Visual computing for medical diagnosis and treatment

Diagnostic algorithms and efficient visualization techniques are of major importance for preoperative decisions, intra-operative imaging and image-guided surgery. Complex diagnostic decisions are characterized by a high information flow and fast decisions, requiring efficient and intuitive presentation of complex medical data and precision in the visualization. For intra-operative medical treatment, the pre-operative visualization results of the diagnostic systems have to be transferred to the patient on the operation room table. Via augmented reality, additional information of the hidden regions can be displayed virtually. This state-of-the-art report summarizes visual computing algorithms for medical diagnosis and treatment. After starting with direct volume rendering and tagged volume rendering as general techniques for visualizing anatomical structures, we go into more detail by focusing on the visualization of tissue and vessel structures. Afterwards, algorithms and techniques that are used for medical treatment in the context of image-guided surgery, intra-operative imaging and augmented reality are discussed and reviewed.     

Work environment and computer systems development

Work environment and occupational health problems of different nature are constantly increasing in computer supported work. Most efforts to improve the work environment are focused primarily on physical aspects, and to some extent on psychosocial aspects. Mental workload and cognitive problems are of a more complex nature, more difficult to measure and provide efficient solutions to, and are more seldom studied or solved. Solutions to work environment problems are usually applied to already existing work situations through improved equipment and work place design, health programmes, education, reorganizations, etc. The problems are seldom prevented by means of applying relevant methods early in the systems development process, before the artefacts have been designed and implemented. This paper, and the following papers of this special issue, will focus on the need to integrate different interdisciplinary methods at different phases in the development process of computerized support systems, with the ultimate goal to prevent work environment problems and decrease the health risks to the users.     

Engineering the Ligand Specificity of the Human Galectin-1 by Incorporation of Tryptophan Analogues

Galectin-1 is a β-galactoside-binding lectin with manifold biological functions. A single tryptophan residue (W68) in its carbohydrate binding site plays a major role in ligand binding and is highly conserved among galectins. To fine tune galectin-1 specificity, we introduced several non-canonical tryptophan analogues at this position of human galectin-1 and analyzed the resulting variants using glycan microarrays. Two variants containing 7-azatryptophan and 7-fluorotryptophan showed a reduced affinity for 3’-sulfated oligosaccharides. Their interaction with different ligands was further analyzed by fluorescence polarization competition assay. Using molecular modeling we provide structural clues that the change in affinities comes from modulated interactions and solvation patterns. Thus, we show that the introduction of subtle atomic mutations in the ligand binding site of galectin-1 is an attractive approach for fine-tuning its interactions with different ligands.     

Classification of hydropeaking impacts on Atlantic salmon populations in regulated rivers

This article proposes and demonstrates a new classification system of fish population level effects of hydropeaking operations in rivers. The classification of impacts is developed along two axes; first, the hydromorphological effect axis assesses the ecohydraulic alterations in rivers introduced by rapid and frequent variations in flow and water level, second the vulnerability axis assesses the site-specific vulnerability of the fish population. Finally, the population level impact is classified into four classes from small to very large by combining the two axes. The system was tested in four rivers in Norway exposed to hydropeaking, and they displayed a range of outcomes from small to very large impacts on the salmon populations. The river with a relatively high base flow and ramping restrictions scored better than rivers with the lower base flow or limited ramping restrictions, indicating that hydropeaking effects can be mitigated while maintaining high hydropower flexibility. Most effect factors could easily be calculated from timeseries of discharge and water level, whereas the use of hydraulic models to estimate potential stranding areas may require more work. The vulnerability factors are mainly qualitative and depend more heavily on expert judgments and are thus more uncertain. The system was deemed suitable for the purpose of supporting management decisions for rivers exposed to hydropeaking operations. It evaluates the severity of the additional pressures due to hydropeaking operations and proved useful to identify mitigating measures. While the system was developed for Atlantic salmon river systems, it could be adapted to other species or systems.     

Gamma Irradiation Assisted the Sol–Gel Method for Silver Modified-Nickel Molybdate Nanoparticles Synthesis: Unveiling the Antimicrobial,and Antibiofilm Activities Against Some Pathogenic Microbes

Herein, this work aims to reveal the gamma irradiation-assisted the sol–gel method for the synthesis of silver (Ag) modified-nickel molybdate nanoparticles (NiMoO₄; NMO NPs) and tested for their antimicrobial and antibiofilm activities against some pathogenic bacteria and unicellular fungi. The prepared samples were characterized via XRD, HR-TEM, SEM, EDX, and elemental mapping analysis. The antimicrobial potential was tested as ZOI and MIC, while antibiofilm was estimated by tube method. The detected diffraction peaks of bare NMO NPs affirmed the successful synthesis of NMO NPs without any foreign phases. Also, three diffraction peaks were detected affirming the formation of Ag NPs on the surface of NMO NPs. The average crystallite size for the bare NMO NPs and Ag@NMO NPs was found to be 71.8 nm and 48.28 nm, respectively. Also, the SEM images have illustrated the decoration of Ag NPs on the NMO surface. Further, the TEM image illustrated that the particles of NMO possess a hexagonal shape in the nanoscale regime. Also, the elemental mapping images confirm the uniform distribution of these elements over the Ag@NMO sample. Antimicrobial results revealed that the synthesized Ag@NMO NPs recorded the most significant inhibition zone more than NMO NPs against Enterococcus columbae (33.3?±?0.115 mm), and Candida albicans (30.8?±?0.572 mm), and the lowest MIC (0.048 µg/ml) against E. columbae. Antibiofilm activity of Ag@NMO NPs recording 94.32% for E. columbae, 91.99% for S. vitulinus, and 90.98% for C. albicans. SEM imaging in the lack of Ag@NMO NPs exhibited normally grown bacterial cells with standard typical semi-formed biofilm. After Ag@NMO NPs treatment, remarkable morphological changes; including the total lysis of the outer surface attended by deformations with the reduction in the whole viable number.

     

Identification of Genes Essential for Sulfamate and Fluorine Incorporation During Nucleocidin Biosynthesis

Nucleocidin is an adenosine derivative containing 4’-fluoro and 5’-O-sulfamoyl substituents. In this study, nucleocidin biosynthesis is examined in two newly discovered producers, Streptomyces virens B-24331 and Streptomyces aureorectus B-24301, which produce nucleocidin and related derivatives at titers 30-fold greater than S. calvus. This enabled the identification of two new O-acetylated nucleocidin derivatives, and a potential glycosyl-O-acetyltransferase. Disruption of nucJ, nucG, and nucI, within S. virens B-24331, specifying a radical SAM/Fe−S dependent enzyme, sulfatase, and arylsulfatase, respectively, led to loss of 5’-O-sulfamoyl biosynthesis, but not fluoronucleoside production. Disruption of nucN, nucK, and nucO specifying an amidinotransferase, and two sulfotransferases respectively, led to loss of fluoronucleoside production. Identification of S. virens B-24331 as a genetically tractable and high producing strain sets the stage for understanding nucleocidin biosynthesis and highlights the utility of using 16S-RNA sequences to identify alternative producers of valuable compounds in the absence of genome sequence data.