First-Principles Investigation of the Optical Properties of Eumelanin Protomolecules.

Using first-principles calculations, we investigate the absorption spectra (in the near-infrared, visible, and first UV range) of the two most probable eumelanin tetrameric molecules exhibiting either a linear open-chain or a cyclic porphyrine-like configuration. In order to simulate a realistic molecular system, an implicit solvent model is used in our calculations to mimic the effect of the solvated environment around the eumelanin molecule. Although the presence of solvent is found not to significantly affect the absorption pattern of both molecules, the onset of the spectra are shifted toward higher energies, especially for the linear tetramer. Interestingly, the absorption spectra and optical onsets of the two molecules differ significantly both in a vacuum and in ethanol. However, the two predicted spectra do not allow us to definitely discriminate between the two configurations when comparing the theoretical predictions with the available experimental spectrum. In addition, a mix of the two eumelanin configurations (close to fifty-fifty) leads to a maximum overlap between theoretical and experimental spectra. Consequently, this theoretical research shows that deeper insight can be gained using beyond DFT techniques on the real form of eumelanin protomolecules present in living systems as well as on their possible use in hybrid solar cells.

A computational study on the electronic and optical properties of boron-nitride circumacenes.

We report a comparative and systematic computational analysis on the electronic and optical properties of the boron-nitride-made (BN) counterparts of the carbon-made circumacenes. Recently, these planar molecules have attracted interest for applications in the condensed matter physics domain. In particular, we focus on the five first members of this BN-family (from BN-coronene to BN-circumpentacene) presenting a comparison with their carbon analogues. For all the systems investigated, we calculate different electronic properties and the optical absorption spectra, performing all electron Density Functional Theory (DFT) and Time Dependent-DFT (TD-DFT) calculations. In the context of ab initio calculations we select a localized Gaussian basis-set matched with a hybrid exchange-correlation functional. We discuss possible implications of the observed BN cluster properties, which could be an alternative material or complementar as compared to their carbon analogues. In particular, concerning the optical properties, we have found that the main difference between the two families is that the BN molecules absorb in the UV, rather than in the visible as happens for the C-made parents. Moreover, we demonstrate that the electronic and optical observables of the BN clusters are nearly independent of the cluster size in contrast to what happens for their carbonaceous counterparts.

Deciphering Molecular Mechanisms of Interface Buildup and Stability in Porous Si/Eumelanin Hybrids.

Porous Si/eumelanin hybrids are a novel class of organic-inorganic hybrid materials that hold considerable promise for photovoltaic applications. Current progress toward device setup is, however, hindered by photocurrent stability issues, which require a detailed understanding of the mechanisms underlying the buildup and consolidation of the eumelanin-silicon interface. Herein we report an integrated experimental and computational study aimed at probing interface stability via surface modification and eumelanin manipulation, and at modeling the organic-inorganic interface via formation of a 5,6-dihydroxyindole (DHI) tetramer and its adhesion to silicon. The results indicated that mild silicon oxidation increases photocurrent stability via enhancement of the DHI-surface interaction, and that higher oxidation states in DHI oligomers create more favorable conditions for the efficient adhesion of growing eumelanin.

Intratumoral injection of IFN-alpha dendritic cells after dacarbazine activates anti-tumor immunity: results from a phase I trial in advanced melanoma.

BACKGROUND: Advanced melanoma patients have an extremely poor long term prognosis and are in strong need of new therapies. The recently developed targeted therapies have resulted in a marked antitumor effect, but most responses are partial and some degree of toxicity remain the major concerns. Dendritic cells play a key role in the activation of the immune system and have been typically used as ex vivo antigen-loaded cell drugs for cancer immunotherapy. Another approach consists in intratumoral injection of unloaded DCs that can exploit the uptake of a wider array of tumor-specific and individual unique antigens. However, intratumoral immunization requires DCs endowed at the same time with properties typically belonging to both immature and mature DCs (i.e. antigen uptake and T cell priming). DCs generated in presence of interferon-alpha (IFN-DCs), due to their features of partially mature DCs, capable of efficiently up-taking, processing and cross-presenting antigens to T cells, could successfully carry out this task. Combining intratumoral immunization with tumor-destructing therapies can induce antigen release in situ, facilitating the injected DCs in triggering an antitumor immune response. METHODS: We tested in a phase I clinical study in advanced melanoma a chemo-immunotherapy approach based on unloaded IFN-DCs injected intratumorally one day after administration of dacarbazine. Primary endpoint of the study was treatment safety and tolerability. Secondary endpoints were immune and clinical responses of patients. RESULTS: Six patients were enrolled, and only three completed the treatment. The chemo-immunotherapy was well tolerated with no major side effects. Three patients showed temporary disease stabilization and two of them showed induction of T cells specific for tyrosinase, NY-ESO-1 and gp100. Of interest, one patient showing a remarkable long-term disease stabilization kept showing presence of tyrosinase specific T cells in PBMC and high infiltration of memory T cells in the tumor lesion at 21 months. CONCLUSION: We tested a chemo-immunotherapeutic approach based on IFN-DCs injected intratumorally one day after DTIC in advanced melanoma. The treatment was well tolerated, and clinical and immunological responses, including development of vitiligo, were observed, therefore warranting additional clinical studies aimed at evaluating efficacy of this approach. TRIAL REGISTRATION: Trial Registration Number not publicly available due to EudraCT regulations: https://www.clinicaltrialsregister.eu/doc/EU_CTR_FAQ.pdf.

Optical properties of nanostructured antiviral and anticancer drugs.

We present a computational study on the optical absorption properties of some systems of interest in the field of drug delivery. In particular we considered as drug molecules favipiravir (T705, an antiviral molecule) and 5-fluorouracil (5FU, an anticancer molecule) and, on the other hand, pure fullerenes (C24, B12N12, Ga12N12) and doped fullerenes (C23B, CB11N12) are considered as nanocarriers. Some combined configurations between the drug molecules and the carrier nanostructures have been then studied. The optical absorption properties of the above mentioned drug molecules and their carrier nanostructures in the free and bound states are obtained by a TD-DFT method, in gas phase and in aqueous solution. We perform a detailed analysis of the modifications arising in the absorption spectra that take place in some linked configurations between the drug molecules and the carrier nanostructures. These changes could be of importance as an optical fingerprint of the realized drug/carrier link.

Molecular simulations of SSTR2 dynamics and interaction with ligands.

The cyclic peptide hormone somatostatin regulates physiological processes involved in growth and metabolism, through its binding to G-protein coupled somatostatin receptors. The isoform 2 (SSTR2) is of particular relevance for the therapy of neuroendocrine tumours for which different analogues to somatostatin are currently in clinical use. We present an extensive and systematic computational study on the dynamics of SSTR2 in three different states: active agonist-bound, inactive antagonist-bound and apo inactive. We exploited the recent burst of SSTR2 experimental structures to perform µs-long multi-copy molecular dynamics simulations to sample conformational changes of the receptor and rationalize its binding to different ligands (the agonists somatostatin and octreotide, and the antagonist CYN154806). Our findings suggest that the apo form is more flexible compared to the holo ones, and confirm that the extracellular loop 2 closes upon the agonist octreotide but not upon the antagonist CYN154806. Based on interaction fingerprint analyses and free energy calculations, we found that all peptides similarly interact with residues buried into the binding pocket. Conversely, specific patterns of interactions are found with residues located in the external portion of the pocket, at the basis of the extracellular loops, particularly distinguishing the agonists from the antagonist. This study will help in the design of new somatostatin-based compounds for theranostics of neuroendocrine tumours.

[Management of the patient with extensive stage microcytoma. The importance of collaboration between oncology and radiotherapy.] / Gestione del paziente con microcitoma a stadio esteso. L'importanza della collaborazione tra oncologia e radioterapia.

Small cell lung cancer (SCLC) represents one of the most complex challenges in the oncological field, with a very slow advancement in research, contrary to the rapid evolutionary of the disease. For nearly two years, the mainstay of treatment for extensive-stage disease (ES-SCLC) has been the combination of platinum-based chemotherapy and immunotherapy, following the approval of atezolizumab and subsequently durvalumab, based on a modest, but significant improvement in overall survival compared to chemotherapy alone. The poor prognosis after the failure of first-line treatment explains the need to maximize the duration and efficacy of up-front systemic therapies, in particular, the emerging role of radiotherapy, also in ES-SCLC. On 10 November 2022, a meeting concerning the integrated treatment of patients with ES-SCLC was held in Rome and was attended by 12 specialists in oncology and radiotherapy from various centers in Lazio, under the direction of Federico Cappuzzo, Emilio Bria and Sara Ramella. The aim of the meeting was to share their clinical experience and to provide a series of practical indications in order to support physicians in the correct integration between first-line chemo-immunotherapy and radiotherapy treatments in ES-SCLC.

[Use of the complex network theory to study inpatient flow between health facilities in Sardinia (Italy)]. / Sardegna, salute e strutture: studio dei flussi dei pazienti nella Regione Sardegna mediante la teoria delle reti complesse.

Analysing the organizational structure and functioning of health systems is fundamental for improving healthcare services and for using available resources efficiently. In this study, data regarding the flow of hospital inpatients to and from the various healthcare facilities in the Sardinia Region (Italy) were analysed, by using techniques borrowed from the theory of complex networks. First data regarding the total number of patients were analysed, then data were analysed according to clinical specialty and finally a more detailed analysis was performed for the clinical specialties of general surgery, haematology, cardiology and ophthalmology. Factors that were found to influence patient transfers between hospitals in the healthcare network in Sardinia (Italy) are the type of route, including the distance to cover, and the type of specialty clinics present in the various facilities.

Time-Dependent Density Functional Theory Investigation on the Electronic and Optical Properties of Poly-C,Si,Ge-acenes.

We report a comparative computational investigation on the first six members of linear poly-C,Si,Ge-acenes (X4n+2H2n+4, X = C,Si,Ge; n = 1, 2, 3, 4, 5, 6). We performed density functional theory (DFT) and time-dependent DFT calculations to compare morphological, electronic, and optical properties. While C-acenes are planar, Si- and Ge-acenes assume a buckled configuration. Electronic properties show similar trends as a function of size for all families. In particular, differently from C-based compounds, in the case of both Si- and Ge-acenes, the excitation energies of the strongest low-lying electronic transition (ß peaks) span the visible region of the spectrum, demonstrating their size tunability. For all families, we assessed the plasmonic character of this transition and found a linear relationship for the wavelength-dependence of the ß peaks as a function of the number of rings. A similar slope of about 56 nm is observed for Si- and Ge-acenes, although the peak positions of the former are located at lower wavelengths. Outcomes of this study are compared with existing theoretical results for 2D lattices and nanoribbons, and experiments where available.

Electronic and Optical Properties of Small Metal Fluoride Clusters.

We report a systematic investigation on the electronic and optical properties of the smallest stable clusters of alkaline-earth metal fluorides, namely, MgF2, CaF2, SrF2, and BaF2. For these clusters, we perform density functional theory (DFT) and time-dependent DFT (TDDFT) calculations with a localized Gaussian basis set. For each molecule ((MF2) n , n = 1-3, M = Mg, Ca, Sr, Ba), we determine a series of molecular properties, namely, ground-state energies, fragmentation energies, electron affinities, ionization energies, fundamental energy gaps, optical absorption spectra, and exciton binding energies. We compare electronic and optical properties between clusters of different sizes with the same metal atom and between clusters of the same size with different metal atoms. From this analysis, it turns out that MgF2 clusters have distinguished ground-state and excited-state properties with respect to the other fluoride molecules. Sizeable reductions of the optical onset energies and a consistent increase of excitonic effects are observed for all clusters under study with respect to the corresponding bulk systems. Possible consequences of the present results are discussed with respect to applied and fundamental research.

A complex network analysis of a health organization.

The analysis of organizational structures of healthcare organizations such as University teaching hospitals is a fundamental step toward improving health care services and making more efficient use of available resources. In this study, discharge abstract data from the University of Cagliari teaching hospital was analysed by using techniques borrowed from the theory of complex networks. A bipartite network was constructed by linking the physician and diagnosis fields of the discharge abstract data. The unipartite projection network was then constructed by quantifying the number of diagnoses the connected physicians had in common in one year. Community detection algorithms were then used to identify the 'best' community structure (i.e. organizational subdivisions) for the hospital organization. The identified community structure could lead to improved efficiency with respect to existing departmental divisions. Results show how the theory of complex networks can be a very powerful data mining tool with very promising implications for research in the fields of health care organizations and social networks.

Electronic properties of fluorides by efficient approximated quasiparticle DFT-1/2 and PSIC methods: BaF2, CaF2 and CdF2 as test cases.

Dialkali halides are materials of great interest from both fundamental and technological viewpoints, due to their wide transparency range. The accurate determination of their electronic, excitation and optical properties in bulk and low dimensional systems is therefore of crucial importance. Moreover, it is a challenge from the theoretical point of view to deal with quasiparticle band structure calculations for such large energy gap materials, requiring very expensive methods for achieving a desirable accuracy. Here we report electronic quasiparticle band structures for three representative bulk fluorides, BaF2, CaF2 and CdF2, calculated using two low computational cost methods, the DFT-1/2 and the PSIC schemes, which have been relatively little explored by the theoretical community so far. Our results, compared with both available experimental data and previous heavyweight DFT-GW self-energy calculations, demonstrate a satisfactory accuracy for the examined compounds, at a level comparable with the perturbative G0W0 approach. Remarkably, both our proposed methods scale quite similarly to standard local density functional approaches, thus resulting in a large saving of computational effort with respect to the computationally heavyweight GW. Our results open up the perspective of the computational exploration of much bigger fluoride systems. As a significant proof of concept of this capability, we also calculated the quasiparticle properties of the (1 1 1) surfaces of all the three systems under study. Very good agreement with experiment was found.

Vibrational and optical characterization of s-triazine derivatives.

The optical and electron properties of three different s-triazine derivatives are investigated to ascertain the role of the donor acceptor character in amine-triazine systems depending on the bridging radical of the ammine group. The three derivatives were obtained starting from three different ammine compounds allowing to achieve a structure with a triazine core, surrounded by three ammine group and terminated with cyano or methyl or oxy-methyl functional group. Experimental optical data were interpreted in view of the electronic insights gathered by means of density functional theory simulations on base compounds. As compared to the reference electron donating triazine core, the resulting compounds show different donor acceptor character, from electron accepting to electron donating feature. Among the analyzed derivatives, the cyano terminated ammino-triazine compound shows the most promising optical features for photonics and lighting applications.

Weekly administration of paclitaxel: theoretical and clinical basis.

The rationale for weekly administration of paclitaxel, which acts on microtubules to arrest mitosis, is that more frequent delivery of moderate doses may achieve greater efficacy than standard doses every 3 weeks, through more sustained exposure of dividing tumor cells to its cytotoxic effects. This dose-dense approach to treatment may inhibit tumor regrowth between cycles and limit the emergence of malignant cell populations resistant to chemotherapy. More frequent exposure to paclitaxel may also enhance its apoptotic and antiangiogenic effects. Paclitaxel activity is considered to be independent of p53 status, in contrast to anticancer drugs that produce lesions on DNA, which achieve a better response if p53 is functional. Weekly therapy also has advantages in terms of improving paclitaxel therapeutic index. Clinical studies show that weekly paclitaxel is effective and that toxicity is acceptable. The response rates of single-agent paclitaxel varied from 21 to 86% in breast cancer, from 20% to 65% in ovarian cancer and from 30% to 56% in non-small cell lung cancer.

High-dose chronomodulated infusion of 5-fluorouracil (5-FU) and folinic acid (FA) (FF5-16) in advanced colorectal cancer patients.

PURPOSE: The best way to deliver infusional 5-fluorouracil (5-FU) and folinic acid (FA) has yet to be determined. The aim of this prospective phase II trial was to verify the tolerability, activity and efficacy of chronomodulated 5-FU-FA (FF(5-16)) every 3 weeks in 48 untreated patients (group A), and 28 pretreated and four non-measurable, advanced colorectal cancer (ACC) patients (group B). METHODS: The sinusoidal delivery of both drugs started at 10.00 p.m. and ended at 10.00 a.m., with peak flow at 4.00 a.m. for 5 consecutive days. The initial 5-FU dose was 900 mg/m(2)/day with intra-patient dose increase at 1,000 and 1,100 mg/m(2)/day, at the second and third course, respectively; FA was injected at a fixed dose of 150 mg/m(2)/day (Garufi et al.1997). RESULTS: Neither death from toxicity nor hematological toxicities were encountered. Maximal toxicity consisted of Grade 3 oral mucositis in 41% of patients, in only 8% of 535 courses. It was possible to achieve objective responses in 31% of untreated patients, with a progression free survival (PFS) of 7 months, median survival of 14 months and a 2-year survival rate of 28%. Similar results for PFS and survival were obtained in pretreated patients as well. Univariate analysis and multivariate analysis showed that response was related to the occurrence of mucositis and diarrhea ( p=0.03 and p=0.0007) and to performance status (PS) ( p=0.01). Quality of life, measured with the EORTC QLQ-C30+3 questionnaire, was unaffected by treatment and was better in patients with good PS and responsiveness. CONCLUSIONS: In this chronomodulated FF(5-16) phase II study, the probability of obtaining a relevant tumor reduction was significantly correlated with a patient variable such as PS, and toxicity variables such as mucositis and diarrhea. This observation and the validation of predictive factors for QoL deserve further investigation in ACC patients.

One- and two-particle effects in the electronic and optical spectra of barium fluoride.

One- and two-particle effects in the electronic and optical spectra of the fluoride compound BaF2 are determined using density functional theory and a many-body perturbation scheme. A wide energy range has been considered, including the visible and all the ultraviolet region. The GW approximation for the electronic self-energy has been used to tackle the one-particle excitations problem, enabling us to determine the electronic energy bands and densities of states of this fluoride. For the optical properties, the two-particle effects calculated with the Bethe-Salpeter scheme turn out to play a fundamental role. A bound exciton positioned at about 1.5 eV below the one-particle gap is forecasted. The optical absorption and the electron energy loss spectra together with other optical functions are in good agreement with the experimental results up to 15 eV. In fact, for this part of the spectrum a self-consistent one-particle scheme along with the Bethe-Salpeter approach produces notable results. Less satisfactory results for the higher energy region in the spectra have been produced with the proposed method. Possible causes of these discrepancies are fully discussed.

Differential denaturation of serum proteome reveals a significant amount of hidden information in complex mixtures of proteins.

UNLABELLED: Recently developed proteomic technologies allow to profile thousands of proteins within a high-throughput approach towards biomarker discovery, although results are not as satisfactory as expected. In the present study we demonstrate that serum proteome denaturation is a key underestimated feature; in fact, a new differential denaturation protocol better discriminates serum proteins according to their electrophoretic mobility as compared to single-denaturation protocols. Sixty nine different denaturation treatments were tested and the 3 most discriminating ones were selected (TRIDENT analysis) and applied to human sera, showing a significant improvement of serum protein discrimination as confirmed by MALDI-TOF/MS and LC-MS/MS identification, depending on the type of denaturation applied. Thereafter sera from mice and patients carrying cutaneous melanoma were analyzed through TRIDENT. Nine and 8 protein bands were found differentially expressed in mice and human melanoma sera, compared to healthy controls (p<0.05); three of them were found, for the first time, significantly modulated: α2macroglobulin (down-regulated in melanoma, p<0.001), Apolipoprotein-E and Apolipoprotein-A1 (both up-regulated in melanoma, p<0.04), both in mice and humans. The modulation was confirmed by immunological methods. Other less abundant proteins (e.g. gelsolin) were found significantly modulated (p<0.05). CONCLUSIONS: i) serum proteome contains a large amount of information, still neglected, related to proteins folding; ii) a careful serum denaturation may significantly improve analytical procedures involving complex protein mixtures; iii) serum differential denaturation protocol highlights interesting proteomic differences between cancer and healthy sera.

Intradermal lymphoscintigraphy at rest and after exercise: a new technique for the functional assessment of the lymphatic system in patients with lymphoedema.

AIM: The aim of this study was to evaluate the effect of implementing a new technique, intradermal injection lymphoscintigraphy, at rest and after muscular exercise on the functional assessment of the lymphatic system in a group of patients with delayed or absent lymph drainage. METHODS: We selected 44 patients (32 women and 12 men; 15 of 44 with upper limb and 29 of 44 with lower limb lymphoedema). Thirty of 44 patients had bilateral limb lymphoedema and 14 of 44 had unilateral disease; 14 contralateral normal limbs were used as controls. Twenty-three patients had secondary lymphoedema after lymphadenectomy and the remaining 21 had idiopathic lymphoedema. Each of the 44 patients was injected with 50 MBq (0.3-0.4 ml) of (99m)Tc-albumin-nanocolloid, which was administered intradermally at the first interdigital space of the affected limb. Two planar static scans were performed using a low-energy general-purpose collimator (acquisition matrix 128 x 128, anterior and posterior views for 5 min), and in which drainage was slow or absent, patients were asked to walk or exercise for 2 min. A postexercise scan was then performed to monitor and record the tracer pathway and the tracer appearance time (TAT) in the inguinal or axillary lymph nodes. RESULTS: The postexercise scans showed that (i) 21 limbs (15 lower and six upper limbs) had accelerated tracer drainage and tracer uptake in the inguinal and/or axillary lymph nodes. Two-thirds of these showed lymph stagnation points; (ii) 27 limbs had collateral lymph drainage pathways; (iii) in 11 limbs, there was lymph drainage into the deeper lymphatic channels, with unusual uptake in the popliteal or antecubital lymph nodes; (iv) six limbs had dermal backflow; (v) three limbs did not show lymph drainage (TAT=not applicable). TAT=15 + or - 3 min, ranging from 12 to 32 min in limbs with lymphoedema versus 5 + or - 2 min, ranging from 1 to 12 min in the contralateral normal limbs (P<0.001). CONCLUSION: Intradermal injection lymphoscintigraphy gives a better imaging of the lymph drainage pathways in a shorter time, including cases with advanced lymphoedema. In some patients with lymphoedema, a 2-min exercise can accelerate tracer drainage, showing several compensatory mechanisms of lymph drainage. The effect of the exercise technique on TAT and lymphoscintigraphy findings could result in a more accurate functional assessment of lymphoedema patients.