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Bass Wilhelmsen posted an update 6 months, 2 weeks ago
Analysis of the model finds that positive feedback controls the properties of the traveling wavefront and that negative feedback controls the duration of Erk activity peak and the period of Erk activity waves. The geometrical properties of the waves facilitate constraints on the effective diffusivity of the activator, indicating that waves are an efficient mechanism to transfer growth factor signaling rapidly across a large tissue.The structure-driven assembly of multimeric protein complexes and the formation of intracellular phase-like protein condensates have been the subject of intense research. However, the assembly of larger superstructures comprising cellular components, such as protein nanoparticles driven by general physical rather than specific biochemical interactions, remains relatively uncharacterized. Here, we use gas vesicles (GVs)-genetically encoded protein nanoparticles that form ordered intracellular clusters-as a model system to study the forces driving multiparticle assembly under cytoplasm-like conditions. Our calculations and experimental results show that the ordered assembly of GVs can be achieved by screening their mutual electrostatic repulsion with electrolytes and creating a crowding force with dissolved macromolecules. The precise balance of these forces results in different packing configurations. Biomacromolecules such as polylysine and DNA are capable of driving GV clustering. These results provide basic insights into how physically driven interactions affect the formation of protein superstructures, offer guidance for manipulating nanoparticle assembly in cellular environments through synthetic biology methods, and inform research on the biotechnology applications of GVs.Cyanobacteria and microalgae are considered as interesting feedstocks for either the production of high value bio-based compounds and biofuels or wastewater treatment. Nevertheless, the high costs of production, mainly due to the harvesting process, hamper a wide commercialization of industrial cyanobacteria and microalgae based products. Recent studies have found in autoflocculation and bioflocculation promising spontaneous processes for a low-cost and environmentally sustainable cyanobacteria and microalgae biomass harvesting process. In the present work, bioflocculation process has been studied for three different inocula filamentous cyanobacteria, microalgae and their mixture. Their cultivation has been conducted in batch mode using two different cultivation media synthetic aqueous solution and urban wastewater. The removal of nutrients and flocculation process performance were monitored during the entire cultivation time. Results have proved that bioflocculation and sedimentation processes occur efficiently for filamentous cyanobacteria cultivated in synthetic aqueous solution, whereas such processes are less efficient in urban wastewater due to the specific characteristics of this medium that prevent bioflocculation to occur. ISA-2011B research buy Besides different efficiencies associated to cultivation media, this work highlighted that bioflocculation of sole microalgae is not as effective as when they are cultivated together with filamentous cyanobacteria.The intensive production and utilization of antibiotics worldwide has inevitably led to releases of very large amounts of these medicines into the environment, and numerous strategies have recently been developed to eliminate antibiotic pollution. Therefore, bismuth-based photocatalysts have attracted much attention due to their high adsorption of visible light and low production cost. This review summarizes the performance, degradation pathways and relevant mechanisms of typical antibiotics during bismuth-based photocatalytic degradation. First, the band gap and redox ability of the bismuth-based catalysts and modified materials (such as morphology, structure mediation, heterojunction construction and element doping) were compared and evaluated. Second, the performance and potential mechanisms of bismuth oxides, bismuth sulfides, bismuth oxyhalides and bismuth-based metal oxides for antibiotic removal were investigated. Third, we analysed the effect of co-existing interfering substances in a real water matrix on the photocatalytic ability, as well as the coupling processes for degradation enhancement. In the last section, current difficulties and future perspectives on photocatalytic degradation for antibiotic elimination by bismuth-based catalysts are summarized. Generally, modified bismuth-based compounds showed better performance than single-component photocatalysts during photocatalytic degradation for most antibiotics, in which h+ played a predominant role among all the related reactive oxygen species. Moreover, the crystal structures and morphologies of bismuth-based catalysts seriously affected their practical efficiencies.
Due to partial or poorly enforced restrictions secondhand tobacco smoke (SHS) is still present in outdoor hospitality venues in many European countries. This study aimed to assess SHS concentrations in outdoor hospitality venues across Europe and identify contextual exposure determinants.
Cross-sectional study. We measured airborne nicotine and evidence of tobacco use in terraces of bars, cafeterias, and pubs from 11 European countries in 2017-2018. Sites were selected considering area-level socioeconomic indicators and half were visited during nighttime. We noted the smell of smoke, presence of smokers, cigarette butts, ashtrays, and number of physical covers. Contextual determinants included national smoke-free policies for the hospitality sector, the Tobacco Control Scale score (2016), and the national smoking prevalence (2017-2018). We computed medians and interquartile ranges (IQR) of nicotine concentrations and used multivariate analyses to characterize the exposure determinants.
Nicotine was presption of total smoking bans in outdoor areas of hospitality venues.
Vitamin D facilitates the absorption of calcium but may also increase absorption of other metals; the literature is conflicting.
To examine whether 25OHD in the first trimester of pregnancy was associated with subsequent metals levels in the late second trimester of pregnancy.
We used data from a sample of women in the LIFECODES pregnancy cohort (N=381). 25-hydroxyvitamin D (25OHD) was measured with a chemiluminescence immunoassay in plasma samples drawn at 10 weeks of gestation. A panel of 17 metals and elements was measured in urine collected at 26 weeks of gestation. We used linear or logistic regression to estimate associations between 25OHD (dichotomous, linear, and in tertiles) and either urinary metal concentrations or the proportion of samples below the limit of detection, respectively. Multivariable models included urinary specific gravity, age, race/ethnicity, education, body mass index, insurance type, gestational age, and season.
After multivariable adjustment, low 25OHD was associated with a 47% increase in lead level, a 60% increase in tin level, and 1.
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