Competition between the Pseudogap and superconducting states of Bi2Sr2Ca0.92Y0.08Cu2O8+δ single crystals revealed by ultrafast broadband optical reflectivity.

Ultrafast broadband transient reflectivity experiments are performed to study the interplay between the nonequilibrium dynamics of the pseudogap and the superconducting phases in Bi(2)Sr(2}Ca(0.92)Y(0.08)Cu(2)O(8+δ). Once superconductivity is established, the relaxation of the pseudogap proceeds ~2 times faster than in the normal state, and the corresponding transient reflectivity variation changes sign after ~0.5 ps. The results can be described by a set of coupled differential equations for the pseudogap and for the superconducting order parameter. The sign and strength of the coupling term suggest a remarkably weak competition between the two phases, allowing their coexistence.

Disentangling the electronic and phononic glue in a high-Tc superconductor.

Unveiling the nature of the bosonic excitations that mediate the formation of Cooper pairs is a key issue for understanding unconventional superconductivity. A fundamental step toward this goal would be to identify the relative weight of the electronic and phononic contributions to the overall frequency (Ω)-dependent bosonic function, Π(Ω). We performed optical spectroscopy on Bi(2)Sr(2)Ca(0.92)Y(0.08)Cu(2)O(8+δ) crystals with simultaneous time and frequency resolution; this technique allowed us to disentangle the electronic and phononic contributions by their different temporal evolution. The spectral distribution of the electronic excitations and the strength of their interaction with fermionic quasiparticles fully account for the high critical temperature of the superconducting phase transition.

[Defect fractures of the upper arm and their treatment in difficult circumstances. 3 case reports from Ethiopian and Somalian provincial hospitals]. / Defektschussbrüche des Oberarms und ihre Behandlung unter Schwierigen Bedingungen.Drei Fallberichte aus Provinzhospitälern Athiopiens und Somalias.

Gunshot fractures of the extremities often result in large bone defects and disability. The reconstruction of the bone is the essential precondition for a successful rehabilitation. This is a report on three patients who suffered from substantial bone defects of the humerus shaft caused by high-velocity bullets. In one patient the injury happened 3 days before admission, in another patient 5 months before. The third patient had a history of 11 years since the injury with numerous operations, bone grafts included. He presented with an infected non-union. All three patients had a complete radial nerve paralysis right from the beginning, as they have reported. Debridement, sequestrectomy and immobilisation by an external fixator with a device for compression and distraction were the first steps in management, followed by slow compression and, after a free interval, by distraction for 1 mm per day over a period of ca. 4 weeks. After distraction, one patient had early spontaneous callus formation. Two patients received a spongious bone graft, and in one of them decompression of the radial nerve was carried out during the operation for bone grafting. Subsequently, all three patients showed good callus formation. When strong ossification was visible on the X-rays, the fixator was removed and a PoP brace applied. The change from the external fixator to an internal fixation by a plate was not necessary and, under the prevailing conditions, not even possible. The patients were discharged with the brace and encouraged to continue with exercises. When the patients came back for a follow-up examination, the fracture sites were stable and the bones showed good consolidation. In two cases, the function of the radial nerve was nearly completely restored, in the patient with the long history, of course, there was no change. All three patients were free of infection. These three cases show that, even under the unfavourable conditions of civil war and in hospitals of less prosperous countries, the treatment of large bone defects can be successful, provided material and sometimes personnel support is, if necessary, given to the hospitals dealing with war and accident victims.

[Ilisarov callus distraction and callus compression in treatment of defect gunshot fractures, pseudarthroses and post-traumatic deformities in developing countries. A report of experiences in Cambodian and Ethiopian provincial hospitals]. / Kallusdistraktion und Kalluskompression nach Ilisarov in der Behandlung von Defektschussbrüchen, Pseudarthrosen und posttraumatischen Fehlstellungen in Ländern der Dritten Welt. Ein Erfahrungsvericht aus Provinzhospitälern Kambodschas and Athiopiens.

Between March 1989 and May 1993, a total of 22 patients were treated by Ilisarov's method of callus distraction and compression in provincial hospitals in Cambodia and Ethiopia. In both countries were times of civil war and unrest. The indications were high-velocity gunshot and explosive injuries with defect fractures (9 patients), infected and non-infected non-unions after gunshot injuries (6 patients) and civil accidents (3 patients), and deformities after civil accidents and gunshot injuries (4 patients). The deformities were leg shortening by between 5 and 7 cm and in 1 case ankylosis of the knee joint in 110 degrees flexion. A simple unilateral or V-shaped external fixator with devices for distraction and compression was applied. The results in 19 patients are known, while 3 patients have been lost to follow-up since discharge. In 1 case of an infected defect fracture (12 cm) fo the femur amputation was necessary because of sepsis. In all 6 other cases the bone defects were bridged by means of segmental transport, distraction and compression; in all 3 cases of shortening it was possible to restore the original length; similarly, in the case of knee joint ankylosis flexion of 10 degrees was achieved. All 5 infected non-unions healed well after sequesterectomy and segmental bone transport with distraction and compression, and the same holds for the 3 non-infected non-unions. However, in 7 cases a minor spongiosa bone graft was needed to consolidate the ossification at the contact point after distraction and/or compression.(ABSTRACT TRUNCATED AT 250 WORDS)