Radiation damage buildup and dislocation evolution in Ni and equiatomic multicomponent Ni-based alloys

Single-phase multicomponent alloys of equal atomic concentrations ("equiatomic") have proven to exhibit promising mechanical and corrosion resistance properties, that are sought after in materials intended for use in hazardous environments like next-generation nuclear reactors. In this article, we investigate the damage production and dislocation mobility by simulating irradiation of elemental Ni and the alloys NiCo, NiCoCr, NiCoFe and NiFe, to assess the effect of elemental composition. We compare the defect production and the evolution of dislocation networks in the simulation cells of two different sizes, for all five studied materials. We find that the trends in defect evolution are in good agreement between the different cell sizes. The damage is generally reduced with increased alloy complexity, and the dislocation evolution is specific to each material, depending on its complexity. We show that increasing complexity of the alloys does not always lead to decreased susceptibility to damage accumulation under irradiation. We show that, for instance, the NiCo alloy behaves very similarly to Ni, while presence of Fe or Cr in the alloy even as a third component reduces the saturated level of damage substantially. Moreover, we linked the defect evolution with the dislocation transformations in the alloys. Sudden drops in defect number and large defect fluctuations from the continuous irradiation can be explained from the dislocation activity. (C) 2017 Elsevier B.V. All rights reserved.Peer reviewe

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significant increase in CAT-1 abundance in BUO. Expression of both glomerular arginase I and II mRNA and protein content were significantly elevated in BUO. Conclusions: BUO induces an increase in glomerular arginine transport via upregulation of CAT-1, probably due to increase in arginine utilization by a non-NO pathway

Mixed cryoglobulinemia

Mixed cryoglobulinemia (MC), type II and type III, refers to the presence of circulating cryoprecipitable immune complexes in the serum and manifests clinically by a classical triad of purpura, weakness and arthralgias. It is considered to be a rare disorder, but its true prevalence remains unknown. The disease is more common in Southern Europe than in Northern Europe or Northern America. The prevalence of 'essential' MC is reported as approximately 1:100,000 (with a female-to-male ratio 3:1), but this term is now used to refer to a minority of MC patients only. MC is characterized by variable organ involvement including skin lesions (orthostatic purpura, ulcers), chronic hepatitis, membranoproliferative glomerulonephritis, peripheral neuropathy, diffuse vasculitis, and, less frequently, interstitial lung involvement and endocrine disorders. Some patients may develop lymphatic and hepatic malignancies, usually as a late complication. MC may be associated with numerous infectious or immunological diseases. When isolated, MC may represent a distinct disease, the so-called 'essential' MC. The etiopathogenesis of MC is not completely understood. Hepatitis C virus (HCV) infection is suggested to play a causative role, with the contribution of genetic and/or environmental factors. Moreover, MC may be associated with other infectious agents or immunological disorders, such as human immunodeficiency virus (HIV) infection or primary Sjögren's syndrome. Diagnosis is based on clinical and laboratory findings. Circulating mixed cryoglobulins, low C4 levels and orthostatic skin purpura are the hallmarks of the disease. Leukocytoclastic vasculitis involving medium- and, more often, small-sized blood vessels is the typical pathological finding, easily detectable by means of skin biopsy of recent vasculitic lesions. Differential diagnoses include a wide range of systemic, infectious and neoplastic disorders, mainly autoimmune hepatitis, Sjögren's syndrome, polyarthritis, and B-cell lymphomas. The first-line treatment of MC should focus on eradication of HCV by combined interferon-ribavirin treatment. Pathogenetic treatments (immunosuppressors, corticosteroids, and/or plasmapheresis) should be tailored to each patient according to the progression and severity of the clinical manifestations. Long-term monitoring is recommended in all MC patients to assure timely diagnosis and treatment of the life-threatening complications. The overall prognosis is poorer in patients with renal disease, liver failure, lymphoproliferative disease and malignancies

Colorectal Cancer in Inflammatory Bowel Diseases: Epidemiology and Prevention: A Review

Simple Summary Colorectal cancer (CRC) is one of the most serious potential complications of inflammatory bowel diseases (IBDs). The aging of patients affected by IBDs makes this issue a challenge that will increasingly be faced by clinicians in clinical practice, especially in light of the poorer prognosis for CRC in this group of people when compared with the general population. In this review, we summarize the current epidemiology, risk factors and various prevention strategies proposed for CRC in patients with IBDs. Colorectal cancer (CRC) is currently the third most frequent form of malignancy and the second in terms of mortality. Inflammatory bowel diseases (IBDs) are recognized risk factors for this type of cancer. Despite a worldwide increase in the incidence of CRC, the risk of CRC-related death in IBD patients has declined over time, probably because of successful surveillance strategies, the use of more effective drugs in the management of remission and improved indications to colectomy. This notwithstanding, CRC 5-year survival in patients with IBD is poorer than in the general population. This review provides a summary of the epidemiological features, risk factors and various prevention strategies proposed for CRC in IBD patients. Moreover, there is a special focus on reporting and highlighting the various prevention strategies proposed by the most important international scientific societies, both in terms of chemoprevention and endoscopic surveillance. Indeed, in conducting the analysis, we have given attention to the current primary, secondary and tertiary prevention guidelines, attempting to emphasize unresolved research and clinical problems related to this topic in order to improve diagnostic strategies and management

Recent progress on understanding the temperature-dependent irradiation resistance ranking among NiFe, NiCoCr, and NiCoFeCr alloys : A review

Systematic temperature-effects investigations on damage evolution in ion-irradiated Ni-based concentrated solid-solution alloys (CSAs) are pivotal to provide reliance on their use in nuclear applications. In search of the origin behind the temperature-dependent irradiation resistance ranking among equiatomic NiFe, NiCoCr, and NiCoFeCr alloys, we have compared previously experimental and theoretical published data involving ion irradiation experiments performed on these alloys with new ion channeling results from ion-irradiated NiCoFeCr at 500 K. Moreover, the current results are compared with independent theoretical calculations and relevant TEM results from the literature, which allow us to suggest that the lower migration energy of vacancies in NiCoCr, as compared with those in NiFe and NiCoFeCr, is the reason behind why NiCoCr is no longer outperforming NiFe under ion irradiation above 300 K.Peer reviewe

Correlation between serum levels of soluble tumor necrosis factor receptor and disease activity in systemic lupus erythematosus.

OBJECTIVE: To determine the value of measurement of serum soluble tumor necrosis factor receptor (sTNFR), compared with established parameters such as anti-double-stranded DNA, in monitoring systemic lupus erythematosus (SLE) disease activity, and to determine whether serum sTNFR are bioactive and can effectively inhibit TNF bioactivity. METHODS: Fifty-three consecutive ambulatory or hospitalized SLE patients and 140 consecutive healthy subjects were enrolled in a prospective cohort study. Serum levels of sTNFR were measured by a unique 2-sided capture enzyme-linked immunosorbent assay using mouse monoclonal antibodies and rabbit antisera against the sTNFR. RESULTS: The mean +/- SD concentrations of both the p55 (type I) and p75 (type II) soluble receptors were significantly higher in a group of 46 SLE patients than in controls: 1.89 +/- 0.89 ng/ml versus 0.77 +/- 0.19 ng/ml and 7.25 +/- 3.89 ng/ml versus 3.02 +/- 0.57 ng/ml, respectively (P < 0.0001 for both). The incidence and the extent of the increase among the healthy subjects and these patients (as well as in 7 additional patients on whom sequential studies were performed) correlated with disease activity more than did the occurrence of serum anti-DNA antibodies (correlation coefficients with disease activity 0.81 and 0.85 for p55 and p75 sTNFR, respectively, and 0.51 for anti-DNA antibodies). The increase in sTNFR levels seems to reflect, largely, enhanced formation, and only to a minor extent, reduced clearance due to impairment of renal function. Sera of the SLE patients had a marked inhibitory effect on the in vitro cytocidal activity of TNF, and this was shown to result entirely from their higher sTNFR receptor concentration. CONCLUSION: An increase in serum levels of sTNFR may become a useful marker for SLE activity since it shows a stronger correlation than do any other laboratory or clinical parameters employed presently in the daily clinical setting. At the concentrations attained in the serum of SLE patients, sTNFR effectively inhibit the bioactivity of TNF and may thus be a significant determinant of the intensity of the manifestations of SLE