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Introduction Breast cancer survivors are at increased risk of developing unrelated primary cancers, particularly lung cancer. Evidence indicates that sex hormones as well as a deregulation of DNA-repair pathways may contribute to lung cancer onset. We investigated whether the hormone status and expression of markers involved in DNA repair (BRCA1/2, ERCC1, and P53R2), synthesis (TS and RRM1), and cell division (TUBB3) might be linked to lung cancer risk. Patients and Methods Thirty-seven breast cancer survivors with unrelated lung cancer and 84 control subjects comprising women with breast cancer (42/84) or lung cancer (42/84) were enrolled. Immunohistochemistry on tumor tissue was performed. Geometric mean ratio was used to assess the association of marker levels with patient groups. Results Estrogen receptor was expressed in approximately 90% of the breast cancer group but was negative in the majority of the lung cancer group, a result similar to the lung cancer control group. Likewise, ER isoform β was weakly expressed in the lung cancer group. Protein analysis of breast cancer versus control had a significantly lower expression of BRCA1, P53R2, and TUBB3. Likewise, a BRCA1 reduction was observed in the lung cancer group concomitant with a BRCA2 increase. Furthermore, BRCA2 and TUBB3 increased in ipsilateral lung cancer in women who had previously received radiotherapy for breast cancer. Conclusion The decrease of DNA-repair proteins in breast cancer could make these women more susceptible to therapy-related cancer. The increase of BRCA2 and TUBB3 in lung cancer from patients who previously received radiotherapy for breast cancer might reflect a tissue response to exposure to ionizing radiation.

Purpose Adjuvant chemotherapy improves survival of patients with gastric cancer. Intergroup Trial of Adjuvant Chemotherapy in Adenocarcinoma of the Stomach (ITACA-S) was a phase III study comparing sequential FOLFIRI followed by docetaxel/cisplatin versus 5-fluorouracil monotherapy. The intensive regimen was not superior in terms of disease-free survival (DFS) and overall survival (OS). Methods The treatment was to be started within 8 weeks from surgery. This analysis evaluates the impact of time from surgery to chemotherapy start (TSC) on outcomes. Results Out of 1,106 randomized, 1,072 patients without major violations of eligibility criteria and receiving at least one treatment cycle were analyzed. Median TSC was 50 days. Chemotherapy was interrupted in 201 (18.8%) cases, whereas it was completed without or with modifications in 277 (25.8%) and 594 (55.4%), respectively. At a median follow-up of 56.9 months, 513 progressions and 472 deaths occurred. A longer TSC was significantly associated with longer DFS (hazard ratio [HR] 0.95; 95% confidence interval [CI] 0.89-1.00; p = 0.05) and OS (HR 0.91; 95% CI 0.86-0.97; p = 0.004), after adjustment for treatment arm, age, sex, primary tumor site, number of resected nodes, and tumor stage. Better treatment compliance was associated with improved survival. Conclusions Our findings suggest that longer TSC had at least no detrimental effect on DFS and OS, whereas treatment completion had a protective effect. Our findings need to be confirmed prospectively.

Cell-free DNA (cfDNA) and circulating tumor cells (CTCs) are promising prognostic and predictive biomarkers in non-small cell lung cancer (NSCLC). In this study, we examined the prognostic role of cfDNA and CTCs, in separate and joint analyses, in NSCLC patients receiving first line chemotherapy. Seventy-three patients with advanced NSCLC were enrolled in this study. CfDNA and CTC were analyzed at baseline and after two cycles of chemotherapy. Plasma cfDNA quantification was performed by quantitative PCR (qPCR) whereas CTCs were isolated by the ScreenCell Cyto (ScreenCell, Paris, France) device and enumerated according to malignant features. Patients with baseline cfDNA higher than the median value (96.3 hTERT copy number) had a significantly worse overall survival (OS) and double the risk of death (hazard ratio (HR): 2.14; 95% confidence limits (CL) = 1.24–3.68; p-value = 0.006). Conversely, an inverse relationship between CTC median baseline number (6 CTC/3 mL of blood) and OS was observed. In addition, we found that in patients reporting stable disease (SD), the baseline cfDNA and CTCs were able to discriminate patients at high risk of poor survival. cfDNA demonstrated a more reliable biomarker than CTCs in the overall population. In the subgroup of SD patients, both biomarkers identified patients at high risk of poor prognosis who might deserve additional/alternative therapeutic interventions.

Background: VeriStrat is a blood-based proteomic test with predictive and prognostic significance in second-line treatments for non-small cell lung cancer (NSCLC). This trial was designed to investigate the role of VeriStrat in first-line treatment of advanced NSCLC with standard chemotherapy. Here we present the results for 76 non-squamous patients treated with a combination of carboplatin or cisplatin with pemetrexed. Methods: The test-assigned classifications of VeriStrat Good or VeriStrat Poor to samples collected at baseline. The primary end point was progression-free survival (PFS); secondary end points included overall survival (OS) and objective response. Exploratory analyses of end points separately in carboplatin/pemetrexed and cisplatin/pemetrexed subgroups were also conducted. Results: Patients classified as VeriStrat Good had longer PFS and OS than VeriStrat Poor: 6.5 vs 1.6 months and 10.8 vs 3.4 months, respectively; the corresponding hazard ratios (HRs) were 0.36 (P

Originally formulated as an intravenous (i.v.) agent, vinorelbine is also currently available as an oral chemotherapeutic agent. Oral vinorelbine has demonstrated significant activity in different settings for NSCLC, including adjuvant treatment for resected disease, concurrent chemoradiation for locally advanced NSCLC and palliative chemotherapy for recurrent/metastatic NSCLC, as part of combination schedules or as a single-agent treatment.The authors explored the available data describing the use of oral vinorelbine in NSCLC. PubMed articles and abstracts presented at international conferences were analysed, and relevant trials were reported and discussed. Specific settings, including the treatment of elderly and unfit patients and metronomic schedules including oral vinorelbine, were evaluated. Available pharmacoeconomic data were also assessed.Oral vinorelbine is an appealing agent, particularly as part of combination regimens containing platinum derivatives, although it can have a role as a single-agent treatment as well. Its safety profile is generally favourable and its route of administration is generally preferred by patients receiving chemotherapy. Compared to i.v. vinorelbine and other antineoplastic agents, oral vinorelbine has been reported to be advantageous in terms of cost savings.

Introduction: Despite recent advances with new chemotherapeutic agents and target therapies, the prognosis of NSCLC remains poor. Recent results from clinical trials of immunotherapeutic agents, especially with immune checkpoint inhibitors, make this approach very exciting in NSCLC. Ipilimumab is a monoclonal antibody directed against cytotoxic T-lymphocyte antigen 4 that is able to stimulate the antitumour immune response by promoting T-cell activation. Areas covered: We have reviewed the literature and have described the most important results obtained with ipilimumab in NSCLC in recent trials with a specific focus on its peculiar toxicity profile and pattern of response. Trials ongoing with ipilimumab are also reported. Expert opinion: The results from clinical trials with ipilimumab are promising. Some important issues in the near future will be to identify prognostic and predictive biomarkers to select patients who could benefit from this drug. Further studies are warranted to understand how to combi...

An original polymer technology, successfully used in Underground Gas Storage (UGS) wells, has been recently applied in offshore gas producing wells. Many gas wells in this area are facing combined water and sand problems due to reservoir depletion, water entries and clayey formation. To avoid critical problems connected to water/sand production, the most common action has been so far to reduce gas production by choking down the wells. The new technique consists of bullhead injection of water soluble polymers with the main objective to form an adsorbed polymer layer on the surface of the rock, thus providing stabilization. In addition, the products have RPM properties (Relative Permeability Modifiers). They have little impact on gas permeability while strongly reducing water permeability. The combination of both effects will result in a reduction of water and sand production. Laboratory studies were performed to optimize polymer formulation and evaluate flow properties in reservoir cores. Because of the low reservoir rock permeability (around 10-20 mD), high focus was put on polymer injectivity and RPM effects. Since 2013, nine offshore gas wells have been treated with polymers. Treatments have shown positive results combining gas rate increase up to 100% and water reduction around 50% while stopping the sand. Details regarding well and polymer selection, job design, execution and production data are provided.

Lung cancer is still the leading cause of cancer related death worldwide. Fibroblast growth factor receptor (FGFR) is a tirosine-kinase receptor that is seen to be amplified or mutated in non-small cell lung cancer (NSCLC) and it plays a crucial role in tumour development and maintenance. The authors analyzed the state of the art of FGFR by reviewing the current literature. Fibroblast growth factor (FGF)-FGFR pathway and their aberrations are described, with the evaluation of their possible prognostic role in NSCLC and in particular in squamous cell carcinomas, in which FGFR is more often amplified. New therapeutic agents targeting FGFR signaling have been developed and are now in clinical evaluation. Dysregulation of FGF signaling in tumour cells is related to FGFR gene amplification or mutation, although it is still uncertain which of these aberrations represents a real predictor of response to specific inhibitors. However, recent evidence has questioned whether FGFR is a real target in squamous cell histology. The effectiveness of FGFR inhibitors is also still unclear since there are no clinical data on selected patients. Moreover, the management of specific side effects related to inhibition of the physiological role of FGF should be more thorough.

For a few years at the Azienda Ospedaliero - Universitaria “Policlinico - Vittorio Emanuele” of Catania (Italy), ocular melanoma brachytherapic treatments with Ru-106 plaques have been made. This type of treatment is planned using the specific Treatment Planning System (TPS) BEBIG “Plaque Simulator” software that simulates the delivered dose distribution from the source used on the eye tissue. Improving dosimetry for ophthalmic therapeutic applications is worthwhile. Accurate dose measurements require detectors of adequate dimensions with respect to small distances involved. The main objective of the work is the improvement of dosimetry accuracy with a high sensitivity and spatial resolution system such as EBT2 Gafchromic ® film. The relative depth dose, the 2D and 3D distributions, the source uniformity and asymmetry were obtained using custom tissue equivalent phantom. Experimental results were compared with manufacturer’s calibration certificate data, TPS calculated values and Monte Carlo simulation results.

Non-small cell lung cancer (NSCLC) is one of the most common causes of cancer-related death worldwide. Based on the patient's stage of disease, treatment options include surgery, radiotherapy, and chemotherapy. Although chemotherapy remains the main therapeutic approach for advanced NSCLC, targeted therapy represents a good chance of treatment for this subgroup of patients. Currently this approach is based on previous evaluation of clinically relevant mutations and the Sanger sequencing is the main approach to assign mutational status and to guide the appropriate treatment; however this tool is characterized by a low sensitivity. Recently, the advent of next-generation sequencing (NGS) has dramatically revolutionized the molecular knowledge of cancer by increasing the feasibility and possibility to sequence DNA ranging from large scale studies to targeted regions. This review reports an overview of different applications of the NGS as novel approach to study NSCLC, thereby providing information about mutational spectrum of this cancer in order to identify novel targetable mutations and to predict the emergence of drug resistance. All studies demonstrated several advantages of this approach over the traditional tools. In particular the NGS was also able to reveal mutations in low percentage, and to screen the mutational status of different critical samples such as biopsies, cytological samples and circulating plasma DNA, offering innovative diagnostic opportunities. Despite several problems have to be overcome toward the personalized therapy, the NGS represents a highly attractive system to identify mutations improving the outcome of patients with this deadly disease.

An on-line database was compiled for the Raman and fluorescence spectra, obtained using three different excitation wavelengths (531.5, 632.8 and 780 nm), of 99 pigments analysed dry and already applied with four painting techniques (egg tempera, casein tempera, oil and fresco). The database makes it possible to determine easily the most suitable excitation wavelength for the identification of pigments already applied with these painting techniques. Copyright © 2004 John Wiley & Sons, Ltd.

Background: Some trial have demonstrated a benefit of adjuvant fluoropirimidine with or without platinum compounds compared with surgery alone. ITACA-S study was designed to evaluate whether a sequential treatment of FOLFIRI [irinotecan plus 5-fluorouracil/folinic acid (5-FU/LV)] followed by docetaxel plus cisplatin improves disease-free survival in comparison with 5-FU/LV in patients with radically resected gastric cancer. Patients and methods: Patients with resectable adenocarcinoma of the stomach or gastroesophageal junction were randomly assigned to either FOLFIRI (irinotecan 180 mg/m 2 day 1, LV 100 mg/m 2 as 2 h infusion and 5-FU 400 mg/m 2 as bolus, days 1 and 2 followed by 600 mg/m 2 /day as 22 h continuous infusion, q14 for four cycles) followed by docetaxel 75 mg/m 2 day 1, cisplatin 75 mg/m 2 day 1, q21 for three cycles (sequential arm) or De Gramont regimen (5-FU/LV arm). Results: From February 2005 to August 2009, 1106 patients were enrolled, and 1100 included in the analysis: 562 in the sequential arm and 538 in the 5-FU/LV arm. With a median follow-up of 57.4 months, 581 patients recurred or died (297 sequential arm and 284 5-FU/LV arm), and 483 died (243 and 240, respectively). No statistically significant difference was detected for both disease-free [hazard ratio (HR) 1.00; 95% confidence interval (CI): 0.85–1.17; P= 0.974] and overall survival (OS) (HR 0.98; 95% CI: 0.82–1.18; P= 0.865). Five-year disease-free and OS rates were 44.6% and 44.6%, 51.0% and 50.6% in the sequential and 5-FU/LV arm, respectively. Conclusions: A more intensive regimen failed to show any benefit in disease-free and OS versus monotherapy. Clinical trial registration: ClinicalTrials.gov Identifier: NCT01640782.

The inhibition of the epidermal growth factor receptor (EGFR) through tyrosine kinase inhibitors (TKIs) represents an effective strategy for EGFR-mutated NSCLC. Afatinib is an irreversible erythroblastosis oncogene B (ErbB) family blocker, able to inhibit the kinase domains of EGFR, HER2 and HER4, and the transphosphorylation of ErbB3 that has recently been approved in the United States for the first-line treatment of EGFR-mutated NSCLC and in Europe and Japan for the treatment of EGFR-mutated TKI-naive patients.The authors analyzed the pharmacology and the clinical activity of afatinib in NSCLC through a review of the literature. Trials exploring different settings have been reported, including LUX-Lung 3 and LUX-Lung 6, where the drug achieved better outcomes in terms of response rate, progression-free survival and quality of life compared with chemotherapy. The main toxicities of afatinib are gastrointestinal and skin-related adverse events.Afatinib showed remarkable efficacy as a first-line treatment in the presence of common EGFR mutations. Afatinib showed some activity in NSCLC with acquired resistance to EGFR TKIs, although, currently, its efficacy after the failure of erlotinib or gefitinib has not been clearly stated. Direct clinical data comparing the activity and tolerability of different inhibitors are still needed.

Malignant mesothelioma (MM) is an aggressive tumor, mainly derived from the pleura, which is predominantly associated with exposure to asbestos fibers. The prognosis of MM patients is particularly severe, with a median survival of approximately 9-12 months and latency between exposure and diagnosis ranging from 20-50 years (median 30 years). Emerging evidence has demonstrated that tumor aggressiveness is associated with genome and gene expression abnormalities; therefore, several studies have recently focused on the role of microRNAs (miRNAs) in MM tumorigenesis. miRNAs are small non-protein coding single-stranded RNAs (17-22 nucleotides) involved in numerous cellular processes that negatively regulate gene expression by modulating the expression of downstream target genes. miRNAs are often deregulated in cancer; in particular, the differential miRNA expression profiles of MM cells compared to unaffected mesothelial cells have suggested potential roles of miRNAs as either oncogenes or tumor suppressor genes in MM oncogenesis. In this review, the mechanism of MM carcinogenesis was evaluated through the analysis of the published miRNA expression data. The roles of miRNAs as diagnostic biomarkers and prognostic factors for potential therapeutic strategies will be presented and discussed.

The thermally stimulated luminescence of oxides, carbonates and high T C ceramic superconductors (perovskites of the (BiPb)SrCaCuO type obtained by solid state reaction) was measured in the temperature interval 20–500°C. The glow-curves obtained on the perovskites are compared with those determined for both the precursor compounds and pure (BiPb)SrCaCuO powders of the same stoichiometry. The analysis of the data evidences the possibility of characterising the oxides and carbonates and of detecting very low intensity TL signals produced in the superconductors by precursor compounds, which can be identified in some cases, and/or low amounts of semiconducting or insulating compounds probably formed during the sintering procedure.

The cation exchange capacity (CEC) of clay minerals has been determined by titration of aqueous suspension of clays with hexadecylpyridinium chloride, monitored using surface tension measurements. In order to make the method suitable for an accurate analysis of the CEC of the clays in drilling fluids or in soils, some parameters affecting the CEC determination (e.g. the presence of carboxymethylcellulose, mixing time and measurement device) have been investigated.

Since the dating of a stalactite from the Akiyoshi cave in Japan by Ikeya (1975), significant progress has been made in the utilisation of electron spin resonance spectroscopy (ESR) for the assessment of past radiation doses in the context of archaeological and geological dating (Rink 1997). The method is applicable to various materials such as speleothems, spring deposited travertines, mollusc shells and corals (Grun 1989). Discoveries of human remains in Western Europe have been proposed to indicate the sites of the earliest arrival of humans there, and have been dated to the Early Pleistocene by ESR using quartz and tooth enamel (Falgueres 2003). The researches based on the dating of quartz allow the age assessment of heated ceramics, volcanic rocks, intrafault material, or windblown sediments (Grun 1989). The method is also used on archaeological artefacts made of obsidian, which are precious for archaeologists, allowing them to obtain information about cultural, social and economic relations between prehistoric populations (Duttine et al. 2003).

The NEMO.RD Project is a feasibility study of a km 3 underwater telescope for high energy astrophysical neutrinos to be located in the Mediterranea Sea. At present this study concerns: i) Monte Carlo simulation study of the capabilities of various arrays of phototubes in order to determine the detector geometry that can optimize performance and cost; ii) design of low power consumption electronic cards for data acquisition and transmission to shore; iii) feasibility study of mechanics, deployment, connection and maintenance of such a detector in collaboration with petrol industries having experience of undersea operations; iv) oceanographic exploration of various sites in search for the optimal one. A brief report on the status of points i) and iv) is presented here.

We report here about measurements of resistance vs. temperature, alternating current (a.c.) susceptibility and X-ray diffraction performed on Ba2Sr2Ca2Cu3Ox superconductor doped with various amounts of Pb. The results could be explained in terms of Pb contribution in increasing both the amount of the highest T C 0 phase and connectivity between superconductive regions. The Pb substitution on Bi sites is also discussed.

Summary form only given. The shape of alkali halides TL glow curves can be used to calculate traps parameters from different models. Different crystals have been studied using different beta calibrated doses. All the crystals measured showed intense TL emissions hut with different behaviour and efficiency from crystal to crystal, and also of the same crystal, according to the stimulation wavelength. The peaks present in the glow-curves were analysed for a rough characterization of the crystals themselves using deconvolution of the experimental curve through a theoretical model. From the curves deconvolution we obtain, as fit parameters, information on energy trap levels and kinetic order of process. Then it is possible to compare different values calculated to the different beta doses, to evaluate the existence of an accord of the parameters value obtained on the same crystal, the eventual effect of deformations due to irradiation and the dosimetric efficiency of different alkali halides crystals.

Aim: The mass-spectrometry based serum test VeriStrat□ (VS) was shown to be prognostic in various therapies and predictive of differential overall survival (OS) benefit for erlotinib vs. chemotherapy (CT) in second line NSCLC setting. Performance of the test in CT is of clinical interest. We investigated the role of VS in 1st line advanced NSCLC patients (pts) treated with Cisplatin (Cis) or Carboplatin (Carbo) plus Pemetrexed (P). Methods: VS classification was available for 55 eligible stage IV,pts with non-squamous histology; pts were classified as VS Good (VSG) or VS Poor (VSP), VS testing of pretreatment serum samples was done blinded to clinical data. OS and progression-free survival (PFS) were analyzed by Kaplan-Meier method and compared using log-rank p-values; Cox models were used in multivariate analysis. Association with categorical variables was analyzed by Fisher's exact test. Results: 36 (65%) pts were classified as VSG and 19 (35%) as VSP. In the overall population, median PFS was 5.7 months (mo) for VSG vs.1.4 mo for VSP (hazard ratio (HR) 0.37 [0.19-0.72], p = 0.002 ); adjusted HR (AHR) 0.38 [0.17-0.86], p = 0.021). Median OS was 10.8 mo for VSG vs. 3.4 mo for VSP (HR 0.23 [0.11-0.51], p Conclusions: In Platinum-based doublet CT, VSP pts had much shorter PFS and OS than VSG. The behavior was similar in CisP and CarboP arms. Further research is needed to find alternative treatments to improve outcomes for VSP pts. ClinicalTrials.gov Identifier: NCT02055144. Disclosure: J. Grigorieva: stock options of Biodesix; H. Roder: stock options of Biodesix. All other authors have declared no conflicts of interest.

e19090 Background: The mass-spectrometry based serum test VeriStrat (VS) was shown to be prognostic in various therapies and predictive of differential overall survival (OS) benefit for erlotinib v...

Optically stimulated luminescence (OSL) dating methodology was applied on the coarse grain fraction (100÷500 μm thick) of quartz crystals (green light stimulated luminescence, GLSL) and feldspar crystals (infrared stimulated luminescence, IRSL) taken from sections at different depths of cores bored in various coastal lagoons (Longarini, Cuba, Bruno) in the south-east coast of Sicily. The results obtained give a sequence of congruent relative ages and maximum absolute ages compatible with the sedimentary structure, thus confirming the excellent potential of the methodology.

Recent years have seen many scientific and technical progress in the field of wellbore stability understanding. The main causes of instabilities have been identified, models developed and practical remedies proposed and often tried successfully in the field. Yet despite this scientific effort, drilling extra costs associated with wellbore instabilities remain very high. This in turn demonstrates that until now, scientific and technical progress have somehow failed to reach their final technico-economical objectives. This paper shows that the main reason for such a state of affairs is the complexity of wellbore stability analysis which cannot be performed for every single well on a worldwide basis. Having identified this, Agip undertook a vast effort of field data back analysis in order to identify from historical records the best way to optimize its drilling planning, practice and post-evaluation procedures. The paper presents part of this effort and in particular the back analysis of four clusters drilled in Southern Italy -i.e. 38 wells in total. It then draws conclusions in terms of procedure optimization. Finally, it presents how the approach is used during the appraisal phase of a field in order to speed up the learning curve and hence significantly cut the development drilling costs.

e15544 Background: Platinum resistant-refractory ovarian cancer (PRROC) patients have a poor outcome; single-agent therapy is still the gold standard, with overall response rate lesser than 20% and progression-free-survival is not higher than 4 months. Methods: We tested safety and activity of a two-drugs-regimen containing NPLED and cyclophosphamide in a phase II open label study. From October 2007 to October 2011 thirty-two patients with platinum-resistant/refractory disease were enrolled. Enrolled patients were pretreated with a median number of 2 lines of chemotherapy, ranging from 1 to 5. NPLED and cyclophosphamide were administered at the dose of 60 mg. and 600 mg p.s.m. respectively. Results: Patients received a median number of three cycles of chemotherapy. A total of 145 cycles were administered: as G3 toxicities we registered emesis (6%), diaorrhea (3%), asthenia, and alopecia. No grade 4 adverse events occurred. Among the 30 patients evaluable for response we observed 5 (17%) partial responses and 10 (33%) stable diseases. The median progression-free-survival was 13 weeks and the median survival was 46 weeks. Conclusions: These results are similar to other data reported in literature. In conclusion we may affirm that the association of NPLED and cyclophosphamide is active and safe when administered in PRROC, but it don’t modify the prognosis of this subset of patients.

The functions Δ(ω), α 2 (ω) F(ω) and Z(ω) and the parameters λ, , μ* of Pb are calculated by analysing the tunnel characteristics of Al/Formvar/Pb junctions. The results, in comparison with those obtained on Al/Al x O y /Pb tunnel junctions, seem to exclude the direct influence of the Formvar on the electron-phonon interaction function via the transfer of vibrational structures in the explored energy range. All the observed modifications (the lowering of the amplitude of the phononic peaks of the Pb and the variation of their ratio, the reduction of λ, the negative value of (μ*) are connected with the particular structure of the insulator-superconductor interface. This interpretation is supported by the data of the ESCA analysis of the tunnel structure Les fonctions Δ(ω), α 2 (ω)F(ω), Z(ω) et les parametres λ, , μ* de Pb ont ete evalues a partir de l'analyse directe des caracteristiques tunnel de jonctions Al/Formvar/Pb

The Ginzburg's «generalized jellium» model of the proximity effect in superconductor-dielectric systems is tested against a wide phenomenology occurring in formvar-metal multilayers. The experimental evidence gained from enhanced superconductivity, critical magnetic fields, energy gap and pair-breaking parameter values seems to support the hypothesis that a formvar eigenfrequency plays the same role as the Debye frequency in setting up the superconductivity of these systems.

The behaviour of the superconducting resistive transition temperature was studied in Pb granulated filmsvs. the grain size both for films grown directly on glass and for those interfaced with Formvar. The experimental data were analysed with reference to the Garland theory as extended by Watton. An increase of the average coupling energy (ω) and a decrease of the coupling parameter (λ) were revealed in the films interfaced with Formvar. These results were correlated to the modifications of the vibrational spectrum observed, by tunnelling, in A1/Formvar/Pb junctions.

The morphological structure of SnTe very thin films is here studied by X-ray photoemission spectroscopy, by transmission electron spectroscopy and by X-ray diffraction. The analisys of experimental data evidences the superficial confinement of Sn, with different oxidation states, and the Te excess in the inner layers. The energy shift of the valence band peaks is attributed to modifications induced by the nonstoichiometry of the compound. Preliminary Hall and resistivity measurements seem to confirm the structural obtained results.

Procedures for synthesizing high-T c YBa2Cu3O7−x superconductors, alternative to the standard ones, are here studied by four-contact resistance measurementsvs. temperature and by X-ray diffraction. While X-ray spectra are consistent with the known ones, small changes in the transition temperatureT c and in shape of the resistancevs. temperature curve in the transition zone are observed. These changes could be explained in terms of volume fraction occupied by superconductive grains rather than as due to the different adopted procedures of preparation.

Low-energy structures, observed in tunnelling characteristics of Al/formvar/Sn and Al/formvar/Al junctions are reported and discussed. Their connection to tbe vibrational excitation spectrum of the insulator is indicated. Arguments are given to interpret them as excited by an inelastic tunnel mechanism of quasi-holes. A spectroscopic classification of these structures is attempted according to some results previously published. The relevance of these results, obtained for an energy range in which no data from current molecular spectroscopy are available, is stressed.

That an inelastic electron tunneling experiment can be a powerful tool to investigate molecular vibrational spectra was first shown by JAc~VVlC and LAMBE (1). Since that t ime much progress has been accomplished on this field: a fairly up-to-date review can be found in WOLF (2). Tunnel junctions where the insulating barrier is a thin (50--100)• film of Polyvinyl Formate have been extensively investigated by our group in the last few years (3.5). For the reader's opportunity let us briefly summarize the main results that have been obtained. First ly it was shown in (3) that, when the insulating barrier is a Formvar film, proper vibrational modes can be transferred from the metallic electrodes to the

The tunnel characteristics (J vs. V) of Al−Al2O3−InSb (n type) structures with thin (100÷400)A semiconducting electrode are presented. They are analysed by utilizing the model proposed by Chang, Esaki and Styles. The data obtained by a nonlinear best fit on experimental points describe the MOS structure and the negative-resistance region exibited by the characteristics. Furthermore, the semiconductor gap shows a dependence on the thickness and this variation is explainable with the quantum effects presence in the thinnest films.

Measurements of the resistivity and the Hall coefficient versus the temperature (77–300 K) and the magnetic field (0–11 kG) were performed on InAs thin films (100–1500 A thick) obtained by vacuum evaporation from an electron gun and condensation onto glass substrates at room temperature. Analysis of the electrical results reveals the typical behaviour of disordered structures. The conductivity versus temperature curves exhibit an anomalous sharp variation which appears to separate two temperature ranges characterized by different conductivity slopes. Observation of the samples in a transmission electron microscope reveals the polycrystalline structure of the films. Electron spectroscopy for chemical analysis shows the sample to be non-stoichiometric with an excess of indium in the inner layers and the presence of indium and arsenic oxides at the surface of the films. Numerical analysis, performed with a multiparametric best-fit procedure, shows that the conductivity conforms to the percolation conductivity model but with an exponential temperature dependence, in accordance in the high temperature region with the more recent hypotheses regarding disordered structures.

Tunnelling anomalies in Al–formvar–Sn junctions operated at temperatures slightly below the transition temperature of the Al arm, are detected as function of externally applied magnetic fields. Evidence is given to interpret these anomalies as due to the thermodynamic fluctuations of the superconducting order parameter in the Al side. A transverse fluctuation mode appears to be present, in good agreement with the theoretical model proposed by Simanek and Hayward. Nous avons etudie le comportement anomal d'une jonction Al–formvar–Sn a une temperature peu au deseous de quelle de transition de I'electrode de Al, en fonction d'un champ magnetique applie exterieurement. On a mis en evidence I'interpretation des anomalies observees comme dues a les fluctuations thermodynamiques du parametre d'ordre du Al. Nous avons, donc, revele la presence d'un mode de fluctuation transverse, en bon accord avec le modele theorique propose de Simanek et Hayward.

A new method of numerical analysis is presented which allows the determination of the electron-phonon interaction function α2(ω)F(ω) using the experimental data obtained from a superconducting tunnel junction. This method utilizes the dispersion relation for Δ(ω) (complex energy gap function) proposed by Galkin, D'yachenko and Svistunov. The method and the hypotheses which allow the numerical solution of the first-kind integral equation derived from the Eliashberg equations are shown and discussed. Δ(ω) and α2(ω)F(ω) of Pb are obtained by applying this method to the tunnel data of an Al−Al2O3-Pb (superconducting electrode) junction. The results are discussed with particular reference to the stability and convergence of the method applied.

The phonon excitation spectra of Pb and Sn have been obtained from an analysis of the electron tunnel characteristics of junctions with the electrodes in the normal and the superconducting state. Metallic junctions with two different types of insulating barrier Al2O3 and Formvar, are used. The large resonant peak due to the Formvar long molecular chains has been resolved for lead. Self energy effects for the quasi-electrons in tin have been revealed and are interpreted in terms of coulombic contributions since tin is a weakly coupled electron-phonon system. Similar effects for the quasi-holes have been observed for tin in the presence of Formvar. It is also found that proper vibrations of the insulators and the metals may be reciprocally transferred.