Feasibility study of the cut and weld operations by RH on the cooling pipes of ITER NB components

The maintenance operations of ITER NB components inside the vessel - Beam Line Components (BLC's) involve the removal of the faulty component, its transport to the hot cell as well as the reverse operations of transport of the repaired/new component and its reinstallation inside the vessel. Prior to the removal of the BLC's the cooling pipes must be detached from the component following a procedure that applies to the cutting of the pipes and subsequent welding when the component is re-installed. The purpose of this study, conducted in the framework of EFDA, is to demonstrate the feasibility of the cut and weld operations on the water pipes of the BLC's using fully remote handling techniques. Viable technologies for the cut and weld operations have been identified within the study; in particular the following aspects will be presented in the paper:

• Different strategies can be pursued in the detachment of the components depending on the number of cut and weld operations to be performed on the pipes. The selected strategy will impact on the procedure to be followed likewise on important aspects as the requirements of the flexible joints assembled on the pipes.

• The existing cutting techniques have been examined in the light of the remotely performed pipe cutting at the NB cell. Modifications of commercial tools have been proposed in order to adapt them to the BLC's pipes requirements. The debris produced during the cutting process must be controlled and collected, therefore a cleaning system has been integrated in the adapted cutting tool referred above.

• The existing welding techniques have been also examined and compared based on different criteria such as complexity, reliability, alignment tolerances, etc. TIG welding is the preferred technique as it stands out for its superior performance. The commercial tools identified need to be adapted to the NB environment.

• The alignment of the pipes is a critical issue concerning the remote welding. A proper alignment system has been proposed taking into account the pre-selected welding technique.

Neural Crest-Derived Stem Cells (NCSCs) Obtained from Dental-Related Stem Cells (DRSCs): A Literature Review on Current Knowledge and Directions toward Translational Applications

Evidence from dental-related stem cells (DRSCs) suggests an enhanced potential for ectodermal lineage differentiation due to their neural crest origin. Growing evidence that DRSC cultures can produce cells with a neural crest-derived stem cell (NCSC)-like phenotype supports their potential for future therapeutic approaches for neurodegenerative diseases and nerve injuries. However, most of the evidence is limited to the characterization of DRSCs as NCSCs by detecting the expression of neural crest markers. Only a few studies have provided proof of concept of an improved neuro-glial differentiation or direct applicability in relevant models. In addition, a current problem is that several of the existing protocols do not meet manufacturing standards for transferability to a clinical scenario. This review describes the current protocols to obtain NCSCs from DRSCs and their characterization. Also, it provides important considerations from previous work where DRSCs were established and characterized as mesenchymal stromal cells but studied for their neuro-glial differentiation potential. The therapeutic advancement of DRSCs would depend on establishing protocols that can yield a neural crest-like phenotype efficiently, using appropriate manufacturing standards and testing them in relevant models of disease or injury. Achieving these conditions could then facilitate and validate the therapeutic potential of DRSC-NCSCs in regenerative therapies.     

Assessment of Mineralogical,Textural, and Water Chemistry Changes During Long-Distance Tailings-Slurry Transport

An exploratory study demonstrated that subtle changes in solids and process water were caused by long-distance turbulent transport of tailings from the concentrator to the impoundment of a Cu (Mo) porphyry copper deposit. Slurry water chemical analysis was complemented by modelling potential phase precipitation or dissolution and speciation of dissolved metals. It was found that transport did not affect major insoluble mineral phases. However, the degrees of liberation of several phyllosilicates, as determined by automated mineralogy, were reduced close to the impoundment, which points to separation of clay particles from tectosilicate surfaces by the turbulence; this also was observed by SEM examination of micro-aggregate specimens. Reduction of maximum particle sizes, increased N2 monolayer adsorption, and resultant specific surface areas indicate that transport modified the micro-aggregates. Major element water chemistry is controlled by the presence of soluble mineral phases, such as gypsum, and reagents, such as lime, in the flotation process. Changes in the dissolved concentrations of some elements could potentially affect tailings deportment in the impoundment. Increased concentrations of Al may affect the clay settling behaviour, while Mo and As levels will require treatment prior to the discharge of water from the tailings impoundment. This study demonstrated that systematic scrutiny of tailings slurries leaving the concentrator and before entering the impoundment can be potentially useful, though care will have to be exercised to replicate sample handling and analytical conditions, during any long-term monitoring.     

Antioxidant and antibacterial activities of a starch film with bioextracts microencapsulated from cactus fruits (Opuntia oligacantha)

Food Science and Biotechnology - The use of unconventional sources is very relevant in the food area. In the present study the development of active films with the addition of bioextract (BE) or...     

Stability,performance and sensitivity analysis of I.I.D. jump linear systems

This paper presents a symmetric Kronecker product analysis of independent and identically distributed jump linear systems to develop new, lower dimensional equations for the stability and performance analysis of this type of systems than what is currently available. In addition, new closed form expressions characterising multi-parameter relative sensitivity functions for performance metrics are introduced. The analysis technique is illustrated with a distributed fault-tolerant flight control example where the communication links are allowed to fail randomly.     

A review of adaptive online learning for artificial neural networks

In real applications learning algorithms have to address several issues such as, huge amount of data, samples which arrive continuously and underlying data generation processes that evolve over time. Classical learning is not always appropriate to work in these environments since independent and indentically distributed data are assumed. Taking into account the requirements of the learning process, systems should be able to modify both their structures and their parameters. In this survey, our aim is to review the developed methodologies for adaptive learning with artificial neural networks, analyzing the strategies that have been traditionally applied over the years. We focus on sequential learning, the handling of the concept drift problem and the determination of the network structure. Despite the research in this field, there are currently no standard methods to deal with these environments and diverse issues remain an open problem.     

Fast and Selective Determination of Ochratoxin A in Wines Using an Optimized and Validated Liquid Chromatographic Method

Determination of ochratoxin A (OTA) in wines requires a cleanup step using solid phase extraction (SPE). Immunoaffinity columns are commonly the columns of choice but due to its high cost, other SPE columns have been assayed without optimal results. The present work reports an optimized and validated liquid chromatographic method for a fast and selective quantification of OTA in wines using C₁₈ columns for cleanup. Chromatographic conditions were optimized using a central composite design, establishing the following optimal conditions: acetonitrile/water/acetic acid (59.5:39.5:1.0 v/v/v) as mobile phase, flow rate of 1.2 mL min^?1, and column temperature of 30 °C. With these conditions, OTA had a retention time (~4 min) up to five times lower than those reported earlier. Regarding validation, calibration data (n?=?8) fitted a linear regression model with a determination coefficient (R ²) of 0.9992. Repeatability (relative standard deviation (RSD)) and intermediate precision (RSD) in matrix showed values of 1.3 % (n?=?6) and 0.8 % (n?=?3), respectively. Recoveries at five levels ranged from 87.2 to 118.9 % (mean RSD of 7.4 %). Fifty-three samples from different origins were analyzed, finding only seven samples (13 %) with quantifiable OTA content (0.15–0.26 μg L^?1). According to the levels found, the contribution of wine consumption to OTA daily intake was at least 58 times lower than the current tolerable daily intake. In view of optimization and validation results as well as its applicability to real samples, this method could be considered a good alternative for routine analysis of OTA in wines.     

ESR spectra of copper complexes of cellulose

The ESR spectra of complexes of fibrous cotton cellulose and cupriammonia dihydroxide or cupriethylene diamine dihydroxide under various experimental conditions were determined. The spectra of both complexes with cotton cellulose were almost identical at ?100 and 25°C. The spectrum of the complex of cupriethylene diamine dihydroxide with cellulose was stable to temperatures as high as 100°C. The sum of the linewidths of the hyperfine components of the spectra for each complex was about 180 gauss. Cotton fibers were combed and aligned with their axes (lengths) parallel to the magnetic field (B_∥); after formation of either of the complexes with cellulose a minumum of hyperfine structure of components centered at H_∥ was observed. A maximum of hyperfine structure of these components was observed when the complexed fibers were aligned with their axes perpendicular to the magnetic field (B_⊥). The opposite was true of components centered at H_⊥. For a complex of cupriethylene diamine dihydroxide and cellulose at 25°C. and at high pH the g_∥ was 2.2127 and the g_∥ was 2.0476. It was suggested that the alignment of most of the complex was its axis of symmetry at a maximum angle to the axes of the cotton fiber, when the axes of the fibers were in the parallel alignment with the magnetic field. At high pH these observations were even more marked. When ramie was used with cupriethylene diamine dihydroxide at high pH, the contribution of components centered at H_∥ to the spectra was zero. Spectra for the copper compounds alone and complexed with cellobiose are also reported.     

Serendipitous Identification of a Covalent Activator of Liver Pyruvate Kinase

Enzymes are effective biological catalysts that accelerate almost all metabolic reactions in living organisms. Synthetic modulators of enzymes are useful tools for the study of enzymatic reactions and can provide starting points for the design of new drugs. Here, we report on the discovery of a class of biologically active compounds that covalently modifies lysine residues in human liver pyruvate kinase (PKL), leading to allosteric activation of the enzyme (EC₅₀=0.29 μM). Surprisingly, the allosteric activation control point resides on the lysine residue K282 present in the catalytic site of PKL. These findings were confirmed by structural data, MS/MS experiments, and molecular modelling studies. Altogether, our study provides a molecular basis for the activation mechanism and establishes a framework for further development of human liver pyruvate kinase covalent activators.