225Ac and 223Ra production via 800 MeV proton irradiation of natural thorium targets.

Cross sections for the formation of (225,227)Ac, (223,225)Ra, and (227)Th via the proton bombardment of natural thorium targets were measured at a nominal proton energy of 800 MeV. No earlier experimental cross section data for the production of (223,225)Ra, (227)Ac and (227)Th by this method were found in the literature. A comparison of theoretical predictions with the experimental data shows agreement within a factor of two. Results indicate that accelerator-based production of (225)Ac and (223)Ra is a viable production method.

Primary arthroplasty of infected hips and knees in special cases using antibiotic-loaded bone-cement for fixation.

As a consequence of successful 1-stage exchange of infected joint prostheses, we decided to treat bacterial infection of the hip or knee by joint resection, synovectomy, and primary implantation of a hip or stabilized knee prosthesis. Since 1984, we have performed this procedure on 51 hips and 32 knees. All operations were preceded by identification of the causative organism and choice of appropriate antibiotics for addition to the bone-cement. The long-term rate of success corresponds to that of 1-stage exchange of infected prostheses. The different anatomic conditions at the hip and knee have to be taken into consideration. This treatment is restricted to special cases and should be performed only in specialized clinics with competent assistance from a bacteriologist.

Coordination trends in alkali metal crown ether uranyl halide complexes: the series [A(crown)]2[UO(2)X(4)] where A=Li, Na, K and X=Cl, Br.

UO(2)(C(2)H(3)O(2))(2).2H(2)O reacts with AX or A(C(2)H(3)O(2) or ClO(4)) (where A = Li, Na, K; X = Cl, Br) and crown ethers in HCl or HBr aqueous solutions to give the sandwich-type compounds [K(18-crown-6)](2)[UO(2)Cl(4)] (1), [K(18-crown-6)](2)[UO(2)Br(4)] (2), [Na(15-crown-5)](2)[UO(2)Cl(4)] (3), [Na(15-crown-5)](2)[UO(2)Br(4)] (4), [Li(12-crown-4)](2)[UO(2)Cl(4)] (5), and [Li(12-crown-4)](2)[UO(2)Br(4)] (6). The compounds have been characterized by single-crystal X-ray diffraction, powder diffraction, elemental analysis, IR, and Raman spectroscopy. The [UO(2)X(4)](2-) ions coordinate to two [A(crown)](+) cations through the four halides only (2), through two halides only (3), through the two uranyl oxygens and two halides (3, 4), or through the two uranyl oxygen atoms only (5, 6). Raman spectra reveal nu(U-O) values that correlate with expected trends. The structural trends are discussed within the context of classical principles of hard-soft acid-base theory.

Hydrothermal synthesis of the first organically templated open-framework uranium phosphate.

[(C2H5)2NH2]2[(UO2)5(PO4)4] was prepared from U3O8, HONEt2 and phosphoric acid under hydrothermal conditions (180 degrees C, 5 days) and represents the first three-dimensional open-framework uranium phosphate prepared to date.

[Therapy of bacterial knee joint infection by radical synovectomy and implantation of a cemented stabilized knee joint endoprosthesis]. / Therapie der bakteriellen Gonitis durch radikale Synovektomie und Einsetzen einer zementierten stabilisierten Kniegelenkendoprothese.

INTRODUCTION: The report presents an alternative to the treatment of joint destruction in cases of knee joint empyema by resection or arthrodesis: implantation of a stabilised knee prosthesis using antibiotic-loaded bone cement for fixation. METHOD: From 1985 to 1997 a total of 33 knees in 32 patients (21 female, 12 male) were treated for knee empyema by radical synovectomy and implantation of a stabilised knee prosthesis fixed in position with antibiotic-loaded bone cement. The antibiotics were chosen according to the antibiogram of the pathogen. In all these cases the infections had not responded to previous treatment. The criterion for success was the elimination of infection. The follow-up period ranged from 2 to 15 years. RESULTS: Of 33 infected knees 31 (93.9%) were followed up. In 22 cases (71.0%) the infection was eliminated by primary surgery. In five cases (16.1%) further exchange operations were necessary to eliminate the infection. In four cases (12.9%) preservation of the joint was not possible. CONCLUSION: Uncontrolled infection in cases of knee empyema and destruction of the joint can be treated by radical synovectomy and implantation of a stabilised knee prosthesis using antibiotic-loaded bone cement for fixation. The success rate corresponds to the results of one-stage exchange arthroplasty to treat periprosthetic infection of knee prostheses. This therapy should be performed only in specialised centres which have the facilities and personnel essential for accurate bacteriological diagnosis and recommendation.