The GAUGAA Motif Is Responsible for the Binding between circSMARCA5 and SRSF1 and Related Downstream Effects on Glioblastoma Multiforme Cell Migration and Angiogenic Potential

Circular RNAs (circRNAs) are a large class of RNAs with regulatory functions within cells. We recently showed that circSMARCA5 is a tumor suppressor in glioblastoma multiforme (GBM) and acts as a decoy for Serine and Arginine Rich Splicing Factor 1 (SRSF1) through six predicted binding sites (BSs). Here we characterized RNA motifs functionally involved in the interaction between circSMARCA5 and SRSF1. Three different circSMARCA5 molecules (Mut1, Mut2, Mut3), each mutated in two predicted SRSF1 BSs at once, were obtained through PCR-based replacement of wild-type (WT) BS sequences and cloned in three independent pcDNA3 vectors. Mut1 significantly decreased its capability to interact with SRSF1 as compared to WT, based on the RNA immunoprecipitation assay. In silico analysis through the “Find Individual Motif Occurrences” (FIMO) algorithm showed GAUGAA as an experimentally validated SRSF1 binding motif significantly overrepresented within both predicted SRSF1 BSs mutated in Mut1 (q-value = 0.0011). U87MG and CAS-1, transfected with Mut1, significantly increased their migration with respect to controls transfected with WT, as revealed by the cell exclusion zone assay. Immortalized human brain microvascular endothelial cells (IM-HBMEC) exposed to conditioned medium (CM) harvested from U87MG and CAS-1 transfected with Mut1 significantly sprouted more than those treated with CM harvested from U87MG and CAS-1 transfected with WT, as shown by the tube formation assay. qRT-PCR showed that the intracellular pro- to anti-angiogenic Vascular Endothelial Growth Factor A (VEGFA) mRNA isoform ratio and the amount of total VEGFA mRNA secreted in CM significantly increased in Mut1-transfected CAS-1 as compared to controls transfected with WT. Our data suggest that GAUGAA is the RNA motif responsible for the interaction between circSMARCA5 and SRSF1 as well as for the circSMARCA5-mediated control of GBM cell migration and angiogenic potential.     

The Role of Thyroid Hormone Signaling in the Prevention of Digestive System Cancers

Thyroid hormones play a critical role in the growth and development of the alimentary tract in vertebrates. Their effects are mediated by nuclear receptors as well as the cell surface receptor integrin α_Vβ₃. Systemic thyroid hormone levels are controlled via activation and deactivation by iodothyronine deiodinases in the liver and other tissues. Given that thyroid hormone signaling has been characterized as a major effector of digestive system growth and homeostasis, numerous investigations have examined its role in the occurrence and progression of cancers in various tissues of this organ system. The present review summarizes current findings regarding the effects of thyroid hormone signaling on cancers of the esophagus, stomach, liver, pancreas, and colon. Particular attention is given to the roles of different thyroid hormone receptor isoforms, the novel integrin α_Vβ₃ receptor, and thyroid hormone-related nutrients as possible protective agents and therapeutic targets. Future investigations geared towards a better understanding of thyroid hormone signaling in digestive system cancers may provide preventive or therapeutic strategies to diminish risk, improve outcome and avert recurrence in afflicted individuals.     

Picosecond GaAs photoconductors on silicon substrates for localintegration with silicon devices and circuits

A fabrication procedure for local integration of GaAs photoconductive devices with processed silicon circuits is discussed. The process allows isolated regions of GaAs to be epitaxially grown by MBE at temperatures which are compatible with already processed silicon circuits with first-level metallization. GaAs photoconductors with 15-μm gap lengths fabricated on silicon substrates have exhibited >16-mA sampling-oscilloscope-limited responses, with electrical pulse widths less than 20 ps as determined by autocorrelation measurements     

Guar gum methyl ethers. Part I. Synthesis and macromolecular characterization

Guar gum (GG) has been partially methyl-etherified under heterogeneous reaction conditions. The resulting products, (methyl ether guar: MG) with different degrees of substitution, have been characterized by means of viscosity, ¹H NMR, and FTIR measurements. The introduction of methoxyl groups along the polysaccharidic chains reduces the hydrogen bonding sites on the guar backbone reducing primarely the extent of hydrogen bonding between guar macromolecules, hence their aggregation tendency. A comparative analysis of Mark–Houwink–Sakurada parameters and of the characteristic ratio (C_∞) of GG and MG samples in aqueous solution has been carried out using the Burchard–Stockmayer–Fixman method for flexible and semiflexible chains. The MG chains exhibit more flexibility than those of native guar gum which is traceable to a disruption of intrachain hydrogen bonds.     

Silver nanoparticles enhance Pseudomonas aeruginosa PAO1 biofilm detachment

Objectives: Silver nanoparticles (AgNPs) with a size ranging from 7 to 70?nm were synthesized using the ascorbic acid-citrate seed-mediated growth approach at room temperature.

Methods: The 8?nm silver particles were prepared using gallic acid in alkaline conditions and used as seed to prepare AgNPs.

Results: The presence of ascorbic acid and citrate allows the regulation of size and size distribution of the nanoparticles. The increase in free silver ion-to-seed ratio (Ag⁺/Ag⁰) resulted in changes of particle shape from spherical to pseudo-spherical and minor cylindrical shape. Further, a repetitive seeding approach resulted in the formation of pseudo-spherical particles with higher polydispersity index and minor distributions of tetrahedral particles. Citrate-capped AgNPs were stable and did not agglomerate upon centrifugation. The effect of AgNPs on biofilm reduction was evaluated using static culture on 96-well microtiter plates. Results showed that AgNPs with the smallest average diameter were most effective in the reduction of Pseudomonas aeruginosa biofilm colonies, which accounted for 90% of removal.

Conclusion: The biofilm removal activities of the nanoparticles were found to be concentration-independent particularly for the concentration within the range of 80–200?µg/mL.     

Characterization of microorganisms in Argentinean honeys from different sources

Seventy polyfloral honeys including commercial samples obtained from supermarkets, harvested from apiaries and purchased in bulk were initially examined for total antibacterial activity. From each sample, numbers of aerobic mesophilic bacteria, total coliforms, moulds and yeasts were determined and the presence of Salmonella spp., Shigella spp., Clostridium sulfite-reducers, Paenibacillus larvae and Bacillus spp. was investigated. Moisture content, pH and total acidity were also determined for all samples. Any honey diluted to concentrations from 75% to 1% (w/v) of full-strength honey showed total antibacterial activity. The numbers of aerobic mesophilic bacteria, moulds and yeasts were less than 10(3) cfu/g for all 70 samples. Faecal coliforms, Escherichia coli, Salmonella spp., Shigella spp. and Clostridium sulfite-reducers were not detected but P. larvae subspp. larvae, Bacillus cereus, Bacillus pumilus and Bacillus laterosporus were found among samples. For commercial, apiary and bulk honey the mean values for moisture content, pH and acidity, respectively, were 17.50%, 17.40% and 17.50%; 4.60, 4.10 and 4.20; and 18.30, 20.60 and 21 meq NaOH/kg. P. larvae was recovered from 35% of apiaries including hives in which the bees did not display symptoms of American foulbrood disease.     

An anion-permeable polymeric coating for the protection of a semiconductor photoelectrode against decomposition

An anion-permeable polymeric film has been applied to the surfaces of cadmium sulfide photoanodes to decrease the rate of electrode corrosion which is observed during the photoelectro-chemical oxidation of aqueous species. Although the rate of surface corrosion was reduced, film adhesion problems were observed.     

The imaginary,the computer,artificial intelligence: A cultural anthropological approach

The role of the cultural anthropologist in studying the results of information technology and artificial intelligence should be to contribute and reaffirm a sense of life which considers the human being in his or her totality, and to recognize the role of diversity and the imaginary. Technical revolutions have also proved to be cultural revolutions. The skills required by one culture, the identification and creation of problems and the solutions are interrelated. These interrelationships are worked out in a cultural context endowed with its own experiences, knowledge and needs which define and make it different from other societies. The advanced technologies require new competences and new skills. This paper examines imaginary from two different viewpoints: (a) the imaginary aspect of body-mind relations, influenced by research into artificial intelligence and its prospects for the future; and (b) the roles and forms assumed by the imaginary in human-computer relations.     

Physicochemical,Nutritional, and Functional Characterization of Fruits Xoconostle (Opuntia matudae) Pears from Central-México Region

Abstract: Xoconostle cv. Cuaresmeño (Opuntia matudae) has attracted domestic and international industry attention; however, variations of composition from xoconostle structures have not been evaluated. Industries discard the pulp (endocarp) and peel (pericarp) as wastes and utilize the skin (mesocarp), which is the edible portion. The physicochemical, nutritional, and functional characterization of structures from xoconostle pear from 3 major sites of production in Mexico were assessed. Skin yield ranged from 58% to 64% and was higher to that of peel (22% to 24%) and pulp (12% to 18%) yields. pH, °Brix, and acidity were similar among xoconostle structures. Total fiber showed by peel (18.23% to 20.37%) was 2-fold higher than that of skin. Protein and ether extract were higher in xoconostle pulp compared to that showed by peel and skin. Iron content of xoconostle peel (6 to 9.6 mg/100 g, DWB) was higher to that of skin and pulp and prickly pear pulp. Soluble phenols of peel (840 to 863 mg GAE/100 g, DWB) were almost similar to that of skin (919 to 986 mg GAE/100 g, dry weigh basis); meanwhile, ascorbic acid concentration of skin was 2-fold higher compared to that of peel. The phenolic fraction of xoconostle structures consisted of gallic, vanillic, and 4-hydroxybenzoic acids; catechin, epicatechin, and vanillin were also identified by high-performance liquid chromatography–didoe array detection (HPLC-DAD). Xoconostle peel showed higher antioxidant activity (TEAC) compared to that of skin (2-fold) and pulp (6-fold) of commonly consumed fruits and vegetables. The potential of xoconostle peel and pulp for the production of feed or food is promissory. Practical Application: Outstanding nutritional and functional properties of xoconostle cv. Cuaresmeño fruits are demonstrated. Increased consumption could contribute positively to improve the diet of rural and urban consumers. The high fiber, mineral, and antioxidant components of xoconostle peel and pulp suggest that these fruit structures, which are currently discarded as waste, have promissory use as feed or food by industry.