Rheological,textural and calorimetric modifications of dark chocolate during process

The influence of several process steps on the rheological, textural and calorimetric characteristics of dark chocolate was evaluated. Samples were obtained at each phase of the manufacturing process: mixing, pre-refining, refining, conching and tempering. Rheological fundamental and empirical properties and thermal characteristics were evaluated on samples. Samples showed marked shear thinning behaviour with yield stress strictly related with the different process steps. Fundamental measurements results were well fitted by the power-law model. From the mixing to the refining samples underwent a drastic significantly (p < 0.05) increase of all considered fundamental (yield stress, apparent viscosity, G′, G″ and K index), empirical (firmness, consistency, cohesiveness, viscosity index) and thermal parameters (T onset, T end, ΔH). This could be attributed to the reduction of samples particle size that involve an increase of the contact point between them. Subsequently, the addition of fat and lecithin in conching and tempering phase, covering the sugar and cocoa particles, reduced interactions and caused a significantly (p < 0.05) decrease in all rheological, textural and thermal parameters.     

Model predictive in vitro dissolution testing in pharmaceutical continuous manufacturing: An equivalence study

A predictive mathematical model for tablet dissolution was developed and implemented in an end-to-end integrated continuous manufacturing pilot plant. The tablets were produced for immediate release with a proprietary extrusion-molding-coating (EMC) unit operation. Besides the mass balance of API solute in the buffer solution, the model consisted of the dissolution, diffusion, and population balance of API particles in the swollen tablet, which was mainly controlled by the swelling and erosion of the polymeric excipient matrix. An equivalence study was investigated by comparing the model prediction to the experiments that were conducted according to USP42-NF37 General Chapter <711> Dissolution, during which the drug dose level was varied in a range from 60 to 80 wt%. Consistent equivalence was demonstrated with the similarity factor f₂ > 50 for all sampled tablets. Concluding remarks and industrial perspectives on model predictive in vitro dissolution testing are provided.     

Stereoselective Biocatalyzed Reductions of Ginger Active Components Recovered from Industrial Wastes

Ginger is among the most widespread and widely consumed traditional medicinal plants around the world. Its beneficial effects, which comprise e. g. anticancer and anti-inflammatory activities as well as gastrointestinal regulatory effects, are generally attributed to a family of non-volatile compounds characterized by an arylalkyl long-chained alcohol, diol, or ketone moiety. In this work, ginger active components have been successfully recovered from industrial waste biomass of fermented ginger. Moreover, their recovery has been combined with the first systematic study of the stereoselective reduction of gingerol-like compounds by isolated alcohol dehydrogenases (ADHs), obtaining the enantioenriched sec-alcohol derivatives via a sustainable biocatalytic path in up to >99 % conversions and >99 % enantiomeric/diastereomeric excesses.     

The virtualization of human–robot interactions: a user-centric workload assessment

Virtual Reality - Interest in the virtualization of human–robot interactions is increasing, yet the impact that collaborating with either virtual or physical robots has on the human...     

High-Density Plasmonic Nanopores for DNA Sensing at Ultra-Low Concentrations by Plasmon-Enhanced Raman Spectroscopy

Solid-state nanopores are implemented in new and promising platforms that are capable of sensing fundamental biomolecular constituents at the single-molecule level. However, several limitations and drawbacks remain. For example, the current strategies based on both electrical and optical sensing suffer from low analyte capture rates and challenging nanofabrication procedures. In addition, their limited discrimination power hinders their application in the detection of complex molecular constructs. In contrast, Raman spectroscopy has recently demonstrated the ability to discriminate both nucleotides and amino acids. Herein, a plasmonic nanoassembly is proposed supporting nanopores at high density, in the order of 100 pores per µm². These findings demonstrate that the device has a high capture rate in the range of a few fm . The pore size is ≈10 nm in diameter and provides an amplification of the electromagnetic field exceeding 10³ in intensity at 785 nm. Owing to these features, single-molecule detection is achieved by means of surface-enhanced Raman scattering from a solution containing 50 fm DNA molecules (≈4.4 kilobase pairs). Notably, the reported spectra show an average number of 2.5 Raman counts per nucleotide. From this perspective, this number is not far from what is necessary to discriminate the DNA sequence.     

Fatty Acid Ratios as Parameters to Discriminate Between Normal and Tumoral Cells and Compare Drug Treatments in Cancer Cells

The fatty acid (FA) composition of cell membranes represents a metabolic biomarker. However, the FA profile reproducibility in cell cultures remains a significant challenge. In this study, cell FA ratios are validated as metabolic markers alternative to cell FA. To this goal, cell samples belonging to cancer HeLa cells and normal 3T3 fibroblasts, from various experimental sets, are analyzed by a high-performance liquid chromatography system coupled with a photodiode array detector and evaporative light scattering detector (HPLC-DAD/ELSD), and the ratios among the main FA are calculated. Principal component analysis (PCA) separately performed on FA and FA ratio data indicates similar clustering of cell samples concerning the cell type. Moreover, similar scores values t[1] and t[2] and graphical distances are calculated in the PCA plots separately performed on FA and FA ratios measured in cancer HeLa cells subjected to various antitumoral compounds. Last, PCA applied to selected FA ratios measured in various cell lines, obtained in similar experimental conditions, allows to discriminate between normal and tumoral cells. The results substantiate FA ratios as a cell-specific fingerprint, characterized by reproducibility across intra-laboratory conditions, useful for cell characterization, discrimination between normal and tumoral cells, and the comparison of different drug treatments. Practical Applications: The reproducibility of the fatty acid (FA) profile in cell cultures remains a significant challenge. Results obtained from this study improve knowledge about the role of the FA ratio profile as a cell-specific fingerprint characterized by reproducibility across intra-laboratory conditions. The characterization of the specific FA ratio profile of a cell culture, under standardized experimental conditions, can facilitate the comparative evaluation of cell data sets for nutritional, metabolic, and pharmacological studies, overcoming differences in cell culture conditions and FA extraction/analytical procedures.     

1,2,4-Triazole-3-Thione Analogues with a 2-Ethylbenzoic Acid at Position 4 as VIM-type Metallo-β-Lactamase Inhibitors

Metallo-β-lactamases (MBLs) are increasingly involved as a major mechanism of resistance to carbapenems in relevant opportunistic Gram-negative pathogens. Unfortunately, clinically efficient MBL inhibitors still represent an unmet medical need. We previously reported several series of compounds based on the 1,2,4-triazole-3-thione scaffold. In particular, Schiff bases formed between diversely 5-substituted-4-amino compounds and 2-carboxybenzaldehyde were broad-spectrum inhibitors of VIM-type, NDM-1 and IMP-1 MBLs. Unfortunately, these compounds were unable to restore antibiotic susceptibility of MBL-producing bacteria, probably because of poor penetration and/or susceptibility to hydrolysis. To improve their microbiological activity, we synthesized and characterized compounds where the hydrazone-like bond of the Schiff base analogues was replaced by a stable ethyl link. This small change resulted in a narrower inhibition spectrum, as all compounds were poorly or not inhibiting NDM-1 and IMP-1, but showed a significantly better activity on VIM-type enzymes, with K_i values in the μM to sub-μM range. The resolution of the crystallographic structure of VIM-2 in complex with one of the best inhibitors yielded valuable information about their binding mode. Interestingly, several compounds were shown to restore the β-lactam susceptibility of VIM-type-producing E. coli laboratory strains and also of K. pneumoniae clinical isolates. In addition, selected compounds were found to be devoid of toxicity toward human cancer cells at high concentration, thus showing promising safety.     

Gamifying model-based engineering: the PapyGame experience

Software and Systems Modeling - Modeling is an essential and challenging activity in any engineering environment. It implies some hard-to-train skills such as abstraction and communication....