Prognostic factors in seminomas with special respect to HCG: Results of a prospective multicenter study

Objective: In a prospective multicenter trial, it was our intention to elucidate clinical prognostic factors of seminomas with special reference to the importance of human chorionic gonadotropin (HCG) elevations in histologically pure seminomas. Methods: Together with 96 participating urological departments in Germany, Austria, and Switzerland, we recruited 803 seminoma patients between 1986 and 1991. Out of 726 evaluable cases, 378 had elevated, while 348 had normal HCG values in the cubital vein. Histology was reviewed by two reference pathologists. HCG levels were determined in local laboratories and in a study laboratory. Standard therapy was defined as radiotherapy in stages I (30 Gy) and IIA/B (36 Gy) to the paraaortal and the ispilateral (stage I) and bilateral (stage IIA/B) iliac lymph nodes; higher stages received polychemotherapy and surgery in case of residual tumor masses. Statistics included chi-square tests, linear Cox regression, and log-rank test. Results: The HCG elevation is associated with a larger tumor mass (primary tumor and/or metastases). HCG-positive and HCG-negative seminomas had no different prognostic outcome after standard therapy. The overall relapse rate of 6% and the survival rate of 98% after 36 months (median) indicate an excellent prognosis. The calculation of the relative risk of developing a relapse discovered only stage of the disease and elevation of the lactate dehydrogenase concentration and its prolonged marker decay as independent prognostic factors for seminomas. A more detailed analysis of the prognostic significance of the stage revealed that the high relapse rate in stage IIB seminomas after radiotherapy (24%) is responsible for this result. Conclusions: We conclude that HCG-positive seminomas do not represent a special entity. Provided standard therapy is applied, HCG has no influence on the prognosis. Patients with stage IIB disease should be treated with chemotherapy because of the demonstrated higher relapse rate outside the retroperitoneum. Copyright (C) 1999 S. Karger AG. Basel

Physical map location of the peptide methionine sulfoxide reductase gene on the Escherichia coli chromosome

This is the publisher's version, also available electronically from "http://jb.asm.org".No abstract available

Novel Simulation-Inspired Roller Spreading Strategies for Fine and Highly Cohesive Metal Powders

When fine powders are to be used in powder bed metal additive manufacturing (AM), a roller is typically utilized for spreading. However, the cohesive nature of fine metal powder still presents challenges, resulting in low density and/or inconsistent layers under sub-standard spreading conditions. Here, through computational parameter studies with an integrated discrete element-finite element (DEM-FEM) framework, we explore roller-based strategies that are predicted to achieve highly cohesive powder layers. The exemplary feedstock is a Ti-6Al-4V 0-20 um powder, that is emulated using a self-similarity approach based on experimental calibration. The computational studies explore novel roller kinematics including counter-rotation as well as angular and transverse oscillation applied to standard rigid rollers as well as coated rollers with compliant or non-adhesive surfaces. The results indicate that most of these approaches allow to successfully spread highly cohesive powders with high packing fraction (between 50%-60% in a single layer) and layer uniformity provided that the angular/oscillatory, relative to the transverse velocity, as well as the surface friction of the roller are sufficiently high. Critically, these spreading approaches are shown to be very robust with respect to varying substrate conditions (simulated by means of a decrease in surface energy), which are likely to occur in LBPF or BJ, where substrate characteristics are the result of a complex multi-physics (i.e., powder melting or binder infiltration) process. In particular, the combination of the identified roller kinematics with compliant surface coatings, which are known to reduce the risk of tool damage and particle streaking in the layers, is recommended for future experimental investigation

Constructing the Cubus simus and the Dodecaedron simum via paper folding

The archimedean solids Cubus simus (snub cube) and Dodecaedron simum (snub dodecahedron) cannot be constructed by ruler and compass. We explain that for general reasons their vertices can be constructed via paper folding on the faces of a cube, respectively dodecahedron, and we present explicit folding constructions. The construction of the Cubus simus is particularly elegant. We also review and prove the construction rules of the other Archimedean solids.Comment: 13 pages, 12 figures, v2: as published in Geometriae Dedicat

Interaction of the 89K murine cytomegalovirus immediate-early protein with core histones

The conditions that permit the interaction of immediate-early proteins of murine cytornegalovirus (MCMV) with DNA were studied. Chromatography of extracts from infected cells on MCMV DNA cellulose and calf thymus DNA cellulose showed that pp89, the regulatory major immediate-early protein, interacts with DNA and dissociates at salt concentrations between 0.3 and 0.6 M NaCl. pp76, a cleavage product of pp89, and additional minor ie1 proteins eluted already at low ionic strength. Cellular DNA-binding factors were required for association of pp89 with DNA. These factors were identified as core histones. Chromatography of IE proteins on histone-Sepharose in the absence of DNA revealed a high-binding affinity that was resistant to 2 M NaCl. These results suggest that pp89 has no direct DNA-binding activity. A role for an amino acid sequence homology in the N-terminal region of pp89 with histone H2B in the pp89-histone-DNA Interaction is discussed

Escherichia coli peptide methionine sulfoxide reductase gene:regulation of expression and role in protecting against oxidative damage

This is the publisher's version, also available electronically from "http://jb.asm.org".The Escherichia coli peptide methionine sulfoxide reductase gene (msrA) encodes a single-subunit polypeptide of 212 amino acid residues (M. A. Rahman, H. Nelson, H. Weissbach, and N. Brot, J. Biol. Chem. 267:15549-15551, 1992). RNA blot analysis showed that the gene is transcribed into an mRNA of about 850 nucleotides. The promoter region was characterized, and the transcription initiation site was identified by primer extension. The synthesis of the MsrA protein increased about threefold in a growth-phase-dependent fashion. In an attempt to define the in vivo role of msrA, a chromosomal disruption was constructed. This mutant was more sensitive to oxidative stress, suggesting that oxidation of methionine in proteins plays an important role in oxidative damage

Spatial Mapping of Powder Layer Density for Metal Additive Manufacturing via X-ray Microscopy

Uniform powder spreading is a requisite for creating consistent, high-quality components via powder bed additive manufacturing (AM), wherein layer density and uniformity are complex functions of powder characteristics, spreading kinematics, and mechanical boundary conditions. High spatial variation in particle packing density, driven by the stochastic nature of the spreading process, impedes optical interrogation of these layer attributes. Thus, we present transmission X-ray imaging as a method for directly mapping the effective depth of powder layers at process-relevant scale and resolution. Specifically, we study layers of nominal 50-250 micrometer thickness, created by spreading a selection of commercially obtained Ti-6Al-4V, 316 SS, and Al-10Si-Mg powders into precision-depth templates. We find that powder layer packing fraction may be predicted from a combination of the relative thickness of the layer as compared to mean particle size, and flowability assessed by macroscale powder angle of repose. Power spectral density analysis is introduced as a tool for quantification of defect severity as a function of morphology, and enables separate consideration of layer uniformity and sparsity. Finally, spreading is studied using multi-layer templates, providing insight into how particles interact with both previously deposited material and abrupt changes in boundary condition. Experimental results are additionally compared to a purpose-built discrete element method (DEM) powder spreading simulation framework, clarifying the competing role of adhesive and gravitational forces in layer uniformity and density, as well as particle motion within the powder bed during spreading

Operator Method for Nonperturbative Calculation of the Thermodynamic Values in Quantum Statistics. Diatomic Molecular Gas

Operator method and cumulant expansion are used for nonperturbative calculation of the partition function and the free energy in quantum statistics. It is shown for Boltzmann diatomic molecular gas with some model intermolecular potentials that the zeroth order approximation of the proposed method interpolates the thermodynamic values with rather good accuracy in the entire range of both the Hamiltonian parameters and temperature. The systematic procedure for calculation of the corrections to the zeroth order approximation is also considered.Comment: 22 pages, 7 Postscript figures, accepted for publication in Journal of Physics