The manipulation of ferromagnetic layer magnetization via electrical pulse is driving an intense research due to the important applications that this result will have on memory devices and sensors. ...In this study we realized a magnetotunnel junction in which one layer is made of Galfenol (Fe1-xGax) which possesses one of the highest magnetostrictive coefficient known. The multilayer stack has been grown by molecular beam epitaxy and e-beam evaporation. Optical lithography and physical etching have been combined to obtain 20x20 micron sized pillars. The obtained structures show tunneling conductivity across the junction and a tunnel magnetoresistance (TMR) effect of up to 11.5% in amplitude.
Magnetic refrigeration based on the magnetocaloric effect at room temperature is one of the most attractive alternative to the current gas compression/expansion method routinely employed. ...Nevertheless, in giant magnetocaloric materials, optimal refrigeration is restricted to the narrow temperature window of the phase transition (Tc). In this work, we present the possibility of varying this transition temperature into a same giant magnetocaloric material by ion irradiation. We demonstrate that the transition temperature of iron rhodium thin films can be tuned by the bombardment of ions of Ne 5+ with varying fluences up to 10 14 ions cm −2 , leading to optimal refrigeration over a large 270–380 K temperature window. The Tc modification is found to be due to the ion-induced disorder and to the density of new point-like defects. The variation of the phase transition temperature with the number of incident ions opens new perspectives in the conception of devices using giant magnetocaloric materials.
The nucleoside analog, gemcitabine, has shown activity as a single agent in the treatment of metastatic non-small-cell lung cancer (NSCLC). Its combination with cisplatin in preclinical models ...suggested synergy between the two drugs. The aim of the study was to evaluate the clinical efficacy and toxicity of the cisplatin-gemcitabine combination in advanced NSCLC.
Forty-eight consecutive previously untreated NSCLC patients entered the trial from January to June 1994. The median age was 60 years (range, 37 to 70) and performance status (PS) was 0 or 1; 22 patients had unresectable stage III disease (21 stage IIIB and one stage IIIA) and 26 had stage IV disease. Gemcitabine 1 g/m2 was administered weekly (days 1, 8, and 15) followed by a 1-week rest and cisplatin 100 mg/m2 on day 2 of each 28-day cycle. Survival and response were determined in accordance with the intention-to-treat principle in all enrolled patients.
Of 48 assessable patients, one (stage IV) had a complete response (CR) and 25 achieved a partial response (PR). The overall response rate was 54% (95% confidence interval CI, 40% to 68%). Thrombocytopenia was the main side effect, with 52% of patients experiencing grade III to IV toxicity, which was usually short-lived and responsible for the omission of gemcitabine administration on day 15 in 50% of chemotherapy courses. The median survival time was 61.5 weeks (95% CI, 40 to 71).
The combination of gemcitabine and cisplatin induced a high response rate in both stage IIIB and IV NSCLC, with modest side effects. The regimen deserves further careful evaluation in a phase III prospective randomized trial.
The alpha-beta magnetostructural phase transition in MnAs/GaAs(111) epilayers is investigated by elastic neutron scattering. The in-plane parameter of MnAs remains almost constant with temperature ...from 100 to 420 K, following the thermal evolution of the GaAs substrate. This induces a temperature dependent biaxial strain that is responsible for an alpha-beta phase coexistence and, more importantly, for the stabilization of the ferromagnetic alpha phase at a higher temperature than in the bulk. We explain the premature appearance of the beta phase at 275 K and the persistence of the ferromagnetic alpha phase up to 350 K with thermodynamical arguments based on the MnAs phase diagram. It results that the biaxial strain in the hexagonal plane is the key parameter to extend the ferromagnetic phase well over room temperature.
In a recent experiment we demonstrated the possibility to suppress the thermal hysteresis of the phase transition in giant magnetocaloric MnAs thin film by interaction with slow highly charged ions ...(Ne9+ at 90 keV) 1. This phenomenon has a major impact for possible applications in magnetic refrigeration and thus its reproducibility and robustness are of prime importance. Here we present some new investigations about the origin and the nature of the irradiation-induced defects responsible for the thermal hysteresis suppression. Considering in particular two samples that receive different ion fluences (two order of magnitude of difference), we investigate the reliability of this process. The stability of the irradiation-induced defects with respect to a soft annealing is studied by X-ray diffraction and magnetometry measurements, which provide some new insights on the mechanisms involved.
Small cell lung cancer accounts for 13–15% of all lung cancer worldwide. There has been a decrease in the number of cases, with no clear explanation, except probably to changing in smoking habits in ...the last two decades. In the early 1980s, it became clear that SCLC was an extremely sensitive tumour to radiation as it was to chemotherapeutic agents. With cisplatinum etoposide combinations or cyclophosphamide, anthracycline and vincristine/etyoposide regimens responses were observed in 50–70%, with 20–30% complete remissions in extensive disease. For limited-stage patients chemotherapy associated with thoracic radiation was able to produce a cure rate of 10–20%.The addition of prophylactic brain irradiation to limited stage cases has reduced mortality by a factor of nearly 5%. But despite these early good results no breakthrough came later on, and in the last decade or so, we are still facing this plateau. New agents have recently been included in the therapeutic armamentarium, such as gemcitabine, irinotecan, paclitaxel and more recently pemetrexed. This fact has allowed many patients to receive a relatively active second line therapy, but the overall survival remains unchanged. Targeted therapies are undergoing some evaluations, but the data are too premature and, so far, quite discouraging. At the present time there is an urgent need to improve clinical research in this somehow forgotten disease.
Synopsis Investigation on modifications of structural and magnetic properties of magnetocaloric thin films induced by slow highly charged ions bombardment under well-controlled conditions is ...presented. The ions induce defects constraints that facilitate nucleation of one phase with respect to the other in the first-order magnetostructural MnAs, with a consequent suppression of thermal hysteresis, but without any significant perturbation on the other structural and magnetic properties.
A comprehensive investigation of rotatable anisotropy in a Fe0.8Ga0.2 thin film with a stripe domain structure has been performed comparing static and dynamic measurements. The stripes' domain ...formation and their rotation under a transverse magnetic field have been imaged by magnetic force microscopy. The rotatable anisotropy field H-rot was determined by fitting the frequency evolution of the dipole-dominated magnetostatic spin-wave mode versus the in-plane orientation of the stripe domains, measured by Brillouin light scattering in the absence of any dc or ac magnetic field. We obtained H-rot approximate to 1.35 kOe, which is nearly ten times larger than the crystallographic in-plane anisotropy field. By applying a dc magnetic field along the stripes' axis, H-rot decreases, and eventually vanishes for saturated in-plane magnetization. At remanence, we established a quantitative relationship between static and dynamic properties, that is, the stripes' rotation angle and the in-plane angle dependence of spin-wave frequency.
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