Three-dimensional network structures based on pyridylcalix[4]arene metal complexes

A new series of supramolecular assemblies is obtained through the interaction of 3-pyridylmethyl-calixarenes and copper or zinc ions. The complexes formed are characterized both in solution and in the solid state. The results offer appealing insights into how the steric crowding of the lower rim and different coordination modes of the metal centers have a great impact on the overall architecture of the complexes with the formation of monomeric, dimeric, or oligomeric/polymeric species

Factors driving the self-assembly of water-soluble calix[4]arene and gemini guests: a combined solution, computational and solid-state study

Negatively charged gemini guests in the presence of a tetracationic host trigger the formation of self-assembling structures at physiological pH in water generating entities of the HG and H2G type (H = host and G = guest). ITC measurements show that the gemini guests are included via concerted electrostatic and hydrophobic interactions and that the formation of the HG adduct is enthalpically driven while the formation of the capsular entity (H2G) is driven by entropy gain. It is shown that the efficiency of capsule formation is influenced by the number of \u2013CH2\u2013 units contained in the spacer and that spacers with an even number of methylene groups seem to be the best templating agents. In line with the above picture, MD simulations and DFT calculations show that the entropic contribution strongly depends on the length of the polymethylenic spacer. In the solid state, for the HG assembly three different structures are revealed by single crystal X-ray diffraction; the flexible interacting units create multiple interactions reaching the optimum balance between inter- and intramolecular energies. To the best of our knowledge, these are the first structures ever reported for water-soluble calixarenes and organic anions

The Italian Unitary Society of Colon-proctology (SIUCP: Società Italiana Unitaria di Colonproctologia) guidelines for the management of anal fissure

Abstract Introduction The aim of these evidence-based guidelines is to present a consensus position from members of the Italian Unitary Society of Colon-Proctology (SIUCP: Società Italiana Unitaria di Colon-Proctologia) on the diagnosis and management of anal fissure, with the purpose to guide every physician in the choice of the best treatment option, according with the available literature. Methods A panel of experts was designed and charged by the Board of the SIUCP to develop key-questions on the main topics covering the management of anal fissure and to performe an accurate search on each topic in different databanks, in order to provide evidence-based answers to the questions and to summarize them in statements. All the clinical questions were discussed by the expert panel in different rounds through the Delphi approach and, for each statement, a consensus among the experts was reached. The questions were created according to the PICO criteria, and the statements developed adopting the GRADE methodology. Conclusions In patients with acute anal fissure the medical therapy with dietary and behavioral norms is indicated. In the chronic phase of disease, the conservative treatment with topical 0.3% nifedipine plus 1.5% lidocaine or nitrates may represent the first-line therapy, eventually associated with ointments with film-forming, anti-inflammatory and healing properties such as Propionibacterium extract gel. In case of first-line treatment failure, the surgical strategy (internal sphincterotomy or fissurectomy with flap), may be guided by the clinical findings, eventually supported by endoanal ultrasound and anal manometry