ESTUDO DO COMPORTAMENTO ESTRUTURAL DE TRELIÇAS DE AÇO EM FORMA DE ARCO UTILIZADAS NO PROJETO DE COBERTURAS PROTENDIDAS

O efeito da protensão pode ser introduzido sobre estruturas de aço, de tal modo que é adicionado um estado de tensões oposto ao estado proveniente das cargas de sucção devidas a ação do vento atuante sobre a estrutura. Dentro deste escopo, este trabalho visa apresentar os resultados obtidos em um estudo teórico do comportamento estrutural de treliças de aço utilizadas no projeto de coberturas protendidas. Para tal, a modelagem numérica é realizada com base em formulações lineares, a partir do emprego do Método dos Elementos Finitos (MEF), com base no uso do programa computacional SAP2000-V17. Com base nos resultados obtidos através de uma análise linear, no que tange a comparações entre os valores de resistência das treliças protendidas investigadas, são estabelecidas conclusões e recomendações de projeto. Cabe ressaltar que a economia de material obtida na solução estrutural com base no uso da protensão é resultante do aumento dos níveis de esforços de tração nas barras da estrutura, diminuindo-se as de compressão que são menos eficientes. Neste sentido, as soluções estruturais com protensão apresentam diversas vantagens que compensam o custo adicional da protensão

Klebsiella pneumoniae y Escherichia coli productoras de carbapenemasas en instituciones de salud del Caribe colombiano

Introduction: bacterial resistance has become a problematic situation that increasingly threatens public health worldwide. The emergence of strains that produce carbapenemases, enzymes, with a broad spectrum to hydrolyze beta-lactams and resist the action of inhibitors. This puts at risk the use of carbapenem antibiotics as the last treatment of choice in infections caused by these isolates. Objective: determine the frequency of carbapenemase-producing Klebsiella pneumoniae and Escherichia coli isolated in four health institutions in Barranquilla and Valledupar. Methodology: cross-sectional, retrospective descriptive study of molecular detection of six carbapenemase genes in Klebsiella pneumoniae and Escherichia coli between March 2019 and March 2020 using multiplex PCR. Results: of 86 clinical isolates, E. coli was recovered in 32% of emergencies, 31% of outpatient clinics, 28% of hospitalized patients and 9% of ICUs. K. pneumoniae was recovered in 46.87% of hospitalized patients, 32.81% of ICU patients, 12.50% of emergency patients, and 7.81% of outpatient patients. At least one carbepenemase gene was detected in 77.9% of K. pneumoniae and 22% of E. coli. Of these, 88.37% (76/86) were blaKPC type carbapenemases and 1.16% (1/86) were blaVIM type carbapenemases. Conclusions: K. pneumoniae was the most frequent microorganism in hospitalization (46.87%) and ICU (32.81%), which reflects its affinity for the hospital setting. Global resistance to carbapenems was confirmed in 89.53%, while the remaining percentage of isolates are attributed to another resistance mechanism not confirmed in the study.Introducción: la resistencia bacteriana se ha convertido en una situación problemática que amenaza cada vez más la salud pública a nivel mundial. La aparición de cepas productoras de carbapenemasas, enzimas, con un amplio espectro para hidrolizar betalactámicos y resistir la acción de los inhibidores. Esto pone en riesgo el uso de los antibióticos carbapenémicos como último tratamiento de elección en las infecciones producidas por estos aislamientos.                    Objetivo: determinar la frecuencia de Klebsiella pneumoniae y Escherichia coli productoras de carbapenemasas aisladas en cuatro instituciones de salud de Barranquilla y Valledupar. Metodología: estudio descriptivo transversal, retrospectivo de detección molecular de seis genes de carbapenemasas en Klebsiella pneumoniae y Escherichia coli entre marzo 2019 a marzo 2020 mediante una PCR múltiple. Resultados: de 86 aislamientos clínicos, E. coli se recuperó en un 32% de urgencias, 31% de consulta externa, 28% de hospitalizados y 9% de UCI. K. pneumoniae se recuperó 46,87 % de hospitalizados, 32,81% de UCI, 12,50 % de urgencias y 7,81% de consulta externa. En el 77,9% de K. pneumoniae y 22% de E. coli se detectó al menos un gen de carbepenmasas. De estos el 88,37% (76/86) fueron carbapenemasas tipo blaKPC y el 1,16% (1/86) carbapenmemasas tipo blaVIM. Conclusiones: K. pneumoniae fue el microorganismo más frecuente en hospitalización (46,87%) y UCI (32,81%), lo que refleja su afinidad por el ámbito hospitalario. La resistencia global a carbapenémicos se confirmó en 89,53%, mientras que al porcentaje restante de aislamientos se le atribuye otro mecanismo de resistencia no confirmado en el estudio

Exploring the secrets of virus entry: the first respiratory syncytial virus carrying beta lactamase

BackgroundRespiratory Syncytial Virus (RSV) presents a significant health threat, especially to young children. In-depth understanding of RSV entry mechanisms is essential for effective antiviral development. This study introduces an innovative RSV variant, featuring the fusion of the beta-lactamase (BlaM) enzyme with the RSV-P phosphoprotein, providing a versatile tool for dissecting viral entry dynamics.MethodsUsing the AlphaFold2 algorithm, we modeled the tertiary structure of the P-BlaM chimera, revealing structural similarities with both RSV-P and BlaM. Functional assessments, utilizing flow cytometry, quantified beta-lactamase activity and GFP expression in infected bronchial epithelial cells. Western blot analysis confirmed the integrity of P-BlaM within virions.ResultsThe modeled P-BlaM chimera exhibited structural parallels with RSV-P and BlaM. Functional assays demonstrated robust beta-lactamase activity in recombinant virions, confirming successful P-BlaM incorporation as a structural protein. Quercetin, known for its antiviral properties, impeded viral entry by affecting virion fusion. Additionally, Ulixertinib, an ERK-1/2 inhibitor, significantly curtailed viral entry, implicating ERK-1/2 pathway signaling.ConclusionsOur engineered RSV-P-BlaM chimera emerges as a valuable tool, illuminating RSV entry mechanisms. Structural and functional analyses unveil potential therapeutic targets. Quercetin and Ulixertinib, identified as distinct stage inhibitors, show promise for targeted antiviral strategies. Time-of-addition assays pinpoint quercetin’s specific interference stage, advancing our comprehension of RSV entry and guiding future antiviral developments

Molecular identification and antimicrobial susceptibility of Staphylococcus aureus nasal isolates from medical students in Cartagena, Colombia

Staphylococcus aureus (SA) remains a major cause of nosocomial and community-acquired infections worldwide. Nasal carriage of this bacterium among hospital personnel constitutes an important source for nosocomial infections. A cross-sectional study enrolling the whole medical student population (n = 387) of the School of Medicine at the Universidad de Cartagena, Colombia, was conducted to evaluate the carriage rates of both methicillin sensitive-and methicillin resistant-SA, the frequency of Panton-Valentine leukocidin genes in the isolates, and risk factors associated with carriage in this selected population. After signing an informed consent, participants completed a survey related to possible risk factors for colonization, and nasal swabs were collected from anterior nares. Staphylococcus aureus strains isolated from carriers were subjected to DNA extraction and PCR assays to determine the presence of MecA and Panton-Valentine leukocidin genes. Typing of the staphylococcal chromosomal cassette was performed for methicillin resistant strains. Molecular analysis was performed for only one strain per carrier. Prevalence of carriage for methicillin sensitiveand methicillin resistant-SA was 25% and 1.6% respectively. Most of the methicillin resistant isolates carried the staphylococcal chromosomal cassette type IV and the genes for Panton-Valentine leukocidin. To determine carrier types among medical students, each participant was subjected to four additional swabs, each taken two weeks apart. 9.8% persistent carriers, 53.1% intermittent carriers, and 37.1% non-carriers of SA were found. There was no association between risk factors analyzed and carriage of the bacterium. The study was conducted from April to September 2009 and found a persistent carriage of methicillin resistant-SA strains bearing the genes for Panton-Valentine leukocidin among medical students, evidencing the potential contribution of this portion of healthcare personnel either to the spread or introduction of these strains into the healthcare environment

Problemas de comportamiento y estrés emocional en escolares con bruxismo

Tesis (Odontólogo). -- Universidad de Cartagena. Facultad de Odontología. Departamento de Investigación, 2014El propósito de este estudio fue demostrar la relación existente entre los problemas de comportamiento y estrés emocional en niños con bruxismo, realizado en un colegio de la zona sur oriental de la ciudad de Cartagena, con un total de 200 muestras. Se le aplicó el instrumento a los padres o tutores legales la escala de Comportamiento Preescolar y Jardín Infantil (Preschool and Kindergarten Behavior Scales - PKBS) el cuál evalúa problemas de conducta en niños de 3 a 7 años, pero se decidió aplicar en niños de 7 a 12 años, además se aplicó el Inventario Infantil de Estresores Cotidiano (IIEC). Para la evaluación clínica se aplicó la clasificación del grado de bruxismo mediante 15 signos y síntomas propuesta por Molina, dos Santos, Nelson, y Nowlin en 1999. Se obtuvo un bajo índice de bruxismo en la muestra, encontrándose una importante relación entre el mal comportamiento y el padecimiento de esta patología.; sin embargo, no hubo una significativa relevancia de la presencia de estrés y bruxismo

Methicillin resistant Staphylococcus aureus isolated from meat raw in Cartagena, Colombia

To determine the prevalence of Methicillin Resistant Staphylococcus aureus (MRSA) isolated in establishments that commercialize raw ground beef and pork chops in Cartagena- Colombia. 160 samples were analyzed through microbiological cultures in Baire Parcker agar, and it was determined the presence of mecA gen that codifies the methicillin resistance and the pvl that codifies the Panton- Valentine leukocidin toxin (PVL) by the multiplex PCR technique. The antibiotic susceptibility profile for MRSA strains was realized by automatized methods and for MSSA strains it was used Kirby Bauver. 66 samples were confirmed as S. aureus by PCR. The prevalence of MRSA was 7.5% and 33.8% of MSSA. The 66% of the strains were isolated from raw ground beef and the 34% of pork chop meat. The isolations presented about 2 – 12% of multi-resistance to the antibiotics used. The MRSA showed resistance to amoxicillin- clavulanate (57%), ampicillin-sulbactam and cefazolin (85%), erythromycin and clindamycin (7%), tetracycline (35%). The 10% of the isolated strains had the gen of PVL toxin and the 71% of those were identified in samples of raw pork meat and the 28% in raw ground beef. This study reports for the first time, how meat raw products commercialized in the city of Cartagena could build a dissemination source of MRSA carrier of PVL toxin that could generate a public health disease

Staphylococcus aureus resistente a meticilina aislado de productos cárnicos crudos en Cartagena, Colombia

To determine the prevalence of Methicillin Resistant Staphylococcus aureus (MRSA) isolated in establishments that commercialize raw ground beef and pork chops in Cartagena- Colombia. 160 samples were analyzed through microbiological cultures in Baire Parcker agar, and it was determined the presence of mecA gen that codifies the methicillin resistance and the pvl that codifies the Panton- Valentine leukocidin toxin (PVL) by the multiplex PCR technique. The antibiotic susceptibility profile for MRSA strains was realized by automatized methods and for MSSA strains it was used Kirby Bauver. 66 samples were confirmed as S. aureus by PCR. The prevalence of MRSA was 7.5% and 33.8% of MSSA. The 66% of the strains were isolated from raw ground beef and the 34% of pork chop meat. The isolations presented about 2 – 12% of multi-resistance to the antibiotics used. The MRSA showed resistance to amoxicillin- clavulanate (57%), ampicillin-sulbactam and cefazolin (85%), erythromycin and clindamycin (7%), tetracycline (35%). The 10% of the isolated strains had the gen of PVL toxin and the 71% of those were identified in samples of raw pork meat and the 28% in raw ground beef. This study reports for the first time, how meat raw products commercialized in the city of Cartagena could build a dissemination source of MRSA carrier of PVL toxin that could generate a public health disease.Se determinó la prevalencia de Staphylococcus aureus resistente a Meticilina (SARM) aislado en expendios que comercializaban carne cruda molida de res y chuleta de cerdo en Cartagena - Colombia. Fueron analizadas 160 muestras a través de cultivo microbiológico en agar Baire Parcker y se determinó la presencia del gen mecA que codifica la resistencia a la meticilina y de pvl que codifica la toxina leucocidina de Panton-Valentine (PVL) mediante la técnica de PCR múltiple. El perfil de susceptibilidad antibiótica para las cepas SARM fue realizado por métodos automatizados y para cepas SASM se utilizó Kirby Bauver. 66 muestras fueron confirmadas como S. aureus por PCR, la prevalencia de SARM fue de 7.5% y 33.8% de SASM. El 66% de las cepas fueron aisladas de carne molida de res y 34% de carne de chuleta de cerdo. Los aislamientos presentaron entre 2 a 12% de multirresistencia a los antibióticos utilizados. Los SARM mostraron resistencia a amoxacilinaclavulonato (57%), ampicilina ¿ sulbatam y cefazolina (85%), eritromicina y clindamicina (7%), tetraciclina (35%). El 10% de las cepas aisladas tenían el gen de la toxina PVL y el 71% de estos fue identificado en muestras de carne cruda de cerdo y el 28% en carne cruda molida de res. Este estudio reporta por primera vez, como productos cárnicos crudos comercializados en la ciudad de Cartagena pueden constituir una fuente de diseminación de cepas SARM portadoras de la toxina PVL, lo cual podría generar un problema de salud pública

Evaluación de un método de amplificación isotérmica medida por bucle para la detección rápida del virus sincitial respiratorio en niños con infección respiratoria aguda

Introduction: Human respiratory syncytial virus (hRSV) is the most frequent cause of acute respiratory infection of the lower respiratory tract in children under the age of five. The development of molecular techniques able to identify hRSV is one of the current challenges in the field of clinical research.Objective: To evaluate the ability of an isothermal amplification method to rapidly detect hRSV in children with acute respiratory infection.Materials and methods: We collected 304 nasopharyngeal swab samples from children with symptoms of acute respiratory infection who attended the emergency unit at Hospital de la Universidad del Norte in Barranquilla from April, 2016, to July, 2017. After extracting viral RNA from the samples, we evaluated the ability of the reverse transcriptase-loop-mediated isothermal amplification (RT-LAMP) M assay to rapidly detect hRSVA and hRSVB compared to other molecular techniques: quantitative PCR (qPCR), reverse transcriptase-LAMP L assay, and as a standard, the multiplex nested reverse transcriptase polymerase chain reaction (nested RT-PCR).Results: The RT-LAMP M assay had a sensitivity of 93.59% and a specificity of 92.92%, and a concordance of 0.83 ± 0.036 as compared with the nested RT-PCR test. While the Kappa index of the RT-LAMP M assay was higher than the values for the RT-LAMP L assay and the qPCR, the values of the latter two methods were in agreement (0.75 ± 0.043 and 0.71 ± 0.045, respectively).Conclusion: Due to the shorter running times, lower costs and better performance of the RT-LAMP M assay, it can be considered as a useful clinical tool for the detection of RSVA.Introducción. El virus sincicial respiratorio humano (hRSV) es la causa más frecuente de infección respiratoria aguda de las vías respiratorias inferiores en niños menores de cinco años. El desarrollo de técnicas moleculares para identificarlo es uno de los retos actuales en el campo de la investigación clínica.Objetivo. Evaluar un método de amplificación isotérmica para la detección rápida del hRSV en niños con infección respiratoria aguda.Materiales y métodos. Se extrajo el ARN viral de 304 muestras de hisopado nasal en niños con síntomas de infección respiratoria aguda atendidos en el servicio de urgencias del Hospital de la Universidad del Norte en Barranquilla entre abril del 2016 y julio del 2017. Se evaluó la prueba de amplificación isotérmica mediada por bucle mediante transcriptasa inversa de la proteína de la matriz (M) (Reverse Transcription Loop-Mediated Isothermal Amplification, RT-LAMP) comparada con técnicas moleculares como la reacción en cadena de la polimerasa mediante transcriptasa inversa múltiple anidada (Reverse Transcription-Polymerase Chain Reaction, RT-PCR), la cual se empleó como la prueba estándar, la PCR en tiempo real (quantitative PCR, qPCR) y la RT-LAMP de la proteína L (L) para la detección rápida del virus sincicial respiratorio (VSR), subtipo A y subtipo B.Resultados. La prueba de RT-LAMP (M) tuvo una sensibilidad de 93,59 %, una especificidad de 92,92 % y una concordancia de 0,83 ± 0,036 comparada con la prueba de RT-PCR anidada. El índice kappa del RT-LAMP (M) fue superior, y los valores del RTLAMP (L) y la qPCR concordaron (0,75 ± 0,043 y 0,71 ± 0,045, respectivamente)