Microwave effects on NiMoS and CoMoS single-sheet catalysts

Single-sheet nanoclusters of MoS₂, NiMoS or CoMoS are widely used in hydrodesulfurization (HDS) catalysis in the petroleum industry. In HDS reactions under microwave irradiation, experiments indirectly pointed out that for pristine MoS₂ reaction rates are accelerated because hot spots are generated on the catalyst bed. In this work, we investigated NiMoS and CoMoS isolated single-sheet substituted catalysts before and after thiophene adsorption focusing on quantifying the effect of microwave irradiation. For that purpose, density functional theory (DFT) molecular charge densities of each system were decomposed according to the distributed multipole analysis (DMA) of Stone. Site dipole values of each system were directly associated with a larger or smaller interaction with the microwave field according to a proposed general approach. We showed that microwave enhancement of HDS reaction rates can occur more efficiently in the CoMoS and NiMoS promoted clusters compared to pristine MoS₂ in the following order: CoMoS > NiMoS > MoS₂. The atomic origin of the catalyst hot spots induced by microwaves was clearly established in the promoted clusters.     

Trisomy iop.

A stillborn male fetus having a trisomy of the short arm of chromosome No 10 is described. The father is a carrier of the reciprocal translocation 46XY,t(10;21) (10pter leads to 10p11::21p11 leads to 21qter). The clinical picture included growth retardation, bilateral cleft lip and palate, micrognathia, short neck, microphalus and bilateral clubbed feet. The long bones were markedly thinned with spontaneous fractures. Autopsy findings included pulmonary hypoplasia and renal dysplasia. Previous reports of trisomy 10 and trisomy of the short arm of chromosome 10 are discussed.     

Validation of Housekeeping Genes in the Brains of Rats Submitted to Chronic Intermittent Hypoxia,a Sleep Apnea Model

Obstructive sleep apnea (OSA) is a syndrome characterized by intermittent nocturnal hypoxia, sleep fragmentation, hypercapnia and respiratory effort, and it has been associated with several complications, such as diabetes, hypertension and obesity. Quantitative real-time PCR has been performed in previous OSA-related studies; however, these studies were not validated using proper reference genes. We have examined the effects of chronic intermittent hypoxia (CIH), which is an experimental model mainly of cardiovascular consequences of OSA, on reference genes, including beta-actin, beta-2-microglobulin, glyceraldehyde-3-phosphate dehydrogenase, hypoxanthine guanine phosphoribosyl transferase and eukaryotic 18S rRNA, in different areas of the brain. All stability analyses were performed using the geNorm, Normfinder and BestKeeper software programs. With exception of the 18S rRNA, all of the evaluated genes were shown to be stable following CIH exposure. However, gene stability rankings were dependent on the area of the brain that was analyzed and varied according to the software that was used. This study demonstrated that CIH affects various brain structures differently. With the exception of the 18S rRNA, all of the tested genes are suitable for use as housekeeping genes in expression analyses.     

Analysis of the Paracoccidioides brasiliensis triosephosphate isomerase suggests the potential for adhesin function

Paracoccidioides brasiliensis is an important fungal pathogen. The disease it causes, paracoccidioidomycosis (PCM), ranges from localized pulmonary infection to systemic processes that endanger the life of the patient. Paracoccidioides brasiliensis adhesion to host tissues contributes to its virulence, but we know relatively little about molecules and the molecular mechanisms governing fungal adhesion to mammalian cells. Triosephosphate isomerase (TPI: EC 5.3.1.1) of P. brasiliensis (PbTPI) is a fungal antigen characterized by microsequencing of peptides. The protein, which is predominantly expressed in the yeast parasitic phase, localizes at the cell wall and in the cytoplasmic compartment. TPI and the respective polyclonal antibody produced against this protein inhibited the interaction of P. brasiliensis to in vitro cultured epithelial cells. TPI binds preferentially to laminin, as determined by peptide inhibition assays. Collectively, these results suggest that TPI is required for interactions between P. brasiliensis and extracellular matrix molecules such as laminin and that this interaction may play an important role in the fungal adherence and invasion of host cells.     

Do pollination syndromes cause modularity and predict interactions in a pollination network in tropical high‐altitude grasslands?

The concept of pollination syndromes has been widely questioned, since plant–pollinator interactions have proved to be more generalist than was previously thought. We examined whether the network of a tropical high‐altitude grassland contained groups of plants and pollinators that interact preferentially with each other. A general binary matrix was created. To assess the robustness of myophily, in all analyses we considered: 1) the whole network, 2) the network after the wasps were removed, and 3) the network after the flies were removed. For each network we evaluated whether: 1) the observed interactions were more related to syndromes than expected by chance, compared to an expected matrix; 2) there was a modular structure; 3) the modules found were more related to syndromes than expected by chance, compared to another expected matrix; 4) the syndromes were equally robust. For this analysis, the general matrix was subdivided into smaller matrices that included each pollination syndrome separately. To test the influence of the functional groups of pollinators and the phylogeny of plants, in addition to the general matrix, we also considered the first expected matrix, a quantitative functional group and a plant phylogeny matrix. The pollination syndromes determined the pattern of interactions in the network: 69% of the total interactions resulted from the functional group of pollinators predicted by the plant syndrome. The network showed greater modularity (13 modules) than expected by chance, mostly consisting of the expected functional groups of pollinators and plant syndromes. The modules were associated with pollination syndromes more than was predicted by chance. Most of the variation in interactions was explained by functional groups of pollinators or by plant syndromes. Plant phylogeny did not account for a significant amount of variation in the interactions. Our findings support the concept of pollination syndromes. However, the interactions were not equally predicted by different pollination syndromes, and the accuracy of the prediction was strongest for ornithophily and melittophily.     

Development,characterization, validation,and mapping of SSRs derived from <Emphasis Type="Italic">Theobroma cacao</Emphasis> L.<Emphasis Type="Italic">–Moniliophthora perniciosa</Emphasis> interaction ESTs

In this study, we report results of the detection and analysis of SSR markers derived of cacao–Moniliophthora perniciosa expressed sequence tags (ESTs) in relation to cacao resistance to witches’ broom disease (WBD), and we compare the polymorphism of those ESTs (EST-simple sequence repeat (SSR)) with classical neutral SSR markers. A total of 3,487 ESTs was used in this investigation. SSRs were identified in 430 sequences: 277 from the resistant genotype TSH 1188 and 153 from the susceptible one Catongo, totalizing 505 EST-SSRs with three types of motifs: dinucleotides (72.1%), trinucleotides (27.3%), and tetranucleotides (0.6%). EST-SSRs were classified into 16 main categories; most of the EST-SSRs belonged to “Unknown function” and “No homology” categories (45.82%). A high frequency of SSRs was found in the 5’UTR and in the ORF (about 27%) and a low frequency was observed in the 3’UTR (about 8%). Forty-nine EST-SSR primers were designed and evaluated in 21 cacao accessions, 12 revealed polymorphism, having 47 alleles in total, with an average of 3.92 alleles per locus. On the other hand, the 11 genomic SSR markers revealed a total of 47 alleles, with an average of 5.22 alleles per locus. The association of EST-SSR with the genomic SSR enhanced the analysis of genetic distance among the genotypes. Among the 12 polymorphic EST-SSR markers, two were mapped on the F₂ Sca 6 × ICS 1 population reference for WBD resistance.     

Nef genes of SIV

Molecular clones of SIVmac were constructed that differed only in sequences within the nef gene. DEAE-transfection of viral DNA containing an open from of nef yielded virus that replicated with similar kinetics and to a similar extent in macaque peripheral blood lymphocyte (PBL) cultures as virus with a deletion or stop codon within nef. Rhesus monkeys that received each kind of molecularly cloned virus became infected. Our results additionally suggest that mutant forms of virus are selected in vitro while open, functional forms are selected in vivo. In animals infected with virus containing a stop codon within nef, reversion of the stop codon to a coding codon was demonstrated in five of five clones analyzed. These results indicate that nef is playing some role crucial to the virus life cycle in vivo.     

Cryopreservation of preantral ovarian follicles in situ from domestic cats (Felis catus) using different cryoprotective agents

The objective of this investigation was to verify the structural characteristics of preantral follicles (PAF) of cat ovarian tissue after cryopreservation in 1.5 M glycerol or ethylene glycol, using a slow-freezing procedure. Ovaries (n = 10) from domestic cats were divided into fragments. One fragment was immediately preserved for classical histology (fresh control), and additional fragments were immersed in minimum essential medium plus 10% bovine fetal serum (MEM+BFS), or MEM+BFS supplemented with 1.5 M glycerol or ethylene glycol. The samples were frozen and plunged into liquid nitrogen. After 1 wk, the samples were thawed. A total of 600 PAF were evaluated. In the fresh control, there were 71.3% normal PAF. After thawing, the rates of normal PAF were 26.0, 39.3 and 58.0% for samples without cryoprotectant or with glycerol or ethylene glycol, respectively. We concluded that ethylene glycol was useful for the cryopreservation of feline PAF in situ.     

Clamp techniques in paediatrics: what have we learned?

The marked increase in conditions associated with insulin resistance in youth, including obesity, polycystic ovary syndrome, type 2 diabetes mellitus etc., has prompted the need to assess insulin sensitivity in this age group. Even though insulin resistance plays an important role in disorders of glucose metabolism and other pathological conditions, both insulin sensitivity and insulin secretion should be determined for a comprehensive evaluation of glucose homeostasis disorders. Insulin sensitivity and secretion are intricately coupled with a delicate feedback mechanism governing their relationship. This article will delineate our paediatric experience with the clamp technique, the hyperinsulinaemic-euglycaemic clamp in assessing in vivo insulin sensitivity, and the hyperglycaemic clamp in assessing insulin secretion.     

Determination of the core of a minimal bacterial gene set.

The availability of a large number of complete genome sequences raises the question of how many genes are essential for cellular life. Trying to reconstruct the core of the protein-coding gene set for a hypothetical minimal bacterial cell, we have performed a computational comparative analysis of eight bacterial genomes. Six of the analyzed genomes are very small due to a dramatic genome size reduction process, while the other two, corresponding to free-living relatives, are larger. The available data from several systematic experimental approaches to define all the essential genes in some completely sequenced bacterial genomes were also considered, and a reconstruction of a minimal metabolic machinery necessary to sustain life was carried out. The proposed minimal genome contains 206 protein-coding genes with all the genetic information necessary for self-maintenance and reproduction in the presence of a full complement of essential nutrients and in the absence of environmental stress. The main features of such a minimal gene set, as well as the metabolic functions that must be present in the hypothetical minimal cell, are discussed.