Weldability of high-toughness iron - 12 percent-nickel alloys with reactive metal additions of titanium, aluminum, or niobium

Three exceptionally high toughness Fe-12Ni alloys designed for cryogenic service were welded by using the gas tungsten arc welding process. Evaluation of their weldability included equivalent energy fracture toughness tests, transverse weld tensile tests at -196 and 25 C, and weld crack sensitivity tests. The Fe-12Ni-0.25Ti alloy proved extremely weldable for cryogenic applications, having weld and heat affected zone properties comparable to those of the wrought base alloy. The Fe-12Ni-0.5Al alloy had good weld properties only after the weld joint was heat treated. The Fe-12Ni-0.25Nb alloy was not considered weldable for cryogenic use because of its poor weld joint properties at -196 C and its susceptibility to hot cracking

Züchtung von Saflor für den ökologischen Landbau

Safflower (Carthamus tinctorius L.) yields valuable oil for human consumption be-cause of its high amount of linoleic acid. A large demand exists for this oil, but there is no organic production in Germany. The main objective of this research is to compare different methods of selection, to develop a simple non-destructive method for analyz-ing seed constituents such as oil content, and to develop lines with increased oil content and higher disease resistance

Aortic stent-grafting: successful introduction into the combined procedure for coronary artery bypass grafting and aortic aneurysm repair

Objectives: Coronary artery bypass grafting (CABG) and combined stent-grafting (SG) were evaluated to reduce morbidity and mortality of patients with descending or infrarenal aortic aneurysm. Methods: CABG and SG (thoracic n=6, infrarenal n=36) were performed during the same hospitalization in 42 patients (mean age of 73±14 years). In 29 patients (mean Euroscore: 9), SG was performed under local anesthesia 9±3 days after coronary surgery (simultaneous) and in 13 patients (mean Euroscore: 7) during the same anesthesia (synchronous). In the latter group, 11 out of 13 patients underwent off-pump CABG. All aneurysms were treated by implantation of commercially available self-expanding grafts. Results: CABG was successful in all, but one patient with left internal mammary artery hypoperfusion syndrome, requiring an additional distal saphenous graft to the left anterior descending coronary artery. SG was uneventful in 98% (41/42 patients). Postoperative computerized tomography showed incomplete sealing in seven patients (17%), but only the two attachment endoleaks had to be treated by one proximal and one distal SG extension. Overall hospital stay for the synchronous repair was 12.5±6 days and that of the simultaneous group 17.5±7 days. Thirty-day mortality was 5% (2/42) as one patient of the simultaneous group experienced a lethal cerebral embolism during SG and one patient of the synchronous group developed an untreatable infection. In the follow-up of 4 years, there were two vascular reinterventions but no additional procedure-related morbidity or mortality. Conclusions: This experience shows that combined CABG and SG of thoracic or infrarenal aortic aneurysm is a safe and less-invasive alternative to the open graft repair, especially in the older patients or patients with severe comorbiditie

Acute traumatic aortic rupture: early stent-graft repair

Objective: Prospective evaluation of early stent-graft repair of acute traumatic aortic rupture. Methods: Twelve patients with acute traumatic aortic rupture of the descending aorta, out of a series of 337 endovascular aortic procedures, were treated by implantation of self-expanding stent-grafts. The procedures were performed within a mean post-injury time-period of 5±7 days (median: 1 day). The feasibility of stent-grafting was assessed by CT scanning and echography. Implantation was performed under local (n=6), or general anesthesia (n=6) if patients were already intubated (n=5) or required a common iliac artery access (n=1). Results: The immediate technical success rate was 100%. There were no post-procedure complications in all but one patient, who died 12 h postoperatively (8% mortality). Complete sealing of the aortic rupture in the remaining 11 patients was confirmed by postoperative CT scans. There were no intervention-related morbidity or mortality during the mean follow-up of 17 months. One patient with peri-graft leakage was successfully repaired with an additional stent-graft 12 months postoperatively. Conclusion: Non-delayed or early stent-grafting in acute traumatic rupture of the descending aorta is feasible. This technique seems to be a valuable option, in particular when associated lesions may interfere with the surgical outcome. Immediate post-procedural CT scanning and/or echography should be performed, in order to rule out residual leakag

Beurteilung der Anbauwürdigkeit unterschiedlicher Herkünfte von Saflor (Carthamus tinctorius) und Leindotter (Camelina sativa) zur Speiseölgewinnung unter den Bedingungen des Ökologischen Landbaus in Mitteleuropa

Der Anbau von Ölpflanzen im Ökologischen Landbau Mitteleuropas beschränkt sich auf Raps und Sonnenblumen und erfolgt derzeit auf einem geringen Anteil der biologisch bewirtschafteten Fläche. Als alternative Ölpflanzenarten lassen Saflor und Leindotter für den Einsatz im Ökologischen Landbau eine besondere Eignung erwarten. 2002 wurden in einer zweiortigen Prüfung auf Mikroparzellen unter insgesamt nahezu 1000 Genotypen (Genbank-Akzessionen, Sorten, Zuchtstämme) beider Arten hierzu geeignete Formen gesucht. Neben der Resistenz gegen verschiedene Krankheiten wurden weitere agronomisch relevante Merkmale, ein daraus errechneter Index sowie das Parzellengewicht erhoben. Bei beiden Arten wurden für viele Merkmale eine große Variabilität sowie hohe Heritabilitäten gefunden. Insbesondere für Saflor war dies der Fall, wo die am besten adaptierten Herkünfte des geprüften Weltsortimentes - von wenigen Ausnahmen abgesehen - aus Europa stammten. Auch bei Leindotter konnten überlegene Formen identifiziert werden, die sich jedoch mehrheitlich unter dem Material außerhalb der GUS-Staaten befanden

Small-scale Dynamo in Cool Stars: I. Changes in stratification and near-surface convection for main-sequence spectral types

Some of the small-scale solar magnetic flux can be attributed to a small-scale dynamo (SSD) operating in the near-surface convection. The SSD fields have consequences for solar granular convection, basal flux, as well as chromospheric heating. A similar SSD mechanism is expected to be active in the near-surface convection of other cool main-sequence stars, but this has never been investigated. We aim to investigate changes in stratification and convection due to inclusion of SSD fields for F3V, G2V, K0V and M0V spectral types in the near-surface convection. 3D magnetohydrodynamic (MHD) models of the four stellar boxes, covering the subsurface convection zone up to the lower photosphere in a small cartesian box, are studied using the \textit{MURaM} radiative-MHD simulation code. The SSD runs are compared against reference hydrodynamic runs. An SSD is found to efficiently produce magnetic field with energies ranging between 5\% to 80\% of the plasma kinetic energy at different depths. This ratio tends to be larger for larger $T_{\mathrm{eff}}$. The relative change in density and gas pressure stratification for the deeper convective layers due to SSD magnetic fields is negligible, except for the F-star. For the F-star, there is a substantial reduction in convective velocities due to Lorentz force feedback from magnetic fields, which, in turn, reduces the turbulent pressure. SSD in near-surface convection for cool main-sequence stars introduces small but significant changes in thermodynamic stratification (especially for the F-star) due to reduction in convective velocities.Comment: 10 pages, 7 figures, accepted for publication in A&

Selektion anbauwürdiger Saflor-Formen für den Ökologischen Landbau aus einem zweijährigen Screening-Experiment

Als alternative Ölpflanze mit hervorragender Speiseölqualität könnte Saflor für den ökologischen Landbau dort in Frage kommen, wo Raps und Sonnenblumen weniger hohe Erträge zu liefern imstande sind. In der vorliegenden Studie sollte die Anbauwürdigkeit des Saflors unter den Bedingungen des Ökologischen Landbaues mit einem Screening von 741 ausgewählten Formen dieser Art überprüft werden. Das Experiment fand 2002 an zwei Standorten statt. Eine hieraus getroffene Auswahl von 65 geeigneten Herkünften wurde 2003 in einer dreiortigen Leistungsprüfung weiter getestet. 2002 wurden sowohl bei morphologischen als auch agronomisch wichtigen Merkmalen große Unterschiede zwischen den Herkünften gefunden. Besonders in der Anfälligkeit für verschiedene Krankheiten zeigte das Material eine große Variabilität. Neben ertragslosen Formen konnten eine Reihe von Genotypen mit ausreichendem Kornansatz geerntet werden, die zusätzlich im Mittel einen Kernanteil bis zu 40% aufwiesen. Das weitergeprüfte Material zeigte 2003 eine mit den Daten aus 2002 gut übereinstimmende Krankheitsanfälligkeit. Es kann hieraus gefolgert werden, dass es bei Saflor anbauwürdige Formen gibt, die auch unter unseren eher humiden Klimabedingungen noch ausreichende Leistungen erbringen können

Small-scale dynamo in cool main sequence stars. II. The effect of metallicity

All cool main sequence stars including our Sun are thought to have magnetic fields. Observations of the Sun revealed that even in quiet regions small-scale turbulent magnetic fields are present. Simulations further showed that such magnetic fields affect the subsurface and photospheric structure, and thus the radiative transfer and emergent flux. Since small-scale turbulent magnetic fields on other stars cannot be directly observed, it is imperative to study their effects on the near surface layers numerically. Until recently comprehensive three-dimensional simulations capturing the effect of small-scale turbulent magnetic fields only exists for the solar case. A series of investigations extending SSD simulations for other stars has been started. Here we aim to examine small-scale turbulent magnetic fields in stars of solar effective temperature but different metallicity. We investigate the properties of three-dimensional simulations of the magneto-convection in boxes covering the upper convection zone and photosphere carried out with the MURaM code for metallicity values of $\rm M/H = \{-1.0, 0.0, 0.5\}$ with and without a small-scale-dynamo. We find that small-scale turbulent magnetic fields enhanced by a small-scale turbulent dynamo noticeably affect the subsurface dynamics and significantly change the flow velocities in the photosphere. Moreover, significantly stronger magnetic field strengths are present in the convection zone for low metallicity. Whereas, at the optical surface the averaged vertical magnetic field ranges from 64G for M/H = 0.5 to 85G for M/H = -1.0.Comment: 13 pages, 18 figures, submitted to A&

CD107a(+) (LAMP-1) Cytotoxic CD8(+) T-Cells in Lupus Nephritis Patients

Cytotoxic CD8(+) T-cells play a pivotal role in the pathogenesis of systemic lupus erythematosus (SLE). The aim of this study was to investigate the role of CD107a (LAMP-1) on cytotoxic CD8(+) T-cells in SLE-patients in particular with lupus nephritis. Peripheral blood of SLE-patients (n = 31) and healthy controls (n = 21) was analyzed for the expression of CD314 and CD107a by flow cytometry. Kidney biopsies of lupus nephritis patients were investigated for the presence of CD8(+) and C107a(+) cells by immunohistochemistry and immunofluorescence staining. The percentages of CD107a(+) on CD8(+) T-cells were significantly decreased in SLE-patients as compared to healthy controls (40.2 +/- 18.5% vs. 47.9 +/- 15.0%, p = 0.02). This was even more significant in SLE-patients with inactive disease. There was a significant correlation between the percentages of CD107a(+)CD8(+) T-cells and SLEDAI. The evaluation of lupus nephritis biopsies showed a significant number of CD107a(+)CD8(+) T-cells mainly located in the peritubular infiltrates. The intrarenal expression of CD107a(+) was significantly correlated with proteinuria. These results demonstrate that CD8(+) T-cells of patients with systemic lupus erythematosus have an altered expression of CD107a which seems to be associated with disease activity. The proof of intrarenal CD107a(+)CD8(+) suggests a role in the pathogenesis of lupus nephritis