Electrosynthesized poly(o-aminophenol) films as biomimetic coatings for dopamine detection on Pt substrates

Dopamine (DA) is a neurotransmitter, and its levels in the human body are associated with serious diseases. The need for a suitable detection method in medical practice has encouraged the development of electrochemical sensors that take advantage of DA electroactivity. Molecularly imprinted polymers (MIPs) are biomimetic materials able to selectively recognize target analytes. A novel MIP sensor for DA is proposed here based on a thin film of poly(o-aminophenol) electrosynthesized on bare Pt. A fast and easy method for executing the procedure for MIP deposition has been developed based on mild experimental conditions that are able to prevent electrode fouling from DA oxidation products. The MIP exhibited a limit of detection of 0.65 µM, and appreciable reproducibility and stability. The high recognition capability of poly(o-aminophenol) towards DA allowed for the achievement of notable selectivity: ascorbic acid, uric acid, serotonin, and tyramine did not interfere with DA detection, even at higher concentrations. The proposed sensor was successfully applied for DA detection in urine samples, showing good recovery

Mars Regolith Simulant Ameliorated by Compost as In Situ Cultivation Substrate Improves Lettuce Growth and Nutritional Aspects

Heavy payloads in future shuttle journeys to Mars present limiting factors, making self-sustenance essential for future colonies. Therefore, in situ resources utilization (ISRU) is the path to successful and feasible space voyages. This research frames the concept of planting leafy vegetables on Mars regolith simulant, ameliorating this substrate’s fertility by the addition of organic residues produced in situ. For this purpose, two butterhead lettuce (Lactuca sativa L. var. capitata) cultivars (green and red Salanova®) were chosen to be cultivated in four dierent mixtures of MMS-1 Mojave Mars simulant:compost (0:100, 30:70, 70:30 and 100:0; v:v) in a phytotron open gas exchange growth chamber. The impact of compost rate on both crop performance and the nutritive value of green- and red-pigmented cultivars was assessed. The 30:70 mixture proved to be optimal in terms of crop performance, photosynthetic activity, intrinsic water use eciency and quality traits of lettuce. In particular, red Salanova® showed the best performance in terms of these quality traits, registering 32% more phenolic content in comparison to 100% simulant. Nonetheless, the 70:30 mixture represents a more realistic scenario when taking into consideration the sustainable use of compost as a limited resource in space farming, while still accepting a slight significant decline in yield and quality in comparison to the 30:70 mixture

Validation of an analytical method for nitrite and nitrate determination in meat foods for infants by ion chromatography with conductivity detection

Nitrate and nitrite as sodium or potassium salts are usually added to meat products to develop the characteristic flavor, to inhibit the growth of microorganisms (particularly Clostridium botulinum), and effectively control rancidity by inhibiting lipid oxidation. However, both nitrate and nitrite ions need to be monitored for ensuring the quality and safety of cured meats. In this work, for the first time the content of nitrite and nitrate ions in homogenized meat samples of baby foods was determined by a validated method based on ion chromatography (IC) coupled with conductivity detection. Recoveries of nitrate and nitrite ions in meat samples were not lower than 84 ± 6%. The detection limits of nitrate and nitrite were 0.08 mg L−1 and 0.13 mg L−1, respectively. Five commercial samples of homogenized meat, namely lamb, rabbit, chicken, veal, and beef, for infant feeding were investigated; while nitrite content was below the detection limit, nitrate ranged from 10.7 to 21.0 mg kg−1. The results indicated that nitrate contents were below the European (EU) fixed value of 200 mg kg−1, and an acceptable daily intake of 3.7 mg kg−1 was estimated

Whole-genome doubling drives oncogenic loss of chromatin segregation.

Whole-genome doubling (WGD) is a recurrent event in human cancers and it promotes chromosomal instability and acquisition of aneuploidies <sup>1-8</sup> . However, the three-dimensional organization of chromatin in WGD cells and its contribution to oncogenic phenotypes are currently unknown. Here we show that in p53-deficient cells, WGD induces loss of chromatin segregation (LCS). This event is characterized by reduced segregation between short and long chromosomes, A and B subcompartments and adjacent chromatin domains. LCS is driven by the downregulation of CTCF and H3K9me3 in cells that bypassed activation of the tetraploid checkpoint. Longitudinal analyses revealed that LCS primes genomic regions for subcompartment repositioning in WGD cells. This results in chromatin and epigenetic changes associated with oncogene activation in tumours ensuing from WGD cells. Notably, subcompartment repositioning events were largely independent of chromosomal alterations, which indicates that these were complementary mechanisms contributing to tumour development and progression. Overall, LCS initiates chromatin conformation changes that ultimately result in oncogenic epigenetic and transcriptional modifications, which suggests that chromatin evolution is a hallmark of WGD-driven cancer

Development and Validation of a Reversed-Phase HPLC Method with UV Detection for the Determination of L-Dopa in Vicia faba L. Broad Beans

L-Dopa (LD), a substance used medically in the treatment of Parkinson's disease, is found in several natural products, such as Vicia faba L., also known as broad beans. Due to its low chemical stability, LD analysis in plant matrices requires an appropriate optimization of the chosen analytical method to obtain reliable results. This work proposes an HPLC-UV method, validated according to EURACHEM guidelines as regards linearity, limits of detection and quantification, precision, accuracy, and matrix effect. The LD extraction was studied by evaluating its aqueous stability over 3 months. The best chromatographic conditions were found by systematically testing several C-18 stationary phases and acidic mobile phases. In addition, the assessment of the best storage treatment of Vicia faba L. broad beans able to preserve a high LD content was performed. The best LD determination conditions include sun-drying storage, extraction in HCl 0.1 M, chromatographic separation with a Discovery C-18 column, 250 x 4.6 mm, 5 mu m particle size, and 99% formic acid 0.2% v/v and 1% methanol as the mobile phase. The optimized method proposed here overcomes the problems linked to LD stability and separation, thus contributing to the improvement of its analytical determination

An Interplay between a Face-Centred Composite Experimental Design and Solid-Phase Microextraction for Wine Aroma GC/MS Analysis

For oenological products, most of the intrinsic and extrinsic drivers of perceived quality are associated with specific aromatic profiles. Aromatic diversity has been recognized as a central element in perceived quality as it is able to transmit the complex interactions between grape variety, geographical characteristics, and viticultural and winemaking practices, including the fermentative process. A comprehensive characterization of flavour compounds by headspace solid-phase microextraction (HS-SPME) and gas chromatography coupled to mass spectrometric analysis is often needed in order to ascertain the quality of wine. HS-SPME requires a proper optimization that can be achieved through an adequate experimental design. Here, a HS-SPME/GC-MS based method was developed to investigate the volatile compounds of wine samples obtained by laboratory-scale fermentations. This was performed by inoculating a commercial Saccharomyces cerevisiae strain, which is used both as single starter and as mixed starter, with an indigenous Hanseniaspora osmophila strain. The experimental conditions of HS-SPME (extraction temperature and time) were optimized by applying a face-centred composite experimental design. Up to 95% of the total variance was explained by the proposed model. The optimized method allowed us to confirm the usefulness of combining the inoculation of grapes with selected yeast strains in co-culture situations in order to improve the wine bouquet

Genotype and Successive Harvests Interaction Affects Phenolic Acids and Aroma Profile of Genovese Basil for Pesto Sauce Production

Basil (Ocimum basilicum L.) is an essential ingredient of the Mediterranean cuisine due to its distinctive aroma. Genovese basil leaves are used to prepare "pesto", a condiment that has always caught the interest of consumers and producers. Usually, basil for industrial processing is harvested more than once to extract a higher yield. However, successive cuts can affect quality traits that play a crucial role in defining the product's final sensory profile. This research was aimed to evaluate the impact of cut on the quantitative and qualitative properties of three Genovese basil cultivars (Aroma 2, Eleonora and Italiano Classico) grown in an open field. Nitrate content, phenolic acids and aromatic profile were determined by ion chromatography (IC), high-performance liquid chromatography (HPLC), and gas chromatography coupled to a mass spectrometer (GC/MS) analysis, respectively. The second harvest increased fresh biomass and total phenolic acids content by 172% and 413%, respectively, with Italiano Classico recording the highest values. The combination of second-cut Aroma 2 yielded the lowest nitrate (473.8 mg kg-1 of fresh weight) and Eugenol (2.4%) levels. In the second harvest, Eleonora showed an increase in eugenol and trans-α-bergamotene of 75.3% and 48.2%, respectively; whereas, eucalyptol and β-cis-ocimene decreased by 34.4% and 51.6%, respectively. Although successive harvests may increase basil yield and quality overall, the cultivar-dependent response to successive cuts needs to be accounted for in order to accomplish standardization of industrial "pesto" sauce

Legal Cannabis sativa L. Dried Inflorescences: Cannabinoids Content and Cytotoxic Activity against Human HepG2 Cell Line

Cannabis sativa L. has health benefits, principally due to the levels and ratios of two impor- tant cannabinoids, ∆9-tetrahydrocannabinol (THC) and cannabidiol (CBD). THC:CBD ratio affects their pharmacological interaction for the treatment of different diseases as well as its modulation allows for a custom-made product that utilizes the distinguishing effects of CBD, THC, or both, for a peculiar patient or clinical effect. This study aims to investigate the total content of THC, CBD, and their ratio in 34 dried inflorescence legally sold in physical and online stores, by using a validated liquid chromatography-ultraviolet (HPLC-UV) method, after cannabinoids identification performed through MSn studies. Cannabinol (CBN) content was also monitored to evaluate hemp age or con- servation status. CBN content always resulted lower than limit of quantification, thus confirming well-stored fresh hemp. All investigated samples showed a total THC amount below 0.59% w/w, thus responding to legal requirements.. The total CBD amount ranged from 2.62 to 20.27% w/w and it was not related to THC level. THC:CBD ranged among 1:3 and 1:26, thus ascertaining their suitability for different target pharmacological uses. In vitro studies using human hepatoblastoma cell line HepG2 suggested that hemp extracts with THC:CBD ratios of 1:9 exhibited higher toxicity than pure cannabinoids