Enhancement of rare-earth--transition-metal exchange interaction in Pr2_{2}Fe17_{17} probed by inelastic neutron scattering

The fundamental magnetic interactions of Pr$_{2}$Fe$_{17}$ are studied by inelastic neutron scattering and anisotropy field measurements. Data analysis confirms the presence of three magnetically inequivalent sites, and reveals an exceptionally large value of the exchange field. The unexpected importance of $J$-mixing effects in the description of the ground-state properties of Pr$_{2}$Fe$_{17}$ is evidenced, and possible applications of related compounds are envisaged.Comment: 4 RevTeX pages, 4 EPS figures. Accepted for publication by Appl. Phys. Lett. (will be found at http://apl.aip.org

Giant entropy change at the co-occurrence of structural and magnetic transitions in the Ni2.19Mn0.81Ga Heusler alloy

In this paper we report the existence of a giant magnetocaloric effect (MCE) in a intermetallic compound non-containing rare-earth. This effect is associated with the concomitant occurrence of a structural and a magnetic transition. The result has been compared with that obtained in a parent compound in which magnetic and structural transition occur separately.Comment: PDF file from MS-Word 2000 document, 13 pages (text) plus 6 figures; corrected typo

Direct and indirect measurement of magnetocaloric effect in NiCoMnGa alloys

The Co-substitution for Ni in the Mn-rich NiMnGa Heusler alloys changes substantially their structural and magnetic ordering. The results will be discussed within the basic thermodynamic relations

Pressure dependence of magnetism and martensitic properties in Co-doped NiMnGa alloys

NiMnGa alloys display several "giant" effects due to the interplay between magnetic and structural degrees of freedom. A large magnetization difference, between martensitic phases and austenitic phases iso f great importance to obtain higher performances due to the improbe possibilit? of driving structural trasformations by magnetic fields. A deltaM enhancement was recently achieved by adding Co to Mn-rich NiMnGa alloy

Tips and tricks for the diagnosis and management of biliary stenosis-state of the art review

Biliary stenosis may represent a diagnostic and therapeutic challenge resulting in a delay in diagnosis and initiation of therapy due to the frequent difficulty in distinguishing a benign from a malignant stricture. In such cases, the diagnostic flowchart includes the sequential execution of imaging techniques, such as magnetic resonance, magnetic resonance cholangiopancreatography, and endoscopic ultrasound, while endoscopic retrograde cholangiopancreatography is performed to collect tissue for histopathological/cytological diagnosis or to treat the stenosis by insertion of stent. The execution of percutaneous transhepatic drainage with subsequent biopsy has been shown to increase the possibility of tissue diagnosis after failure of the above techniques. Although the diagnostic yield of histopathology and imaging has increased with improvements in endoscopic ultrasound and peroral cholangioscopy, differential diagnosis between malignant and benign stenosis may not be easy in some patients, and strictures are classified as indeterminate. In these cases, a multidisciplinary workup including biochemical marker assays and advanced technologies available may speed up a diagnosis of malignancy or avoid unnecessary surgery in the event of a benign stricture. Here, we review recent advancements in the diagnosis and management of biliary strictures and describe tips and tricks to increase diagnostic yields in clinical routine

Randomised clinical trial : A comparative dose-finding study of three arms of dual release mesalazine for maintaining remission in ulcerative colitis

Background Comparative data regarding different regimens of oral mesalazine (mesalamine) for maintaining remission in ulcerative colitis are limited. Aim To evaluate whether 3.0 g mesalazine once-daily (OD) is superior to the standard treatment of 0.5 g mesalazine three times daily (t.d.s.) and to prove the therapeutic equivalence of OD vs. t.d.s. dosing of total 1.5 g mesalazine for remission maintenance in patients with ulcerative colitis. Methods A 1-year, multicentre, double-blind, double-dummy study was undertaken in patients with endoscopically and histologically confirmed ulcerative colitis in remission. Patients were randomised to oral mesalazine 3.0 g OD, 1.5 g OD or 0.5 g t.d.s. The primary efficacy endpoint was the proportion of patients still in clinical remission at the final visit, with clinical relapse being defined as CAI score >4 and an increase of â¥3 from baseline. Results The primary efficacy endpoint occurred in 162/217 3.0 g OD patients (75%), 129/212 1.5 g OD patients (61%) and 150/218 0.5 g t.d.s. patients (69%) in the intention-to-treat population, and in 152/177 (86%), 121/182 (67%) and 144/185 (78%) in the per protocol population respectively; 3.0 g OD was superior to both low-dose regimens for the primary endpoint (i.e. P < 0.001, 3.0 g OD vs. 1.5 g OD; P = 0.024, 3.0 g OD vs. 0.5 g t.d.s.; superiority test, per protocol population). Safety analysis, including comprehensive renal monitoring, revealed no concern in any treatment group. Conclusion Mesalazine 3.0 g once daily was the most effective dose for maintenance of remission in ulcerative colitis of the three regimens assessed, with no penalty in terms of safety.publishersversionPeer reviewe

Efficacy of hemostatic powders as monotherapy or rescue therapy in gastrointestinal bleeding related to neoplastic or non-neoplastic lesions

Background Hemostatic powder (HP) in gastrointestinal bleeding (GIB) is mainly used as rescue therapy after failure of conventional hemostatic procedures (CHP). Aim To define the best field of application and the efficacy of HP as first choice monotherapy or rescue therapy. Methods We compared the efficacy of HP monotherapy, HP rescue therapy, and CHP in the management of active GIB due to neoplastic and non-neoplastic lesions. Results A total of 108 patients, 43 treated with HP as either first choice or rescue therapy and 65 with CHP, were included in the study. The most frequent sources of bleeding were peptic ulcer and malignancy. Immediate hemostasis rates were: HP monotherapy = 100% in peptic ulcer and 100% in malignancy; HP rescue therapy = 93.2% in peptic ulcer and 85.7% in malignancy; CHP = 77.9% in peptic ulcer and 41.7 in malignancy. Definitive hemostasis rates were: HP monotherapy = 50% in peptic ulcer and 45.5% in malignancy; HP rescue therapy = 73.3% in peptic ulcer and 85.7% in malignancy; CHP = 69.1% in peptic ulcer and 33.3% in malignancy. No difference was found in terms of additional intervention between the three groups. Conclusions HP is highly effective as monotherapy and rescue therapy in GIB. GIB related to malignancy may be the best field of application of HP, but confirmatory studies are necessary

From direct to inverse Giant Magnetocaloric Effect in Co-doped NiMnGa multifunctional alloys

We report the magnetic and magnetocaloric properties in Co-doped Ni–Mn–Ga Heusler alloys around the Mn-rich composition Ni50Mn30Ga20. The presence of Co affects profoundly the critical temperatures and alters the exchange interactions of martensite and austenite to different extents; by varying the composition it is possible to tune the critical temperatures and to induce a paramagnetic gap between the magnetically ordered martensite and magnetic austenite, thus giving rise to a reverse magnetostructural transformation. Contrary to the Co-free alloys, the saturation magnetization moment of austenite is strongly enhanced by Co with respect to the martensitic one: thus the magnetocaloric effect turns from direct into inverse. Remarkable values of the magnetic properties related to the magnetocaloric effect, e.g. the saturation magnetization jump at the transformation (DM) and the field dependence of the transformation temperature (dT/dH) are reported, together with high positive values of the isothermal magnetic entropy change (DS). The conditions for enhancing the magnetocaloric properties and triggering the sign reversal of the magnetocaloric effect are discussed