Feed-Forward Prediction of Product Qualities in Enzymatic Protein Hydrolysis of Poultry By-products: a Spectroscopic Approach

Enzymatic protein hydrolysis (EPH) is one of the industrial bioprocesses used to recover valuable constituents from food processing by-products. Extensive heterogeneity of by-products from, for example, meat processing is a major challenge in production of protein hydrolysates with stable and desirable quality attributes. Therefore, there is a need for process control tools for production of hydrolysates with defined qualities from such heterogeneous raw materials. In the present study, we are reporting a new feed-forward process control strategy for enzymatic protein hydrolysis of poultry by-products. Four different spectroscopic techniques, i.e., NIR imaging scanner, a miniature NIR (microNIR) instrument, fluorescence and Raman, were evaluated as tools for characterization of the raw material composition. Partial least squares (PLS) models for ash, protein, and fat content were developed based on Raman, fluorescence, and microNIR measurements, respectively. In an effort to establish feed-forward process control tools, we developed statistical models that enabled prediction of end-product characteristics, i.e., protein yield and average molecular weight of peptides (Mw), as a function of raw material quality and hydrolysis time. A multiblock sequential orthogonalised-PLS (SO-PLS) model, where spectra from one or more techniques and hydrolysis time were used as predictor variables, was fitted for the feed-forward prediction of product qualities. The best model was obtained for protein yield based on combined use of microNIR and fluorescence (R²?=?0.88 and RMSE?=?4.8). A Raman-based model gave a relatively moderate prediction model for Mw (R²?=?0.56 and RMSE?=?150). Such statistical models based on spectroscopic measurements of the raw material can be vital process control tools for EPH. To our knowledge, the present work is the first example of a spectroscopic feed-forward process control for an industrially relevant bioprocess.     

Preparation and characterisation of PZT films by RF-magnetron sputtering

Stoichiometric films were prepared by rf-magnetron sputtering from a Pb(Zr_0.54Ti_0.46)O₃ ceramic target onto Au-electroded substrates of alumina. During deposition the substrate holder was kept at a temperature of 300 °C. Post-deposition heat treatment in air at 650 °C was carried to promote the full crystallization and to result in pure perovskite PZT phase. SEM-EDX measurements for the films were performed both on surface and on cross-section. The impedance spectroscopy data demonstrates that the films have rather good dielectric properties and low losses. The recorded P-E loops prove their macroscopic ferroelectric characteristics, while piezoresponse force microscopy experiments confirm a nanoscale switching mechanism based on domain nucleation-growth.     

The effect of processing parameters on the bond strength and electrical conductivity of multi-wall carbon nanotube/low-density polyethylene composite

The objective of this paper is to study the influence of processing parameters, such as melt temperature and mold temperature, on the adhesion of low density polyethylene (LDPE) to 2.5?wt/% multi-wall carbon nanotube-filled polyethylene (LDPE/MWCNT). The adhesion was obtained using two-component injection-molding method and measured using tensile experiments. The electrical conductivity of the two-component injection-molded specimens was also measured through DC voltage and compared to the volume resistivity of the LDPE and LDPE/MWCNT composite. It was found that the bond strength increases with increasing melt and mold temperatures. However, increasing the melt and mold temperatures over a certain limit can decrease the bond strength. The range of the electrical conductivity of the LDPE-LDPE/MWCNT two-component injection-molded samples was in the range of dissipative materials.     

The effect of Si/Al ratio and moisture on an organic/inorganic hybrid material: Thioindigo/montmorillonite

Colored Organic/Inorganic Hybrid Materials (OIHM) with reversible properties were prepared by a solid-state reaction between several montmorillonites (MMT) with different Si/Al ratio (Bentolite L^®, Texas, Wyoming and Kunipia deposits) and a neutral organic dye (thioindigo) at 413 K for nine hours. Spectroscopic and thermogravimetric analysis of the above mentioned interactions were evaluated. Results obtained by these techniques revealed an influence of Si/Al ratio in dehydrated MMT, where the intramolecular charge-transfer (IMCT) in thioindigo progressively red-shifted and increased in intensity in the following order: BentoT (Si/Al = 8.2) > TexasT (Si/Al = 7) > WyomingT (Si/Al = 5.6) > KunipiaT (Si/Al = 4.8). Moreover, a disturbance of thioindigo C=O at 1654 cm^?1 to lower frequencies occurred due to C=O---Lewis acid sites (LAS) and Brønsted (B) interaction in MMT with high Si/Al ratio. In the presence of water, a smaller C=O shift due to C=O---(H₂O)LAS or B interaction was identified. In addition, displacement of the basal spacing (001) in all MMT confirmed the effect of water on the reversible color changes displayed by UV–Vis diffuse reflectance spectroscopy. The existence of different binding strengths in OIHM was also evaluated by TGA and UV–Vis spectroscopy of their ethanol Soxhlet extractions.     

A Drude model analysis of conductivity and free carriers in boron-doped diamond films and investigations of their internal stress and strain

Boron-doped diamond (BDD) has seen a substantial increase in interest for use as electrode coating material for electrochemistry and studies of deep brain stimulation mechanism. In this study, we present an alternative method for determining important characteristics, including conductivity, carrier concentration, and time constant, of such material by the signature of Drude-like metallic behavior in the far-infrared (IR) spectral range. Unlike the direct determination of conductivity from the four-point probe method, using far-IR transmittance provides additional information, such as whether the incorporation of boron results in a large concentration of carriers or in inducing defects in the diamond lattice. The slightly doped to medium-doped BDD samples that were produced using chemical vapor deposition and analyzed in this work show conductivities ranging between 5.5 and 11 (Ω cm)^?1. Different growth conditions demonstrate that increasing boron concentration results in an increase in the carrier concentration, with values between 7.2 × 10¹⁶ and 2.5 × 10¹⁷ carriers/cm³. Addition of boron, besides leading to a decrease in the resistivity, also resulted in a decrease in the time constant, limiting BDD conductivity. Investigations, by confocal Raman mapping, of the induced stress in the material due to interaction with the substrate or to the amount of doping are also presented and discussed. The induced tensile stress, which was distributed closer to the film-substrate interface decreased slightly with doping.     

Enantioselective Benzylic Hydroxylation with Pseudomonas monteilii TA‐5: A Simple Method for the Syntheses of (R)‐Benzylic Alcohols Containing Reactive Functional Groups

Highly enantioselective benzylic hydroxylations of benzene derivatives ( 1–4 ) containing reactive functional groups were achieved for the first time with Pseudomonas monteilii TA‐5 as biocatalyst, giving the corresponding (R)‐benzylic alcohols 5 – 8 in 93–99% ee as the only products. Preparative biotransformations were demonstrated by the biohydroxylation of 1 and 2 with resting cells of P. monteilii TA‐5 to afford (R)‐ 5 in 94% ee and 66% yield and (R)‐ 6 in 94% ee and 56% yield, respectively. The highly enantioselective biohydroxylations represent a simple access to (R)‐benzylic alcohols containing reactive functional groups that are useful pharmaceutical intermediates and versatile chiral building blocks.     

Undoped and Cr-doped TiO2 thin films obtained by spray pyrolysis

Undoped and chromium doped titanium oxide thin films were fabricated by spray pyrolysis by using a solution of titanium tetrachloride and ethyl alcohol. The films have been deposited on heated glass substrates at 373 K. After annealing for 90 min at 723 K, the initially amorphous films became polycrystalline with a predominant anatase structure and average crystallite sizes depending on dopant (Cr) concentration. The repartition of chromium impurities in the matrix of titanium oxide films, analyzed by electron paramagnetic resonance and X-ray photoelectron spectroscopy showed that the entrance of chromium into the anatase structure is mainly achieved by substitution. A decrease in unit cell parameters ratio (c/a) with the increase of chromium content sustains this assertion. The wetting properties of the titanium oxide films were evaluated from contact angle measurements between de-ionized water and films surface during- and post-irradiation with UV light. The correlation between the concentration of the dopant, film structure, surface morphology and wettability characteristics is discussed.     

Feedback to teachers on student engagement as a consultation tool.

Estimated the time 3 academically delayed mainstreamed students (aged 8–9 yrs old) and their peers spent participating in their classroom assignments, using the Planned Activity Check (PLAC) observation and recording system. Teachers used the information to modify instructional strategies as they saw fit. As the feedback phase continued, despite no major increases in teacher attention, the mainstreamed Ss consistently improved their participation to close to 100%. The strategy proved practical as well as effective because teachers could use their own expertise to solve the problems that were revealed by the PLAC data. This method may be broadly used by school psychologists and educators concerned with increasing levels of student participation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transcytosis of plasma macromolecules in endothelial cells: a cell biological survey

The modern exploration of endothelial cell biology is a largely interdisciplinary exercise. Cell biological, physiological, and more recently molecular biology approaches were used to study the pathways and the organelles involved in transcytosis of macromolecules in endothelial cell (EC). Here we discuss mainly the cell biological findings that revealed that EC have the attributes to fulfill the transport function. They are polarized cells, heterogeneous, and, thus, structurally and functionally adapted to the vascular bed in which they reside. The structural heterogeneity involves the number and distribution of plasmalemmal vesicles (caveolae), their generated channels, and the organization of intercellular junctions. The closely related functional heterogeneity comprises the degree of permeability for plasma molecules that vary as a function of organ. The EC are endowed with the cellular machinery to perform (1) endocytosis, that is to take up plasma proteins and the molecules they carry to be used for themselves (cholesterol-carrying low density lipoproteins, fatty acid carrying albumin, iron carrying transferrin, etc.), and (2) transcytosis, which implies to transport plasma proteins to the subjacent cells and tissues. The possible pathways for transport of molecules are transcellular, via caveolae and channels, and paracellular via intercellular junctions. Most of the results obtained, so far, indicate that transcytosis of albumin, low-density lipoproteins, metaloproteases, and insulin, is performed by cargo-vesicles and their generated channels. The paracellular pathway can be used for water and ions; in postcapillary venules, at the level of which approximately 30% of junctions are open to a space of 6 nm, small molecules may take this route. Recent data obtained by molecular biology techniques revealed that caveolae are endowed with the molecular machinery for fusion/fission, docking, and movement across cells. Moreover, the various and numerous molecules that have been detected in the caveolae membrane and the different functions assumed by this differentiated microdomain strengthen the postulate that there are at least two or more types of vesicles molecularly tailored for the local physiological requirements.     

Perisomatic Inhibition and Its Relation to Epilepsy and to Synchrony Generation in the Human Neocortex

Inhibitory neurons innervating the perisomatic region of cortical excitatory principal cells are known to control the emergence of several physiological and pathological synchronous events, including epileptic interictal spikes. In humans, little is known about their role in synchrony generation, although their changes in epilepsy have been thoroughly investigated. This paper demonstraits how parvalbumin (PV)- and type 1 cannabinoid receptor (CB1R)-positive perisomatic interneurons innervate pyramidal cell bodies, and their role in synchronous population events spontaneously emerging in the human epileptic and non-epileptic neocortex, in vitro. Quantitative electron microscopy showed that the overall, PV+ and CB1R+ somatic inhibitory inputs remained unchanged in focal cortical epilepsy. On the contrary, the size of PV-stained synapses increased, and their number decreased in epileptic samples, in synchrony generating regions. Pharmacology demonstrated—in conjunction with the electron microscopy—that although both perisomatic cell types participate, PV+ cells have stronger influence on the generation of population activity in epileptic samples. The somatic inhibitory input of neocortical pyramidal cells remained almost intact in epilepsy, but the larger and consequently more efficient somatic synapses might account for a higher synchrony in this neuron population. This, together with epileptic hyperexcitability, might make a cortical region predisposed to generate or participate in hypersynchronous events.