During limb development, digits emerge from the undifferentiated mesenchymal tissue that constitutes the limb bud. It has been proposed that this process is controlled by a self-organizing Turing ...mechanism, whereby diffusible molecules interact to produce a periodic pattern of digital and interdigital fates. However, the identities of the molecules remain unknown. By combining experiments and modeling, we reveal evidence that a Turing network implemented by Bmp, Sox9, and Wnt drives digit specification. We develop a realistic two-dimensional simulation of digit patterning and show that this network, when modulated by morphogen gradients, recapitulates the expression patterns of Sox9 in the wild type and in perturbation experiments. Our systems biology approach reveals how a combination of growth, morphogen gradients, and a self-organizing Turing network can achieve robust and reproducible pattern formation.
Microbial fuel cells (MFCs) have been receiving an increased attention over the last years due to their potential to combat two global problems: waste pollution and energy demand. Additionally, when ...a wastewater is used, MFCs can perform its treatment while recovering energy, leading to the possibility of energy-producing wastewater treatment plants, offsetting their operational costs. However, to overcome their current limitations (lower power outputs and higher costs), a clear understanding of the effect of operation and design parameters on its overall performance is mandatory. Therefore, the goal of this work was to evaluate the effect of operating conditions - batch cycle and yeast extract concentration, and design parameters - anode electrode area, membrane thickness and active area, on the overall performance of a single chamber MFC. The MFC operated with a pure culture of Lactobacillus pentosus and a synthetic wastewater based on a real dairy industry effluent. The overall performance was evaluated through the power output and the COD removal rate. Additionally, the biofilm formed at the anode electrode was characterized in terms of biomass, proteins and polysaccharides content. For the conditions used in this work, a maximum power density of 5.04 ± 0.39 mW/m2 was achieved with an anode electrode area of 61 cm2, a batch cycle of 48 h, 50 mg/L of yeast extract and a Nafion 212 membrane with an active area of 25 cm2. The different conditions tested had a clear effect on the MFC energy production and biofilm characteristics, but not on the ability of L. pentosus to treat the dairy wastewater. The COD removal rates were in the range between 42% and 58%, for all the conditions tested.
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•An experimental study of a feed-batch SCMFC with L. pentosus is described.•The effect of different parameters on the SCMFC performance is presented.•Different parameters were tested in order to achieve high power outputs.•The biofilm formed on the anode electrode was characterized for each parameter studied.•The maximum power density achieved was 5.04 mW/m2 with a COD removal rate of 50%.
Goals of work
Patients with head and neck cancer (HNC) undergoing chemoradiotherapy are at high risk of malnutrition, which is related to complication rate. The aim of this study was to investigate ...the impact of an early intensive nutritional intervention on nutritional status and outcomes in patients undergoing chemoradiotherapy for HNC.
Materials and methods
We analysed retrospectively the clinical documentation of 33 HNC patients who were referred for early nutritional intervention (nutrition intervention group, NG) before they were submitted to chemoradiotherapy. The outcome of these patients was compared to that of 33 patients who received chemoradiotherapy without receiving a specifically designed early nutrition support programme (control group, CG).
Main results
NG patients lost less weight during chemoradiotherapy compared to CG patients (−4.6 ± 4.1% vs −8.1 ± 4.8% of pre-treatment weight,
p
< 0.01, at the completion of treatment). Patients in the NG experienced fewer radiotherapy breaks (>5 days) for toxicity (30.3% vs 63.6%,
p
< 0.01); the mean number of days of radiation delayed for toxicity was 4.4 ± 5.2 in NG vs 7.6 ± 6.5 in CG (
p
< 0.05); a linear correlation was found between percentage of weight lost from baseline to chemoradiotherapy completion and days of radiation delays (
p
< 0.01). There were less patients who had an unplanned hospitalisation in the NG relative to the CG (16.1% vs 41.4%,
p
= 0.03). In the NG, symptoms having an effect on the nutritional status developed early and were present in the nearly totality of patients at chemotherapy completion; 60.6% of NG patients needed tube feeding.
Conclusions
Early nutrition intervention in patients with HNC receiving chemoradiotherapy resulted in an improved treatment tolerance and fewer admissions to hospital. This result suggests that nutritional intervention must be initiated before chemoradiotherapy, and it needs to be continued after treatment completion.
In order to try explaining the present accelerated expansion of the universe, we consider the most complete noncommutativity, of a certain type, in a Friedmann–Robertson–Walker cosmological model, ...coupled to a perfect fluid. We use the ADM formalism in order to write the gravitational Hamiltonian of the model and the Schutz’s formalism in order to write the perfect fluid Hamiltonian. The noncommutativity is introduced by four nontrivial Poisson brackets between all geometrical as well as matter variables of the model. Each nontrivial Poisson bracket is associated with a noncommutative parameter. We recover the description in terms of commutative variables by introducing four variables transformations that depend on the noncommutative parameters. Using those variables transformations, we rewrite the total noncommutative Hamiltonian of the model in terms of commutative variables. From the resulting Hamiltonian, we obtain the scale factor dynamical equations for a generic perfect fluid. In order to solve these equations, we restrict our attention to a model where the perfect fluid is radiation. The solutions depend on six parameters: the four noncommutative parameters, a parameter associated with the fluid energy
C
, and the curvature parameter
k
. They also depend on the initial conditions of the model variables. We compare the noncommutative solutions to the corresponding commutative ones and determine how the former ones differ from the latter ones. The comparison shows that the noncommutative model is very useful for describing the accelerated expansion of the universe. We also obtain estimates for one of the noncommutative parameters.
•The performance of a MFC was studied using a wastewater from a dairy industry.•A maximum power density, 8.09±1.52mWm−2 was achieved with the lower flow rate.•L. pentosus is capable of developing ...active biofilms at the anode electrode.•The biofilms of L. pentosus were characterized.•L. pentosus can treat dairy wastewaters and produce energy without mediators.
A microbial fuel cell (MFC) is a novel biotechnological system able to simultaneously produce renewable energy and perform wastewater treatment. The aim of this work was to study the effect of configurational parameters, such as membrane area, anode electrode size and cell design and operating conditions, such as flow rate and shear stress on the MFC performance toward its optimization. A synthetic wastewater based on a dairy industry effluent and pure culture of Lactobacillus pentosus was used. For each condition tested, the MFC performance was evaluated in terms of power density, chemical oxygen demand (COD) removal rate and the characteristics of the L. pentosus biofilm attached to the anode electrode (biomass amount, cell viability and total and extracellular proteins and polysaccharides). The maximum power density, 8.09±1.52mWm−2, was achieved with the lower flow rate tested (0.05Lh−1). For all the conditions tested the COD removal rates were between 56% and 61%. The different configurational and operating conditions tested influenced the energy production and the biofilm characteristics. However, the wastewater treatment efficiency was not considerably affected. L. pentosus proved to be capable of treating a dairy wastewater and produce electricity without the presence of a mediator. Further investigation needs to be done to improve the MFC overall performance.
Porous collagen/chitosan scaffolds with different Collagen:Chitosan (Coll:Ch) ratios were prepared by freeze-drying followed by self-crosslinking via dehydrothermal treatment (DHT) and characterized ...as biomaterials for tissue engineering. Cy7 and Cy5.5 fluorochromes were covalently grafted to collagen and chitosan, respectively. Thus, it was possible, using optical fluorescence imaging of the two fluorochromes, to simultaneously track their in vivo biodegradation, in a blend scaffold form. The fluorescence signal evolution, due to the bioresorption, corroborated with histological analysis. In vitro cytocompatibility of Coll:Ch blend scaffolds were evaluated with standardized tests. In addition, the scaffolds showed a highly interconnected porous structure. Extent of crosslinking was analyzed by convergent analysis using thermogravimetry, Fourier Transform Infrared Spectroscopy and PBS uptake. The variations observed with these techniques indicate strong interactions between collagen and chitosan (covalent and hydrogen bonds) promoted by the DHT. The mechanical properties were characterized to elucidate the impact of the different processing steps in the sample preparation (DHT, neutralization and sterilization by β-irradiation) and showed a robust processing scheme with low impact of Coll:Ch composition ratio.
•Collagen/chitosan blends were prepared by freeze-drying followed by self-crosslinking via dehydrothermal treatment (DHT).•Collagen/chitosan scaffolds biodegradation was followed in vivo by optical fluorescence imaging with two fluorochromes.•Chitosan imposed the bioresorption rate of implants.•DHT on the collagen/chitosan blends yields crosslinker-free materials tunable for different applications.
•Our results suggest a possible gene-nutrient interaction in maternal plasma concentrations of n−3 PUFAS.•In pregnant women, increased dietary intake of ALA and LA/ALA ratio promoted plasma ALA ...accumulation in homozygotes for the minor alleles for polymorphisms rs174561 and rs3834458.•Moderate intake of LA/ALA ratio may reduce plasma concentration of EPA in pregnant women carrying the rs174575 minor allele.
There is a lack of studies about polymorphisms in FADS genes in pregnant women. We aimed to verify the interaction between three FADS gene polymorphisms (rs174561; rs174575; rs3834458) and dietary α-linolenic acid (ALA) or linoleic/α-linolenic acid ratio (LA/ALA) and plasma concentrations of omega-3 (n−3) PUFAs in pregnant women. Of the 250 women evaluated, the homozygous for the rs174561 and rs3834458 minor allele had high plasma ALA concentrations at the highest ALA and LA/ALA ratio tertile (p < 0.05). Plasma concentrations of EPA and DHA were not influenced by diet. For the rs174575 SNP, pregnant women who carried the minor allele presented lower proportions of plasma EPA in the second LA/ALA ratio tertile (p < 0.05). Increased dietary intake of ALA and LA/ALA ratio promoted plasma ALA accumulation in homozygotes for the minor allele rs174561 and rs3834458. Moderate intake of LA/ALA ratio may reduce plasma concentration of EPA in pregnants carrying the rs174575 minor allele.
A microbial fuel cell (MFC) uses electroactive microorganisms, usually bacteria, to provide electrical energy while treating wastewater. The yeast-based MFCs are gaining relevance since yeasts ...present a higher ability to grow in harsh environments than most bacteria. Zygosaccharomyces bailii was used in an MFC to treat a synthetic winery wastewater, operating in sequential batch mod. The effect of yeast inoculum medium, pH, anodic conditions and the cathode current collector characteristics (configuration and material) on the system performance was evaluated, through polarisation measurements. A maximum power density of 1.34 ± 0.01 mW/m2 was achieved under anaerobic conditions, a synthetic winery wastewater with a pH of 7, and a cathode current collector made of titanium with an open ratio of 41 %. The wastewater treatment efficiency ranged between 27 % and 35 %. This study highlighted how alterations in the MFC characteristics can minimise these systems limitations, leading to improved performances. Moreover, the present work is an important step in yeast-based MFCs applied to wastewater treatment.
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•Zygosaccharomyces bailii performance was evaluated in a microbial fuel cell.•An experimental study of a SCMFC with Z. bailii and a winery wastewater is described.•The effect of the anodic medium and condition, pH and the cathode current collector was studied.•The biofilm formed on the anode was characterised for each parameter studied.•The maximum power density achieved was 1.34 mW/m2 with a COD removal rate of 27–35 %.
Abstract
Future upgrades of the CERN Experiments and Accelerators require optical links capable of handling the large data volume generated in particle detectors and beam position (BPMs) sensors. ...Silicon Photonics optical transceivers are a promising candidate to process the required data rate as well as efficiently operate in the harsh radiation environment. We present the experimental characterisation of silicon modulators together with demonstration of optical transmitters based on custom designed Silicon Photonics integrated circuits.
Abstract
Silicon photonics technology promises significant improvements for fibre optic links of future upgrades of HEP experiments. Such systems will require high levels of radiation tolerance and ...silicon photonics modulators have been shown to be very robust when exposed to high levels of radiation under certain conditions. We demonstrate for the first time that changing the temperature of ring modulators during or after irradiation can significantly improve their performance.
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