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CO 2 absorption-microalgae conversion (CAMC) system can be a sustainable technology to achieve low-energy carbon capture and resource utilization in response to zero carbon. However, light stress could restrict the carbon utilization efficiency of CAMC system. In this study, melatonin (MT) and indole-propionic acid (IPA) as phytohormones, were used to promote the carbon fixation capacity and biomass yield of CAMC system under light stress, and the potential mechanism was also discussed. Both MT and IPA promoted the growth of Spirulina , and 10 mg-MT group obtained the highest biomass and carbon fixation capacity, which were 27.61 % and 30.62 % higher than control. MT and IPA promoted the activity of superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR), enhancing antioxidant activity to avoid oxidative damage. The results of transmission electron microscopy (TEM) and cell apoptosis showed MT and IPA reduced cell membrane damage and apoptosis. Phytohormones induced the carbon flux flow to the synthesis of carbohydrate and protein, and increased carbohydrate and protein productivity. Moreover, the maximum phycocyanin content and yield were 13.74 % and 43.25 % higher than the control. Therefore, adding phytohormones was an effective strategy to achieve high-value bioresources of microalgae in CAMC system under light stress. [Display omitted] • MT and IPA improved the performance of CAMC under light stress. • The maximum carbon fixation capacity improved 30.62 %. • MT and IPA reduced cell membrane damage and apoptosis. • Phytohormones induced the carbon flux toward carbohydrate and protein synthesis. [ABSTRACT FROM AUTHOR]

CO 2 absorption-microalgae conversion (CAMC) system is a promising carbon capture and utilization technology. However, the use of HCO 3 − as a carbon source often led to a slower growth rate of microalgae, which also limited the application of CAMC system. In this study, the assimilation efficiency of HCO 3 − in CAMC system was improved through mixotrophic, and the potential mechanism was investigated. The HCO 3 − assimilation efficiency and biomass under mixotrophic were 34.79% and 31.76% higher than that of control. Mixotrophic increased chlorophyll and phycocyanin content, which were beneficial to capture more light energy. The content of ATP and NADPH reached 566.86 μmol/g prot and 672.86 nmol/mg prot , which increased by 31.83% and 27.67% compared to autotrophic. The activity of carbonic anhydrase and Rubisco increased by 18.52% and 22.08%, respectively. Transcriptome showed that genes related to photosynthetic and respiratory electron transport were up-regulated. The synergy of photophosphorylation and oxidative phosphorylation greatly improved energy metabolism efficiency, thus accelerating the assimilation of HCO 3 −. These results revealed a potential mechanism of promoting the HCO 3 − assimilation under mixotrophic, it also provided a guidance for using CAMC system to serve carbon neutrality. [Display omitted] • Mixotrophic improved the assimilation rate of HCO 3 − by Spirulina in CAMC system. • The ATP and NADPH content increased by 31.83% and 27.67%. • Mixotrophic promoted carbonic anhydrase and Rubisco activity. • Mixotrophic upregulated the photophosphorylation and oxidative phosphorylation. [ABSTRACT FROM AUTHOR]

CO 2 absorption-microalgae conversion (CAMC) system is a promising alternative to simultaneous CO 2 capture and utilization. However, it is necessary to explore the stability of recycled absorption solvent for subsequent culture of CAMC system. In this work, dilution, activated carbon adsorption and H 2 O 2 /UV photocatalytic treatment were used to treat the absorption solution that had been run once in CAMC system and then the subsequent culture was performed and its performance was evaluated. It was found that these treatments could restore the performance of circulating absorption solution and H 2 O 2 /UV photocatalytic treatment showed the best effect. The biomass concentration, NADPH content and RubisCO enzyme activities increased by 18 %, 92.0 %, and 26.5 % by H 2 O 2 /UV photocatalytic treatment. H 2 O 2 /UV photocatalytic treatment enhanced carbon fixation rate, which was 7.05 % higher than untreated group. H 2 O 2 /UV photocatalytic treatment could improve the yield of lipid and protein. These results showed that H 2 O 2 /UV photocatalytic treatment could restore the performance of circulating solution to the level of primary culture and maintain the cyclic stability of CAMC system. Therefore, this study provided a certain guiding significance for the application of CAMC system. [Display omitted] • The cyclic stability of the absorption solution in CAMC system was evaluated. • H 2 O 2 /UV photocatalytic treatment could improve the performance of CAMC system. • The dry weight of microalgae increased by H 2 O 2 /UV photocatalytic treatment. • H 2 O 2 /UV photocatalytic treatment increased protein and lipid yield. [ABSTRACT FROM AUTHOR]

During the process of recovering microalgae culture media, the culture media will age and inhibit the growth of microalgae. When the culture media was reused for the third time, the maximum biomass of Spirulina platensis FACHB-439 was only 56.13% of the fresh culture media. But the inhibitors in the aging solution are not known. In this study, the growth inhibition mechanism of Spirulina platensis aging solution was clarified through the identification of target organic matter by cyclic culture experiment and ion chromatography. The results showed that the growth inhibitors in the aging solution were polysaccharides, mainly including fucose and rhamnose. Further reverse addition experiments confirmed that polysaccharide inhibitors would increase with the increase of repeated use of the culture media. By inhibiting the synthesis of photosynthetic pigments in microalgae, they could cause oxidative damage and membrane peroxidation of microalgae cells, resulting in stress on the growth of microalgae. At the same time, this study established a purification method for reusing aging solution of heterologous microalgae (Chlorella sp. L166) to obtain high lipid and high carbohydrate biomass energy. The results showed that the biomass of Chlorella sp. L166 in the first circulating aging solution of S.platensis FACHB-439 increased by 25%, the carbon utilization rate reached 21.36%, the lipid content per cell increased by 1.61 times, and the carbohydrate content increased by 86.71%. This work is helpful to solve the problem that aging of culture media inhibits carbon sequestration efficiency and biomass yield of microalgae in large-scale production of microalgae. And the results of this study have achieved high utilization rate of water resource for large-scale cultivation of microalgae, which is conducive to realize the scale development of microalgae biotechnology. [Display omitted] • The biomass of S.platensis in the aging solution was inhibited to 56.13%. • The inhibitor of S.platensis aging solution were polysaccharides mainly composed of fucose and rhamnose. • Polysaccharide inhibitors cause oxidative damage to S.platensis and alter the metabolic processes of microalgae. • The heterogeneous microalgae was used as the biological material for purifying the aging solution. [ABSTRACT FROM AUTHOR]

Network-matrix architectures have drawn considerable attention in wide varieties of practical applications. Networks are the highways for perfusing (or extracting) physical flows into (or from) matrices, thus determine the performance of network-matrix architectures. Constructal law states that “for a finite-size system to persist in time (to live), it must evolve in such a way that it provides greater and greater access to the currents flowing through it”. Plant leaves are ubiquitous network-matrix architectures selected by nature during the long evolution, which will shed light on efficient network-matrix architectures. The two basic kinds of plant leaves are pinnate and palmate leaves. Palmate leaf vein networks with multiple first-order veins confer greater tolerance of vein damage, especially the first-order vein damage, than pinnate leaf vein networks with a single first-order vein. However, few studies have been conducted to analyze the effect of first-order vein number on the transport efficiency of leaf vein networks. In this study, inspired by palmate leaves, we analytically investigate the effect of first-order channel number on physical flow transport efficiency of the network in the network-matrix architecture. The results show that the palmate leaf-like network is more efficient, which can achieve lower maximum and total potential drops than the pinnate leaf-like network. The results can be applied to designing more efficient network-matrix architectures. [ABSTRACT FROM AUTHOR]

Background: Few studies, to our knowledge, have examined the longitudinal association of snacking with child body mass index (BMI), especially in China, where the incidence of overweight and obesity has increased rapidly.Objectives: Our objective was to examine the longitudinal association between snacking and BMI z score and to test whether this association differs by baseline weight status.Methods: Using data from the China Health and Nutrition Survey (2006, 2009, and 2011), we characterized snack intake for 9 provinces and 3 megacities. We used linear mixed-effects models to examine longitudinally the association between snacking (none, low, medium, and high tertiles according to energy) and BMI z score in children aged 2-13 y at baseline, controlling for sex, urbanicity, parental education, physical activity, and foods consumed at meals (n = 2277 observations). We tested whether this association differed by baseline underweight, normal weight, or overweight/obese.Results: Snacking is prevalent in Chinese children, with fruit being the most common snack. Snacking was not associated with meaningful BMI z score changes in normal-weight children. However, in children who were underweight at baseline, snacking in the top tertiles was associated with increases in BMI z scores from 2006 to 2011 (+1.2 and +1.1 BMI z score units for ages 2-6 and 7-13 y, respectively) (P < 0.05). In overweight/obese 2- to 6-y-old children at baseline, being in the lowest snacking tertile was associated with declines in BMI z score (-3.3), whereas in overweight 7- to 13-y-old children, being in the top tertile of snacking was associated with the greatest decline in BMI z score (-2.1) (P < 0.05). The direction and magnitude of associations did not vary regardless of adjustment for total energy intake.Conclusions: Snacking in China, dominated by fruit consumption, is associated with decreased BMI in overweight/obese children and increased BMI in underweight children. More work will be needed to monitor this relation as Chinese diets continue to westernize. [ABSTRACT FROM AUTHOR]

In an aqueous electrolyte under an anodic polarization, most of the conductive polymers could undergo an overoxidation due to the hydroxyl radicals formed during water oxidation. Regarding poly(3,4-ethylenedioxythiophene) (PEDOT) only a few reports studied its overoxidation. In this paper, we propose a facile and rapid strategy to prepare an ultrathin (15 nm), pinhole-free and non-conductive overoxidized PEDOT film by electropolymerization of EDOT under potentiostatic conditions in the presence of solely weak-acid anions in the monomer solution. The influence of the pH of this solution as well as the applied potential was studied notably by electrochemical impedance spectroscopy. It was pointed out that the PEDOT film is overoxidized when its electrosynthesis is performed in an aqueous monomer solution of pH 10.5, at 1.1 V/SCE, the monomer solution containing only weak-acid ions as anions (phosphates or carbonates). XPS analyses show that some C and S atoms of the film are oxidized leading to a break of the polymer conjugation and therefore to a decrease of its electronic conductivity. Finally, after adding in the monomer phosphate solution of pH 10.5 perchlorate ions that allow to avoid total overoxidation of the film formed at the very beginning of the process, PEDOT nanowires were obtained. [Display omitted] [ABSTRACT FROM AUTHOR]

Survival or apoptosis is a binary decision in individual cells. However, at the cell-population level, a graded increase in survival of colony-forming unit-erythroid (CFU-E) cells is observed upon stimulation with erythropoietin (Epo). To identify components of Janus kinase 2/signal transducer and activator of transcription 5 (JAK2/STAT5) signal transduction that contribute to the graded population response, we extended a cell-population-level model calibrated with experimental data to study the behavior in single cells. The single-cell model shows that the high cell-to-cell variability in nuclear phosphorylated STAT5 is caused by variability in the amount of Epo receptor (EpoR):JAK2 complexes and of SHP1, as well as the extent of nuclear import because of the large variance in the cytoplasmic volume of CFU-E cells. 24–118 pSTAT5 molecules in the nucleus for 120 min are sufficient to ensure cell survival. Thus, variability in membrane-associated processes is sufficient to convert a switch-like behavior at the single-cell level to a graded population-level response. [Display omitted] • Mathematical modeling enables integration of heterogeneous data • Single-cell modeling captures a binary decision process • Multiple sources of cell-to-cell variability exist in erythroid progenitor cells • Minimal amount of active STAT5 is sufficient for erythroid progenitor cell survival Adlung et al. analyze cell-to-cell variability in the response of precursors of red blood cells to the hormone Epo. Experimental data and mathematical modeling show that the survival of an individual cell depends on the amount of signal transduction proteins and the size of the cell. [ABSTRACT FROM AUTHOR]

Objective Evaluate foods and beverages consumed, and energy and nutrient densities that constitute morning, afternoon, and evening snacking periods among children in the US. Design Evaluate snacking behavior using the National Health and Nutrition Examination Survey, 2009–2012. Participants Children aged 4–8 and 9–13 years (n = 3,647). Variables Measured Self-reported foods and beverages reported as snacks were aggregated into morning (0:00–12:00 hours), afternoon (12:00–18:00 hours), and evening (18:00–24:00 hour) snacking periods. Analysis Intakes and amounts consumed during different snacking periods were analyzed from per capita weighted averages using SAS 9.2 and SUDAAN software. Statistical differences were detected using Student t test for means and chi-square test for prevalence data. Results Snacking contributed 25% of daily energy in both age groups, with the morning snacking period contributing the least energy. The most frequently consumed food groups across all snacking periods were water, snacks and sweets, nonalcoholic beverages, milk and dairy, and fruit. Nutrient densities varied among different snacking periods; the morning snack period for 4- to 8-year-olds was the most nutrient dense. Conclusions and Implications Snacking is an important contributor to energy and nutrients in children's diets, but foods and beverages selected vary by time of day and age. Modifying snacking choices, especially in the afternoon, could improve the nutritional quality of children's diets. [ABSTRACT FROM AUTHOR]