Effect of sulfides in the passive layer of steel reinforcement in alkali-activated slags

Steel reinforcing elements (rebars) embedded in Portland cement concretes are protected from corrosion by a thin passive film that is formed and maintained on rebar surfaces due to the high pH level of the surrounding concrete. Corrosion of reinforcing steel is frequently induced by its interaction with chloride ions, leading to local destruction of the passive layer. The nature and stability of this layer change when the surrounding concrete is produced with different cementitious materials, as the permeability of the matrix as well as the chemistry of pore solution can vary significantly. This is particularly the case when using non-Portland cements, such as alkali-activated slags (AAS). Ground granulated blast furnace slag can contains sulfur at levels between 1-2 wt.%, mostly in a reduced state. The sulfide ions are released during the alkali-activation of vitreous slag into the alkaline aqueous solution, and subsequently can alter the nature of the passive film formed on a steel surface. In this study the influence of sulfide on the stability, chemical composition and morphology of the passive layer forming in steel embedded in alkali-activated slags mortars, and in simulated alkali-activated slag pore solutions were investigated. The potential influence of sulfide in corrosion induced in the presence of chlorides was also assessed. This was carried out by combining electrochemical measurement with a detailed inspection of the rebars specimens using different analytical techniques. The outcomes of this study revealed that in absence of sulfides, corrosion initiation is governed by localised breakdown of the passive film, followed by metastable/stable pit growth. However, in sulfide containing pore solutions localised pitting induced by chlorides was not identified. The presence of sulfides in these systems alters the mechanism of corrosion initiation, and its influence is strongly dependent on sulfides concentration at the steel/solution interface

Ureteroarterial Fistula

Ureteral-iliac artery fistula (UIAF) is a rare life threatening cause of hematuria. The increasing frequency is attributed to increasing use of ureteral stents. A 68-year-old female presented with gross hematuria. She had prior low anterior resection for rectal cancer and a retained ureteral stent. CT abdomen and pelvis showed a large recurrent pelvic mass and a retained stent. The patient underwent cystoscopy which showed a normal bladder. Upon removal of the stent, brisk bleeding was noted coming from the ureteral orifice. Antegrade pyelogram was done which revealed a UIAF. Angiography was done and a covered stent was placed. Multiple treatment options are available. All must consider management of the arterial and ureteral side. The arterial side may be addressed by primary open repair, embolization with extra-anatomic vascular reconstruction, or endovascular stenting. The ureter can be managed with nephroureterectomy, ureteral reconstruction, placement of a nephrostomy tube, or ureteral stenting. Being minimally invasive, we believe that endovascular stenting should be the preferred therapeutic option as it also corrects the source of bleeding while preserving distal blood flow

Practical Scrum-Scrum Team: Way to Produce Successful and Quality Software

Scrum is the most popular agile methodology in software industry. By using scrum practices, several companies have improved their quality and productivity. This paper presents a practical view inside the Scrum practices, specifically, the team size, team structure and description of roles in Scrum teams are explained. The paper is based on our experiences in multiple projects executed in Scrum Agile methodology. Scrum is most suitable for products with team size of 3-9 members. For larger products, Scrum provides a mechanism called Scrum of Scrums. Scrum of Scrums distribute the large work/project into several teams and to control the quality and speed of each team, regular meetings are organized amongst the representatives of each team. We also present the guidelines for work distribution for the Scrum of Scrum (SoS) teams

Colloidal Nanocrystals Embedded in Macrocrystals: Robustness, Photostability, and Color Purity

Cataloged from PDF version of article.The incorporation of colloidal quantum dots (QDs) into ionic crystals of various salts (NaCl, KCl, KBr, etc.) is demonstrated. The resulting mixed crystals of various shapes and beautiful colors preserve the strong luminescence of the incorporated QDs. Moreover, the ionic salts appear to be very tight matrices, ensuring the protection of the QDs from the environment and as a result providing them with extraordinary high photo- and chemical stability. A prototype of a white light-emitting diode (WLED) with a color conversion layer consisting of this kind of mixed crystals is demonstrated. These materials may also find applications in nonlinear optics and as luminescence standards

Generating and detecting bound entanglement in two-qutrits using a family of indecomposable positive maps

The problem of bound entanglement detection is a challenging aspect of quantum information theory for higher dimensional systems. Here, we propose an indecomposable positive map for two-qutrit systems, which is shown to generate a class of positive partial transposed (PPT) states. A corresponding witness operator is constructed and shown to be weakly optimal and locally implementable. Further, we perform a structural physical approximation of the indecomposable map to make it a completely positive one, and find a new PPT entangled state which is not detectable by certain other well-known entanglement detection criteria.Comment: 9 pages, 3 figures, Comments are welcome

Sunglasses to hide behind may also prevent melanoma of the eyes

From Springer Nature via Jisc Publications RouterHistory: received 2021-02-05, rev-recd 2021-02-26, accepted 2021-03-02, registration 2021-03-04, pub-electronic 2021-04-06, online 2021-04-06, pub-print 2021-08-17Publication status: PublishedFunder: Cancer Research UK (CRUK); doi: https://doi.org/10.13039/501100000289; Grant(s): A27412 and A22902Summary: In 1967, Sandy Posey pronounced that sunglasses are essential beachwear (https://www.youtube.com/watch?v=4HVBEb-GA1Y). Now, whole-genome sequencing reveals that ultraviolet radiation (UVR) can contribute to melanomas in the iris and conjunctiva, data that provide a molecular explanation for why it is important to protect our eyes from exposure to UVR

Identification of disease-causing genes using microarray data mining and gene ontology

Background: One of the best and most accurate methods for identifying disease-causing genes is monitoring gene expression values in different samples using microarray technology. One of the shortcomings of microarray data is that they provide a small quantity of samples with respect to the number of genes. This problem reduces the classification accuracy of the methods, so gene selection is essential to improve the predictive accuracy and to identify potential marker genes for a disease. Among numerous existing methods for gene selection, support vector machine-based recursive feature elimination (SVMRFE) has become one of the leading methods, but its performance can be reduced because of the small sample size, noisy data and the fact that the method does not remove redundant genes. Methods: We propose a novel framework for gene selection which uses the advantageous features of conventional methods and addresses their weaknesses. In fact, we have combined the Fisher method and SVMRFE to utilize the advantages of a filtering method as well as an embedded method. Furthermore, we have added a redundancy reduction stage to address the weakness of the Fisher method and SVMRFE. In addition to gene expression values, the proposed method uses Gene Ontology which is a reliable source of information on genes. The use of Gene Ontology can compensate, in part, for the limitations of microarrays, such as having a small number of samples and erroneous measurement results. Results: The proposed method has been applied to colon, Diffuse Large B-Cell Lymphoma (DLBCL) and prostate cancer datasets. The empirical results show that our method has improved classification performance in terms of accuracy, sensitivity and specificity. In addition, the study of the molecular function of selected genes strengthened the hypothesis that these genes are involved in the process of cancer growth. Conclusions: The proposed method addresses the weakness of conventional methods by adding a redundancy reduction stage and utilizing Gene Ontology information. It predicts marker genes for colon, DLBCL and prostate cancer with a high accuracy. The predictions made in this study can serve as a list of candidates for subsequent wet-lab verification and might help in the search for a cure for cancers

The T cell receptor repertoire of tumor infiltrating T cells is predictive and prognostic for cancer survival.

From Europe PMC via Jisc Publications RouterHistory: ppub 2021-07-01, epub 2021-07-02Publication status: PublishedFunder: Wellcome Trust; Grant(s): 100282/Z/12/ZFunder: Cancer Research UK; Grant(s): A22902, A27412Tumor infiltration by T cells is paramount for effective anti-cancer immune responses. We hypothesized that the T cell receptor (TCR) repertoire of tumor infiltrating T lymphocytes could therefore be indicative of the functional state of these cells and determine disease course at different stages in cancer progression. Here we show that the diversity of the TCR of tumor infiltrating T cell at baseline is prognostic in various cancers, whereas the TCR clonality of T cell infiltrating metastatic melanoma pre-treatment is predictive for activity and efficacy of PD1 blockade immunotherapy

Brain microenvironment-driven resistance to immune and targeted therapies in acral melanoma.

BACKGROUND: Combination treatments targeting the MEK-ERK pathway and checkpoint inhibitors have improved overall survival in melanoma. Resistance to treatment especially in the brain remains challenging, and rare disease subtypes such as acral melanoma are not typically included in trials. Here we present analyses from longitudinal sampling of a patient with metastatic acral melanoma that became resistant to successive immune and targeted therapies. METHODS: We performed whole-exome sequencing and RNA sequencing on an acral melanoma that progressed on successive immune (nivolumab) and targeted (dabrafenib) therapy in the brain to identify resistance mechanisms. In addition, we performed growth inhibition assays, reverse phase protein arrays and immunoblotting on patient-derived cell lines using dabrafenib in the presence or absence of cerebrospinal fluid (CSF) in vitro. Patient-derived xenografts were also developed to analyse response to dabrafenib. RESULTS: Immune escape following checkpoint blockade was not due to loss of tumour cell recognition by the immune system or low neoantigen burden, but was associated with distinct changes in the microenvironment. Similarly, resistance to targeted therapy was not associated with acquired mutations but upregulation of the AKT/phospho-inositide 3-kinase pathway in the presence of CSF. CONCLUSION: Heterogeneous tumour interactions within the brain microenvironment enable progression on immune and targeted therapies and should be targeted in salvage treatments

Why decision support systems are important for medical education

During the last decades the inclusion of digital tools in health education has rapidly lead to a continuously enlarging digital era. All the online interactions between learners and tutors, the description, creation, reuse and sharing of educational digital resources and the interlinkage between them in conjunction with cheap storage technology has led to an enormous amount of educational data. Medical education is a unique type of education due to accuracy of information needed, continuous changing competences required and alternative methods of education used. Nowadays medical education standards provide the ground for organizing the educational data and the paradata. Analysis of such education data through education data mining techniques is in its infancy, but decision support systems for medical education need further research. To the best of our knowledge, there is a gap and a clear need for identifying the challenges for decision support systems in medical education in the era of medical education standards. Thus, in this paper the role and the attributes of such a decision support system for medical education are delineated and the challenges and vision for future actions are identified