High-temperature dislocation plasticity in the single-crystal superalloy LEK94.

The evolution of the dislocation structure that forms during uniaxial creep deformation in the single-crystal superalloy LEK94 of low density and with Re additions was analysed using transmission electron microscopy. The material has a gamma/gamma'-microstructure consisting of gamma'-cubes (L12 phase, 80 vol.%) separated by thin gamma-channels (face-centred cubic). <100> tensile creep tests were performed at 980 and 1020 degrees C at stresses of 200 and 240 MPa. The microstructure was investigated at three characteristic stages of creep (directly after loading, at 5% strain and after rupture) to show the evolution of the dislocation structure during high-temperature creep. It was found that in the early stages of creep, a(0)/2<011> dislocations form within the gamma-channels. Later on, dislocation networks form and gamma' cutting processes with a(0)/<001> superdislocations are observed. The results are in line with observations made for other superalloy single crystals in the high-temperature low-stress creep regime.

[Catamnestic evaluation of patients in a sterility consultation with reference to andrologic prognosis of fertility]. / Katamnestische Auswertung der Patientinnen der Sterilitätssprechstunde unter dem Aspekt der andrologischen Fertilitätsprognose.

In the present article the rate of conceptions of 463 couples were catamnestically analysed concerning the andrological prognosis and gynecological causes of infertility. 49,9% of the men had a normal spermiogram, 10,2% were infertile and 39,9% of patients were subfertile. Disturbances of ovarian function represented the main cause of the female sterility (62,7%). 36,2% of the patients conceived during the gynecological and andrological treatment. The rate of pregnancies decreased dependent on reduction of male fertility. We observed 19,6% abortions and 3,1% ectopic pregnancies. The percentage of abortions and ectopic pregnancies increased in case of pathological spermiograms.

[Information obtainable from hysterosalpingography and laparoscopy and importance of tubal factor in sterile patients (author's transl)]. / Der Aussagewert von Hysterosalpingographie und Laparoskopie und die Bedeutung des Tubenfaktors bei Sterilitätspatientinnen.

Hysterosalpingography was used in 437 instances and laparoscopy in 99 to check 455 women for tubal patency who come to seek special advice for sterility. Hysterosalpingography was used together with laparoscopy, the latter second in time, on 81 women. Findings agreed in 64.2 per cent and differed in 35.8 per cent. Tubal occlusion was recorded from 106 patients (23.3 per cent). They were unilateral in 70 cases (66.04 per cent) and collateral in 36 cases (33.96 per cent). Thirty-one of the latter 106 women (29.24 per cent) with unilateral or collateral tubal occlusion turned pregnant. Yet, pregnancy occurred only to five of the above 36 women with collateral occlusion. The causes of those apparent tubal occlusions are discussed.

[Results obtained from sterility treatment at Gynaecological Hospital of Leipzig (author's transl)]. / Ergebnisse der Sterilitätsbehandlung an der Städtischen Frauenklinik Leipzig.

Between May 1974 and December 1977, the authors were consulted for sterility problems by 698 women, among them 693 together with their partners. Thirty-three of them were unmarried, 642 married, and 23 divorced. Primary sterility was recorded from 478 women (68.48 per cent) and secondary sterility from 220 women (31.52 per cent). A total of 318 pregnancies then was diagnosed, which corresponded to a rate of success of 46 per ent, uncorrected.

[Does the HLA-system enrich our possibilities within the scope of sterility diagnosis?]. / Bereichert das HLA-System unsere Möglichkeiten im Rahmen der Sterilitäts-Diagnostik?

Since the HLA antigens were discovered there were great advances especially in organ transplantation, paternity test and human genetics. --It follows the question after the relevance of HLA antibodies as a reason for infertility. --Bachner, Stolp and coworkers estimated a high frequency of HLA antibodies in infertile women. --In contrast we found in our own investigations: 367 unselected women with undesired infertility showed HLA antibodies in none of the cases.