Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 11 de 11
Filter
1.
Inorg Chem ; 62(35): 14147-14151, 2023 Sep 04.
Article in English | MEDLINE | ID: mdl-37619251

ABSTRACT

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.

2.
iScience ; 24(1): 102007, 2021 Jan 22.
Article in English | MEDLINE | ID: mdl-33490915

ABSTRACT

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.

3.
Vertex ; 28(132): 145-151, 2017 Mar.
Article in Spanish | MEDLINE | ID: mdl-29522637

ABSTRACT

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.


Subject(s)
Munchausen Syndrome/diagnosis , Female , Humans , Middle Aged , Munchausen Syndrome/complications
4.
Braz. j. infect. dis ; 20(6): 525-533, Nov.-Dec. 2016. tab, graf
Article in English | LILACS | ID: biblio-828162

ABSTRACT

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.


Subject(s)
Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Adult , Middle Aged , Aged , Aged, 80 and over , Young Adult , Staphylococcal Infections/microbiology , Staphylococcus aureus/genetics , Bacterial Toxins/genetics , Exotoxins/genetics , Leukocidins/genetics , Anti-Bacterial Agents/pharmacology , Staphylococcus aureus/isolation & purification , Staphylococcus aureus/classification , DNA, Bacterial , Microbial Sensitivity Tests , Prevalence , Virulence Factors/genetics , Ecuador , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Methicillin-Resistant Staphylococcus aureus/classification , Methicillin-Resistant Staphylococcus aureus/genetics , Multilocus Sequence Typing , Genotype
5.
Braz J Infect Dis ; 20(6): 525-533, 2016.
Article in English | MEDLINE | ID: mdl-27638417

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.


Subject(s)
Anti-Bacterial Agents/pharmacology , Bacterial Toxins/genetics , Exotoxins/genetics , Leukocidins/genetics , Staphylococcal Infections/microbiology , Staphylococcus aureus/genetics , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , DNA, Bacterial , Ecuador , Female , Genotype , Humans , Infant , Infant, Newborn , Male , Methicillin-Resistant Staphylococcus aureus/classification , Methicillin-Resistant Staphylococcus aureus/genetics , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Microbial Sensitivity Tests , Middle Aged , Multilocus Sequence Typing , Prevalence , Staphylococcus aureus/classification , Staphylococcus aureus/isolation & purification , Virulence Factors/genetics , Young Adult
6.
J Infect Dev Ctries ; 8(1): 116-9, 2014 Jan 15.
Article in English | MEDLINE | ID: mdl-24423721

ABSTRACT

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.


Subject(s)
Carrier State/epidemiology , Health Personnel , Intensive Care Units , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Staphylococcal Infections/epidemiology , Adult , Bacteriological Techniques , Carrier State/microbiology , Ecuador/epidemiology , Female , Humans , Male , Middle Aged , Prevalence , Real-Time Polymerase Chain Reaction , Staphylococcal Infections/microbiology , Young Adult
7.
BMC Res Notes ; 6: 132, 2013 Apr 04.
Article in English | MEDLINE | ID: mdl-23557107

ABSTRACT

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.


Subject(s)
Black People/genetics , Hemoglobinopathies/ethnology , Hemoglobinopathies/genetics , Hemoglobins/genetics , Adolescent , Adult , Aged , Aged, 80 and over , Ecuador , Electrophoresis, Capillary , Female , Fetal Hemoglobin/genetics , Genetic Predisposition to Disease , Genetics, Population , Hemoglobin C/genetics , Hemoglobin E/genetics , Hemoglobin, Sickle/genetics , Heterozygote , Humans , Male , Middle Aged , Sickle Cell Trait/genetics , Young Adult
9.
Article in Spanish | LILACS | ID: lil-353279

ABSTRACT

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.


Subject(s)
Humans , Adolescent , Female , Pregnancy , Abortion, Induced , Contraceptive Agents , Sex Education/methods , Observer Variation , Pregnancy in Adolescence , Data Collection/methods , Chi-Square Distribution , Contraception , Family Development Planning , Probability , Risk-Taking , Sexually Transmitted Diseases
10.
Article in Spanish | BINACIS | ID: bin-5064

ABSTRACT

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. (AU)


Subject(s)
Humans , Adolescent , Female , Pregnancy , Pregnancy in Adolescence/statistics & numerical data , Pregnancy in Adolescence/prevention & control , Pregnancy in Adolescence/psychology , Sex Education/methods , Abortion, Induced/adverse effects , Contraceptive Agents/administration & dosage , Data Collection/methods , Observer Variation , Chi-Square Distribution , Probability , Risk-Taking , Family Development Planning , Contraception , Sexually Transmitted Diseases/prevention & control
SELECTION OF CITATIONS
SEARCH DETAIL
...