A Comparative Study Of The Magnetocaloric Effect In Rni2 (r=nd,gd,tb) Intermetallic Compounds

Conventional and anisotropic magnetocaloric effects were studied in cubic rare earth RNi2 (R=Nd,Gd,Tb) ferromagnetic intermetallic compounds. These three compounds are representative of small, null, and large magnetocrystalline anisotropy in the series, respectively. Magnetic measurements were performed in polycrystalline samples in order to obtain the isothermal magnetocaloric data, which were confronted with theoretical results based on mean field calculations. For the R=Tb case, we explore the crystalline electrical-field anisotropy to predict the anisotropic magnetocaloric behavior due to the rotation of an applied magnetic field of constant intensity. Our results suggest the possibility of using both conventional and anisotropic magnetic entropy changes to extend the range of temperatures for use in the magnetocaloric effect. © 2009 American Institute of Physics.1051Pecharsky, V.K., Gschneidner Jr., K.A., (1997) Phys. Rev. Lett., 78, p. 4494. , 0031-9007 10.1103/PhysRevLett.78.4494Pecharsky, V.K., Gschneidner Jr., K.A., (1997) Appl. Phys. Lett., 70, p. 3299. , 0003-6951 10.1063/1.119206Von Ranke, P.J., De Oliveira, N.A., Mello, C., Garcia, D.C., De Souza, V.A., Carvalho, A.M.G., (2006) Phys. Rev. B, 74, p. 054425. , 0163-1829 10.1103/PhysRevB.74.054425De Oliveira, I.G., Garcia, D.C., Von Ranke, P.J., (2007) J. Appl. Phys., 102, p. 073907. , 0021-8979 10.1063/1.2783781Lima, A.L., Tsokol, A.O., Gschneidner Jr., K.A., Pecharsky, V.K., Lograsso, T.A., Schlagel, D.L., (2005) Phys. Rev. B, 72, p. 024403. , 0163-1829 10.1103/PhysRevB.72.024403Von Ranke, P.J., De Oliveira, N.A., Garcia, D.C., De Souza, V.S.R., De Souza, V.A., Carvalho, A.M.G., Gama, S., Reis, M.S., (2007) Phys. Rev. B, 75, p. 184420. , 0163-1829 10.1103/PhysRevB.75.184420Carvalho, A.M.G., Campoy, J.C.P., Coelho, A.A., Plaza, E.J.R., Gama, S., Von Ranke, P.J., (2005) J. Appl. Phys., 97, p. 083905. , 0021-8979 10.1063/1.1876575Plaza, E.J.R., De Sousa, V.S.R., Alho, B.P., Von Ranke, P.J., (unpublished)Von Ranke, P.J., De Oliveira, N.A., Plaza, E.J.R., De Souza, V.S.R., Alho, B., Carvalho, A.M.G., Gama, S., Reis, M.S., (2008) J. Appl. Phys., 104, p. 093906. , 0021-8979 10.1063/1.3009974Lindbaum, A., Gratz, E., Heathman, S., (2002) Phys. Rev. B, 65, p. 134114. , 0163-1829 10.1103/PhysRevB.65.134114Purwins, H.G., Leson, A., (1990) Adv. Phys., 39, p. 309. , 0001-8732 10.1080/00018739000101511Lea, K.R., Leask, M.J.M., Wolf, W.P., (1962) J. Phys. Chem. Solids, 23, p. 1381. , 0022-3697 10.1016/0022-3697(62)90192-0Stevens, K.W.H., (1952) Proc. Phys. Soc., London, Sect. A, 65, p. 209. , 0370-1298 10.1088/0370-1298/65/3/308Von Ranke, P.J., Pecharsky, V.K., Gschneidner Jr., K.A., (1998) Phys. Rev. B, 58, p. 12110. , 0163-1829 10.1103/PhysRevB.58.12110Von Ranke, P.J., Nóbrega, E.P., De Oliveira, I.G., Gomes, A.M., Sarthour, R.S., (2001) Phys. Rev. B, 63, p. 184406. , 0163-1829 10.1103/PhysRevB.63.18440

Percolation Processes And Spin-reorientation Of Prni5-xco X

In the present work we report on the structural and magnetic behaviors of the PrNi5-xCox intermetallic compounds. Due to the competition between the anisotropy energies of both Co and Pr sublattices, this series has a spin-reorientation phenomenon at low temperature (140 K). The Curie temperature, as a function of Co content, has a sudden increase above a critical concentration xc ∼1.9 and this feature is assigned as a percolation of geometrically spaced Co clusters. This assumption is explained based on the critical exponent of percolation theory. The series presents therefore a rich magnetic phase diagram, which could be established over a full doping range, i.e., from x=0 to x=5. We have also studied these compounds on the magnetocaloric point of view and found a quite large full width at half maximum (δ TFWHM) of the magnetic entropy change curves for some of the compositions, due to the merging of the ΔS peaks associated with the spin-reorientation process and the Curie temperature TC. In addition, the series has an appreciable relative cooling power, which is therefore suitable to be used in a magnetic refrigerator operating in a large range of temperature. © 2009 The American Physical Society.791Wallace, W., Craig, R., Gupta, H., Hirosawa, S., Pedziwiatr, A., Oswald, E., Schwab, E., (1984) IEEE Trans. Magn., 20, p. 1599. , 10.1109/TMAG.1984.1063241Velu, E.M.T., Obermyer, R.T., Sankar, S.G., Wallace, W.E., (1989) IEEE Trans. Magn., 25, p. 3779. , 10.1109/20.42431Von Ranke, P.J., Pecharsky, V.K., Gschneidner, K.A., Korte, B.J., (1998) Phys. Rev. B, 58, p. 14436. , 10.1103/PhysRevB.58.14436Ermolenko, A.S., Rozhda, A.F., (1977) IEEE Trans. Magn., 13, p. 1339. , 10.1109/TMAG.1977.1059573Chuang, Y.C., Wu, C.H., Chang, S.C., Li, T.C., (1984) J. Less Common Met., 97, p. 245. , 10.1016/0022-5088(84)90029-8Andreyev, A.V., Deryagin, A.V., Zadvorkin, S.M., (1985) Phys. Met. Metallogr., 60, p. 96Van Mal, H.H., Buschow, K.H.J., Kuijpers, F.A., (1973) J. Less Common Met., 32, p. 289. , 10.1016/0022-5088(73)90095-7Ermolenko, A.S., (1979) IEEE Trans. Magn., 15, p. 1765. , 10.1109/TMAG.1979.1060377Von Ranke, P.J., Mota, M.A., Grangeia, D.F., Carvalho, A.M.G., Gandra, F.C.G., Coelho, A.A., Caldas, A., Gama, S., (2004) Phys. Rev. B, 70, p. 134428. , 10.1103/PhysRevB.70.134428Chuang, Y.C., Wu, C.H., Chang, Y.C., (1982) J. Less Common Met., 84, p. 201. , 10.1016/0022-5088(82)90145-XCoroian, N., Klosek, V., Isnard, O., (2007) J. Alloys Compd., 427, p. 5. , 10.1016/j.jallcom.2006.02.061Ibarra, M.R., Morellon, L., Algarabel, P.A., Moze, O., (1991) Phys. Rev. B, 44, p. 9368. , 10.1103/PhysRevB.44.9368Stauffer, D., Aharony, A., (1992) Introduction to Percolation Theory, , Taylor and Francis, LondonLopes, A.M.L., Araújo, J.P., Ramasco, J.J., Rita, E., Amaral, V.S., Correia, J.G., Suryanarayanan, R., (2006) Phys. Rev. B, 73, p. 100408. , 10.1103/PhysRevB.73.100408Zlotea, C., Isnard, O., (2002) J. Alloys Compd., 346, p. 29. , 10.1016/S0925-8388(02)00500-5Buschow, K.H.J., Brouha, M., (1976) J. Appl. Phys., 47, p. 1653. , 10.1063/1.322787Fahnle, M., Oesterreicher, H., (1984) Phys. Rev. B, 29, p. 2793. , 10.1103/PhysRevB.29.2793Fahnle, M., Oesterreicher, H., (1983) Phys. Rev. B, 27, p. 5586. , 10.1103/PhysRevB.27.5586Bray, A.J., (1987) Phys. Rev. Lett., 59, p. 586. , 10.1103/PhysRevLett.59.586Salamon, M.B., Lin, P., Chun, S.H., (2002) Phys. Rev. Lett., 88, p. 197203. , 10.1103/PhysRevLett.88.197203Magen, C., Algarabel, P.A., Morellon, L., Araujo, J.P., Ritter, C., Ibarra, M.R., Pereira, A.M., Sousa, J.B., (2006) Phys. Rev. Lett., 96, p. 167201. , 10.1103/PhysRevLett.96.167201Pecharsky, V.K., Gschneidner, K.A., (1999) J. Appl. Phys., 86, p. 565. , 10.1063/1.370767Gschneidner, K.A., Pecharsky, V.K., (2000) Annu. Rev. Mater. Sci., 30, p. 387. , 10.1146/annurev.matsci.30.1.38

A systematic survey of floral nectaries

The construction of classifications, as well as the understanding of biological diversity, depends upon a careful comparison of attributes of the organisms studied (Stuessy, 1990). It is widely known that data from diverse sources showing differences from taxon to taxon are of systematic significance. Dur-ing the 20th century, systematists have emphasized that their discipline involves a synthesis of all knowledge (Stevens, 1994) or, in other words, the variation of as many relevant characters as possible should be incorporated into the natural system to be constructed. The extent to which particular characters are constant or labile will determine their usefulness to syste-matics. In general, more conservative characters will be valuable in defining families and orders, whereas more labile characters may be useful at the ge-neric and specific levels (Webb, 1984). There is no doubt that floral characters are among the most used in the classification of flowering plants. At the same time, they constitute essential features in diagnostic keys to taxa in both taxonomic treatments and Floras (Cronquist, 1981, 1988).Fil: Bernardello, Gabriel Luis Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin

Anticoagulant selection in relation to the SAMe-TT2R2 score in patients with atrial fibrillation: The GLORIA-AF registry

Aim: The SAMe-TT2R2 score helps identify patients with atrial fibrillation (AF) likely to have poor anticoagulation control during anticoagulation with vitamin K antagonists (VKA) and those with scores >2 might be better managed with a target-specific oral anticoagulant (NOAC). We hypothesized that in clinical practice, VKAs may be prescribed less frequently to patients with AF and SAMe-TT2R2 scores >2 than to patients with lower scores. Methods and results: We analyzed the Phase III dataset of the Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation (GLORIA-AF), a large, global, prospective global registry of patients with newly diagnosed AF and 651 stroke risk factor. We compared baseline clinical characteristics and antithrombotic prescriptions to determine the probability of the VKA prescription among anticoagulated patients with the baseline SAMe-TT2R2 score >2 and 64 2. Among 17,465 anticoagulated patients with AF, 4,828 (27.6%) patients were prescribed VKA and 12,637 (72.4%) patients an NOAC: 11,884 (68.0%) patients had SAMe-TT2R2 scores 0-2 and 5,581 (32.0%) patients had scores >2. The proportion of patients prescribed VKA was 28.0% among patients with SAMe-TT2R2 scores >2 and 27.5% in those with scores 642. Conclusions: The lack of a clear association between the SAMe-TT2R2 score and anticoagulant selection may be attributed to the relative efficacy and safety profiles between NOACs and VKAs as well as to the absence of trial evidence that an SAMe-TT2R2-guided strategy for the selection of the type of anticoagulation in NVAF patients has an impact on clinical outcomes of efficacy and safety. The latter hypothesis is currently being tested in a randomized controlled trial. Clinical trial registration: URL: https://www.clinicaltrials.gov//Unique identifier: NCT01937377, NCT01468701, and NCT01671007

International Nosocomial Infection Control Consortium report, data summary of 50 countries for 2010-2015: Device-associated module

•We report INICC device-associated module data of 50 countries from 2010-2015.•We collected prospective data from 861,284 patients in 703 ICUs for 3,506,562 days.•DA-HAI rates and bacterial resistance were higher in the INICC ICUs than in CDC-NHSN's.•Device utilization ratio in the INICC ICUs was similar to CDC-NHSN's. Background: We report the results of International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2010-December 2015 in 703 intensive care units (ICUs) in Latin America, Europe, Eastern Mediterranean, Southeast Asia, and Western Pacific. Methods: During the 6-year study period, using Centers for Disease Control and Prevention National Healthcare Safety Network (CDC-NHSN) definitions for device-associated health care-associated infection (DA-HAI), we collected prospective data from 861,284 patients hospitalized in INICC hospital ICUs for an aggregate of 3,506,562 days. Results: Although device use in INICC ICUs was similar to that reported from CDC-NHSN ICUs, DA-HAI rates were higher in the INICC ICUs: in the INICC medical-surgical ICUs, the pooled rate of central line-associated bloodstream infection, 4.1 per 1,000 central line-days, was nearly 5-fold higher than the 0.8 per 1,000 central line-days reported from comparable US ICUs, the overall rate of ventilator-associated pneumonia was also higher, 13.1 versus 0.9 per 1,000 ventilator-days, as was the rate of catheter-associated urinary tract infection, 5.07 versus 1.7 per 1,000 catheter-days. From blood cultures samples, frequencies of resistance of Pseudomonas isolates to amikacin (29.87% vs 10%) and to imipenem (44.3% vs 26.1%), and of Klebsiella pneumoniae isolates to ceftazidime (73.2% vs 28.8%) and to imipenem (43.27% vs 12.8%) were also higher in the INICC ICUs compared with CDC-NHSN ICUs. Conclusions: Although DA-HAIs in INICC ICU patients continue to be higher than the rates reported in CDC-NSHN ICUs representing the developed world, we have observed a significant trend toward the reduction of DA-HAI rates in INICC ICUs as shown in each international report. It is INICC's main goal to continue facilitating education, training, and basic and cost-effective tools and resources, such as standardized forms and an online platform, to tackle this problem effectively and systematically