1,392 research outputs found

    Estimation of Fatigue Limit of a A356-T6 Automotive Wheel in Presence of Defects

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    The automotive wheel is a critical safety component in the vehicle and, for such a reason, it has also to meet strict requirements about technological properties. This component is produced by low pressure die casting technique and the casting defects related to the process have to be properly considered having a high effect in decreasing both static and dynamic resistance of the component. Effectively, casting defects like porosities influence the fatigue crack initiation and strongly affect the fatigue life too. One of the most common problem in the real component is the mismatch between the experimental data and literature. In fact, many scientific researches were carried out on small samples produced in a controlled condition and therefore it is difficult to direct transfer the laboratory results to a real cast component with a well-defined shape and different thicknesses. In the present study, an aluminum alloy A356-T6 wheel was analyzed in order to correlate the fatigue performance taking in to account the casting defects. The fatigue limit of the component was studied by rotating bending fatigue tests executed on the whole wheels. Microfractographic analyses on the broken wheels were carried out on the fracture surfaces using a Scanning Electron Microscope in order to identify the crack initiation zone: it was recognized that the crack always started from shrinkage porosities. The statistical population of these defects was therefore investigated on samples taken from the wheel in crack nucleation positions of the spoke and the maximum expected defect size on the component was estimated by the statistics of extreme values. The experimental fatigue limit was finally compared with the theoretical value predicted with the Murakami’s method

    A meta-analysis of alcohol drinking and cancer risk

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    To evaluate the strength of the evidence provided by the epidemiological literature on the association between alcohol consumption and the risk of 18 neoplasms, we performed a search of the epidemiological literature from 1966 to 2000 using several bibliographic databases. Meta-regression models were fitted considering linear and non-linear effects of alcohol intake. The effects of characteristics of the studies, of selected covariates (tobacco) and of the gender of individuals included in the studies, were also investigated as putative sources of heterogeneity of the estimates. A total of 235 studies including over 117 000 cases were considered. Strong trends in risk were observed for cancers of the oral cavity and pharynx, oesophagus and larynx. Less strong direct relations were observed for cancers of the stomach, colon and rectum, liver, breast and ovary. For all these diseases, significant increased risks were found also for ethanol intake of 25 g per day. No significant nor consistent relation was observed for cancers of the pancreas, lung, prostate or bladder. Allowance for tobacco appreciably modified the relations with laryngeal, lung and bladder cancers, but not those with oral, oesophageal or colorectal cancers. This meta-analysis showed no evidence of a threshold effect for most alcohol-related neoplasms. The inference is limited by absence of distinction between lifelong abstainers and former drinkers in several studies, and the possible selective inclusion of relevant sites only in cohort studies. © 2001 Cancer Research Campaign http://www.bjcancer.co

    Risk factors for adenocarcinoma of the cervix: a case-control study.

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    To assess risk factors for cervical adenocarcinoma data were collected in a case-control study of 39 cases and 409 controls conducted in the greater Milan area. Questions were asked about personal characteristics and habits, gynaecologic and obstetric data, history of lifetime use of oral contraceptives and other female hormones, and general indicators of sexual habits (age at first intercourse and total number of sexual partners). The relative risk of cervical adenocarcinoma increased with number of births and abortions, early age at first birth and early age at first intercourse. These estimates did not materially change after adjustment for the potential reciprocal confounding effect. Further, there was a positive association with overweight, but an apparent association with lower education was not significant. No relationship emerged with oral contraceptive use. Thus, despite the similarities with the epidemiology of squamous cell cancer, reproductive patterns and other factors related to the risk of endometrial cancer (i.e., overweight) seem to play an important role in the risk of adenocarcinoma of cervix uteri

    Effectiveness and healthcare cost of adding trastuzumab to standard chemotherapy for first-line treatment of metastatic gastric cancer: A population-based cohort study

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    A randomized clinical trial showed that trastuzumab, added to traditional chemotherapy, significantly improved overall survival in human epidermal growth factor receptor 2 (HER2)-overexpressing metastatic gastric cancer patients. This population-based study aimed at evaluating both the clinical and economic impact of trastuzumab in a real-world setting. By using the healthcare utilization databases of Lombardy, Italy, a cohort of patients newly diagnosed with metastatic gastric cancer during the period 2011–2016 was selected. Among these, patients initially treated with either trastuzumab-based chemotherapy or standard chemotherapy alone were followed up until death, migration in other regions or June 2018. Overall survival and average cumulative costs were estimated and compared between the two treatment arms. Among the 1198 metastatic gastric cancer patients who started therapy within six months after metastasis detection, 87 were initially treated with trastuzumab-based chemotherapy and 1111 with standard chemotherapy. Median overall survival and restricted mean survival were 10.2 and 7.4 months, and 14.9 and 11.4 months, respectively, in the two treatment arms. The adjusted hazard ratio of death was 0.73 (95% CI 0.57–0.93). The average per capita cumulative healthcare costs were, respectively, EUR 39,337 and 26,504, corresponding to an incremental cost-effectiveness ratio of EUR 43,998 for each year of survival gained. Our study shows that adding trastuzumab to conventional chemotherapy is effective and cost-effective

    Interventi funzionali dedicati alla modifica della superficie degli ingranaggi: la cementazione e la nitrurazione come pretrattamento di rivestimenti PVD

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    Per contrastare i meccanismi di danneggiamento degli ingranaggi (usura, fatica da contatto e fatica) èprassi comune intervenire con trattamenti a carico della superficie in grado, non solo di aumentare ladurezza superficiale, ma, anche, di indurre uno stato di compressione in corrispondenza della dentatura.Oltre ai tradizionali trattamenti di cementazione e di nitrurazione sono sempre più frequenti lesperimentazioni dedicate all’analisi degli effetti di rivestimenti sottili quali quelli ottenuti con tecniche PVD.Partendo da questi presupposti, nel presente lavoro è stata valutata la resistenza a fatica di un rivestimentodi nitruro di cromo depositato rispettivamente su di un acciaio da cementazione (16MnCrS5) e su di unacciaio da nitrurazione (42CrMo4) entrambi sottoposti a trattamento termochimico prima del rivestimento.La caratterizzazione delle modifiche superficiali è stata effettuata mediante analisi al SEM, misure dimicrodurezza e di nanoindentazione oltre che di stato tensionale residuo

    Epidemiology of biliary tract cancers: an update

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    Background: Biliary tract cancer (BTC) is a rare cancer in Europe and North America, characterized by wide geographic variation, with high incidence in some areas of Latin America and Asia. Materials and methods: BTC mortality and incidence have been updated according to recent data, using joinpoint regression analysis. Results: Since the 1980s, decreasing trends in BTC mortality rates (age-standardized, world standard population) were observed in the European Union as a whole, in Australia, Canada, Hong Kong, Israel, New Zealand, and the United States, and high-risk countries such as Japan and Venezuela. Joinpoint regression analysis indicates that decreasing trends were more favorable over recent calendar periods. High-mortality rates are, however, still evident in central and eastern Europe (4-5/100 000 women), Japan (4/100 000 women), and Chile (16.6/100 000 women). Incidence rates identified other high-risk areas in India (8.5/100 000 women), Korea (5.6/100 000 women), and Shanghai, China (5.2/100 000 women). Conclusions: The decreasing BTC mortality trends essentially reflect more widespread and earlier adoption of cholecystectomy in several countries, since gallstones are the major risk factor for BTC. There are, however, high-risk areas, mainly from South America and India, where access to gall-bladder surgery remains inadequat

    European cancer mortality predictions for the year 2020 with a focus on prostate cancer

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    Background: Current cancer mortality figures are important for disease management and resource allocation. We estimated mortality counts and rates for 2020 in the European Union (EU) and for its six most populous countries. Materials and methods: We obtained cancer death certification and population data from the World Health Organization and Eurostat databases for 1970-2015. We estimated projections to 2020 for 10 major cancer sites plus all neoplasms and calculated the number of avoided deaths over 1989-2020. Results: Total cancer mortality rates in the EU are predicted to decline reaching 130.1/100 000 men (-5.4% since 2015) and 82.2 in women (-4.1%) in 2020. The predicted number of deaths will increase by 4.7% reaching 1 428 800 in 2020. In women, the upward lung cancer trend is predicted to continue with a rate in 2020 of 15.1/100 000 (higher than that for breast cancer, 13.5) while in men we predicted further falls. Pancreatic cancer rates are also increasing in women (+1.2%) but decreasing in men (-1.9%). In the EU, the prostate cancer predicted rate is 10.0/100 000, declining by 7.1% since 2015; decreases for this neoplasm are 3c8% at age 45-64, 14% at 65-74 and 75-84, and 6% at 85 and over. Poland is the only country with an increasing prostate cancer trend (+18%). Mortality rates for other cancers are predicted to decline further. Over 1989-2020, we estimated over 5 million avoided total cancer deaths and over 400 000 for prostate cancer. Conclusion: Cancer mortality predictions for 2020 in the EU are favourable with a greater decline in men. The number of deaths continue to rise due to population ageing. Due to the persistent amount of predicted lung (and other tobacco-related) cancer deaths, tobacco control remains a public health priority, especially for women. Favourable trends for prostate cancer are largely attributable to continuing therapeutic improvements along with early diagnosis

    European cancer mortality predictions for the year 2019 with focus on breast cancer

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    Background We predicted cancer mortality figures in the European Union (EU) for the year 2017 using most recent available data, with a focus on lung cancer. Materials and methods We retrieved cancer death certification data and population figures from the World Health Organisation and Eurostat databases. Age-standardized (world standard population) rates were computed for France, Germany, Italy, Poland, Spain, the UK and the EU overall in 1970–2012. We obtained estimates for 2017 by implementing a joinpoint regression model. Results The predicted number of cancer deaths for 2017 in the EU is 1 373 500, compared with 1 333 400 in 2012 (+3%). Cancer mortality rates are predicted to decline in both sexes, reaching 131.8/100 000 men (−8.2% when compared with 2012) and 84.5/100 000 women (−3.6%). Mortality rates for all selected cancer sites are predicted to decline, except pancreatic cancer in both sexes and lung cancer in women. In men, pancreatic cancer rate is stable, in women it increases by 3.5%. Lung cancer mortality rate in women is predicted to rise to 14.6/100 000 in 2017 (+5.1% since 2012, corresponding to 92 300 predicted deaths), compared with 14.0/100 000 for breast cancer, corresponding to 92 600 predicted deaths. Only younger (25–44) women have favourable lung cancer trends, and rates at this age group are predicted to be similar in women (1.4/100 000) and men (1.2/100 000). In men lung cancer rates are predicted to decline by 10.7% since 2012, and falls are observed in all age groups. Conclusion European cancer mortality projections for 2017 confirm the overall downward trend in rates, with a stronger pattern in men. This is mainly due to different smoking prevalence trends in different generations of men and women. Lung cancer rates in young European women are comparable to those in men, confirming that smoking has the same impact on lung cancer in the two sexes
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