[The image diagnosis of dysbaric osteonecrosis].

OBJECTIVE: To investigate the imaging features of dysbaric osteonecrosis. METHODS: The imaging appearances of four patients with dysbaric osteonecrosis caused by diving, were analyzed retrospectively. RESULTS: In four cases with dysbaric osteonecrosis including case 1 with stage I, case 2 with stage II, case 3 and case 4 with stage III, there were a case with the lesion in a bone and other 3 cases with lesions in multiple bones,and a case with the lesion in unilateral bone and 3 cases with the lesions in lateral bones. (1) The juxta-articular lesions: there were 10 long bones with the head lesions, including 6 humerus with the head lesions and 4 femurs with the head lesions in 4 cases. In four cases, 10 sclerosis lesions appeared in the heads of long bones, each case had a "snow-capped" sclerosis lesion for case 2, case 3 and case 4. There were 7 small radiolucent lesions and a large radiolucent lesion involved in femur neck. The ringlike, linear, bending and punctuate calcification lesions were found on CT films of case 2. The osseous collapse in one femur head and the fragmentations in three femur heads could be seen in case 3 and case 4; 2 crescent signs can be seen in the bilateral femur heads of case 4 with secondary osteoarthritis in left hip joint. (2) The diaphyseal and metaphyseal lesions: the X ray film of case 4 showed the streak and irregular calcifications in the shaft of right humerus; there are strip calcifications in diaphyseal and metaphyseal of the left humerus on MPR coronal view in case 2. CONCLUSION: The diagnosis of dysbaric osteonecrosis suggested that the increased bone density or sclerosis lesions appeared in the heads of long bones, and osteonecrosis lesions were found in multiple bones or lateral bones.

Efficient and Recyclable RuCl3 ⋠3H2O Catalyst Modified with Ionic Diphosphine for the Alkoxycarbonylation of Aryl Halides.

A series of ionic (mono-/di-)phosphines (L2, L4, and L6) with structural similarity and their corresponding neutral counterparts (L1, L3, and L5) were applied to modulate the catalytic performance of RuCl3 ⋅ 3H2O. With the involvement of the ionic diphosphine (L4), in which the two phosphino-fragments were linked by butylene group, RuCl3 ⋅ 3H2O with advantages of low cost, robustness, and good availability was found to be an efficient and recyclable catalyst for the alkoxycarbonylation of aryl halides. The L4-based RuCl3 ⋅ 3H2O system corresponded to the best conversion of PhI (96 %) along with 99 % selectivity to the target product of methyl benzoate as well as the good generality to alkoxycarbonylation of different aryl halides (ArX, X=I and Br) with alcohols MeOH, EtOH, i-PrOH and n-BuOH. The electronic and steric effects of the applied phosphines, which were analyzed by the 31P NMR for 1 J 31 P- 77 Se 1 J measurement and single-crystal X-ray diffraction, were carefully co-related to the performance RuCl3 ⋅ 3H2O catalyst. In addition, the L4-based RuCl3 ⋅ 3H2O system could be recycled successfully for at least eight runs in the ionic liquid [Bmim]PF6.