778 research outputs found
Estudio bibliométrico de la evolución de la revista Enseñanza de las ciencias a partir de sus fuentes de información
Science learning research development in Spain can be bibliometrically analyzed using Enseñanza de las Ciencias as indicator, because of the incidence level of this journal in researchers with interest in scientific education. The references which are cited in the articles have been studied in order to analyze the main sources and the most productive authors, using the Bradford model. The evolution of the type of sources and articles which are cited during the period of time studied are considered
Influence of the measurement medium and matrix modifiers on the determination of silicon in waters by graphite furnace atomic absorption spectrometry
An electrothermal atomic absorption (ETAAS) method has been developedfor the direct determination of Si in natural waters. Measurements were carried out on previously alkalinized samples and using a mixture of Pd and Mg(NO3)2 as matrix modifier, with an ashing temperature of 1400 oC and an atomization temperature of 2400 oC. Transversally heated pyrolitically graphite tubes, equipped with Lfvov platform and Zeeman effect correction, was employed in this study. A limit of detection of 2.6 ƒÊg/L Si was obtainedand accuracy was evaluated by analyzing two Standard Reference Material at different concentration levels, a good agreement (<5%) was obtained. This developed procedure was demonstrated of the need of using an alkaline medium for accurate Si determination by ETAAS
Genome-wide discovery and development of polymorphic microsatellites from Leishmania panamensis parasites circulating in central Panama
The parasite Leishmania panamensis is the main cause of leishmaniasis in Panama. The disease is largely uncontrolled, with a rising incidence and no appropriate control measures. While microsatellites are considered some of the best genetic markers to study population genetics and molecular epidemiology in these and other parasites, none has been developed for L. panamensisThe parasite Leishmania panamensis is the main cause of leishmaniasis in Panama. The disease is largely uncontrolled, with a rising incidence and no appropriate control measures. While microsatellites are considered some of the best genetic markers to study population genetics and molecular epidemiology in these and other parasites, none has been developed for L. panamensi
Parietaria major allergens vs pollen in the air we breathe
Background
Parietaria and Urtica are the genera from the Urticaceae family more frequent in Mediterranean and Atlantic areas. Moreover, both genera share pollination periods, and their pollen (of the main species) is so similar that there is no aerobiological evidence of the proportion of each of them in the airborne pollen identification, except in the case of U. membranacea. However, Parietaria is one of the most important causes of pollinosis and Urtica is not. Our aim is determine if airborne Urticaceae pollen concentrations show the aerodynamics of the two major allergens of Parietaria (Par j 1 and Par j 2) as well as the allergen distribution in the different-sized particles.
Methods
The air was sampled during the pollination period of Urticaceae using Hirst Volumetric Sampler and Andersen Cascade Impactor in two cities of Southern Spain (Córdoba and Granada). The samples were analysed by the methodology proposed by the Spanish Aerobiology Network (REA) and the minimum requirements of the European Aeroallergen Society (EAS) for pollen, and by ELISA immunoassay for allergens.
Results
The patterns of airborne pollen and Par j 1-Par j 2 were present in the air during the studied period, although with irregular oscillations. Urticaceae pollen and Par j 1-Par j 2 allergens located in PM2.5 showed positive and significant correlation during the period with maximum concentrations (March to April).
Conclusion
Parietaria aeroallergens show similar pattern of Urticaceae airborne pollen. Urticaceae pollen calendar is as a good tool for allergy prevention. On the other hand, important concentrations of Par j 1 and Par j 2 were located in the breathable fraction (PM2.5), which could explain the asthmatic symptoms in the allergic population to Parietaria
DNA Repair Mechanisms as Drug Targets in Prokaryotes
Nowadays, a great amount of pathogenic bacteria has been identified such as Mycobacterium sp. and Helicobacter pylori and have become a serious health problem around the world. These bacteria have developed several DNA repair mechanisms as a strategy to neutralize the effect of the exposure to endogenous and exogenous agents that will lead to two different kinds of DNA damage: single strand breaks (SSBs) and double strand breaks (DSBs). For SSBs repair, bacteria use the base excision repair (BER) and nucleotide excision repair (NER) mechanisms, which fix the damaged strand replacing the damaged base or nucleotide. DSBs repair in bacteria is performed by homologous recombination repair (HRR) and non-homologous end-joining (NHEJ). HRR uses the homologous sequence to fix the two damaged strand, while NHEJ repair does not require the use of its homologous sequence. The use of unspecific antibiotics to treat bacterial infections has caused a great deal of multiple resistant strains making less effective the current therapies with antibiotics. In this review, we emphasized the mechanisms mentioned above to identify molecular targets that can be used to develop novel and more efficient drugs in future.Nowadays, a great amount of pathogenic bacteria has been identified such as Mycobacterium sp. and Helicobacter pylori and have become a serious health problem around the world. These bacteria have developed several DNA repair mechanisms as a strategy to neutralize the effect of the exposure to endogenous and exogenous agents that will lead to two different kinds of DNA damage: single strand breaks (SSBs) and double strand breaks (DSBs). For SSBs repair, bacteria use the base excision repair (BER) and nucleotide excision repair (NER) mechanisms, which fix the damaged strand replacing the damaged base or nucleotide. DSBs repair in bacteria is performed by homologous recombination repair (HRR) and non-homologous end-joining (NHEJ). HRR uses the homologous sequence to fix the two damaged strand, while NHEJ repair does not require the use of its homologous sequence. The use of unspecific antibiotics to treat bacterial infections has caused a great deal of multiple resistant strains making less effective the current therapies with antibiotics. In this review, we emphasized the mechanisms mentioned above to identify molecular targets that can be used to develop novel and more efficient drugs in future
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