zeolite from electric arc furnace slag was prepared.•Hydrocarbon production ...was greatly enhanced with 74.55% selectivity.•Oxygenate content was considerably decreased with 1.24% selectivity.
This study investigated the catalytic co-pyrolysis of sugarcane bagasse (SCB) and waste high-density polyethylene (HDPE) over faujasite-type zeolite derived from electric arc furnace slag (FAU-EAFS) in a fixed-bed reactor. The effects of reaction temperature, catalyst-to-feedstock ratio, and HDPE-to-SCB ratio on product fractional yields and chemical compositions were discussed. The co-pyrolysis of SCB and HDPE over FAU-EAFS increased the liquid yield and enhanced the quality of bio-oil. The maximum bio-oil (68.56 wt%) and hydrocarbon yield (74.55%) with minimum yield of oxygenated compounds (acid = 0.57% and ester = 0.67%) were achieved under the optimum experimental conditions of catalyst-to-feedstock ratio of 1:6, HDPE-to-SCB ratio of 40:60, and temperature of 500 °C. The oil produced by catalytic co-pyrolysis had higher calorific value than the oil produced by the pyrolysis of SCB alone.
Hypoxic regions are frequent in glioblastoma (GBM), the most common type of malignant adult brain tumor, and increased levels of tumor hypoxia have been associated with worse clinical outcomes. To ...unmask genes important in hypoxia, we treated GBM neurospheres in hypoxia and identified monocarboxylate transporter-4 (MCT4) as one of the most upregulated genes. To investigate the clinical importance of MCT4 in GBM, we examined clinical outcomes and found that MCT4 overexpression is associated with shorter patient survival. Consistent with this, MCT4 upregulation correlated with the aggressive mesenchymal subset of GBM, and MCT4 downregulation correlated with the less aggressive G-CIMP (Glioma CpG Methylator Phenotype) subset of GBM. Immunohistochemical analysis of tissue microarrays confirmed that MCT4 protein levels were increased in high-grade as compared with lower-grade astrocytomas, further suggesting that MCT4 is a clinically relevant target. To test the requirement for MCT4 in vitro, we transduced neurospheres with lentiviruses encoding short-hairpin RNAs (shRNAs) against MCT4, resulting in growth inhibition of 50-80% under hypoxia in two lines. MCT4 knockdown was associated with a decreased percentage of cells expressing the stem-cell marker CD133 and increased apoptotic fraction. We also found that flow-sorted CD133-positive cells had almost sixfold higher MCT4 levels than CD133-negative cells, suggesting that the stem-like population might have a greater requirement for MCT4. Most importantly, MCT4 silencing also slowed GBM intracranial xenograft growth in vivo. Interestingly, whereas MCT4 is a well-characterized lactate exporter, we found that both intracellular and extracellular lactate levels did not change following MCT4 silencing, suggesting a novel lactate export-independent mechanism for growth inhibition in GBMs. To identify this potential mechanism, we performed microarray analysis on control and shMCT4-expressing neurospheres and found a dramatic reduction in the expression of multiple Hypoxia-Inducible Factor (HIF)-regulated genes following MCT4 knockdown. The overall reduction in HIF transcriptional response was further validated using a hypoxia response element (HRE)-dependent green-fluorescent protein (GFP) reporter line.
► We studied the optimization of coagulation in microalgae cultivation using chitosan. ► Chitosan could remove 99% of microalgae cells at the concentration of 10
ppm, mixing time of 20
min, mixing ...rate of 150
ppm and sedimentation time of 20
min. ► The rise in concentration of chitosan shows restabilization of microalgae cultures and reducing the efficiency of the process.
Here, we report on the harvesting of microalgae cells by coagulation using chitosan and the optimization of this process. Chitosan is a natural and environmentally friendly biopolymer created by the extensive deacetylation of chitin from shrimp, crab and crawfish. Although conventional chemical coagulants such as alum may have negative impacts on human health, the use of chitosan as coagulant is suitable to harvest live microalgae. In this paper, the jar-test method was used to identify the best chitosan conditions (including concentration dosage, mixing time, mixing rate and sedimentation time), for harvesting the
Chlorella sp. from their cultures. The effect of mixing time, mixing rate and sedimentation time on microalgae removal were analyzed using the optimized chitosan dosage. The mechanism of coagulation using chitosan appears to consist of adsorption and charge neutralization. Chitosan not only acts as an adsorbent, but also spontaneously coagulates to agglomerate the microalgae cells. This two-in-one process makes the chitosan a good coagulant, allowing removal of microalgae cells, even at low concentrations. Chitosan successfully removed 99.0
±
0.4% of the microalgae cells at the following optimal parameters: chitosan concentration of 10
ppm, mixing time of 20
min, mixing rate of 150
ppm and sedimentation time of 20
min. An increase in chitosan concentration resulted in restabilization of the microalgae cultures, reducing the efficiency of the process.
Visible-wavelength color and reflectance provide information about the geologic history of planetary surfaces. Here we present multispectral images (0.44 to 0.89 micrometers) of near-Earth asteroid ...(101955) Bennu. The surface has variable colors overlain on a moderately blue global terrain. Two primary boulder types are distinguishable by their reflectance and texture. Space weathering of Bennu surface materials does not simply progress from red to blue (or vice versa). Instead, freshly exposed, redder surfaces initially brighten in the near-ultraviolet region (i.e., become bluer at shorter wavelengths), then brighten in the visible to near-infrared region, leading to Bennu’s moderately blue average color. Craters indicate that the time scale of these color changes is ~105 years. We attribute the reflectance and color variation to a combination of primordial heterogeneity and varying exposure ages.
Deoxyxylulose 5-phosphate synthase (DXS) and deoxyxylulose 5-phosphate reductoisomerase (DXR) are the enzymes that catalyze the first two enzyme steps of the methylerythritol 4-phosphate (MEP) ...pathway to supply the isoprene building-blocks of carotenoids. Plant DXR and DXS enzymes have been reported to function differently depending on the plant species. In this study, the differential roles of rice DXS and DXR genes in carotenoid metabolism were investigated.
The accumulation of carotenoids in rice seeds co-expressing OsDXS2 and stPAC was largely enhanced by 3.4-fold relative to the stPAC seeds and 315.3-fold relative to non-transgenic (NT) seeds, while the overexpression of each OsDXS2 or OsDXR caused no positive effect on the accumulation of either carotenoids or chlorophylls in leaves and seeds, suggesting that OsDXS2 functions as a rate-limiting enzyme supplying IPP/DMAPPs to seed carotenoid metabolism, but OsDXR doesn't in either leaves or seeds. The expressions of OsDXS1, OsPSY1, OsPSY2, and OsBCH2 genes were upregulated regardless of the reductions of chlorophylls and carotenoids in leaves; however, there was no significant change in the expression of most carotenogenic genes, even though there was a 315.3-fold increase in the amount of carotenoid in rice seeds. These non-proportional expression patterns in leaves and seeds suggest that those metabolic changes of carotenoids were associated with overexpression of the OsDXS2, OsDXR and stPAC transgenes, and the capacities of the intermediate biosynthetic enzymes might be much more important for those metabolic alterations than the transcript levels of intermediate biosynthetic genes are. Taken together, we propose a 'Three Faucets and Cisterns Model' about the relationship among the rate-limiting enzymes OsDXSs, OsPSYs, and OsBCHs as a "Faucet", the biosynthetic capacity of intermediate metabolites as a "Cistern", and the carotenoid accumulations as the content of "Cistern".
Our study suggests that OsDXS2 plays an important role as a rate-limiting enzyme supplying IPP/DMAPPs to the seed-carotenoid accumulation, and rice seed carotenoid metabolism could be largely enhanced without any significant transcriptional alteration of carotenogenic genes. Finally, the "Three Faucets and Cisterns model" presents the extenuating circumstance to elucidate rice seed carotenoid metabolism.
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