Notes: We describe the fabrication and characterization of super Schottky diodes which are used in the cryogenic part of a 3 GHz radio frequency superconducting quantum interference device (rf SQUID) readout electronics. The diodes were prepared on silicon wafers with an n-doping level of 5×1024 m−3. They exhibited sensitivities of 1500 V−1 at 4.2 K, and a noise equivalent power of 2×10−15 W/(square root of)Hz was measured at 2.1 GHz. Using planar niobium 3 GHz rf SQUIDs and a cooled rf amplifier, experiments have been performed to investigate the feasibility of these super Schottky diodes for demodulation of the SQUID rf signal voltage. A simple cryogenic rf SQUID readout, employing two transistors and one super Schottky diode is described and investigated. Flux noise measurements in an open loop have been performed using this readout. © 1995 American Institute of Physics.

Notes: Measurements of initial adsorption probabilities, S0, as well as the coverage dependence of the adsorption probability, S(aitch-thetaCO), of CO on Zn–ZnO [ZnO(0001)] and O–ZnO [ZnO(0001¯)] are presented. The samples have been characterized by He atom scattering, He atom reflectivity measurements, LEED, and XPS. Samples with different densities of defects were examined, either by investigating different samples with identical surface termination (for O–ZnO) or by inducing defects by ion sputtering at low temperatures (for Zn–ZnO). The influence of kinetic energy and impact angle (for Zn–ZnO) as well as adsorption temperature on the adsorption dynamics have been studied. For both polar surfaces the shape of the coverage dependent adsorption probability curves are consistent with a precursor mediated adsorption mechanism. Adsorbate assisted adsorption dominates the adsorption dynamics for high impact energies and low adsorption temperatures, especially for Zn–ZnO. The He atom reflectivity measurements point to the influence of an intrinsic precursor state. In contrast to the Zn–ZnO surface, for O–ZnO a weak thermal activation of the CO adsorption was observed. Total energy scaling is obeyed for Zn–ZnO. The heat of adsorption for CO on both polar faces varies between 7 kcal/mol (low coverage) and 5 kcal/mol (high coverage). A comparison of He atom reflectivity with S(aitch-thetaCO) curves demonstrates that CO initially populates defect sites on both surfaces. For O–ZnO an increase in S0 with decreasing density of defects was observed, whereas for the Zn-terminated surface S0 was independent of the defect density within the range of parameters studied. © 2000 American Institute of Physics.

Notes: Zusammenfassung Menschliches Pepsinogen II (PgII) wurde aus Magenschleimhautextrakten durch Immunoadsorbentien mit Hilfe von anti-PgII Antiserum isoliert. Spurensubstanzen von Pepsinogen I (PgI) wurden durch eine folgende anti-PgI Immunoadsorption entfernt. PgII wurde weiter auf DEAE-Sephadex A50 aufgetrennt. In der Agargelenzym-Electrophorese (AEE) bei pH 8,2 wurde PgII in fünf proteolytische Banden aufgetrennt. PgII wurde in Pepsin II (PII) durch die Ansäuerung bei pH 2,0 übergeführt und wurde anschließend von einem Inhibitor und von anderen Substanzen über DEAE gereinigt. Gereinigtes PII zeigte zwei proteolytische Bande in AEE bei pH 5,6 und war immunchemisch mit PgII identisch. „Gastricsin“ und „Pepsin“, die von saurem Magensaft durch klassiche Präparation hergestellt wurden, waren mit PII bzw. Pepsin I (PI) identisch. PII zeigte eine relativ breite pH-Aktivität mit einem Maximum bei pH 2,9. PII hydrolisierte in Gegensatz zu PI nicht N-Acetyl-Phenylalanyl-3,5-Diiodotyrosin und zeigte eine höhere Alkalistabilität als PI. Eine modifizierte Nomenklatur wird für das menschliche Pepsinogensystem vorgeschlagen.

Notes: Zusammenfassung Die immunchemisch homogene menschliche Pepsinogen I-Gruppe (PgI) wurde aus Magenschleimhautextrakt durch Immunoadsorbentien und durch DEAE-Chromatographie gereinigt. PgI ergab anläßlich der elektrophoretischen Auftrennung bei pH 8,2 5, bei pH 5,6 nur 4 proteolytische Banden. Nach Säureaktivierung wurde menschliches Pepsin (PI) vom Inhibitor durch Affinitätschromatographie mit Hilfe von Poly-L-Lysine abgetrennt. Gereinigtes PgI enthielt 9–16% des Inhibitor-Peptids. Die Ausbeute von PI betrug 64–85%. Eine Zunahme der spezifischen Aktivität um 65% wurde beobachtet. PI ergab in der Agargelelektrophorese bei pH 5,6 drei proteolytische Banden. Der pH-Bereich von PI war ziemlich weit und ergab zwei Maxima bei pH 2,0 und pH 3,0 unter Verwendung von Hämoglobin als Substrat. Eine irreversible Inaktivierung von PI wurde bei pH 7,0 und bei 60° C beobachtet. Der mit N-Acetyl-L-Phenyl-Alanyl-L-3,5 Diiodotyrosin bestimmte Km-Wert von PI betrug 0,170 mmol. Die spezifische Aktivität betrug 9,6 IU/mg (Hämoglobinsubstrat) und 0,032 IU/mg (Dipeptidsubstrat). Pepsinogen vom Schwein (PPg) und dessen aktiviertes Pepsin (PP) wurde zum Vergleich mit untersucht. PP ergab ein identisches Elutionsmuster in der Affinitätschromatographie. Nach elektrophoretischer Auftrennung ergaben PPg und PP zwei proteolytische Banden bei pH 5,6, die jedoch unterschiedliche elektrophoretische Mobilitäten aufwiesen. Das pH-Optimum von PP lag bei pH 2,0. PP war etwas mehr empfindlich gegenüber Alkali- und Hitzeinaktivierung als menschliches P. Im Vergleich zum menschlichen PI wurden bei PP höhere Km-Werte von 0,082 mmol und höhere spezifische Aktivitäten beobachtet.

Notes: Abstract. —We calculate elastic moduli and viscosities for media containing strongly interacting in-plane shear cracks. The cracks are randomly oriented or aligned, with equal length or a logarithmic size distribution. Our results from both a boundary element and a finite-element method suggest that the average moduli are best approximated by a differential, self-consistent model (DEM). Thus crack-to- crack interaction, which is considered in the DEM model, is important at high crack densities. This result seems to be different to results obtained from numerical experiments with highly fractured anti-plane shear cracks.

Notes: Abstract SQUIDs using Superconductor-Semiconductor-Superconductor (SSmS) proximity effect Josephson junctions were prepared and noise measurements were carried out. Since SSmS junctions are basic elements of Josephson field effect transistors (JoFETs), information about dynamic properties of JoFETs can be gained in this way. A planar geometry was used for the SSmS junctions, with a single crystalline silicon wafer acting as both, substrate and proximity layer. Rf- and dc-SQUIDs could be realized. When the SQUIDs were operated in a flux locked loop, flux noise values comparable to conventional tunnel junction SQUIDs were measured.

Notes: Summary Optimal labelling conditions of human platelets with111In-oxine were determined in vitro. Based on this optimized technique, platelet mean life span (MLS) and platelet sequestration site were comparatively evaluated in 79 patients with two labels,51Cr (n=26) and111In (n=53). Patients were subgrouped according to clinical criteria as autoimmune thrombocytopenic purpura (AITP) (group 1;n=49), hypersplenism (2;n=12), impaired thrombopoiesis (3;n=3), unclassified thrombocytopenia (4;n=6), and nonthrombocytopenic patients (5;n=9). In patients with AITP and hypersplenism the mean values for the MLS determined either with51Cr or with111In were lowered but the difference was not statistically significant, neither for group 1 (18.6 h vs 17.3 h;P〉0.2) nor for group 2 (94.7 vs 122.3 h;P〉0.2). The correlation between MLS and platelet counts in patients with AITP was significant for both labels (P〈0.001). The 15 min recovery tended to be higher with111In in all groups, but the difference was significant (P〈0.05) only for group 1. The sequestration sites were similar with both labels. We conclude that, contrary to previous reports, platelet survival studies yield similar results with both the51Cr and111In methods. Due to its distinct advantages111In is the label of choice for investigation of platelet kinetics.

Notes: Summary To investigate the etiopathogenesis of the common clinical symptoms of the lower lumbar spine (LS) and cervical spine (CS) (lower back pain and local cervical spine syndrome), the dimensions of the third to fifth lumbar vertebral bodies (LVB) and the fifth to seventh cervical vertebral bodies (CVB) were studied quantitatively and morphometrically in frontal and sagittal planes, as a function of sex and age, in 105 human cadavers of both sexes aged between 16 and 91 years. The evaluation was done in X-ray pictures of 100-μm-thick polished bone sections with the aid of the Macro Facility of the Leitz Texture Analysis System. In each case, the maximum and minimum heights and widths and depths and the computed differences in heights, widths, and depths were determined. The results were evaluated statistically and compared within and between the two regions of the spine, using regression-correlation analyses. The heights, widths, and depths of the VB are all greater in men than in women; their behavior during ageing is, however, identical for both sexes. The heights of all the VB examined remain constant throughout life after termination of growth. The maximun widths and the width differences reveal an increase in both LVB and CVB in old age. All depth parameters reveal constancy in the case of the LVB but an increase in the case of the CVB in old age. The correlation coefficients of the maximum width of the VB within the spinal regions are very high in the LVB, but lower in the CVB. Between the two regions, in contrast, they are very low. This behavior suggests a superordinate action principle within each of the spinal regions which is based on characteristic anatomical construction and functional stressing. The static stressing of the LVB leads, laterally to disc protrusions. As a result of this, traction forces acting on the weak lateral elements of the anterior longitudinal ligament, stimulate the accretion of spondylotic osteophytes at the point of insertion of the ligament on the vertebral body. Anteriorly, in contrast, the particular strong anterior longitudinal ligament prevents such a remodelling process. Posteriorly, the longitudinal ligament is attached to the intervertebral discs, and can thus not stimulate the vertebral body to produce osteophytes. The dynamic stressing of the CVB leads laterally to friction between the VB in the region of the uncovertebral joints and to the formation of arthrotic osteophytes. Anteriorly, owing to the weak configuration of the anterior longitudinal ligament in this aspect, disc protrusion occur and, subsequently, spondylotic osteophytes accrete. Posteriorly, the (posterior) longitudinal ligament is also attached to the intervertebral discs, and can thus provide no ossification stimulus. Lateral arthrotic and anterior spondylotic osteophytes at the CVB are thus the result of etiopathogenetically different processes, and can occur independently of each other. The also differing etiopathogenesis of lateral osteophytes in the case of the LVB and CVB, presenting as spondylosis or arthrosis, also finds statistical expression in a very small correlation of the maximum widths of the VB in both regions of the spine. Spondylotic osteophytes occurring laterally at the LVB and anteriorly at the CVB do not of themselves cause clinical symptoms. These are rather a sequela of motion segment instability, where overloading of the supporting structures can give rise to a local chronic spinal syndrome. Arthrotic osteophytes occurring laterally on the CVB, in contrast, can, as a result of the pressure twenty-three consecutive patients aged 33–80 years with a presumed Sudeck's syndrome of one hand or one foot were seen. A fracture initiated the syndrome in three-quarters of them, and the median duration of suffering was 3.5 months in the hand and 7 months in the foot. Osteoporosis and marked 99mTc-labeled methylene diphosphonate uptake were seen in radiographs and scintigrams respectively. Thirteen of the patients were operatively treated; distal fasciotomy on the volar aspect of the forearm or the ventral aspect of the lower leg gave rapid relief from pain at rest in nine of ten patients thus affected. All the patients became symptom-free, except two who underwent closed treatment. At follow-up 2–8 years later radiographic and scintigraphic findings were usually normal.