Size and Electronic Effects on the Performance of (Corrolato)cobalt-Modified Electrodes for Oxygen Reduction Reaction Catalysis.

Considering the worldwide efforts for designing catalysts that are not based on platinum group metals while still reserving the many advantages thereof, this study focused on the many variables that dictate the performance of cathodes used for fuel cells, regarding the efficient and selective reduction of oxygen to water. This was done by investigating two kinds of porous carbon electrodes, modified by molecular cobalt(III) complexes chelated by corroles that differ very much in size and electron-withdrawing capability. Examination of the electronic effect uncovered shifts in the CoII/CoIII redox potentials and also large differences in the affinity of the cobalt center to external ligands. Spontaneous absorption of the catalysts was found to depend on the size of the corrole's substituents (C6F5 ≫ CF3 ≫ H) and the metal's axial ligands (PPh3 versus pyridine), as well as on the porosity of the carbon electrodes (BP2000 > Vulcan). The better-performing cobalt-based catalysts were almost as active and selective as 20% platinum on Vulcan in terms of the onset potential and the only 2-10% undesirable formation of hydrogen peroxide. Durability was also addressed by using the best-performing modified cathode in a proper anion-exchange membrane fuel cell setup, revealing very little voltage change during 12 h of operation.

[Mixed Munchausen Syndrome with organic comorbidity]. / Síndrome de Munchausen mixto con comorbilidad orgánica.

We present a detailed case report that shows a woman patient who has Factitious Disorder manifested by the coexistence both of: A) typical/direct Munchausen and B) Munchausen by proxy or indirect: being the frst one (A) about the own person and the second one (B) about other people (most cases about their own young children). Furthermore, in the reported case we observed that the patient shown the particularity of having positive biological markers for Myasthenia Gravis (serology markers), and having inconsistent clinical manifestations that are typically observed in the exacerbation phase when she still continued in remission phase. In our own bibliographic research we couldn`t fnd anything about this case of "Mixed Munchausen Syndrome with organic comorbidity". In the same way as we tried to get information about the diagnostic algorithms and the possible therapeutic treatment strategies we found nothing like this reported before. Finally, this clinical presentation constitutes a blind spot for the scientifc community generating a lack of recognition for this diagnostic category and above all of the confusion that this mental disorder can generate in: a) the inadequate use of therapeutic resources, b) the irrational use of drugs, c) the distortion of institutional instances, and d) the medical behaviors that occurred in this case.

Genome-wide analysis of DNA uptake across the outer membrane of naturally competent Haemophilus influenzae.

The genomes of naturally competent Pasteurellaceae and Neisseriaceae have many short uptake sequences (USS), which allow them to distinguish self-DNA from foreign DNA. To fully characterize this preference we developed genome-wide maps of DNA uptake using both a sequence-based computational model and genomic DNA that had been sequenced after uptake by and recovery from competent Haemophilus influenzae cells. When DNA fragments were shorter than the average USS spacing of ∼1,000 bp, sharp peaks of uptake were centered at USS and separated by valleys with 1000-fold lower uptake. Long DNA fragments (1.5-17 kb) gave much less variation, with 90% of positions having uptake within 2-fold of the mean. All detectable uptake biases arose from sequences that fit the USS uptake motif. Simulated competition predicted that, in its respiratory tract environment, H. influenzae will efficiently take up its own DNA even when human DNA is present in 100-fold excess.

Local circulating clones of Staphylococcus aureus in Ecuador.

The spread of pandemic Staphylococcus aureus clones, mainly methicillin-resistant S. aureus (MRSA), must be kept under surveillance to assemble an accurate, local epidemiological analysis. In Ecuador, the prevalence of the USA300 Latin American variant clone (USA300-LV) is well known; however, there is little information about other circulating clones. The aim of this work was to identify the sequence types (ST) using a Multiple-Locus Variable number tandem repeat Analysis 14-locus genotyping approach. We analyzed 132 S. aureus strains that were recovered from 2005 to 2013 and isolated in several clinical settings in Quito, Ecuador. MRSA isolates composed 46.97% (62/132) of the study population. Within MRSA, 37 isolates were related to the USA300-LV clone (ST8-MRSA-IV, Panton-Valentine Leukocidin [PVL] +) and 10 were related to the Brazilian clone (ST239-MRSA-III, PVL-). Additionally, two isolates (ST5-MRSA-II, PVL-) were related to the New York/Japan clone. One isolate was related to the Pediatric clone (ST5-MRSA-IV, PVL-), one isolate (ST45-MRSA-II, PVL-) was related to the USA600 clone, and one (ST22-MRSA-IV, PVL-) was related to the epidemic UK-EMRSA-15 clone. Moreover, the most prevalent MSSA sequence types were ST8 (11 isolates), ST45 (8 isolates), ST30 (8 isolates), ST5 (7 isolates) and ST22 (6 isolates). Additionally, we found one isolate that was related to the livestock associated S. aureus clone ST398. We conclude that in addition to the high prevalence of clone LV-ST8-MRSA-IV, other epidemic clones are circulating in Quito, such as the Brazilian, Pediatric and New York/Japan clones. The USA600 and UK-EMRSA-15 clones, which were not previously described in Ecuador, were also found. Moreover, we found evidence of the presence of the livestock associated clone ST398 in a hospital environment.

Prevalence of methicillin-resistant Staphylococcus aureus among health care workers of intensive care units in Ecuador.

INTRODUCTION: Colonization of health care workers with methicillin-resistant Staphylococcus aureus (MRSA) has been an important route of dispersion and infection of MRSA and has been implicated in epidemic outbreaks. The objective of the present study was to assess prevalence of MRSA colonization in the anterior nares of health care personnel at the intensive care unit (ICUs) of three hospital facilities in Quito, Ecuador. METHODOLOGY: The prevalence of MRSA in specimens from all ICU health care workers of three hospitals was measured by using a real-time PCR assay and CHROMagar MRSA. RESULTS: The prevalence of MRSA among the three health care facilities was 2.4%. CONCLUSION: The prevalence of MRSA colonization was relatively low compared to other studies and showed no differences between hospital facilities.

Prevalence of common hemoglobin variants in an afro-descendent Ecuadorian population.

BACKGROUND: Hemoglobinopathies are among the most studied and frequent pathologies. These genetic disorders are considered a very important health care threat in many tropical countries. Ecuador is a tropical Latin-American country with an important presence of afro-descendants (7.2%). Afro-descendants are among the ethnic groups with higher frequency of hemoglobinopathies reported. Ambuqui is a region within the Imbabura province with an important presence of afro-descendants (>50%). The present study analyzed the frequency of the most common hemoglobin variants in an asymptomatic afro-descendent population using capillary electrophoresis. FINDINGS: From 114 individuals, 25 (22%) reported a hemoglobin variant. All individuals that presented hemoglobin variants were heterozygotes (asymptomatic). Hemoglobin S (sickle cell trait) was the most frequent variant found (14%), followed by hemoglobin E (4.4%), Fetal (2.6%) and C (1%). CONCLUSION: Prevalence of hemoglobin S was consistent with populations from other countries, but it was lower than other Ecuadorian afro-descendent populations. Frequency of hemoglobin C was lower than other afro-descendent populations. This data suggests the possibility of gene flow from Native American individuals to the Ambuqui population there by lowering the frequency of their hemoglobin variants compared with other afro-descendant populations. Evaluating the frequency of hemoglobinopathies in Ecuadorian populations is essential. Despite the high frequency of these disorders, very few health care facilities implement hemoglobinopathies tests as a routine practice.

Local circulating clones of Staphylococcus aureus in Ecuador

ABSTRACT The spread of pandemic Staphylococcus aureus clones, mainly methicillin-resistant S. aureus (MRSA), must be kept under surveillance to assemble an accurate, local epidemiological analysis. In Ecuador, the prevalence of the USA300 Latin American variant clone (USA300-LV) is well known; however, there is little information about other circulating clones. The aim of this work was to identify the sequence types (ST) using a Multiple-Locus Variable number tandem repeat Analysis 14-locus genotyping approach. We analyzed 132 S. aureus strains that were recovered from 2005 to 2013 and isolated in several clinical settings in Quito, Ecuador. MRSA isolates composed 46.97% (62/132) of the study population. Within MRSA, 37 isolates were related to the USA300-LV clone (ST8-MRSA-IV, Panton-Valentine Leukocidin [PVL] +) and 10 were related to the Brazilian clone (ST239-MRSA-III, PVL−). Additionally, two isolates (ST5-MRSA-II, PVL−) were related to the New York/Japan clone. One isolate was related to the Pediatric clone (ST5-MRSA-IV, PVL−), one isolate (ST45-MRSA-II, PVL−) was related to the USA600 clone, and one (ST22-MRSA-IV, PVL−) was related to the epidemic UK-EMRSA-15 clone. Moreover, the most prevalent MSSA sequence types were ST8 (11 isolates), ST45 (8 isolates), ST30 (8 isolates), ST5 (7 isolates) and ST22 (6 isolates). Additionally, we found one isolate that was related to the livestock associated S. aureus clone ST398. We conclude that in addition to the high prevalence of clone LV-ST8-MRSA-IV, other epidemic clones are circulating in Quito, such as the Brazilian, Pediatric and New York/Japan clones. The USA600 and UK-EMRSA-15 clones, which were not previously described in Ecuador, were also found. Moreover, we found evidence of the presence of the livestock associated clone ST398 in a hospital environment.

Uso de métodos anticonceptivos e información sexual en relación con los antecedentes de aborto en una muestra de adolescentes embarazadas de 13 a 18 años, escolarizadas, de la Ciudad de Buenos Aires / Use of contraceptive methods and sexual information in relation with abortion antecedents in a sample of pregnant adolescentes from 13 to 18 years old, scholarized of the Buenos Aires city

Se estudiaron las características psicológicas y sociodemográficas en una muestra de adolescentes embarazadas, escolarizadas de 13 a 18 años de la Ciudad de Buenos Aires. Se recolectaron datos primarios a través de la administración de una encuesta con el objetivo de analizar, relacionar y comparar la relación entre la utilización de métodos anticonceptivos y la información y formación sexual recibidas. Los datos se analizaron con los estadísticos Chi-cuadrado (prueba de Mantel-Haenszel), Test de probabilidad exacta de Fisher y V de Cramer. La información recibida no incidiría en la utilización de métodos de control de la natalidad y cuidado de la salud en las jóvenes con antecedentes de aborto.