Structural integrity analysis of notched ferritic steels operating within their ductile-to-brittle transition zone: An approach from Failure Assessment Diagrams and the Notch Master Curve

This paper provides a structural integrity assessment methodology for the analysis of ferritic steels containing notch-type defects and operating within their ductile-to-brittle transition zone. The methodology, based on the use of Failure Assessment Diagrams and the novel concept of the Notch Master Curve, has been applied to 323 experimental results performed on four different steels (S275JR, S355J2, S460M and S690Q), six different notch radii (from 0 mm up to 2.0 mm), two different types of specimens (CT and SENB), and three different temperatures within the corresponding ductile-to-brittle transition zone. The results validate the proposed assessment methodology

The Notch Master Curve: A proposal of Master Curve for ferritic–pearlitic steels in notched conditions

This paper presents a model for the prediction of the apparent fracture toughness of ferritic–pearlitic steels in notched conditions and operating at temperatures corresponding to their ductile-to-brittle transition zone. The model, here named the Notch-Master Curve, is based on the combination of the Master Curve of the material in cracked conditions and the notch corrections provided by the Theory of Critical Distances. In order to validate the model, the fracture resistance results obtained in 168 tests performed on CT specimens (84 for each material) are presented. These tests were carried out, for each material, in specimens with six different notch radii, from 0 mm up to 2.0 mm, and at three different temperatures within their corresponding ductile-to-brittle transition zone. It has been observed that the model provides good predictions of the fracture resistance in notched conditions for the two materials analysed

Mild behavioral impairment in Parkinson's disease: Data from the Parkinson's disease cognitive impairment study (PACOS)

Neuropsychiatric symptoms (NPS) have been frequently described in Parkinson's disease (PD), even in the earliest stages of the disease. Recently the construct of mild behavioral impairment (MBI) has been proposed as an at-risk state for incident cognitive decline and dementia. The aim of the present study is to evaluate the prevalence and associated factors of MBI in PD. Cross-sectional data from 429 consecutive PD patients enrolled in the PArkinson's disease COgnitive impairment Study (PACOS) were included in the study. All subjects underwent neuropsychological assessment, according to the MDS Level II criteria. NPS were evaluated with the Neuropsychiatric Inventory. Multivariate logistic regression models were used to evaluate clinical and behavioral characteristics, which are associated with PD-MBI. The latter was ascertained in 361 (84.1%) subjects of whom 155 (36.1%) were newly diagnosed patients (disease duration ≥1 year) and 206 (48.0%) had a disease duration <1 year. Furthermore, 68 (15.9%) out of 429 subjects were PDw (without MBI). Across the MBI domains, Impulse Dyscontrol was significantly more prevalent among PD-MBI with disease duration <1 year than newly diagnosed patients. The frequency of Social Inappropriateness and Abnormal Perception significantly increased throughout the entire PD-MBI sample with increasing Hoehn andYahr (H&Y) stages. PD-MBI in newly diagnosed PDwas significantly associated with H&Y stage (OR 2.35, 95% CI 1.05-5.24) and marginally with antidepressant drug use (OR 2.94, 95% CI 0.91-9.47), while in patients with a disease duration >1 year was associated with UPDRS-ME (OR 3.37, 95% CI 1.41-8.00). The overall MBI frequency in the PACOS sample was 84% and 36% among newly diagnosed patients. The presence of MBI mainly related to motor impairment and disability

Nephroprotective action of glycosaminoglycans: why the pharmacological properties of sulodexide might be reconsidered

A relatively large body of evidence supports the notion that glomerular capillary wall and mesangial alterations in diabetic nephropathy involve biochemical alterations of glycoproteins in these structures. Evidence in experimental animals rendered diabetic reveals that the administration of heparin and other anionic glycoproteins can effectively prevent the biochemical alterations that promote albuminuria. Moreover, angiotensin II inhibits heparan sulfate synthesis, while heparins modulate angiotensin II signaling in glomerular cells, inhibiting aldosterone synthesis and lowering proteinuria in diabetes patients. Sulodexide, a mixture of heparin and dermatan sulfate, appears to be a promising treatment for diabetic proteinuria partially resistant to renin–angiotensin system blocking agents. Sulodexide prevents heparan sulfate degradation, thus allowing reconstruction of heparan sulfate content and restoration of glomerular basement membrane ionic permselectivity. The antiproteinuric effect appears to be mainly related to the basal proteinuria and consequently to the duration of treatment in a relatively large number of small clinical trials. On the other hand, several sulodexide pharmacodynamic properties could improve the prognosis of chronic kidney disease patients, also independently from its antiproteinuric effect. However, sulodexide development as an antiproteinuric drug needs to be continued, in order to define which kind of patients could better respond to this treatment

Incidence of mild cognitive impairment and dementia in Parkinson's disease: The Parkinson's disease cognitive impairment study

Background: Cognitive impairment in Parkinson's disease (PD) includes a spectrum varying from Mild Cognitive Impairment (PD-MCI) to PD Dementia (PDD). The main aim of the present study is to evaluate the incidence of PD-MCI, its rate of progression to dementia, and to identify demographic and clinical characteristics which predict cognitive impairment in PD patients. Methods: PD patients from a large hospital-based cohort who underwent at least two comprehensive neuropsychological evaluations were retrospectively enrolled in the study. PD-MCI and PDD were diagnosed according to the Movement Disorder Society criteria. Incidence rates of PD-MCI and PDD were estimated. Clinical and demographic factors predicting PD-MCI and dementia were evaluated using Cox proportional hazard model. Results: Out of 139 enrolled PD patients, 84 were classified with normal cognition (PD-NC), while 55 (39.6%) fulfilled the diagnosis of PD-MCI at baseline. At follow-up (mean follow-up 23.5 ± 10.3 months) 28 (33.3%) of the 84 PD-NC at baseline developed MCI and 4 (4.8%) converted to PDD. The incidence rate of PD-MCI was 184.0/1000 pyar (95% CI 124.7-262.3). At multivariate analysis a negative association between education and MCI development at follow-up was observed (HR 0.37, 95% CI 0.15-0.89; p = 0.03). The incidence rate of dementia was 24.3/1000 pyar (95% CI 7.7-58.5). Out of 55 PD-MCI patients at baseline, 14 (25.4%) converted to PDD, giving an incidence rate of 123.5/1000 pyar (95% CI 70.3-202.2). A five time increased risk of PDD was found in PD patients with MCI at baseline (RR 5.09, 95% CI 1.60-21.4). Conclusion: Our study supports the relevant role of PD-MCI in predicting PDD and underlines the importance of education in reducing the risk of cognitive impairment

Cost analysis of planned out-of-hospital births in Italy

Background and aim: In Italy, the main birthplace is a hospital, and only a few women choose an out-of-hospital setting. This study assessed the costs related to delivery in different birthplaces in Italy. Methods: The cost analysis considered direct and amortizable costs associated with mother-child care in physiological conditions. An analysis of the hospital births considered the Diagnoses-Related Groups 373 and 391. To estimate the cost of the births assisted privately by freelance midwives, an evaluation based on an experts’ opinion was carried out. Results: Childbirth hospital care in Italy amounts to € 1832.00, and birth in an out-of-hospital setting accredited with the National Health System has a full cost of € 1345.19 in the ‘maternity home’ and € 909.60 at home. The average cost of the birth in ‘private maternity homes’ amounted to € 3260.00, while at-home births amounted to € 2910.00. Conclusions: Any accreditation of out-of-hospital settings by the NHS would considerably reduce the waste of economic resources compared to hospital childbirth. (www.actabiomedica.it

Assessment of notched structural steel components using failure assessment diagrams and the theory of critical distances

When the structural integrity of notched components is analysed, it is generally assumed that notches behave as cracks, something which generally provides overconservative results. The proposal of this paper consists, on the one hand, in the application of the theory of critical distances for the estimation of the notch fracture toughness and, therefore, for the conversion of the notched situation into an equivalent cracked situation in which the material develops a higher fracture resistance. On the other hand, once the notch fracture toughness has been defined, the assessment is performed using the failure assessment diagram methodology, and assuming that the notch effect on the limit load is negligible. The methodology has been applied to 336 CT notched fracture specimens made of two different structural steels, covering temperatures from the corresponding lower shelf up to the upper shelf, providing satisfactory results and a noticeable reduction in the overconservatism derived from the analyses in which the notch effect is not considered

On the Line Method apparent fracture toughness evaluations: experimental overview, validation and some consequences on fracture assessments

This paper analyses the capacity of the Line Method to provide evaluations of the apparent fracture toughness, which is the fracture resistance exhibited by materials in notched conditions. With this aim, the experimental results obtained in 555 fracture tests are homogeneously presented and compared to the Line Method evaluations. It is remarked that the Line Method provides adequate estimates of the apparent fracture toughness, and also that it conveniently addresses the physics of the notch effect. All this makes the Line Method a valuable scientific and engineering tool for the fracture assessment of materials containing notches

Theoretical investigations of a highly mismatched interface: the case of SiC/Si(001)

Using first principles, classical potentials, and elasticity theory, we investigated the structure of a semiconductor/semiconductor interface with a high lattice mismatch, SiC/Si(001). Among several tested possible configurations, a heterostructure with (i) a misfit dislocation network pinned at the interface and (ii) reconstructed dislocation cores with a carbon substoichiometry is found to be the most stable one. The importance of the slab approximation in first-principles calculations is discussed and estimated by combining classical potential techniques and elasticity theory. For the most stable configuration, an estimate of the interface energy is given. Finally, the electronic structure is investigated and discussed in relation with the dislocation array structure. Interface states, localized in the heterostructure gap and located on dislocation cores, are identified

Effects of diclofenac on the gametes and embryonic development of Arbacia lixula

Diclofenac (DCF), a non-steroidal anti-inflammatory drug (NSAID), is among the main pollutants of aquatic environments. Nevertheless, even if several authors evaluated its effects on marine organisms, no work has ever analysed its impact on the sea urchin Arbacia lixula. The purpose of this study was to analyse, for the first time, the impact of DCF at different concentrations (50 mg/l, 5 mg/l, 0.5 mg/l, 0.05 mg/l) on A. lixula embryos and gametes to indicate possible safe minimum levels of release of this drug in marine environments. Our results showed significant concentration-dependent effects on embryonic development (decrease in the number of developed embryos and increase in the quantity of degenerated eggs) and significant levels of bioaccumulation at DCF concentrations of 50 mg/l in both gametes and embryos. DCF showed a significant impact on the fertilisation of A. lixula due to its effects on gametes, confirming the possibility of environmental risk and highlighting the need to improve wastewater treatment and drug disposal processes