Improving Spin Probe Methodologies to Investigate Supramolecular Assemblies

In this report, our work describing the use of spin probes in the field of supramolecular chemistry and how electron spin resonance (EPR) has been used for detecting and identifying supramolecular assemblies is shortly reviewed. Selected examples are reported, including paramagnetic host-guest complexes, self-assembled systems doped with spin probes, spin-labelled macrocycles and open shell mechanically interlocked structures (MIMs) such as rotaxanes, in which the dumbbell, the wheel or both are tagged with nitroxide radicals

Water-Soluble Gold Nanoparticles Protected by Fluorinated Amphiphilic Thiolates

The preparation and the properties of gold nanoparticles (Au NPs) protected by perfluorinated amphiphiles are described. The thiols were devised to form a perfluorinated region close to the gold surface and to have a hydrophilic portion in contact with the bulk solvent to impart solubility in water. The monolayer protected clusters were prepared, in an homogeneous phase using sodium thiolates because of the low nucleophilicity of the alpha-perfluorinated thiols, and fully characterized with 1H, 19F NMR spectrometry, IR and UV-vis absorption spectroscopies, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). Au NPs with core diameters ranging from 1.6 to 2.9 nm, depending on the reaction conditions, were obtained. Water-soluble NPs (MPC-F8-PEGs) were obtained with the thiol HS-F8-PEG ending with a short poly(ethylene glycol) unit (PEG-OMe 550), whereas thiols with shorter PEG chains give rise to NPs insoluble in water. MPC-F8-PEGs undergo an exchange reaction with amphiphilic alkyl thiols. ESR investigations, using a hydrophobic radical probe, indicate that the MPC-F8-PEG monolayer shows a greater hydrophobicity compared to the analogous hydrogenated monolayer.

Hydrogen atom transfer (HAT) processes promoted by the quinolinimide-N-oxyl radical: a kinetic and theoretical study

A kinetic study of the hydrogen atom transfer (HAT) reactions from a series of organic compounds to the quinolinimide-N-oxyl radical (QINO) was performed in CH3CN. The HAT rate constants are significantly higher than those observed with the phthalimide- N-oxyl radical (PINO) as a result of enthalpic and polar effects due to the presence of the N-heteroaromatic ring in QINO. The relevance of polar effects is supported by theoretical calculations conducted for the reactions of the two N-oxyl radicals with toluene, which indicate that the HAT process is characterized by a significant degree of charge transfer permitted by the π-stacking that occurs between the toluene and the N-oxyl aromatic rings in the transition state structures. An increase in the HAT reactivity of QINO was observed in the presence of 0.15 M HClO4 and 0.15 M Mg(ClO4)2 due to the protonation or complexation with the Lewis acid of the pyridine nitrogen that leads to a further decrease in the electron density in the N-oxyl radical. These results fully support the use of N-hydroxyquinolinimide as a convenient substitute for N-hydroxyphthalimide in the catalytic aerobic oxidations of aliphatic hydrocarbons characterized by relatively high C–H bond dissociation energies

A discrete-time localization method for capsule endoscopy based on on-board magnetic sensing

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Minimally Invasive Surgery for Perihilar Cholangiocarcinoma. A Systematic Review of the Short- and Long-Term Results

Surgery and postoperative systemic chemotherapy represent the standard treatment for patients with perihilar cholangiocarcinoma (PHC). Minimally Invasive Surgery (MIS) for hepatobiliary procedures has spread worldwide in the last two decades. Since resections for PHC are technically demanding, the role of MIS in this field is yet to be established. This study aimed to systematically review the existing literature on MIS for PHC, to evaluate its safety and its surgical and oncological outcomes. A systematic literature review on PubMed and SCOPUS was performed according to the PRISMA guidelines. Overall, a total of 18 studies reporting 372 MIS procedures for PHC were included in our analysis. A progressive increase in the available literature was observed over the years. A total of 310 laparoscopic and 62 robotic resections were performed. A pooled analysis showed an operative time ranging from 205.3 ± 23.9 and 840 (770-890) minutes, and intraoperative bleeding between 101.1 ± 13.6 and 1360 ± 809 mL. Minor and major morbidity rates were 43.9% and 12.7%, respectively, with a 5.6% mortality rate. R0 resections were achieved in 80.6% of patients and the number of retrieved lymph nodes ranged between 4 (3-12) and 12 (8-16). This systematic review shows that MIS for PHC is feasible, with safe postoperative and oncological outcomes. Recent data has shown encouraging results and more reports are being published. Future studies should address differences between robotic and laparoscopic approaches. Given the management and technical challenges, MIS for PHC should be performed by experienced surgeons, in high-volume centers, on selected patients

Comparative spectroscopic and electrochemical study of N-1 or N-2-alkylated 4-nitro and 7-nitroindazoles

Abstract Our research groups are by long time involved in the study of the reactivity and the pharmacological activity of nitrogen-containing heterocyclic compounds: in this line we have now examined the behaviour of some substituted 4- and 7-nitroindazoles. Considering the fact that nitroreduction processes are often essential steps for the biological activity of nitro compounds and remembering that some nitroindazoles show interesting biological activities, we have collected nuclear magnetic resonance, electron spin resonance, and cyclic voltammetry data and carried out density functional theory computations on the above compounds thus obtaining an accurate picture of electronic distribution and reduction processes of the examined substrates as a function of their chemical structure. Looking also to our previous results obtained examining the behaviour of 5- and 6-nitroindazoles, we have confirmed the different general behaviour of 1- and 2-alkyl substituted nitroindazoles strictly related to the known different electronic distribution in these two classes of compounds. Interestingly, cyclic voltammetry data have confirmed the ability of N-1 H nitroindazoles to give rise to the formation of dimers, already observed by us studying 5- and 6-nitroindazoles

An updated checklist of the vascular flora of Montagna di Torricchio State Nature Reserve (Marche, Italy)

This study aims to increase floristic knowledge of Marche by means of a survey in the Montagna di Torricchio State Nature Reserve (central Italy). The Reserve, located in the central Apennines, covers about 3.2 km2 at altitudes ranging from 820 to 1,491 m a.s.l. It has been owned and managed as a strict reserve by the University of Camerino since 1970: all the anthropic activities ceased about 50 years ago, except for a minimal area where mowing and cattle grazing are still allowed. The floristic list consists of 789 specific and subspecific taxa belonging to 81 families and 352 genera. Two species are new for Italy (Taraxacum calocarpum and T. pulchrifolium) and 14 for Marche regional flora. Compared to previous floristic studies, we found 127 more taxa but we showed a certain stability in the life-form spectrum, suggesting limited effects of dynamic processes related to climate and land-use changes. The negligible number of alien species (11) is probably related to the limitations to anthropic activities in the Reserve. The occurrence of taxa never recorded for Italy and Marche highlights the floristic value of the Reserve for species conservation in the central Apennines

Challenging Scenarios and Debated Indications for Laparoscopic Liver Resections for Hepatocellular Carcinoma

Simple Summary Minimally invasive liver resections are nowadays performed worldwide for both benign and malignant lesions. Good short-term and safe long-term outcomes have been reported. Despite this growing implementation of the technique, challenging scenarios and debated indications still exist. There is currently a lack of high-quality evidence regarding minimally invasive liver resections in portal hypertension, advanced cirrhosis, lesions in the posterosuperior segments and large and recurrent tumors. Laparoscopic liver resections (LLRs) have been increasingly adopted for the treatment of hepatocellular carcinoma (HCC), with safe short- and long-term outcomes reported worldwide. Despite this, lesions in the posterosuperior segments, large and recurrent tumors, portal hypertension, and advanced cirrhosis currently represent challenging scenarios in which the safety and efficacy of the laparoscopic approach are still controversial. In this systematic review, we pooled the available evidence on the short-term outcomes of LLRs for HCC in challenging clinical scenarios. All randomized and non-randomized studies reporting LLRs for HCC in the above-mentioned settings were included. The literature search was run in the Scopus, WoS, and Pubmed databases. Case reports, reviews, meta-analyses, studies including fewer than 10 patients, non-English language studies, and studies analyzing histology other than HCC were excluded. From 566 articles, 36 studies dated between 2006 and 2022 fulfilled the selection criteria and were included in the analysis. A total of 1859 patients were included, of whom 156 had advanced cirrhosis, 194 had portal hypertension, 436 had large HCCs, 477 had lesions located in the posterosuperior segments, and 596 had recurrent HCCs. Overall, the conversion rate ranged between 4.6% and 15.5%. Mortality and morbidity ranged between 0.0% and 5.1%, and 18.6% and 34.6%, respectively. Full results according to subgroups are described in the study. Advanced cirrhosis and portal hypertension, large and recurrent tumors, and lesions located in the posterosuperior segments are challenging clinical scenarios that should be carefully approached by laparoscopy. Safe short-term outcomes can be achieved provided experienced surgeons and high-volume centers