Multiband superconductivity in Pb, H under pressure and CaBeSi from ab initio calculations.

Superconductivity in Pb, H under extreme pressure and CaBeSi, in the framework of the density functional theory for superconductors, is discussed. A detailed analysis on how the electron-phonon and electron-electron interactions combine together to determine the superconducting gap and critical temperature of these systems is presented. Pb, H under pressure and CaBeSi are multigap superconductors. We will address the question under which conditions does a system exhibits this phenomenon. The presented results contribute to the understanding of multiband and anisotropic superconductivity, which has received a lot of attention since the discovery of MgB(2), and show how it is possible to describe the superconducting properties of real materials on a fully ab initio basis.

Ab initio description of high-temperature superconductivity in dense molecular hydrogen.

We present a first-principles study of the electron-phonon interaction and the prediction of the superconducting critical temperature in molecular metallic hydrogen. Our study is able to single out the features which drive the system towards superconductivity: mainly, a rich and complex Fermi surface and strongly coupled phonon modes driving the intra- or intermolecular charge transfer. We demonstrate that in this simple system, a very high superconducting critical temperature can be reached via electron-phonon and Coulomb electron-electron interactions.

Evidence for gap anisotropy in CaC6 from directional point-contact spectroscopy.

We present the first results of directional point-contact spectroscopy in high-quality CaC6 samples both along the ab plane and in the c-axis direction. The superconducting order parameter Delta(0), obtained by fitting the Andreev-reflection (AR) conductance curves at temperatures down to 400 mK with the single-band 3D Blonder-Tinkham-Klapwijk model, presents two different distributions in the two directions of the main current injection, peaked at 1.35 and 1.71 meV, respectively. By ab initio calculations of the AR conductance spectra, we show that the experimental results are in good agreement with the recent predictions of gap anisotropy in CaC6.

Effect of magnetic impurities in a two-band superconductor: a point-contact study of mn-substituted single crystals.

We present the first results of directional point-contact measurements in Mg1-xMnxB2 single crystals, with x up to 0.015 and bulk Tc down to 13.3 K. The order parameters Deltasigma and Deltapi were obtained by fitting the conductance curves with the two-band Blonder-Tinkham-Klapwijk model. BothDeltapi and Deltasigma decrease with the critical temperature of the junctions TAC, but remain clearly distinct up to the highest Mn content. Once analyzed within the Eliashberg theory, the results indicate that spin-flip scattering is dominant in the sigma band, as also confirmed by first-principles band-structure calculations.

Superconductivity in lithium, potassium, and aluminum under extreme pressure: a first-principles study.

Extreme pressure strongly affects the superconducting properties of "simple" elemental metals, such as Li, K, and Al. Pressure induces superconductivity in Li (as high as 17 K) while suppressing it in Al. We report first-principles investigations of the superconducting properties of dense Li, K, and Al based on a recently proposed, parameter-free, method. Our results show an unprecedented agreement with experiments, assess the predictive power of the method over a wide range of densities and electron-phonon couplings, and provide predictions for K, where no experiments exist so far. More importantly, our results help uncover the physics of the different behaviors of Li and Al in terms of phonon softening and Fermi surface nesting in Li.

Superconducting properties of MgB2 from first principles.

Solid MgB(2) has rather interesting and technologically important properties, such as a very high superconducting transition temperature. Focusing on this compound, we report the first nontrivial application of a novel density-functional-type theory for superconductors, recently proposed by the authors. Without invoking any adjustable parameters, we obtain the transition temperature, the gaps, and the specific heat of MgB(2) in very good agreement with experiment. Moreover, our calculations show how the Coulomb interaction acts differently on sigma and pi states, thereby stabilizing the observed superconducting phase.

Immunotherapy (recombinant interleukin 2), hormone therapy (medroxyprogesterone acetate) and antioxidant agents as combined maintenance treatment of responders to previous chemotherapy.

An open, non-randomized phase II study was carried out including all patients treated with whatever chemotherapy or combined modality regimen for whatever cancer who were in clinical objective response or stable disease (SD) for more than three months, to receive maintenance treatment with recombinant interleukin-2 (rIL-2) plus medroxyprogesterone acetate (MPA) plus antioxidant agents alpha-lipoic acid (ALA) and N-acetyl cysteine (NAC). The main study endpoints were clinical outcome and toxicity. The secondary endpoints were effects of treatment on cancer-related anorexia/cachexia syndrome (CACS) symptoms, on serum levels of proinflammatory cytokines, IL-2, C-reactive protein (CRP) and leptin as well as the evaluation of quality of life (QL). rIL-2 was administered at a dose of 1.8 MIU subcutaneously three times/week on alternate days for the first two weeks of every month and MPA was given orally at a dose of 500 mg once a day at alternate days without interruption. ALA 300 mg/day orally and NAC 1800 mg/day orally were also administered. The treatment was administered until progression of disease or appearance of toxicity. From July 1998 to May 2000, 16 patients were enrolled in the study (M/F ratio: 15/1; mean age: 62 years, range 45-71). The median duration of maintenance treatment was 10 months (range 5-22). The response to maintenance treatment at September 2000 was: CR (persistent throughout the treatment) 4 patients (25%); SD 1 patient (6.2%); PD 11 patients (68.8%). The median duration of response was 9.8 months (range: 5-22+). The median follow-up duration was 19 months (range: 8-102). The median OS was not reached. The median PFS was 14 months (range 1-29). The 1-year survival rate was 25%. At September 2000, 9 patients are still surviving. No grade 3/4 toxicity was observed. One Grade 2 skin toxicity was observed and Grade 1: 2 fever, 2 thrombocytopenia, 1 neutropenia and 1 skin were observed. The ECOG PS did worsen significantly, the body weight and BMI increased significantly after treatment, whereas the appetite did not change significantly. The QL evaluation showed a significant amelioration of cognitive functions and a borderline significant amelioration of emotional functions after treatment, whereas a borderline worsening of dyspnea was observed. The absolute lymphocyte count increased significantly after the maintenance treatment, as well as the serum IL-2, TNFalpha decreased at borderline statistical significance; the serum levels of leptin did not change significantly. The evaluation of patient subgroups showed that responders/survivors had a pattern superimposable to that of whole patient population, the patients who rapidly progressed and died exhibited no significant changes of these parameters during treatment. The results of the present study suggest that the host immune response, evaluated by several parameters, after IL-2 administration, (e.g. lymphocytosis), are worth further study as potential markers for the major end points of cancer treatment, i.e. OS and QL, in an adequate number of patients.

Phase II study of induction chemotherapy followed by concomitant chemoradiotherapy in advanced head and neck cancer: clinical outcome, toxicity and organ/function preservation.

The purpose of the study was to assess response rate, clinical outcome, organ/function preservation and toxicity in head and neck cancer patients treated with induction chemotherapy followed by concomitant chemoradiotherapy and, when necessary, limited surgery. The study design was a phase II non-randomized trial in hospitalized patients setting. The treatment plan consisted of 3 cycles of induction chemotherapy with cisplatin, fluorouracil (5-FU), leucovorin and interferon alpha2b (PFL-IFN) followed by 7 cycles of 5-FU, hydroxyurea and concomitant radiation for 5 days (FHX) for a total radiation dose of 70 Gy. Surgical resection was performed, when necessary, with the intent to spare organ/function. Seventeen patients were treated at one institution. Three patients had stage III and 14 patients stage IV disease. Twelve patients were analyzed for response to PFL-IFN: 2/12 (16.7%) patients achieved a CR and 10/12 (83.3%) achieved a PR for an ORR of 100%. FHX was administered on protocol to 10 patients: 4 patients (40%) had CR, 3 (30%) had PR >/=70% for an ORR of 70%, 1 patient (10%) had SD and 2 patients (20%) had PD. As for local therapy, of the 8 eligible patients who completed chemoradiotherapy, the 3 patients with CR were submitted to random biopsies, results of which were histologically negative, 3 patients with PR >/=70% underwent conservative organ-preserving surgery, and 1 patient with PR >70% refused surgery, whereas the patient with SD underwent salvage surgery, preserving voice. Thus, organ preservation was achieved in all 8 patients at the completion of all therapy: 4 patients had no surgical procedure and 4 patients only conservative surgery. Overall, after completion of all therapy, 5/8 (62.5%) patients were rendered disease-free. The median overall survival time was 23 months, the median duration of response was 6 months and the median time to progression was 9 months. Both induction chemotherapy and concomitant chemoradiotherapy resulted in significant toxicity, which consisted mainly of mucositis and thrombocytopenia. In conclusion, PFL-IFN was very active, producing high ORRs and, followed by FHX, resulted in high overall survival rates permitting an optimal organ preservation, at the cost of a severe toxicity.

Phase II study of induction chemotherapy followed by concomitant chemoradiotherapy in advanced head and neck cancer: clinical response and organ/function preservation.

We planned to conduct a trial of induction chemotherapy followed by concomitant chemoradiotherapy with the goal of organ-function preservation in advanced head and neck cancer patients with the response rate and local control of disease as primary endpoints and the assessment of toxicity as secondary endpoint. The overall treatment plan consisted of 3 cycles, each q. 28 days, of induction chemotherapy with cisplatin, 5-FU, leucovorin and interferon alpha2b (PFL-IFN), followed by response evaluation and local therapy with concomitant chemoradiotherapy with 5-FU, hydroxyurea and concomitant radiotherapy (FHX). The evaluation of clinical response was performed during the 2nd week after the 3rd cycle of induction chemotherapy and FHX was initiated 28 days after the 3rd cycle of induction chemotherapy. Hydroxyurea was administered orally at doses of 1 g every 12 h x 11, 5-FU was administered on days 1 through 5 at 800 mg/m2/d for 5 days. Daily fraction of radiotherapy were administered at 2.0 Gy on days 1 through 5. FHX cycles were repeated every 14 days until completion of radiotherapy. Total radiotherapy doses consisted of 70 Gy. Seventeen patients (mean age 56.53 years, range 40-73, male/female 15/2, site: oral cavity 6, 35.29%; oropharynx 3, 17.6%; hypopharynx 3, 17.65%; larynx 2, 11.76%; paranasal sinuses 2, 11.76%; salivary glands 1, 5.88%; ECOG PS 0/1: 10/7, stage: III/IV 3/14) were enrolled from January 1998 to August 1998. All 17 patients initiated induction chemotherapy on this protocol. Twelve patients were analyzed for response (5 patients were not evaluable): 2/12 (16.7%) patients achieved a CR and 10/12 (83.3%) achieved a PR for an ORR of 100%. Concomitant chemoradiotherapy was administered on protocol to 10 patients: 4 patients (40%) had CR, 3 patients (30%) had PR >/=70% for an ORR of 70%, 1 patient (10%) had SD and 2 patients (20%) had PD. As for local therapy, according to treatment plan, of the 8 eligible patients who completed chemoradiotherapy, the 4 patients with CR were submitted to random biopsies, which resulted histologically negative, the 3 patients with PR >/=70% underwent conservative organ-preserving surgery, the patient with SD underwent salvage surgery, preserving voice. Thus, organ-preservation was achieved in all 8 patients at the completion of all therapy: 4 patients had no surgical procedure and 3 patients only conservative surgery. Overall, after completion of all therapy, 6/8 (75%) patients were rendered disease-free. Both induction chemotherapy and concomitant chemoradiotherapy resulted in significant toxicity, which consisted mainly of mucositis and thrombocytopenia. In conclusion, in the present study we have achieved a good clinical response and an optimal organ preservation, at the cost of a severe toxicity.