Growth Performance,Biochemical Composition and Nutrient Recovery Ability of Twelve Microalgae Consortia Isolated from Various Local Organic Wastes Grown on Nano-Filtered Pig Slurry

This paper demonstrated the growth ability of twelve algae-microbial consortia (AC) isolated from organic wastes when a pig slurry-derived wastewater (NFP) was used as growth substrate in autotrophic cultivation. Nutrient recovery, biochemical composition, fatty acid and amino acid profiles of algae consortia were evaluated and compared. Three algae-microbial consortia, i.e., a Chlorella-dominated consortium (AC_1), a Tetradesmus and Synechocystis co-dominated consortium (AC_10), and a Chlorella and Tetradesmus co-dominated consortium (AC_12) were found to have the best growth rates (µ of 0.55 ± 0.04, 0.52 ± 0.06, and 0.58 ± 0.03 d⁻¹, respectively), which made them good candidates for further applications. The ACs showed high carbohydrates and lipid contents but low contents of both proteins and essential amino acids, probably because of the low N concentration of NFP. AC_1 and AC_12 showed optimal ω6:ω3 ratios of 3.1 and 3.6, which make them interesting from a nutritional point of view.     

Shotgun Proteomics of Isolated Urinary Extracellular Vesicles for Investigating Respiratory Impedance in Healthy Preschoolers

Urine proteomic applications in children suggested their potential in discriminating between healthy subjects from those with respiratory diseases. The aim of the current study was to combine protein fractionation, by urinary extracellular vesicle isolation, and proteomics analysis in order to establish whether different patterns of respiratory impedance in healthy preschoolers can be characterized from a protein fingerprint. Twenty-one 3–5-yr-old healthy children, representative of 66 recruited subjects, were selected: 12 late preterm (LP) and 9 full-term (T) born. Children underwent measurement of respiratory impedance through Forced Oscillation Technique (FOT) and no significant differences between LP and T were found. Unbiased clustering, based on proteomic signatures, stratified three groups of children (A, B, C) with significantly different patterns of respiratory impedance, which was slightly worse in group A than in groups B and C. Six proteins (Tripeptidyl peptidase I (TPP1), Cubilin (CUBN), SerpinA4, SerpinF1, Thy-1 membrane glycoprotein (THY1) and Angiopoietin-related protein 2 (ANGPTL2)) were identified in order to type the membership of subjects to the three groups. The differential levels of the six proteins in groups A, B and C suggest that proteomic-based profiles of urinary fractionated exosomes could represent a link between respiratory impedance and underlying biological profiles in healthy preschool children.     

Acoustic particle manipulation in a 40 kHz quarter-wavelength standing wave with an air boundary

An implementation of a quarter-wavelength standing wave separator that exploits an air drum to achieve the pressure node is presented and characterized experimentally. The air drum configuration was implemented and tested in a set-up with a 40 kHz transducer immersed in a water tank with the quarter-wavelength gap being approximately 9 mm wide. Injection of suspensions of 5 μm and 45 μm diameter polystyrene particles at flow rates of 30 ml/h and 60 ml/h was studied and particle deflection towards the pressure node at the air drum surface was observed for a range of acoustic pressures. Computational results on single particle trajectories show good agreement with the experimental findings for the 45 μm particles, but not for the 5 μm particles. These were considered to behave as aggregates of higher effective dimension, due to their much higher number density relative to the 45 μm particles in the suspensions used. The set-up developed in this study includes a robust method for achieving a pressure node in a quarter-wavelength system and can represent the first step toward the development of an alternative separator configuration in respect to small channel MHz range operated systems for the manipulation of particles streams.     

Atomistic mechanism of boron diffusion in silicon

B diffuses in crystalline Si by reacting with a Si self-interstitial (I) with a frequency g and so forming a fast migrating BI complex that can migrate for an average length lambda. We experimentally demonstrate that both g and lambda strongly depend on the free hole concentration p. At low p, g has a constant trend and lambda increases with p, while at high p, g has a superlinear trend and lambda decreases with p. This demonstrates that BI forms in the two regimes by interaction with neutral and double positive I, respectively, and its charge state has to change by interaction with free holes before diffusing.     

On the reactivity of some 2-methyleneindolines with β-nitroenamines, α-nitroalkenes, and 1,2-diaza-1,3-butadienes

A study of the behaviour of some electron-rich 2-methyleneindolines (1-3) with different electron-poor reagents (formation of new carbon-carbon and nitrogen-carbon bonds) has furnished interesting results from both synthetic and the mechanistic viewpoints. Enamines 1-3 have been reacted with the β-nitroenamines 4-7 (reaction CeCl₃·7H₂O promoted), giving the polymethine dyes 14-23. The same bases 1-3 have been nitroalkylated with the nitroolefins 8-10, furnishing the indolines 24-32, and the diastereoselectivity of the reaction has been thoroughly investigated. The most unexpected results derived from the first example of reaction of Fischer's bases with 1,2-diaza-1,3-butadienes. In fact, with 11-13, the ‘unknown’ indoline spirodihydropyrroles 33-40 were formed. Their structures were unambiguously assigned, and we determined, as an example, that of 33 by X-ray analysis.     

New one-pot procedure for the synthesis of diprotected amino alcohols from unprotected vinyl aziridines

An unprecedented one-pot reaction that allows the synthesis of diprotected amino alcohols from unprotected vinyl aziridines is reported. The results demonstrate the possibility to use various acyl chlorides in order to obtain differently functionalised fragments. Mechanistic insights are given.     

Electron-Transfer Secondary Reaction Matrices for MALDI MS Analysis of <Emphasis Type="Italic">Bacteriochlorophyll a</Emphasis> in <Emphasis Type="Italic">Rhodobacter sphaeroides</Emphasis> and Its Zinc and Copper Analogue Pigments

Bacteriochlorophyll a (BChl a), a photosynthetic pigment performing the same functions of chlorophylls in plants, features a bacteriochlorin macrocycle ring (18 π electrons) with two reduced pyrrole rings along with a hydrophobic terpenoid side chain (i.e., the phytol residue). Chlorophylls analysis by matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) is not so straightforward since pheophytinization (i.e., release of the central metal ion) and cleavage of the phytol–ester linkage are invariably observed by employing protonating matrices such as 2,5-dihydroxybenzoic acid, sinapinic acid, and α-cyano-4-hydroxycinnamic acid. Using BChl a from Rhodobacter sphaeroides R26 strain as a model system, different electron-transfer (ET) secondary reaction matrices, leading to the formation of almost stable radical ions in both positive ([M]^+?) and negative ([M]^??) ionization modes at m/z 910.55, were evaluated. Compared with ET matrices such as trans-2-[3-(4-t-butyl-phenyl)-2-methyl-2-propenylidene]malononitrile (DCTB), 2,2':5',2''-terthiophene (TER), anthracene (ANT), and 9,10-diphenylanthracene (DP-ANT), 1,5-diaminonaphthalene (DAN) was found to provide the highest ionization yield with a negligible fragmentation. DAN also displayed excellent ionization properties for two metal ion-substituted bacteriochlorophylls, (i.e., Zn- and Cu-BChl a at m/z 950.49 and 949.49), respectively. MALDI MS/MS of both radical charged molecular species provide complementary information, thus making analyte identification more straightforward.

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Assessment of reproducibility and uncertainty of food microbiology methods: statistical approach of a multi-site laboratory

The validation of food microbiology methods and assessment of measurement uncertainty are required for laboratories operating EN ISO/IEC 17025 accreditation systems. This paper aims to describes the statistical approach adopted by a multi-site laboratory to satisfy these requirements and to routinely check the performance of the methods. A validation protocol was performed, reflecting a great variability of experimental conditions, represented by the period of time during which determinations were made, the different laboratories concerned, the large number of technicians involved, the differences in the level of contamination of the matrix analyzed and the operating conditions (equipment, reagents, culture media, environmental conditions, etc.). Despite the very high variability of the experimental conditions, the values of repeatability and reproducibility obtained for the methods were lower than those stated in the respective regulations. In addition, the top-down approach adopted in this study is to be considered effective overtime and allows to randomize all variable factors, including the effects of sensitivity and specificity, in order to simulate the conditions of real reproducibility. A specific Excel spreadsheet was also developed for the routine expression of analytical results. This spreadsheet represents a very useful tool for operators to calculate and routinely check the results, as well as to assess the uncertainty of measurement. This particular quality assessment system is enabling the multi-site laboratory to implement the accuracy, reliability and comparability of the analytical results and to ensure the analytical control of data output.     

X-Ray absorption spectroscopy investigation of 1-alkyl-3-methylimidazolium bromide salts

X-ray absorption spectroscopy (XAS) has been used to unveil the bromide ion local coordination structure in 1-alkyl-3-methylimidazolium bromide [C(n)mim]Br ionic liquids (ILs) with different alkyl chains. The XAS spectrum of 1-ethyl-3-methylimidazolium bromide has been found to be different from those of the other members of the series, from the butyl to the decyl derivatives, that have all identical XAS spectra. This result indicates that starting from 1-buthyl-3-methylimidazolium bromide the local molecular arrangement around the bromide anion is the same independently from the length of the alkyl chain, and that the imidazolium head groups in the liquid ILs with long alkyl chains assume locally the same orientation as in the [C(4)mim]Br crystal. With this study we show that the XAS technique is an effective direct tool for unveiling the local structural arrangements around selected atoms in ILs.     

Co nanoparticles inserted into a porous carbon amorphous matrix: the role of cooling field and temperature on the exchange bias effect

We report unusual cooling field dependence of the exchange bias in oxide-coated cobalt nanoparticles embedded within the nanopores of a carbon matrix. The size-distribution of the nanoparticles and the exchange bias coupling observed up to about 200 K between the Co-oxide shell (～3-4 nm) and the ferromagnetic Co-cores (～4-6 nm) are the key to understand the magnetic properties of this system. The estimated values of the effective anisotropy constant and saturation magnetization obtained from the fit of the zero-field cooling and field cooling magnetization vs. temperature curves agree quite well with those of the bulk fcc-Co.