The electron transfer rate of large TPA based compounds: a joint theoretical and electrochemical approach

A series of triphenylamine (TPA) based compounds is investigated by means of density functional theory and cyclic voltammetry. Using the Nicholson\u27s formalism, the measured D E_p are correlated with B3LYP/6-31G* calculated reorganization energies (lambda), elucidating the trend followed by the self electron transfer rate (k_{ET}) of these compounds. Besides the direct dependency upon the dimension of the cationic fragment contributing to the hole stabilization, the lambdas are tuned by the symmetry local to the TPA units, as evidenced by the structural relaxation of the cations. TAPC turns out to be the most effective compound with respect to the self electron transfer process, while N,N\u27-diphenyl-N,N\u27-bis[N-phenyl-N-3-tolyl(4-aminophenyl)]benzidine (MDTAB) shows the interesting combination of low ionization potential (IP) and high k_{ET}. This can make these compounds interesting for practical applications in organic light emitting diodes (OLEDs) devices, due to the direct correlation of the IP and k_{ET} with the hole transfer efficiency to the anode, along with the hole mobility

A correlation between electrochemical properties and geometrical structure of some triarylamines used as hole transporting materials in organic electroluminescent devices

Two new compounds with four tertiary arylamine moieties connected in a fully para-conjugated system have been synthesised in order to obtain new molecules having low ionisation potentials, as required for hole transporting materials in Organic Light Emitting Diodes (OLEDs). Their electrochemical properties have been measured and compared to seven di erent commercial triarylamines tested in the same experimental conditions. Using the AM1 geometries and the statistical average of orbital potential method (SAOP), the redox potentials of the molecules have been estimated and found to be in good agreement with the experimental data. An evident correlation between the molecular geometry and the electrochemical potential of the rst oxidation exists and shows that, for equal number of para-conjugated triarylamine moieties, the starburst con guration is more e cient than the linear one in lowering the oxidation potential and that the amine moieties of the inner sphere play a more important role than those of the outer sphere. Besides, amine moieties connected by a biphenyl bridge show generally higher ionisation potentials than those connected via one phenylene

Analysis of the lipid binding properties of mutant murine Bid proteins

Bid is a BH3-only member of the Bcl-2 family that regulates cell death at the level of mitochondrial membranes. It is generally assumed that the full length Bid protein becomes activated after a proteolytic cleavage catalized by apical caspases, like caspase 8. The cleaved protein then re-locates to mitochondria and promotes membrane permeabilization, presumably by interaction with mitochondrial lipids and other Bcl-2 proteins that facilitate the release of apoptogenic proteins like cytochrome c. The un-cleaved Bid also has proapoptotic potential when ectopically expressed in cells or in vitro. It has been demonstrated that full length Bid can insert specific lysolipids into the membrane surface and this lipid transfer activity participates to the release of apoptogenic factors from mitochondria. The binding properties of Bid are still unknown. In this work we will present new full length Bid mutants that possess altered lipid binding properties and proapoptotic activities in vitro. We have analysed the binding properties of Bid mutants to LPC species and MCL (or LPG) in order to investigate the protein dual specificity for the diverse lysolipids

Lipid exchange in mitochondrial cytochrome c release: pro-apoptotic effect of maize lipid transfer protein

Membrane lipids and protein-lipid interactions are attracting increasing interest in the field of cell death and apoptosis. Some pro-apoptotic proteins, like Bid, appear to have an intrinsic capacity of binding and exchange lipids but it is still unclear whether this function could be relevant for apoptotic signalling cascade. We have studied the ability of a plant lipid transfer protein, not related to animal apoptotic cascade, to induce cytochrome c release from mammalian mitochondria. Non -specific lipid transfer proteins (nsLTPs) are ubiquitous plant proteins that have been shown to bind, in vitro, various amphiphilic molecules including lysolipids and glycolipids and to facilitate in vitro transfer of phospholipids between membranes. The results showed that, in the presence of specific lipid molecules (i.e. lysolipids), ns-LTP from maize is able to induce cytochrome c release from the intermembrane space of mouse liver mitochondria. These data are discussed with respect to the role played by lipids and lipid binding in apoptosis

The electronic properties of a homoleptic bisphosphine Cu(I) complex: a joint theoretical and experimental insight

The origin of the optical properties of the firstly reported stable luminescent [Cu(PP)_2]^+ complex [Cu(dppb)_2]+ [dppb = 1,2-bis(diphenylphosphino) benzene] is investigated using the exchange-correlation functional PBE0. The choice of the basis set used is discussed and a comparison with the results obtained by other functionals is performed. The role played by the bisphosphine ligands within the complex is elucidated by considering the electronic properties of the ligand alone to evidence how both the geometrical changes and the electronic interactions, induced by the inclusion of the metal cation, affect the electronic behavior of the whole system. The NBO analysis shows how the aryl groups of the ligands act as a reservoir of electrons within the complex. The electronic excitations of both the complex and of the ligand, calculated by including the solvation effects, allow to assign the lowest energy absorption broad band, recorded in CH_2Cl_2 solution. The peculiar contribution of the phosphorus atoms to the description of the high occupied MOs and the participation of the copper cation to the description of the lowest singlet excited state, is pointed out. The origin of the observed phosphorescence of the complex is attributed to a triplet state, whose SOMO is characterized by the contributions of the valence 4s and of the Rydberg 5s AOs of the metal cation, along with the lone pair orbitals of the P atoms.Si sono studiate le proprieta` ottiche del primo complesso stabile e luminescente di tipo [Cu(PP}]^+ [[Cu(dppb)$_2]^+$ [dppb = 1,2-bis(difenilfosfino) benzene], riportato in letteratura utilizzando il metodo PBE0. Si e` discussa la scelta della base orbitale utilizzata nello studio e si e` effettuato un confronto con altri metodi DFT. Si e` illustrato il ruolo dei leganti bisfosfinici nel complesso esaminando come cambia la loro geometria e configurazione elettronica con l\u27inclusione del metallo per formare il complesso. Sono state studiate le eccitazioni elettroniche del complessso e del legante includendo gli effetti di solvatazione. per assegnare la prima banda di assorbimento osservata negli spettri con i campioni in soluzioni di diclorometano. Sono stati evidenziati i contributi dell\u27atomo di fosforo alla descrizione degli orbitali occupati ad alta energia del complesso e del Cu^+ a quelli virtuali a piu` bassa energia. L\u27origine della fosforescenza del complesso e` attribuita ad uno stato di tripletto il cui SOMO e` caratterizzato dagli orbitali atomici di valenza di tipo 4s e da un orbitale di Rydberg 5s di Cu^+ e dagli orbitali atomici singolarmente occupati del fosforo

Analisi della persistenza e delle risorse allocate nel trattamento farmacologico dell’ipertensione arteriosa

In this study, the persistence with treatment and resources allocated in antihypertensive pharmacotherapy has been evaluated. Administrative databases of the Local Health Unit of Ravenna listing patients baseline characteristics, drug prescriptions and hospital admissions were used to perform a population-based retrospective study. All new users 20 years old or over receiving a first prescription for diuretics, beta-blockers, calcium channel-blockers, ACE inhibitors or AII-Antagonists between January 1st, 1997 and December 31st, 1997 were included. A one-year follow-up for prescriptions of anti-hypertensive drugs were considered. According to duration of therapy, treated population was divided in persistent patients (continuers and switchers) and non-persistent patients. A total of 16,783 patients was included in the study of whom 64.9% were non-persistents. Persistence with treatment seems to be associated with the class of anti-hypertensive drug initially prescribed, and with patient-related factors. Patients initially prescribed for AII-Antagonists were more likely to persist than those starting on the other antihypertensive classes. Annual antihypertensive treatment cost accounted for • 1,076,053.55 of which 25.4% for non-persistent patients. An appropriate use of claims data may be considered as a powerful tool, providing detailed epidemiological and economic information concerning the antihypertensive treatment

Spoligotyping and Mycobacterium tuberculosis

Speed of spoligotyping could be a benefit in the clinical setting

A case study of industrial symbiosis to reduce GHG emissions: performance analysis and LCA of asphalt concretes made with RAP and steel slags

The concept of sustainability in the road construction sector is a complex issue because of the various steps that contribute to the production and release of greenhouse gas (GHG) emissions. Addressing this issue, the European Commission has put various policy initiatives in place to encourage the construction industry to adopt circular economy (CE) and industrial symbiosis (IS) principles e.g., the use of recycled materials. Cooperativa Trasporti Imola (CTI), a company located in the Emilia-Romagna region (Italy), has been chosen for the current case study to examine practices, management, and the industrial symbiosis network among various companies in the road construction and rehabilitation sector. In this regard, the use of steel slags, obtained by an electric arc furnace (EAF), and reclaimed asphalt pavement (RAP), obtained by the deconstruction and milling of old asphalt pavement have been investigated. Two mixtures of recycled hot Mix Asphalt (HMA) i) were prepared incorporating different recycled material percentages for the wearing and binder course, respectively, ii) were characterized in terms of size distribution, strength modulus and volumetric properties, iii) and finally were compared to the performances of two mixtures entirely designed by virgin materials for the wearing and binder course, respectively. Therefore, the Life Cycle Assessment (LCA) tool was chosen to evaluate the environmental impacts that affect the designed road life cycle. The results show that recycling RAP and EAF slags in a CTI batch plant provides benefits by reducing the consumption of virgin bitumen and aggregates and by reducing CO2eq emissions. Finally, practical implications on the use of recycled materials in new asphalt mixtures from a life cycle and industrial symbiosis perspective are provided