Antimony-121 Mossbauer spectral study of the Eu14MnSb11 and Yb14MnSb11 Zintl compounds

The antimony-121 Mossbauer spectra of the Yb14MnSb11 and Eu14MnSb11 Zintl compounds have been measured between 2 or 5 and 300 K. The resulting three-dimensional arrays of the spectral counts, velocity, and temperature have been simultaneously fit with a minimum number of free parameters. These fits yield a 0 Kelvin transferred hyperfine field of 2.9(2) T, a Curie temperature of 57(3) K, and a Mossbauer temperature of 182(2) K for Yb14MnSb11; in this case the transferred field arises solely from the ordering of Mn2+. Because Eu14MnSb11 has both Eu2+ and Mn2+ ions that are magnetically ordered, its antimony-121 Mossbauer spectra are more complex and reveal two magnetic transitions, the first at 92(1) K resulting from the ordering of the Mn 2+ ions and the second at 9.5(1.0) K resulting from the ordering of the Eu2+ ions; the corresponding 0 Kelvin transferred hyperfine fields are 1.3(1) and 3.7(1) T. The antimony-121 isomer shifts yield electronic configurations of 5s(1.74)5p(4.28) and 5s(1.74)5p(4.19) for the average antimony anion in Yb14MnSb11 and Eu14MnSb11, respectively

The role of structure and interface in the performance of TiSnSb as an electrode for Li-ion batteries

The lithium-ion battery electrode material TiSnSb shows excellent electrochemical performance related to its high capacity (550 mA h g−1) and rate capability over 210 cycles. To discriminate between the role of active material and the role of the electrode formulation in the good electrochemical features of the TiSnSb electrodes, a full study comparing the electrochemical mechanisms of TiSnSb and a Ti/ Sn/Sb composite vs Li is undertaken by combining X-ray diffraction (XRD), 121Sb, 119Sn Mössbauer and 7Li NMR spectroscopic in situ measurements. During the first discharge, TiSnSb undergoes a direct conversion reaction while Ti/Sn/Sb composites proceed by a stepwise alloying process, both leading to a mixture of lithium antimonide, lithium stannides, and titanium. More surprisingly the charge occurs differently with a reformation of the "TiSnSb" phase in the first case and the formation of Sn and Sb in the second case. The key role of the interfaces in conversion type reactions is discussed. The nature of the interfaces is linked to the long-range order of elements in the starting material. Furthermore, the length scales of the interfaces between Li3Sb, LixSn and Ti appear to control the reactions that occur on charge.Advanced lithium energy storage systems based on the use of nano-powders and nano-composite electrodes/electrolytes (ALISTORE

Efficacy and tolerability of antibiotic combinations in neurobrucellosis: Results of the Istanbul study

PubMed ID: 22155822No data on whether brucellar meningitis or meningoencephalitis can be treated with oral antibiotics or whether an intravenous extended-spectrum cephalosporin, namely, ceftriaxone, which does not accumulate in phagocytes, should be added to the regimen exist in the literature. The aim of a study conducted in Istanbul, Turkey, was to compare the efficacy and tolerability of ceftriaxone-based antibiotic treatment regimens with those of an oral treatment protocol in patients with these conditions. This retrospective study enrolled 215 adult patients in 28 health care institutions from four different countries. The first protocol (P1) comprised ceftriaxone, rifampin, and doxycycline. The second protocol (P2) consisted of trimethoprim-sulfamethoxazole, rifampin, and doxycycline. In the third protocol (P3), the patients started with P1 and transferred to P2 when ceftriaxone was stopped. The treatment period was shorter with the regimens which included ceftriaxone (4.40 ± 2.47 months in P1, 6.52 ± 4.15 months in P2, and 5.18 ± 2.27 months in P3) (P = 0.002). In seven patients, therapy was modified due to antibiotic side effects. When these cases were excluded, therapeutic failure did not differ significantly between ceftriaxone-based regimens (n = 5/166, 3.0%) and the oral therapy (n = 4/42, 9.5%) (P = 0.084). The efficacy of the ceftriaxone-based regimens was found to be better (n = 6/166 [3.6%] versus n = 6/42 [14.3%]; P = 0.017) when a composite negative outcome (CNO; relapse plus therapeutic failure) was considered. Accordingly, CNO was greatest in P2 (14.3%, n = 6/42) compared to P1 (2.6%, n = 3/117) and P3 (6.1%, n = 3/49) (P = 0.020). Seemingly, ceftriaxone-based regimens are more successful and require shorter therapy than the oral treatment protocol. Copyright © 2012, American Society for Microbiology. All Rights Reserved

Neurobrucellosis: Results of the Istanbul Study

No data on whether brucellar meningitis or meningoencephalitis can be treated with oral antibiotics or whether an intravenous extended-spectrum cephalosporin, namely, ceftriaxone, which does not accumulate in phagocytes, should be added to the regimen exist in the literature. The aim of a study conducted in Istanbul, Turkey, was to compare the efficacy and tolerability of ceftriaxone-based antibiotic treatment regimens with those of an oral treatment protocol in patients with these conditions. This retrospective study enrolled 215 adult patients in 28 health care institutions from four different countries. The first protocol (P1) comprised ceftriaxone, rifampin, and doxycycline. The second protocol (P2) consisted of trimethoprim-sulfamethoxazole, rifampin, and doxycycline. In the third protocol (P3), the patients started with P1 and transferred to P2 when ceftriaxone was stopped. The treatment period was shorter with the regimens which included ceftriaxone (4.40 +/- 2.47 months in P1, 6.52 +/- 4.15 months in P2, and 5.18 +/- 2.27 months in P3) (P = 0.002). In seven patients, therapy was modified due to antibiotic side effects. When these cases were excluded, therapeutic failure did not differ significantly between ceftriaxone-based regimens (n = 5/166, 3.0%) and the oral therapy (n = 4/42, 9.5%) (P = 0.084). The efficacy of the ceftriaxone-based regimens was found to be better (n = 6/166 [3.6%] versus n = 6/42 [14.3%]; P = 0.017) when a composite negative outcome (CNO; relapse plus therapeutic failure) was considered. Accordingly, CNO was greatest in P2 (14.3%, n = 6/42) compared to P1 (2.6%, n = 3/ 117) and P3 (6.1%, n = 3/ 49) (P = 0.020). Seemingly, ceftriaxone-based regimens are more successful and require shorter therapy than the oral treatment protocol