OBJECTIVE: This study aims to access the effectiveness of mid-infrared (MIR) spectroscopy on the identification of the reticular form of OLP, following the assessment of gingival crevicular fluid (GCF) and oral mucosa transudate (OMT).
METHODS: The trial follows a case-control design. Samples were characterized through MIR spectroscopy and chemometric tools were applied to distinguish between case and control participants, further identifying the spectral regions with the highest contribution to the developed models.
RESULTS: MIR spectroscopy was capable to discriminate between OLP patients and controls with 95.1% and 85.4% of correct predictions, regarding GCF and OMT samples, respectively. Additionally, the spectral regions mostly contributing to the successful prediction were identified, and possibly related with the distinctive presence of amino acids/proteins and oxidative stress mediators in oral biofluids, supporting the role of the immune-inflammatory activation on OLP etiology and disease course.
CONCLUSIONS: MIR spectroscopy analysis of GCF and OMT may be regarded as an innovative, non-invasive, low cost and sensitive technique, contributing to the identification of the reticular from of OLP.

The rate constants for (L)-N-acetyl homocysteine thiolactone enantiomerization have been obtained from batch-wise studies and by dynamic gas chromatography of racemic mixtures. Results from the batch-wise experiments show that the kinetics of racemization at 150 °C is the same for vials made of glass, silanized glass or Teflon-coated glass so that the vial surface exhibited no effect on the kinetics of racemization. From the temperature dependence of the rate constants the preexponential factor, activation energy, the activation Gibbs energy and activation entropy have been obtained from transition state theory. The catalytic effect of G-DP, G-BP and B-DP GC chiral stationary phases on racemization has been observed and quantified by the values of rate constants; B-DP exhibited the greatest activity. The Eyring activation parameters obtained from batch-wise experiment were compared with theoretical values acquired from quantum chemical modelling. Agreement between the experimental and calculated values of activation Gibbs energy, activation enthalpy and activation entropy is good. The dynamic gas chromatography of racemic mixture on chiral B-DP, G-DP and G-BP capillary columns indicate that the rate constants of forward and reverse reactions are different in chiral environments. The greatest accelerating effect in the process of enantiomerization has been identified for G-BP both in the batch-wise experiments and by the dynamic gas chromatography.

In this work, microwave-assisted ionic liquids treatment, followed by hydro-distillation (MILT-HD), as an efficient extraction technology, was used to extract essential oil. The purpose for this was to use multivariate analysis (MVA) models to investigate the effects of potential critical process parameters on the extraction efficiency of essential oil, and explore the mechanism of ionic liquids (ILs). According to the design of experiment (DoE), under optimal process conditions, the extraction efficiency of essential oil was dramatically enhanced, and had low energy demands. Since little is known regarding those mechanisms, according to the non-covalent interaction analysis, the underlying mechanism for ILs improving extraction efficiency was explored based on the density functional theory (DFT). The results showed that ILs could form intense non-covalent bond interaction with cellulose. It helped destroy the network hydrogen bond structure of cellulose in plant cells and caused the essential oils in the cells to be more easily exposed to the extraction solution, thereby accelerating extraction efficiency. Based on this work, it is conducive to understand the MILT-HD process better and gain knowledge of the mechanism of ILs.

Cocoa flavanols (CF) are a group of dietary bioactives that have been studied for their potential health benefits for over two decades. In this time, multiple methods for CF testing have evolved, introducing the potential for differences in reported CF content. The reliable characterization of CF content in food and test materials used in clinical studies is critical to comparisons of research studies over time, as well as critical to enabling the systematic reviews and meta-analyses required to support dietary recommendations of bioactives. In this work, we compared two analytical methods that have been widely applied to characterize materials used in clinical research and a method newly recognized by AOAC as the official method for CF analysis. Differences in accuracy of -36% to +20% were observed when comparing CF contents determined with these methods, supporting the notion that CF values determined across methods are not directly comparable. To address differences, a linear regression model was developed to predict CF values. This approach was cross-validated and directly applied to the conversion of CF values published in key scientific papers on the benefits of CF. This work provides a valid tool to compare CF values reported across these different methods and enables comparisons and interpretation of studies investigating the bioactivity of CF.

Industrial separation technologies can be improved and greatly simplified by using the methods of counter-current chromatography (CCC). We have previously proposed the use of currently available solvent extraction equipment (a series of multistage columns, a cascade of centrifugal mixer-settler extractors) as large-scale CCC devices. For industrial separations, the application of closed-loop recycling counter-current chromatography (CLR CCC) methods seems to be the most promising. To improve the performance of the CLR CCC separations, semi-continuous three-stage processes (1 - continuous loading of the mixture solution over a definite time; 2 - separation of solutes in recycling closed-loop; 3 - elution of the fractions of the separated solutes with the mobile phase) can be used. The purpose of this study is to present a simple and easy to use mathematical model allowing the simulation and design of various options for implementing such separation processes and analyze the influence of its main parameters on separation efficiency.

The new European In Vitro Diagnostic (IVD) Regulation 2017/746 (IVDR) restricts the use of lab-developed tests (LDT) after 26th May 2022. There are no data on the impact of the IVDR on laboratories in the European Union.
Laboratory tests performed in UZ Leuven were divided in four groups: core laboratory, immunology, special chemistry, and molecular microbiology testing. Each test was classified as Conformité Européenne (CE)-IVD, modified/off-label CE-IVD, commercial Research Use Only (RUO) or LDT. Each matrix was considered a separate test.
We found that 97.6% of the more than 11.5 million results/year were generated with a CE-IVD method. Of the 922 different laboratory tests, however, only 41.8% were CE-IVD, 10.8% modified/off-label CE-IVD, 0.3% RUO, and 47.1% LDT. Off-label CE-IVD was mainly used to test alternative matrices not covered by the claim of the manufacturer (e.g., pleural or peritoneal fluid). LDTs were mainly used for special chemistry, flow cytometry, and molecular testing. Excluding flow cytometry, the main reasons for the use of 377 LDTs were lack of a CE-IVD method (71.9%), analytical requirements (14.3%), and the fact the LDT was in use before CE-IVD available (11.9%).
While the large majority of results (97.6%) were generated with a CE-IVD method, only 41.8% of laboratory tests were CE-IVD. There is currently no alternative on the market for 71.5% of the 537 LDTs performed in our laboratory which do not fall within the scope of the current IVD directive (IVDD). Compliance with the IVDR will require a major investment of time and effort.

Serum-ascites albumin gradient (SAAG) remains the most sensitive and specific marker for the differentiation of ascites due to portal hypertension from ascites due to other causes. SAAG has some limitations and may fail in selected conditions. Voltammetric analysis (VA) has been used for the detection of electroactive species of biological significance and has proven effective for detection infections in biological fluids.
In this study, we compared the accuracy of voltammetric analysis (VA) with that of SAAG to differentiate ascites due to portal hypertension from that having a different origin.
80 ascites samples were obtained from patients undergoing paracentesis at the Campus Bio-Medico Hospital of Rome. VA was performed using the BIONOTE device. The ability of VA to discriminate ascitic fluid etiology and biochemical parameters was evaluated using Partial Least Square Discriminant Analysis (PLS-DA), with ten-fold cross-validations.
Mean age was 68.6 years (SD 12.5), 58% were male. Ascites was secondary to only portal hypertension in 72.5% of cases (58 subjects) and it was secondary to a baseline neoplastic disease in 27.5% of cases (22 subjects). Compared to SAAG≥1.1, e-tongue predicted ascites from portal hypertension with a better accuracy (92.5% Vs 87.5%); sensitivity (98.3% Vs 94.8%); specificity (77.3% Vs 68.2%); predictive values (PPV 91.9% Vs 88.7% and NPV 94.4% Vs 83.3%). VA correctly classified ascites etiology in 57/58 (98.2%) of cases with portal hypertension and in 17/22 (77.2%) of cases with malignancy. Instead, VA showed poor predictive capacities towards total white blood count and polymorphonuclear cell count.
According to this proof of concept study, VA qualifies as a promising low-cost and easy method to discriminate between ascites secondary to portal hypertension and ascites due to malignancy.

Multi-column periodic counter-current chromatography (PCC) has been developed for continuous antibody capture, but the complexity of continuous processes makes experimental optimization time consuming and costly. In this work, with twin-column continuous system as a typical case, mathematical models were established and used to evaluate the impacts of operating parameters for process development. The model fitted well with the experimental breakthrough curves and process performance under varying protein concentrations and residence times. Three important operating parameters, residence time for interconnected feeding (RTC), breakthrough percentage control for interconnected feeding (s) and disconnected feeding time (tDC), were evaluated systematically. The profiles of productivity and resin capacity utilization showed three phases as a function of RTC, which resulted in different optimization strategies towards s and tDC. Based on the model prediction, a working window of RTC and s can be determined for process development. Finally, a model-based design approach was proposed to determine the optimum operating conditions and to design a suitable continuous process for high productivity and capacity utilization. With the model-based design approach developed, the best performance of 12.8 g/L/h productivity and 91.9% capacity utilization was found for MabSelect SuRe resin under 1 mg/mL feeding IgG concentration at RTC = 2 min, s = 65% and tDC = 26 min.

The present contribution reports on the practical implementation and validation of a new experimental method to determine the radial dispersion (Drad) in packed bed liquid chromatography columns, as well as on the results obtained with it. A first important validation was that the measured Drad-values were independent of the applied relative central flow rate (varied from 25% to 57%). The obtained Drad-values did not vary significantly when changing the concentration of the injected tracer to check potential mass overloading effects (25, 50 or 75 ppm of tracer for the acetophenone measurements; 12.5 and 25 ppm of tracer for the toluene measurements). And yet another important validation step was the observation that the Drad-values clearly converged to the value of Deff for velocities going to zero, as physically and theoretically expected. Plotting the obtained results as a plot of Drad/Dmol versus the reduced velocity ν, a quasi-linear relationship is obtained. The slope of the curve (β = 0.38 and β = 0.46 for toluene and acetophenone, respectively) is significantly larger than the value that is most frequently cited in engineering literature. However, the obtained β-values and Drad/Dmol-values still fall within the broad range of β- and Drad/Dmol-values cited in literature.

To fully capture the chemo-diversity of medicinal plants is very essential for understanding of their pharmacological activities and guiding scientific quality control. Aiming to facilitate chemical characterization and novel natural products discovery, the present study proposed an integrated approach based on two-dimensional liquid chromatography coupled with quadrupole-Orbitrap mass spectrometer (2D LC/Q-Orbitrap MS). An offline comprehensive two-dimensional (2D) LC system was constructed to cover and separate multi-type constituents by combining hydrophilic interaction chromatography (HILIC) and conventional reversed phase C18. A two-step mass defect filtering-induced exclusion list-data dependent acquisition was developed to increase MS/MS coverage and selectivity. Additionally, an efficient interpretation strategy, combining an automatic matching algorithm and molecular networking (MN), was introduced for rapid recognition of known compounds and efficient elucidation of unreported ones. As a case study, the integrated approach was tentatively applied for comprehensive characterization of complex multi-type components in Lonicerae Japonicae Flos (LJF), a traditional Chinese medicine. Consequently, a total of 537 compounds were characterized from LJF, including a large number of potential novel structures. It was demonstrated that the integrated approach is powerful in deep investigation on chemical diversity of medicinal plants and discovery of novel structures. Its application could also be extended for global profiling of other complicated chemical systems, such as Chinese medicinal formulas.