A new method for the synthesis of hydrophobized, catalytically active Pt nanoparticles

This is the published version. Copyright © The Royal Society of Chemistry 2002A single step method for the synthesis of catalytically active, hydrophobic Pt nanoparticles by the spontaneous reduction of aqueous PtCl62− ions by hexadecylaniline molecules at a liquid–liquid interface is described

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

Meeting abstrac

Spare PRELI Gene Loci: Failsafe Chromosome Insurance?

LEA (late embryogenesis abundant) proteins encode conserved N-terminal mitochondrial signal domains and C-terminal (A/TAEKAK) motif repeats, long-presumed to confer cell resistance to stress and death cues. This prompted the hypothesis that LEA proteins are central to mitochondria mechanisms that connect bioenergetics with cell responses to stress and death signaling. In support of this hypothesis, recent studies have demonstrated that mammalian LEA protein PRELI can act as a biochemical hub, which upholds mitochondria energy metabolism, while concomitantly promoting B cell resistance to stress and induced death. Hence, it is important to define in vivo the physiological relevance of PRELI expression.Given the ubiquitous PRELI expression during mouse development, embryo lethality could be anticipated. Thus, conditional gene targeting was engineered by insertion of flanking loxP (flox)/Cre recognition sites on PRELI chromosome 13 (Chr 13) locus to abort its expression in a tissue-specific manner. After obtaining mouse lines with homozygous PRELI floxed alleles (PRELI(f/f)), the animals were crossed with CD19-driven Cre-recombinase transgenic mice to investigate whether PRELI inactivation could affect B-lymphocyte physiology and survival. Mice with homozygous B cell-specific PRELI deletion (CD19-Cre/Chr13 PRELI(-/-)) bred normally and did not show any signs of morbidity. Histopathology and flow cytometry analyses revealed that cell lineage identity, morphology, and viability were indistinguishable between wild type CD19-Cre/Chr13 PRELI(+/+) and CD19-Cre/Chr13 PRELI(-/-) deficient mice. Furthermore, B cell PRELI gene expression seemed unaffected by Chr13 PRELI gene targeting. However, identification of additional PRELI loci in mouse Chr1 and Chr5 provided an explanation for the paradox between LEA-dependent cytoprotection and the seemingly futile consequences of Chr 13 PRELI gene inactivation. Importantly, PRELI expression from spare gene loci appeared ample to surmount Chr 13 PRELI gene deficiency.These findings suggest that PRELI is a vital LEA B cell protein with failsafe genetics

PEDO-TRANSFER FUNCTIONS FOR ESTIMATING SOIL BULK DENSITY IN CENTRAL AMAZONIA

Under field conditions in the Amazon forest, soil bulk density is difficult to measure. Rigorous methodological criteria must be applied to obtain reliable inventories of C stocks and soil nutrients, making this process expensive and sometimes unfeasible. This study aimed to generate models to estimate soil bulk density based on parameters that can be easily and reliably measured in the field and that are available in many soil-related inventories. Stepwise regression models to predict bulk density were developed using data on soil C content, clay content and pH in water from 140 permanent plots in terra firme (upland) forests near Manaus, Amazonas State, Brazil. The model results were interpreted according to the coefficient of determination (R2) and Akaike information criterion (AIC) and were validated with a dataset consisting of 125 plots different from those used to generate the models. The model with best performance in estimating soil bulk density under the conditions of this study included clay content and pH in water as independent variables and had R2 = 0.73 and AIC = -250.29. The performance of this model for predicting soil density was compared with that of models from the literature. The results showed that the locally calibrated equation was the most accurate for estimating soil bulk density for upland forests in the Manaus region

Comparative genomics reveals phylogenetic distribution patterns of secondary metabolites in Amycolatopsis species

Background Genome mining tools have enabled us to predict biosynthetic gene clusters that might encode compounds with valuable functions for industrial and medical applications. With the continuously increasing number of genomes sequenced, we are confronted with an overwhelming number of predicted clusters. In order to guide the effective prioritization of biosynthetic gene clusters towards finding the most promising compounds, knowledge about diversity, phylogenetic relationships and distribution patterns of biosynthetic gene clusters is necessary. Results Here, we provide a comprehensive analysis of the model actinobacterial genus Amycolatopsis and its potential for the production of secondary metabolites. A phylogenetic characterization, together with a pan-genome analysis showed that within this highly diverse genus, four major lineages could be distinguished which differed in their potential to produce secondary metabolites. Furthermore, we were able to distinguish gene cluster families whose distribution correlated with phylogeny, indicating that vertical gene transfer plays a major role in the evolution of secondary metabolite gene clusters. Still, the vast majority of the diverse biosynthetic gene clusters were derived from clusters unique to the genus, and also unique in comparison to a database of known compounds. Our study on the locations of biosynthetic gene clusters in the genomes of Amycolatopsis’ strains showed that clusters acquired by horizontal gene transfer tend to be incorporated into non-conserved regions of the genome thereby allowing us to distinguish core and hypervariable regions in Amycolatopsis genomes. Conclusions Using a comparative genomics approach, it was possible to determine the potential of the genus Amycolatopsis to produce a huge diversity of secondary metabolites. Furthermore, the analysis demonstrates that horizontal and vertical gene transfer play an important role in the acquisition and maintenance of valuable secondary metabolites. Our results cast light on the interconnections between secondary metabolite gene clusters and provide a way to prioritize biosynthetic pathways in the search and discovery of novel compounds

Desenvolvimento cognitivo de prematuros à idade escolar: proposta de modelo hierarquizado para investigação dos fatores de risco

O déficit cognitivo é a sequela do neurodesenvolvimento mais prevalente na população de prematuros de muito baixo peso. Poucos são os trabalhos nacionais sobre o desenvolvimento desta população na idade escolar. Este estudo propõe uma discussão teórica sobre os fatores determinantes do desenvolvimento cognitivo na idade escolar de prematuros de muito baixo peso ao nascer, utilizando o modelo hierarquizado de análise. Neste modelo, fatores biológicos e ambientais se relacionariam em diversos níveis: distal, intermediário e proximal, resultando em alterações no desenvolvimento cognitivo. Pretende-se, desta forma, aprofundar a questão das mediações possíveis das variáveis e suas inter-relações e consequentes eventos que podem levar ao desfecho. Para a seleção dos fatores de risco foi realizada uma revisão da literatura sobre fatores associados a resultados cognitivos desfavoráveis. Pressupõe-se que o melhor conhecimento das inter-relações destes fatores auxiliaria na prevenção e intervenção mais adequada nesta população, aumentando suas chances de inclusão escolar e social.Cognitive impairment is a neurodevelopmental sequela that is more prevalent in very low birth weight (VLBW) premature children. There are few Brazilian studies on this group's cognitive development at school age. The current study proposes a theoretical discussion on the determinants of cognitive development at school age in VLBW preterm children, using a hierarchical analytical model. According to this model, biological and environmental factors interrelate on several levels (distal, intermediate, and proximal), resulting in changes in cognitive development. The aim is to investigate the possible mediation of variables and their interrelationships and the resulting events that could lead to cognitive impairment as the outcome. Selection of risk factors was based on a literature review of factors associated with adverse cognitive outcomes. Better understanding of the interrelationships between these factors could lead to more appropriate prevention and intervention in this group, thereby increasing their chances of educational and social inclusion