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Railway axles are designed for an infinite life with admissible stress levels which correspond to generous safety factors applied to full‐scale fatigue properties of materials. Nevertheless, in order to keep an adequate safety level for such a long‐lasting component (an axle can typically run for 3×106km) subjected to surface deterioration or corrosion, the design is complemented by “damage tolerance” analyses, in which it is assumed that a flaw could grow under service loads, in order to define an appropriate inspection plan. The ultimate “damage tolerance” approach is to design an axle so that there is no need for periodic NDT inspections except those carried out at overhauls (the so called “one million miles axle”). The aim of this paper is to describe the application of this concept to the axle of a freight train comparing this new design concept with the traditional fatigue design.

High power ultrasonic technology can currently count on a number of industrial applications. Ultrasonic welding, which is a standard joining technique in many applications on plastics, has few but well established metal applications, such as copper wires, pipes and connectors welding, or, considering spot welding of aluminium thin sheets, is attractive for the automotive industry field, where it could represent a possible cost effective alternative to resistance spot welding, clinching or self‐pierce riveting. The present experimental study is addressed to this kind of application in order to evidence the effects of welding parameters and, most of all, their interactions on the tensile strength of tensile–shear spot welded lap joints. Relevant results have been achieved by dedicated and non‐conventional instrumentations applied to the welder for measuring and controlling the process parameters. The best static performance has been taken as an input for the second part of the study regarding the fatigue behaviour and the joints failure modes.

The present paper reports the second part of a research carried out by the authors on the application of ultrasonic metal spot welding to lap joints made of AA 6022‐T4 thin sheets. In particular, starting from the findings of Part 1, tensile–shear fatigue experiments are carried out on ultrasonically spot welded lap joints both in single and double spot configurations. The analysis of consequent failure causes and modes and the application of traditional approaches for fatigue assessment of resistance spot welded joints allow then effectively predicting experimental evidences. Furthermore, an optimisation of the fatigue behaviour of double spot joints (longitudinal spots configuration) is achieved in terms of endurable load and distance between spots, with a possible generalisation to multiple spot configurations. Finally, a comparison of the fatigue performance of the ultrasonic technique to other spot joining techniques is presented.

Abstract.: The interaction of a Grand Unification Magnetic Monopole with a nucleon can lead to a barion-number violating process in which the nucleon decays into a lepton and one or more mesons (catalysis of nucleon decay). In this paper we report an experimental study of the effects of a catalysis process in the MACRO detector. Using a dedicated analysis we obtain new magnetic monopole (MM) flux upper limits at the level of for , based on the search for catalysis events in the MACRO data. We also analyze the dependence of the MM flux limit on the catalysis cross section.

Muon energy measurement represents an important issue for any experiment addressing neutrino-induced up-going muon studies. Since the neutrino oscillation probability depends on the neutrino energy, a measurement of the muon energy adds an important piece of information concerning the neutrino system. We show in this paper how the MACRO limited streamer tube system can be operated in drift mode by using the TDCs included in the QTPs, an electronics designed for magnetic monopole search. An improvement of the space resolution is obtained, through an analysis of the multiple scattering of muon tracks as they pass through our detector. This information can be used further to obtain an estimate of the energy of muons crossing the detector. Here we present the results of two dedicated tests, performed at CERN PS-T9 and SPS-X7 beam lines, to provide a full check of the electronics and to exploit the feasibility of such a multiple scattering analysis. We show that by using a neural network approach, we are able to reconstruct the muon energy for E μ <40 GeV . The test beam data provide an absolute energy calibration, which allows us to apply this method to MACRO data.

The angular distribution of upward-going muons produced by atmospheric neutrinos in the rock below the MACRO detector shows anomalies in good agreement with two flavor νμ→ντoscillations with maximum mixing and Δm2around 0.0024 eV2. Exploiting the dependence of magnitude of the matter effect on oscillation channel, and using a set of 809 upward-going muons observed in MACRO, we show that the two flavor νμ→νsoscillation is disfavored with 99% C.L. with respect to νμ→ντ.

Available data on changes in serum levels of bone markers after parathyroidectomy (PTx) in dialysis patients are not uniform. Changes are thought to be due to either a reduction in PTH activity per se or to a direct effect of vitamin D therapy on bone cells. We aimed to verify whether treatment with vitamin D modifies serum levels of markers of bone synthesis (alkaline phosphatase (AP), osteocalcin (BGP), procollagen type I C-terminal peptide (PICP)) and resorption (collagen type I C-terminal peptide (ICTP)) within a period of 15 days in haemodialysis patients with severe secondary hyperparathyroidism following PTx.

The postoperative course of 159 patients with early gastric cancer operated on between 1974 and 1987 was followed for a median of 7.3 years. The cumulative 10-year survival rate(s.e.) calculated using follow-up data to the end of 1989 was 90.6(2.7) per cent excluding operative death and that from causes other than gastric cancer, or 86.3(3.0) per cent when operative mortality was included. The overall 10-year survival rate(s.e.) was 77.3(3.7) per cent. Univariate analysis showed a significant difference in survival rates between cancers confined to the mucosa and those with submucosal invasion (P = 0.02), between patients with and without lymph node metastases (P = 0.05) and between those >50 and >50 years of age (P = 0.02). Using Cox multivariate analysis and a stepwise procedure for eight variables (sex, age, depth of invasion, lymph node metastases, presence of ulceration, location, histological type, type of surgery), age and histological type had the most significant effect on survival. Seven operative deaths were recorded. Eleven patients died from recurrent cancer and one is still alive with a gastric remnant recurrence. Other causes of death were metachronous primary cancer (six patients), cardiovascular disease (two), pneumonia (three), sepsis (one) and car accident (one). Although the prognosis of early gastric cancer is relatively good in western countries, patients should be carefully followed over a long period for late recurrence and for metachronous cancer, which has a high incidence.

Detailed analyses of biochemical and microbiological variables such as pH, nitrite concentration, total viable counts (TVC). nitrate reductase-positive bacterial counts (NRPBC), and identification of microorganisms were carried out on 76 fasting gastric juice samples obtained at endoscopy from 64 patients previously submitted to partial gastrectomy (22 end-to-end Billroth I, 42 Billroth II/Reichel-Polya) and from 12 normal controls. Samples from normal controls were sterile, but bacteria were detected in the juice from all the operated patients. Significantly higher mean pH values and nitrite levels (p > 0.001) were found in partial gastrectomies than in normal controls. In relation to surgical methods, higher mean pH values (p > 0.005). nitrite levels (p > 0.01), TVC (p > 0.01), and NRPBC (p > 0.005) were observed in the juice of patients with Billroth II as compared with Billroth I gastrectomies. Anaerobic bacteria, typical of faecal flora, and particularly Escherichia coli (p > 0.05) characterized Billroth II samples. All these data suggest that the presence of bacteria in the gastric juice of gastroresected patients can be considered a risk factor of gastric neoplasia and that the type of operation used for the reconstruction of digestive continuity may influence the magnitude of this risk.

The uncoupling of the calf thymus Topoisomerase I-mediated forward DNA cleavage reaction from the religation event by a rapid shift of cleavage temperature either from 37 °C to 0 °C or from 37 °C to 56 °C has been studied and utilized to elucidate the molecular mechanism by which camptothecin, a clinically relevant antineoplastic agent, influences the half reactions of the enzyme. Results of heating and cooling religation-inducing treatments have been compared: both temperature extremes reduce the amount of protein-linked DNA breaks to background levels, thereby affecting cleavage reversal. Camptothecin is found to stabilize the enzyme-DNA intermediate, by inhibition of the Topoisomerase I-mediated rejoining of cleaved DNA, even when the drug is added after formation of the complex. We conclude that:1.Heating and cooling treatments show a pronounced effect on the DNA cleavage-religation equilibrium. The efficacy of cold is more pronounced than that of heat.2.Reversal of the enzyme-DNA intermediate favors the DNA resealing versus the closed relaxed form.3.Camptothecin affects the heat or cold induced religation: in fact in both cases the drug delays the religation step.

Zusammenfassung Die chronisch atrophische Gastritis gilt als Präcancerose für ein Magencarcinom. Um die Korrelation zwischen fortgeschrittenen Schleimhautveränderungen und von Faktoren, die auf den Magensaft wirken und bei denen man einen Zusammenhang mit der durch Nitratverbindungen verursachten Carcinogenese vermutet, zu studieren, wurde eine sorgfältige Analyse biochemischer und mikrobiologischer Parameter wie pH, die Zählung aller Lebewesen im Mikromilieu (TVC), die Zählung aller Nitratreduktase-positiven Bakterien (NRPBC), Nitrit (NO2-) und Tiocyanat (SNC-)-Spiegel, an 56 Magensaftproben durchgeführt, die endoskopisch von nüchternen Patienten gewonnen wurden; 28 Patienten litten an chronisch atrophischer Gastritis (CAG), 14 hatten ein Magencarcinom (GC) und 14 dienten als Kontrollgruppe (NC). Die Mittelwerte von pH, Nitrit, TVC und NRPBC lagen in der Kontrollgruppe signifikant niedriger als in der Gruppe mit chronisch atrophischer Gastritis und Magencarcinomen. Weiter lagen die Mittelwerte einiger Parameter im Magensaft der Carcinompatienten höher als bei denen mit chronischer atrophischer Gastritis. Kein signifikanter Unterschied wurde zwischen den drei Gruppen für den Tiocyanatspiegel gefunden, der im wesentlichen durch Rauchergewohnheiten beeinflußt wurde. Die 28 Patienten mit chronisch atrophischer Gastritis wurden in zwei Gruppen unterteilt (Gruppe A: diffuse chronisch atrophische Gastritis — DCAG; Gruppe B: multizentrische chronisch atrophische Gastritis — MCAG) entsprechend dem Befall durch Schleimhautatrophie von Magencorpus und -fundus neben dem Antrum. Die Mittelwerte von pH, Nitrit, TVC und NRPBC waren in der MCAG-Gruppe signifikant höher als in der Kontrollgruppe, aber statistisch niedriger als in der DCAG- bzw. Carcinom-Gruppe. In diesen beiden Gruppen wurde kein Unterschied für die gleichen Variablen gefunden. Der Prozentsatz kontaminierten Magensaftes lag in der DCAG- und der Carcinom-Gruppe im Vergleich zur MCAG-Gruppe höher, kein Unterschied wurde zwischen DCAG- und Carcinom-Mägen gefunden. Das Ergebnis dieser Studie legt nahe, daß die diffuse chronisch atrophische Gastritis eher dem Risiko einer durch Nitratverbindungen verursachten Carcinogenese ausgesetzt ist.

Persistent patency of the ductus arteriosus (PDA), common in premature infants, is associated with severe respiratory distress. The likelihood and significance of finding PDA in premature infants beyond the second week of life is unknown. We retrospectively analyzed all echocardiograms obtained between 1987 and 1992 on infants <35 weeks’ gestational age. Of 446 echocardiograms 77 were obtained from infants ≥14 days. Of the 77 infants, 17 (22%) were found to have PDA (group 1) and the remainder did not (group 2). Forty-eight infants had been diagnosed as having PDA prior to 14 days of age. Of these infants, 16 were from group 1. Thus only 1/17 (6%) infants diagnosed as having PDA after 2 weeks did not have a history of PDA. The presence of PDA after 2 weeks did not relate to duration of oxygen therapy, ventilator therapy, or hospital stay. Furthermore, late closure of PDA in a subgroup of 11 infants did not appear to affect these parameters. It was concluded that premature infants beyond the second week of life are unlikely to have PDA if PDA had not been diagnosed during the first 14 days. Closure of PDA beyond the second week may not improve the infant’s respiratory status.