Microstructural characterization of AISI 431 martensitic stainless steel laser-deposited coatings

High cooling rates during laser cladding of stainless steels may alter the microstructure and phase constitution of the claddings and consequently change their functional properties. In this research, solidification structures and solid state phase transformation products in single and multi layer AISI 431 martensitic stainless steel coatings deposited by laser cladding at different processing speeds are investigated by optical microscopy, Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), orientation imaging microscopy (OIM), ternary phase diagram, Schaeffler and TTT diagrams. The results of this study show how partitionless solidification and higher solidification rates alter the microstructure and phase constitution of martensitic stainless steel laser deposited coatings. In addition, it is shown that while different cladding speeds have no effect on austenite–martensite orientation relationship in the coatings, increasing the cladding speed has resulted in a reduction of hardness in deposited coatings which is in contrast to the common idea about obtaining higher hardness values at higher cladding speeds.

Cell-free H-cluster Synthesis and [FeFe] Hydrogenase Activation: All Five CO and CN− Ligands Derive from Tyrosine

[FeFe] hydrogenases are promising catalysts for producing hydrogen as a sustainable fuel and chemical feedstock, and they also serve as paradigms for biomimetic hydrogen-evolving compounds. Hydrogen formation is catalyzed by the H-cluster, a unique iron-based cofactor requiring three carbon monoxide (CO) and two cyanide (CN−) ligands as well as a dithiolate bridge. Three accessory proteins (HydE, HydF, and HydG) are presumably responsible for assembling and installing the H-cluster, yet their precise roles and the biosynthetic pathway have yet to be fully defined. In this report, we describe effective cell-free methods for investigating H-cluster synthesis and [FeFe] hydrogenase activation. Combining isotopic labeling with FTIR spectroscopy, we conclusively show that each of the CO and CN− ligands derive respectively from the carboxylate and amino substituents of tyrosine. Such in vitro systems with reconstituted pathways comprise a versatile approach for studying biosynthetic mechanisms, and this work marks a significant step towards an understanding of both the protein-protein interactions and complex reactions required for H-cluster assembly and hydrogenase maturation

Trends in template/fragment-free protein structure prediction

Predicting the structure of a protein from its amino acid sequence is a long-standing unsolved problem in computational biology. Its solution would be of both fundamental and practical importance as the gap between the number of known sequences and the number of experimentally solved structures widens rapidly. Currently, the most successful approaches are based on fragment/template reassembly. Lacking progress in template-free structure prediction calls for novel ideas and approaches. This article reviews trends in the development of physical and specific knowledge-based energy functions as well as sampling techniques for fragment-free structure prediction. Recent physical- and knowledge-based studies demonstrated that it is possible to sample and predict highly accurate protein structures without borrowing native fragments from known protein structures. These emerging approaches with fully flexible sampling have the potential to move the field forward

Team Sport in the Workplace? A RE-AIM Process Evaluation of ‘Changing the Game’

Background: The workplace is a priority setting to promote health. Team sports can be an effective way to promote both physical and social health. This study evaluated the potential enablers and barriers for outcomes of a workplace team sports intervention programme‘Changing the Game’ (CTG). This study was conducted in a FTSE 100 services organisation. This process evaluation was conducted using the RE-AIM framework. Methods: A mixed methods approach was used. Data were collected from the participants in the intervention group prior to, during and at the end of the intervention using interviews (n = 12), a focus group (n = 5), and questionnaires (n = 17). Organisational documentation was collected, and a research diary was recorded by the lead author. The evidence collected was triangulated to examine the reach, efficacy, adoption, implementation and maintenance of the programme. Data was assessed through template analysis, and questionnaire data were analysed using multiple regression and a series of univariate ANOVAs. Results: CTG improved VO2 Max, interpersonal communication, and physical activity behaviour (efficacy) over 12-weeks. This may be attributed to the supportive approach adopted within the design and delivery of the programme (implementation). Individual and organisational factors challenged the adoption and maintenance of the intervention. The recruitment and communication strategy limited the number of employees the programme could reach. Conclusion: The process evaluation suggests addressing the culture within workplaces may better support the reach, adoption and maintenance of workplace team sport programmes. Future research should consider investigating and applying these findings across a range of industries and sectors