•Four tetrabutylphosphonium-carboxylate ionic liquids are made and characterized.•ILs were more efficient against Gram-positive than Gram-negative bacteria.•The longest-chained anion contributes to ...the best antibacterial activity.•C. guillermondii and all tested fungi are most sensitive to TbpDec.•TBP-based ILs exhibit enhanced antimicrobial activity versus inorganic cations.
The importance of developing effective antimicrobial agents has become more evident recently, and quaternary phosphonium-based ionic liquids with fatty acid anions have shown great potential in this regard. Tetrabutylphosphonium-hexanoate, -octanoate, -decanoate, and -dodecanoate were synthesized as potential antimicrobial ionic liquids. Confirmation of the structure of the synthesized ionic liquids was determined by IR and NMR spectroscopy. Also, the thermal stability was examined by thermogravimetric (TG) and differential scanning calorimetry (DSC) analysis. Physicochemical characterization was carried out, which included the measurement of density, viscosity, and electrical conductivity in a wide temperature range to understand the interactions that occur in synthesized ionic liquids. The antimicrobial activity against various microorganisms was determined, including three Gram-negative and Gram-positive bacteria, two yeast, and four filamentous fungal strains. Based on the results, ILs were more efficient against Gram-positive than Gram-negative bacteria, whereby the longest-chained anion contributes to the best antibacterial activity. Yeast Candida guillermondii and all tested filamentous fungi were most sensitive to tetrabutylphosphonium-decanoate.
Background
Pathological complete response after neoadjuvant chemoradiotherapy in locally advanced rectal cancer (LARC) is achieved in 15–30% of cases. Our aim was to implement and externally validate ...a magnetic resonance imaging (MRI)-based radiomics pipeline to predict response to treatment and to investigate the impact of manual and automatic segmentations on the radiomics models.
Methods
Ninety-five patients with stage II/III LARC who underwent multiparametric MRI before chemoradiotherapy and surgical treatment were enrolled from three institutions. Patients were classified as responders if tumour regression grade was 1 or 2 and nonresponders otherwise. Sixty-seven patients composed the construction dataset, while 28 the external validation. Tumour volumes were manually and automatically segmented using a U-net algorithm. Three approaches for feature selection were tested and combined with four machine learning classifiers.
Results
Using manual segmentation, the best result reached an accuracy of 68% on the validation set, with sensitivity 60%, specificity 77%, negative predictive value (NPV) 63%, and positive predictive value (PPV) 75%. The automatic segmentation achieved an accuracy of 75% on the validation set, with sensitivity 80%, specificity 69%, and both NPV and PPV 75%. Sensitivity and NPV on the validation set were significantly higher (
p
= 0.047) for the automatic
versus
manual segmentation.
Conclusion
Our study showed that radiomics models can pave the way to help clinicians in the prediction of tumour response to chemoradiotherapy of LARC and to personalise per-patient treatment. The results from the external validation dataset are promising for further research into radiomics approaches using both manual and automatic segmentations.
We studied the effects of 24-h fasting on serum levels of guanidinoacetic acid (GAA), creatine, and creatinine in 24 non-vegetarian healthy adults. Blood was taken before and following an ...intervention, with levels corrected for fasting-induced changes in plasma volume. Food abstention induced a significant decrease in serum GAA by 39.5% (p < 0.001), while creatinine levels increased by 14.7% (p < 0.01); the concentration of creatine remains unchanged. The reduction in GAA during fasting may indicate an increased demand for creatine production for this energy-demanding condition and/or potential kidney dysfunction which requires further exploration.
•Limited information is available whether creatine status is influenced by fasting.•A 24-h fasting period compromises balance between creatine precursor (GAA, guanidinoacetic acid) and breakdown product (creatinine) in young men and women•Food abstention induced a significant decrease in serum GAA by 39.5%.•Reduction in GAA during fasting may indicate an increased demand for creatine production and/or potential kidney dysfunction.•GAA might serve as an innovative indicator of kidney stress in food restriction.
While cross-sectional imaging has seen continuous progress and plays an undiscussed pivotal role in the diagnostic management and treatment planning of patients with rectal cancer, a largely unmet ...need remains for improved staging accuracy, assessment of treatment response and prediction of individual patient outcome. Moreover, the increasing availability of target therapies has called for developing reliable diagnostic tools for identifying potential responders and optimizing overall treatment strategy on a personalized basis. Radiomics has emerged as a promising, still fully evolving research topic, which could harness the power of modern computer technology to generate quantitative information from imaging datasets based on advanced data-driven biomathematical models, potentially providing an added value to conventional imaging for improved patient management. The present study aimed to illustrate the contribution that current radiomics methods applied to magnetic resonance imaging can offer to managing patients with rectal cancer.
For the first time, the dicationic biological molecule agmatine in the synthesis of three novel ionic liquids, agmatine ibuprofenate, agmatine salicylate, and agmatine nicotinate, as well as of six ...salts, agmatine citrate, agmatine ascorbate, agmatine glutamate, agmatine m-hydroxybenzoate, agmatine nitrate, and agmatine chloride, was used. First of all, unknown acidity constants for agmatine were determined experimentally and by computational simulations. The synthesis was conducted by neutralization of agmatine hydroxide solution with relevant acids and then characterized by IR, NMR, TG, and DSC measurements. A cytotoxicity study of these compounds has been performed on the human nontumor cell line (normal fetal lung fibroblasts, MRC-5) and human caucasian colon adenocarcinoma (HT-29). The obtained results on MRC-5 cell lines declare the less toxic effect of synthesized ILs and salts compared to the environmentally and body friendly ascorbic acid. Thus, the obtained biocompatible ionic liquids and salts may be potentially beneficial for stabilizing bioactive compounds by improving solubility in aqueous media and biodistribution to target sites. The calculated binding energies between cation and anion for all compounds indicate weaker interactions in ionic liquid structures than in reported salts. This can cause easier and better dissociation of the ionic liquids and, hence, greater biological availability of both cation and anion in the organism. By virtue of the fact that the water has a key role in the living organism, solvation and taste properties for commercially available agmatine sulfate and synthesized agmatine chloride were discussed using obtained results from volumetric and viscosity measurements supported by computational simulation. The negligible effect of the anion nature on the conformation of agmatine cation has been proved in the investigated concentration range indicating that the difference between solvation properties of examined salts originates primarily from water organization around anion.
Goal: Artificial intelligence applied to medical image analysis has been extensively used to develop non-invasive diagnostic and prognostic signatures. However, these imaging biomarkers should be ...largely validated on multi-center datasets to prove their robustness before they can be introduced into clinical practice. The main challenge is represented by the great and unavoidable image variability which is usually addressed using different pre-processing techniques including spatial, intensity and feature normalization. The purpose of this study is to systematically summarize normalization methods and to evaluate their correlation with the radiomics model performances through meta-analyses. This review is carried out according to the PRISMA statement: 4777 papers were collected, but only 74 were included. Two meta-analyses were carried out according to two clinical aims: characterization and prediction of response. Findings of this review demonstrated that there are some commonly used normalization approaches, but not a commonly agreed pipeline that can allow to improve performance and to bridge the gap between bench and bedside.
In this work, the solubility of creatine, creatinine, guanidinoacetic acid, and their hydrochlorides in water at atmospheric pressure and in the temperature range T = (293.15 - 313.15) K was ...determined by the gravimetric method. The thermodynamic parameters of dissolution in water for the mentioned compounds were calculated. The solubility increases significantly by converting the zwitterionic structures of creatine and guanidinoacetic acid into a cationic form, i.e. hydrochloride salt. The effect of increasing solubility is more pronounced for guanidinoacetic acid and decreases with temperature for both compounds. A simple process of transforming electrically neutral zwitterionic structures into cations represents a good way to increase the solubility in water and bioavailability of biologically active compounds.
Due to their appealing physiochemical properties, particularly in the pharmaceutical industry, deep eutectic solvents (DESs) and ionic liquids (ILs) are utilized in various research fields and ...industries. The presented research analyzes the thermodynamic properties of a deep eutectic solvent created from natural molecules, menthol and lauric acid in a 2:1 molar ratio, and an ionic liquid based on two active pharmaceutical ingredients, benzocainium ibuprofenate. Initially, the low solubility of benzocainium ibuprofenate in water was observed, and a hydrophobic natural deep eutectic mixture of menthol:lauric acid in a 2:1 ratio was prepared to improve benzocainium ibuprofenate solubility. In order to determine the solvent properties of DESs and ILs mixtures at different temperatures and their molecular interactions to enhance the solvent performance, the apparent molar volume, limiting apparent molar expansibility, and viscosity B coefficient were estimated in temperature range from 293.15 K to 313.15 K and varying concentration of benzocainium ibuprofenate.
The present work focuses on modifying a local anaesthetic drug procaine into an ionic liquid and evaluating the resulting thermal behaviour and structural changes. Counter ions, salicylate, ...ibuprofenate, and docusate, were chosen due to different hydrogen-bonding abilities, molecular size, charge distribution, and functional groups. After synthesis of procaine salicylate, procaine ibuprofenate, and procaine docusate, spectroscopic investigations were performed using infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy to confirm proton transfer. Differential scanning calorimetry (DSC) and thermogravimetric (TG) analysis were used to determine the obtained ionic liquids' thermal behaviour. Experimental measurements of density, viscosity, and electrical conductivity were performed to get insight into the interactions occurring in the obtained ionic liquids. The viscosity and electrical conductivity data were analysed using the Vogel-Fulcher-Tammann (VFT) equation, while thermal expansion coefficients were calculated from measured density data. The obtained results found that the synthesised procaine salicylate and procaine docusate an ionic liquid's behaviours, including weak intermolecular forces, while procaine ibuprofenate showed more liquid co-crystal behaviour due to the absence of proton transfer for ibuprofen. In a theoretical phase of the investigation, the density functional theory (DFT) and molecular dynamics (MD) calculations were conducted. The obtained descriptors and radial distribution functions were used to analyse the interactions between ions of synthesised ionic liquids. In addition, solubility determination results proved that procaine transformation into procaine salicylate and procaine ibuprofenate ionic liquids enhanced its solubility in water, while procaine docusate reduces procaine solubility.
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The rapid and sensitive voltammetric determination of organic UV filters benzophenone-3 (BP-3) and avobenzone (AVO) was performed by an ionic liquid carbon paste electrode (IL-CPE). Namely, the ...synthesized pyridinium-based ILs, 1-butyl-3-methylpyridinium chloride (N–C4–3C1PyCl) and 1-ethoxyethyl-3-methylpyridinium chloride (N–C2OC2–3C1PyCl) were compared as bulk CPE modifiers for BP-3 determination. N–C4–3C1PyCl-CPE showed more favorable interactions with the target analyte, and it was tested for AVO determination, too. Cyclic voltammetric (CV) studies suggested that the irreversible electrode reaction is adsorption controlled in the case of both UV filters. Also, the square-wave adsorptive stripping voltammetric (SW-AdSV) method was optimized for quantifying selected UV filters. In the model solutions, the linear calibration curve was obtained by the SW-AdSV method in the concentration range from 0.05 to 0.89 μg mL−1 at pH 3.0 for BP-3 (Eacc = −0.7 V, tacc = 100 s), and from 0.05 to 1.77 μg mL−1 at pH 11.98 for AVO (Eacc = 0.2 V, tacc = 100 s). The evaluated limit of detection (LOD) was 0.015 μg mL−1 in both cases, while the relative standard deviation (RSD) was lower than 1.5%. The affordable IL-based voltammetric sensor fulfills the main requirements for application in real samples due to an adequate selectivity towards selected analytes in the presence of interferents usually found in swimming pool water. Therefore, the BP-3 and AVO were quantified in a swimming pool water matrix with good repeatability and recovery. The obtained results demonstrate an excellent potential of the IL-CPEs, especially of the N–C4–3C1PyCl-CPE, for determining selected UV filters in various real samples.
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•Pyridinium-based ionic liquids were used for carbon paste electrode modification.•Simple and reliable SW-AdSV method for selected UV filters sensing was developed.•Achieved LOD for benzophenone-3 (BP-3) and avobenzone (AVO) was 0.015 μg mL−1.•N–C4–3C1PyCl-CPE enables determination of BP-3 and AVO in swimming pool water sample.•Good repeatability and high selectivity towards UV filters sensing were obtained.
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