30 research outputs found

    A Comprehensive Investigation on the Effects of Surface Finishing on the Resistance of Stainless Steel to Localized Corrosion

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    The present research investigates the influence of surface roughness imparted by cold surface finishing processes on the localized corrosion resistance of stainless steel. Five different alloys were studied: ferritic AISI 430, martensitic AISI 430F, austenitic AISI 303, AISI 304L, and AISI 316L. It was demonstrated that the grinding process, executed on previously cold drawn bars, leads to an improvement in corrosion resistance according to the results obtained with electrochemical tests, namely, potentiostatic and potentiodynamic tests in chloride-rich environments, the salt spray test, and long-term exposure in urban and marine atmospheres. This allowed us to establish a trend among the different alloys regarding the resistance to pitting corrosion, which was assessed according to pitting potentials, critical chloride contents, and pitting initiation time. All the tests confirmed that surface finishing, as well as alloy chemical composition, is an important factor in controlling the corrosion resistance of stainless steel

    A novel biweekly pancreatic cancer treatment schedule with gemcitabine, 5-fluorouracil and folinic acid

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    Pancreatic adenocarcinoma is a common disease considered to be poorly responsive to antiblastic treatment. Recent clinical and preclinical results suggest that a combined treatment of gemcitabine (GEM), 5-flurouracil (5-FU) and folinic acid (FA) offers a clinical benefit in patients with advanced pancreas adenocarcinoma. The aim of this phase II clinical trial was to evaluate the antitumour activity and toxicity of a novel biweekly schedule of this combination in patients with pancreatic adenocarcinoma. A total of 42 patients received a 30 min infusion of FA (100 mgm2) and 5-FU (400 mgm2) (FUFA) on days 1–3, and GEM 1000 mgm2 on day 1 every 15 days. We observed 13 objective responses (two complete, 11 partial) and 23 stable diseases. The median time to progression was 9.75 months (95% Confidence Interval (CI), 6.88–12.62) and the median overall survival was 13.10 months (95% CI 9.64–16.56). There were seven cases of each grade III gastroenteric and haematological toxicity. The GEM plus FUFA combination appears to be well tolerated and very active in patients with pancreatic carcinoma

    A novel biweekly multidrug regimen of gemcitabine, oxaliplatin, 5-fluorouracil (5-FU), and folinic acid (FA) in pretreated patients with advanced colorectal carcinoma

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    Previous results suggest that GEM affects 5-fluorouracil (5-FU) metabolism and pharmacokinetics in cancer patients, while combined with oxaliplatin, levo-folinic acid, and 5-FU (GOLF regimen), at doses achievable in cancer patients, determines high cytotoxic and proapoptotic antitumour activity in colon cancer cells in vitro. On these bases we designed a phase I–II clinical trial testing the GOLF regimen in patients with metastatic colorectal carcinoma, who had received at least a prior line of chemotherapy. In total, 29 patients (20 males and nine females) enrolled in the study received every 2 weeks, gemcitabine (patients #1–3 received 600 mgm2; patients # 4–6 received 850 mgm2; while patients # 7–29 received 1000 mgm2) on the day 1, levo-folinic acid (100 mgm2) on the days 1 and 2; 5-fluorouracil (400 mgm2) in bolus injection, followed by a 22-h continuous infusion (800 mgm2) on the days 1 and 2, and oxaliplatin (85 mgm2), 6 h after the 5-FU bolus on day 2. The most frequent side effect was grade I–II haematological toxicity. In total, 28 patients were evaluable for response: three achieved a complete response, nine a partial response, 10 had a stable disease, and six progressed. The average time to progression and overall survival of the patients was, respectively, 7.26 and 22 months. Our GOLF combination is well tolerated and seems promising for the treatment of advanced colorectal cancer

    The molecular network governing nodule organogenesis and infection in the model legume Lotus japonicus

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    Bacterial infection of interior tissues of legume root nodules is controlled at the epidermal cell layer and is closely coordinated with progressing organ development. Using spontaneous nodulating Lotus japonicus plant mutants to uncouple nodule organogenesis from infection, we have determined the role of 16 genes in these two developmental processes. We show that host-encoded mechanisms control three alternative entry processes operating in the epidermis, the root cortex and at the single cell level. Single cell infection did not involve the formation of trans-cellular infection threads and was independent of host Nod-factor receptors and bacterial Nod-factor signals. In contrast, Nod-factor perception was required for epidermal root hair infection threads, whereas primary signal transduction genes preceding the secondary Ca2+ oscillations have an indirect role. We provide support for the origin of rhizobial infection through direct intercellular epidermal invasion and subsequent evolution of crack entry and root hair invasions observed in most extant legumes

    Tafel-Piontelli model for the prediction of uniform corrosion rate of active metals in strongly acidic environments

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    Corrosion represents a threatening and expensive problem for every industrial sector. To address this issue, several predictive models were developed and categorized in empirical, semiempirical and mechanistic, ac-cording to their underlying hypotheses, their representation of major physicochemical phenomena, and their applicability limits. In this work, a mechanistic model strongly based on the theory of kinetics of electrochemical corrosion is presented and validated. The model, called Tafel-Piontelli, was firstly proposed in 2017 as a tool for the calculation of the corrosion rate of active metals in acidic environments, characterized by hydrogen evolution as the dominant cathodic process. Starting from its initial version, the base-equation of the model has been revised and the theoretical architecture improved. The model was validated according to the experimental data collected for a variety of strong acids in a wide range of temperature and pH sets. The kinetic parameters of the equation, such as the cathodic Tafel slope and the hydrogen evolution exchange current density, were deter-mined via cathodic potentiodynamic polarization tests (Tafel extrapolation method), while the iron ion activity and the corrosion rate were determined from mass loss tests and application of the Faraday law. The results show a remarkable improvement in the representation of the iron ion activity and of its exponential dependence on pH and temperature with respect to the original formulation. Additionally, the estimated corrosion rates accurately capture the dynamics observed in the empirical data, thus confirming the validity of the model

    Gemcitabine increases systemic 5-fluorouracil exposure in advanced cancer patients.

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    A number of recent clinical trials testing the combination of 5-fluorouracil (5-FU) and gemcitabine in patients with advanced pancreatic adenocarcinoma have shown a significant clinical response rate, but also significant toxicity. As the two antimetabolites may interact at several biochemical levels along their pathways of activation, we investigated whether gemcitabine (GEM) affects 5-FU pharmacokinetics in cancer patients. Thus, we compared 5-FU pharmacokinetics in two groups of patients with various cancers who received the same schedule of 5-FU and folinic acid (FUFA), with or without GEM. There was a significant increase in systemic (5-FU) exposure and toxicity in the FUFA plus GEM group. Our finding may be useful in designing future studies of the combination in order to reduce the occurrence of side-effects and to maximise the antitumour activity

    Evaluation of cutaneous, oral and intestinal microbiota in patients affected by pemphigus and bullous pemphigoid: A pilot study

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    Significant alterations of the cutaneous microbiota (CM) have been recently demonstrated in bullous pemphigoid (BP). Microbiome data of both oral cavity (OM) and gut (GM) from patients affected by bullous disease are not available yet and, further consistent studies focused on the role of such microbial populations are still missing

    Lymph node evaluation in stage IIA colorectal cancer and its impact on patient prognosis: A population-based study

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    Background. The analysis of regional lymph nodes is particularly relevant in patients with stage II colorectal cancer, in whom the role of adjuvant chemotherapy remains unclear. The aim of this study was to assess the relationship between number of examined lymph nodes and survival in patients with stage IIA (pT3N0M0) colorectal cancer, and to determine the optimal number of lymph nodes that should be examined. Methods. The study group included all the surgically-treated colorectal cancer patients in stage IIA (n = 657) who were identified through the population-based Cancer Registry of the Province of Modena (Northern Italy), during the period 2002-2006. Results. The median number of harvested lymph nodes was 19 (range 1-68). Considering, as a reference point, patients with 12 or less lymph nodes, subjects with n ≥ 20 lymph nodes examined showed, in univariate analysis, a significantly higher cancer specific (p = 0.01) and relapse-free survival (p = 0.003). The results were confirmed by multivariate analysis (Cox model). Conclusion. The result suggests that colorectal cancer patients in stage IIA with n ≥ 20 lymph nodes examined exhibit better survival when compared with subjects in whom fewer lymph nodes were examined. The number of 20 lymph nodes is the essential requirement for an oncologic resection of the large bowel
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