Fracture Assessment of Blunt V-Notches under Prevalent Mode II Loading by Means of Local Energy

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Brittle failure of inclined key-hole notches in isostatic graphite under in-plane mixed mode loading

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the effect of residual stress on fatigue behavior of v notched components a review

Abstract: Fatigue strength of mechanical components in the high cycle regime depends on the intensity of the residual stress field induced by non-homogeneous plastic deformation or the solidification of a local portion of material due to welding operations. In presence of geometric variations modelled as sharp V-notch angle, the residual stress distribution near the notch tip is singular and follows the same solution obtained by Williams in 1952 where the intensity of the asymptotic stress field is quantified by the notch stress intensity factor (NSIF). However, the residual stress varies during fatigue loading until a stationary value is reached. Numerical models were developed for the calculation of the residual NSIFs and their variation under fatigue loading. Taking advantage from these models, new approaches were recently developed which are able to predict the fatigue strength of pre-stressed notched components. A review of such recent advances is described in this work

Fracture behaviour of notched round bars made of PMMA subjected to torsion at -60 °C

This paper presents seventy new experimental results from PMMA notched specimens tested under torsion at 60 C. The notch root radius ranges from 0.025 to 7.0 mm. At this temperature the non-linear effects previously observed on specimens of the same material tested at room temperature strongly reduce. The averaged value of the strain energy density over a control volume is used to assess the critical loads to failure. The radius of the control volume and the critical strain energy density are evaluated a priori by using in combination the mode III critical stress intensity factor from cracked-like specimens and the critical stress to failure detected from semicircular notches with a large notch root radiu

The survival of patients with t(15;17)(q22;q12) positive acute promyelocytic leukemia: A study in north-east of iran

Background & Objective: Acute promyelocytic leukemia (APL) with t(15;17)(q22;q12) is a relatively common subtype of acute myeloid leukemia (AML). Here, our objective was to ascertain the survival of patients with this leukemia in north-east of Iran. Methods: Survival rates of 42 APL patients with t(15;17)(q22;q12) were assessed. Clinical information was obtained from archived medical records. Statistical analysis was performed by SPSS 18 software using log-ranked test and Kaplan Maier survival analysis. Results: Females and males comprised 49 and 51, respectively. The mean age at diagnosis was 34.3±14.1 years old. During the study period, 17 demises occurred in males, while this number was 7 in females. The mean survival of patients (month) was 23.22±3.57 (95 CI: 16.21±30.2). The five-year survival rate obtained 30. Regarding demographic and clinical features, the highest rates of 5-year survival were recorded in patients with 20-35 years old (47.6), males (51), white blood cell count <10� 109 /l (48), and platelet count >140� 109 /l (100). Conclusion: Younger age, lower WBC count and higher platelet count were significantly associated with longer survival in AML patients with t(15;17)(q22; q12). © Iranian Society of Pathology. All rights reserved

Protein tyrosine phosphatase 1B inhibitors isolated from Artemisia roxburghiana

Artemisia roxburghiana is used in traditional medicine for treating various diseases including diabetes. The present study was designed to evaluate the antidiabetic potential of active constituents by using protein tyrosine phosphatase 1B (PTP1B) as a validated target for management of diabetes. Various compounds were isolated as active principles from the crude methanolic extract of aerial parts of A. roxburghiana. All compounds were screened for PTP1B inhibitory activity. Molecular docking simulations were performed to investigate the mechanism behind PTP1B inhibition of the isolated compound and positive control, ursolic acid. Betulinic acid, betulin and taraxeryl acetate were the active PTP1B principles with IC50 values 3.49 ± 0.02, 4.17 ± 0.03 and 87.52 ± 0.03 µM, respectively. Molecular docking studies showed significant molecular interactions of the triterpene inhibitors with Gly220, Cys215, Gly218 and Asp48 inside the active site of PTP1B. The antidiabetic activity of A. roxburghiana could be attributed due to PTP1B inhibition by its triterpene constituents, betulin, betulinic acid and taraxeryl acetate. Computational insights of this study revealed that the C-3 and C-17 positions of the compounds needs extensive optimization for the development of new lead compounds

Rasch analysis of the Multiple Sclerosis Impact Scale (MSIS-29)

<p>Abstract</p> <p>Background</p> <p>Multiple Sclerosis (MS) is a degenerative neurological disease that causes impairments, including spasticity, pain, fatigue, and bladder dysfunction, which negatively impact on quality of life. The Multiple Sclerosis Impact Scale (MSIS-29) is a disease-specific health-related quality of life (HRQoL) instrument, developed using the patient's perspective on disease impact. It consists of two subscales assessing the physical (MSIS-29-PHYS) and psychological (MSIS-29-PSYCH) impact of MS. Although previous studies have found support for the psychometric properties of the MSIS-29 using traditional methods of scale evaluation, the scale has not been subjected to a detailed Rasch analysis. Therefore, the objective of this study was to use Rasch analysis to assess the internal validity of the scale, and its response format, item fit, targeting, internal consistency and dimensionality.</p> <p>Methods</p> <p>Ninety-two persons with definite MS residing in the community were recruited from a tertiary hospital database. Patients completed the MSIS-29 as part of a larger study. Rasch analysis was undertaken to assess the psychometric properties of the MSIS-29.</p> <p>Results</p> <p>Rasch analysis showed overall support for the psychometric properties of the two MSIS-29 subscales, however it was necessary to reduce the response format of the MSIS-29-PHYS to a 3-point response scale. Both subscales were unidimensional, had good internal consistency, and were free from item bias for sex and age. Dimensionality testing indicated it was not appropriate to combine the two subscales to form a total MSIS score.</p> <p>Conclusion</p> <p>In this first study to use Rasch analysis to fully assess the psychometric properties of the MSIS-29 support was found for the two subscales but not for the use of the total scale. Further use of Rasch analysis on the MSIS-29 in larger and broader samples is recommended to confirm these findings.</p