Effect of additive distribution in H2 absorption and desorption kinetics in MgH2 milled with NbH0.9 or NbF5

This paper presents a comparative study of H₂ absorption and desorption in MgH₂ milled with NbF₅ or NbH_0.9. The addition of NbF₅ or NbH_0.9 greatly improves hydriding and dehydriding kinetics. After 80 h of milling the mixture of MgH₂ with 7 mol.% of NbF₅ absorbs 60% of its hydrogen capacity at 250 °C in 30 s, whereas the mixture with 7 mol.% of NbH_0.9 takes up 48%, and MgH₂ milled without additive only absorbs 2%. At the same temperature, hydrogen desorption in the mixture with NbF₅ finishes in 10 min, whereas the mixture with NbH_0.9 only desorbs 50% of its hydrogen content, and MgH₂ without additive practically does not releases hydrogen. The kinetic improvement is attributed to NbH_0.9, a phase observed in the hydrogen cycled MgH₂ + NbF₅ and MgH₂ + NbH_0.9 materials, either hydrided or dehydrided. The better kinetic performance of the NbF₅-added material is attributed to the combination of smaller size and enhanced distribution of NbH_0.9 with more favorable microstructural characteristics. The addition of NbF₅ also produces the formation of Mg(H_xF_1-x)₂ solid solutions that limit the practically achievable hydrogen storage capacity of the material. These undesired effects are discussed.     

Next-Generation Sequencing Workflow for NSCLC Critical Samples Using a Targeted Sequencing Approach by Ion Torrent PGM? Platform

Next-generation sequencing (NGS) is a cost-effective technology capable of screening several genes simultaneously; however, its application in a clinical context requires an established workflow to acquire reliable sequencing results. Here, we report an optimized NGS workflow analyzing 22 lung cancer-related genes to sequence critical samples such as DNA from formalin-fixed paraffin-embedded (FFPE) blocks and circulating free DNA (cfDNA). Snap frozen and matched FFPE gDNA from 12 non-small cell lung cancer (NSCLC) patients, whose gDNA fragmentation status was previously evaluated using a multiplex PCR-based quality control, were successfully sequenced with Ion Torrent PGM™. The robust bioinformatic pipeline allowed us to correctly call both Single Nucleotide Variants (SNVs) and indels with a detection limit of 5%, achieving 100% specificity and 96% sensitivity. This workflow was also validated in 13 FFPE NSCLC biopsies. Furthermore, a specific protocol for low input gDNA capable of producing good sequencing data with high coverage, high uniformity, and a low error rate was also optimized. In conclusion, we demonstrate the feasibility of obtaining gDNA from FFPE samples suitable for NGS by performing appropriate quality controls. The optimized workflow, capable of screening low input gDNA, highlights NGS as a potential tool in the detection, disease monitoring, and treatment of NSCLC.     

Genetic characterization of HHV-8/KSHV-positive primary effusion lymphoma reveals frequent mutations of BCL6: implications for disease pathogenesis and histogenesis

A new type of antimicrobial peptide, snakin-1 (SN1), has been isolated from potato tubers and found to be active, at concentrations < 10 microM, against bacterial and fungal pathogens from potato and other plant species. The action of SN1 and potato defensin PTH1 was synergistic against the bacterium Clavibacter michiganensis subsp. sepedonicus and additive against the fungus Botrytis cinerea. Snakin-1 causes aggregation of both gram-positive and gram-negative bacteria. The peptide has 63 amino acid residues (M(r) 6,922), 12 of which are cysteines, and is unrelated to any previously isolated protein, although it is homologous to amino acid sequences deduced from cloned cDNAs that encode gibberellin-inducible mRNAs and has some sequence motifs in common with kistrin and other hemotoxic snake venoms. A degenerate oligonucleotide probe based on the internal sequence CCEECKC has been used to clone an SN1 cDNA. With the cDNA used as probe, one copy of the StSN1 gene per haploid genome has been estimated and expression of the gene has been detected in tubers, stems, axillary buds, and young floral buds. Expression levels in petals and carpels from fully developed flowers were much higher than in sepals and stamens. The expression pattern of gene StSN1 suggests that protein SN1 may be a component of constitutive defense barriers, especially those of storage and reproductive plant organs.     

Neural Substrates of Coping Behavior in the Rat: Possible Importance of Mesocorticolimbic Dopamine System.

This study measured expression of Fos protein, an indicator of neural activation, in 116 brain regions of rats that were able to control a stressor (i.e., avoid and/or escape an electric shock), and compared the changes with those observed in yoked rats that received the same shocks but without having control over them. The authors' interest was to find brain regions where elevated activity occurs in conjunction with control. Activity in these brain regions might be responsible for the consequences of having control, such as reduction of stress responses. Eleven brain regions were found in which rats with control showed significantly more Fos expression than was seen in yoked rats that did not have control. Six of these brain regions were part of the mesocorticolimbic dopamine system. These results point to the mesocorticolimbic dopamine system as being importantly involved in the mediation and/or the consequences of coping behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Therapy of acute myeloid leukemia: towards a patient-oriented, risk-adapted approach

BACKGROUND AND OBJECTIVE: The successful use of differentiating treatment for patients with acute promyelocytic leukemia (APL) suggests that other acute myeloid leukemias (AML) may benefit from tailored and subtype-specific therapy. Despite the fact that new drugs specifically targeting AML genetic lesions have not yet been developed, distinct karyotypic categories have been identified which may deserve differentiated treatment. In addition, molecular assays to assess response to therapy more sensitively are now available for several AML subsets. In this review, we discuss the role of genetic characterization in the therapy of AML, and the investigative efforts which we believe are still needed for the design of tailored treatment for each and every patient with this disease. DESIGN AND METHODS: The authors have been working in this field for many years and have contributed original papers, the data of which are incorporated in this article. In addition, the material analyzed in this overview includes articles and reviews covered by the Science Citation Index and Medline as well as some more recent unpublished personal observations. RESULTS: Modern therapeutic approaches to AML tend to differentiate post-induction treatment intensity according to cytogenetically defined risk categories. Such prognostic categorization is largely unsatisfactory. In fact, following the advent of newly developed molecular assays (e.g. RT-PCR and FISH), specific and prognostically relevant lesions are frequently found in patients with an apparently normal karyotype, and these patients are, therefore, re-assigned to more appropriate prognostic categories. In addition, recent studies suggest that some patients may benefit from an increase in induction intensity; rapid genetic characterization will be needed for future differentiation of initial therapy. However, preliminary investigation of AML by integrated karyotypic/molecular analyses show that no specific abnormalities are detectable in at least half of the cases. Therefore, use of genetic criteria for prognostic stratification is currently feasible in only a proportion of patients. INTERPRETATIONS AND CONCLUSIONS: The prognostic role of genetic lesions, currently identified by karyotypic studies, needs to be validated in large series of AML patients prospectively characterized by advanced molecular/cytogenetic analyses and treated uniformly. In addition, searches for new clinically relevant genetic abnormalities, and diagnostic tools for their rapid identification are urgently needed to identify prognostic categories better. Elucidation of AML gene alterations should foster basic investigation aimed at developing new drugs targeted to the specific lesion in the individual patient. Before these more specific therapeutic agents are developed, diagnostic genetic characterization should add to other well-established prognostic factors to optimize the use of the presently available therapies.     

Symbol error rate curves for M-QAM signals with multiplecochannel interferers

A recursive algorithm for determining the probability of symbol error in an M-QAM system, subject to multiple-cochannel interferers, is presented. In particular, a recursive formula is derived for determining the symbol-error-rate (SER) of an M-QAM system subject to both multiple-sinusoidal and similar, independent QAM interferers. The result is expected to prove useful in the analysis of such systems exposed to ever-increasing interference     

Charge iteration: A procedure for the finite element computation of unbounded electrical fields

An iterative procedure is presented for the finite element computation of unbounded electrical fields created by voltaged conductors. The procedure is based on successive evaluations of the potential on a fictitious boundary enclosing all the conductors, according to the charge lying on their surface. The convergence of the procedure to the solution of the unbounded field problem is demonstrated. Indications for the optimal placement of the fictitious boundary are provided, also taking into account the accuracy of the solution. The way in which computational efficiency can be reached is also discussed. The main advantage of this procedure lies in its simplicity of implementation in the context of a standard FE code for bounded problems, because a very limited amount of additional software is required; moreover, 2-D and axisymmetric versions can be implemented with minor changes from a suitable 3-D one. Examples of application are given in order to illustrate the practical use of the procedure and to validate it by comparisons with available solutions.