Legumes, especially peas, are sensitive to water shortages, which are becoming increasingly common because of climate change. Peas are beneficial for soil and crop rotation and as a source of protein in nutrition. Therefore, discovering new agrotechnical tools and maintaining plant resistance to environmental influences is essential. The aim of this study was to investigate the effects of silica nanoparticles (SiO₂ NPs) on drought-stressed peas (Pisum sativum L., ‘Respect’) via different exposure routes: through foliar spraying and root watering. The research was conducted in a greenhouse. Ten green pea seeds (‘Respect’) were sown in 10 L vegetative pots and were thinned up to 7 plants per pot after germination. When the peas reached the 39 BBCH growth stage (had nine or more visibly extended internodes), they were foliar sprayed to full wetness (ca. 14±0.5 mL plant⁻¹) or watered (100±1 mL per pot) with suspensions containing 12.5, 25, and 50 ppm of SiO₂ NPs. Untreated NPs plants were watered or sprayed with distilled water. During the 10-day drought period, low substrate moisture (30%) was maintained for peas exposed to SiO₂ NPs, and other plants (controls) were grown under regular substrate moisture (80%). At the end of the experiment, peas were harvested to assess the impact of SiO₂ NPs and drought on plant growth indicators and enzymatic (SOD, GR, APX) and non-enzymatic (TPC, FRAP) antioxidants activity. The results showed that treatment at a concentration of 50 ppm SiO₂ NPs strongly affected pea leaf area, shoot height, and fresh biomass when plants were grown in drought conditions. In addition, positive effects on the activity of enzymatic (APX, CAT, GR, SOD) and non-enzymatic (TPC, DPPH, ABTS, FRAP) antioxidants in the pea plant were found. The SiO₂ NPs reduced hydrogen peroxide and lipid peroxidation in drought-affected plant tissue. SiO₂ NPs protected green peas from the adverse effects of drought stress and maintained pea yield.

Single-walled carbon nanotubes (SWCNTs) are very important material for many applications. The chemical functionalization of carbon nanotubes such as covalent, noncovalent modifications, substitution of carbon atoms in walls, intercalation, filling allow modifying precisely the properties of carbon nanotubes. Here I perform the filling of SWCNTs with gallium selenide [1], lead halogenides [2], and rubidium iodide [3], and investigate the properties with Raman spectroscopy, near edge X-ray absorption fine structure spectroscopy, photoemission spectroscopy, optical absorption spectroscopy [4]. It is shown that the introduced salt leads to the modification of the electronic properties of carbon nanotubes [5]. The p-doping is observed. The successful filling of carbon nanotubes with high filling ratio and high doping level of SWCNTs can find applications in different fields.

[1] M. V. Kharlamova. Novel approach to tailoring the electronic properties of single-walled carbon nanotubes by the encapsulation of high-melting gallium selenide using a single-step process, JETP letters, 2013, V. 98, № 5, p. 272-277

[2] M. V. Kharlamova, C. Kramberger, P. Rudatis, T. Pichler, D. Eder. Revealing the doping effect of encapsulated lead halogenides on single‑walled carbon nanotubes, Appled Physics A, 2019, V. 125, article number 320

[3] M. V. Kharlamova, C. Kramberger, P. Rudatis, K. Yanagi, D. Eder. Characterization of the electronic properties of single-walled carbon nanotubes filled with an electron donor - rubidium iodide: multifrequency Raman and X-ray photoelectron spectroscopy studies, Physica Status Solidi B, 2019, V. 256, № 12, article number 1900209

[4] M. V. Kharlamova, C. Kramberger. Spectroscopy of filled single-walled carbon nanotubes. Nanomaterials 2022, 12, 42.

[5] M. V. Kharlamova. Advances in tailoring the electronic properties of single-walled carbon nanotubes, Progress in Materials Science, 2016, V. 77, p. 125-211

Nowadays, Bio-Electrochemical System such as Microbial Fuel Cells (MFCs) and Microbial Electrolysis Cells (MECs) draw increasing attention for their potential application in sustainable energy production. Both systems leverage the electrogenic ability of selected biofilms, which consume chemical energy to produce electricity, in MFCs, or to promote hydrogen gas production, in MECs. In both MFCs and MECs, the anode electrode offers mechanical support and an electron sink for the biofilm. For this reason, it is crucial to optimize the electrode’s surface morphology and electrical properties, so to promote biofilm adhesion and proliferation, while minimizing electrical losses due to interfacial impedances. To this end, previous studies proposed the decoration of commercial carbon paper with the well-known conducting polymer Poly(3,4-ethylenedioxythiophene):poly-styrene sulfonate (PEDOT:PSS) (http://doi.org/10.1016/j.chemosphere.2020.125985). In addition, the surface decoration with Polyethylene oxide (PEO) demonstrated to promote biofilm proliferation (http://doi.org/10.3390/nano10030523). In this work, we focus on Electrospray and Ultrasonic Spray Coating as two promising and innovative fabrication techniques for the deposition of PEO and PEDOT:PSS solutions on commercial carbon paper. Electrospray offers the advantage of depositing nanoscale droplets with excellent uniformity on conductive substrates. For comparison, Ultrasonic Spray Coating also provides good deposition uniformity over large scale substrates. Employing electron microscopy, for both techniques we determined the deposition conditions providing the best uniformity of the electrodes’ surface morphology. In addition, we investigated the use of Raman spectroscopy to validate and map such spatial uniformity in a more quantitative manner. Moreover, electrochemical impedance spectroscopy and cyclic voltammetry demonstrated the improvements, given by electrodes’ surface decoration, in terms of conductivity and capacitive properties. As final stage, we are currently comparing in complete MFC devices the performance and stability of PEO and PEDOT:PSS decorated electrodes.

The absorption spectra of Ketoprofen in the UV domain was plotted using absolute methanol p.a. as a control solvent. The maximum absorption wavelength was determined to be at λ = 254 nm for a ketoprofen solution of 1,4 µg /mL prepared from pure crystalline standard ketoprofen dissolved in methanol p.a. The applied method was the subject of a statistical validation procedure, which consisted in completion of the following stages: the linearity of the method studied over the entire chosen concentration range 2.0 μg / mL - 80.0 μg / mL; detection limit (LD), quantitation limit (LQ), Sandell’s sensitivity, interference of the excipients, stability of prepared standard solutions, method and system precision and accuracy of this method. All statistical parameters were within the normal limits. This analysis method has been statistically validated and can be used anytime and anywhere for UV Ketoprofen spectrophotometric assay in a wide range of samples. The amount of pure ketoprofen assigned on the pharmaceutical tablet was found to be 146.326 mg ketoprofen / tablet. This value was very close to the official declared content of the active substance (150 mg pure ketoprofen/ tablet) set by the official pharmaceutical company, with an average percentage deviation of only 2,45% from the official declared pure content . This calculated value (2,45%) was situated below the maximum percentage error from the official content. of declared active substance (± 5%) imposed by official Pharmacopoeias. So, the pharmaceutical product fully respects the normal official limits provided by the Romanian Pharmacopoeia, 10th Edition and also by the European and International Pharmacopoeias rules.

Fenretinide (N-(4-hydroxyphenyl)retinamide (4-HPR), is a synthetic derivative of retinoic acid, which proved high antitumor activity against a wide range of cancers. Thanks to its low toxicological profile, 4-HPR has been also used as chemo preventive agent in the treatment of breast and ovarian cancer. Unfortunately, 4-HPR is endowed with poor oral absorption due to its low solubility, and variable blood concentrations for a massive hepatic first pass effect. To overcome these drawbacks, we prepared nanoparticles (NPs) made of 4-Ammoniunbutylstyrene random copolymer (P5), highly soluble in water, with the aim to increase drug apparent solubility and thus enhancing its antitumor effects. The NPs were prepared by the anti-solvent co-precipitation technique, an easy and up-scalable way of obtaining the amorphization of the drug into the polymeric matrix. The encapsulation led to an increase in drug apparent solubility of 1134 folds with a drug loading of 37%. The NPs showed a faster and extended dissolution rate, a mean hydrodynamic diameter of 249 nm, and positive Zeta potential (+41.3 mV) confirming the suitability of the formulation also for the intravenous administration. The loaded were also characterized by a chemometric-assisted Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and assayed for their antitumor activity on neuroblastoma cell lines. 4-HPR-P5 NPs proved an anti-proliferative activity with IC50 values of 1.25 and 1.93 µM on IMR-32 and SH-SY5Y neuroblastoma cells, respectively. Our data suggested that the 4-HPR-P5 formulation could represent a valid approach to increase drug apparent aqueous solubility and thus its therapeutic efficacy.