Epidemiological and microbiological characteristics of S. aureus pediatric infections in Colombia 2018-2021, a national multicenter study (Staphylored Colombia).

Background: Staphylococcus aureus infections are a significant cause of morbidity and mortality in pediatric populations worldwide. The Staphylo Research Network conducted an extensive study on pediatric patients across Colombia from 2018 to 2021. The aim of this study was to describe the epidemiological and microbiological characteristics of S. aureus in this patient group. Methods: We analyzed S. aureus isolates from WHONET-reporting centers. An "event" was a positive culture isolation in a previously negative individual after 2 weeks. We studied center characteristics, age distribution, infection type, and antibiotic susceptibilities, comparing methicillin sensitive (MSSA) and resistant S. aureus (MRSA) isolates. Results: Isolates from 20 centers across 7 Colombian cities were included. Most centers (80%) served both adults and children, with 55% offering oncology services and 85% having a PICU. We registered 8,157 S. aureus culture isolations from 5,384 events (3,345 MSSA and 1,961 MRSA) in 4,821 patients, with a median age of 5 years. Blood (26.2%) and skin/soft tissue (18.6%) were the most common infection sources. Most isolates per event remained susceptible to oxacillin (63.2%), clindamycin (94.3%), and TMP-SMX (98.3%). MRSA prevalence varied by city (<0.001), with slightly higher rates observed in exclusively pediatric hospitals. In contrast, the MRSA rate was somewhat lower in centers with Antimicrobial Stewardship Program (ASP). MRSA was predominantly isolated from osteoarticular infections and multiple foci, while MSSA was more frequently associated with recurrent infections compared to MRSA. Conclusions: This is the largest study of pediatric S. aureus infections in Colombia. We found MSSA predominance, but resistance have important regional variations. S. aureus remains susceptible to other commonly used antibiotics such as TMP-SMX and clindamycin. Ongoing monitoring of S. aureus infections is vital for understanding their behavior in children. Prospective studies within the Staphylored LATAM are underway for a more comprehensive clinical and genetic characterization.

Spectral norm and energy of a digraph with respect to a VDB topological index.

The set of singular values of a digraph with respect to a vertex-degree based topological index is the set of all singular values of its general adjacency matrix. The spectral norm is the largest singular value and the energy the sum of the singular values. In this paper we characterize the digraphs which have exactly one singular value different from zero and the digraphs for which all singular values are equal. As a consequence, we deduce sharp upper and lower bounds for the spectral norm and energy of digraphs. In addition to being a natural generalization, proving the results in the general setting of digraphs allows us to deduce new results on graph energy.

Randic energy of digraphs.

We assume that D is a directed graph with vertex set V ( D ) = { v 1 , … v n } and arc set E ( D ) . A VDB topological index φ of D is defined as φ ( D ) = 1 2 ∑ u v ∈ E ( D ) φ d u + , d v - , where d u + and d v - denote the outdegree and indegree of vertices u and v, respectively, and φ i , j is a bivariate symmetric function defined on nonnegative real numbers. Let A φ = A φ ( D ) be the n × n general adjacency matrix defined as [ A φ ] i j = φ d v i + , d v j - if v i v j ∈ E ( D ) , and 0 otherwise. The energy of D with respect to a VDB index φ is defined as E φ ( D ) = ∑ i = 1 n σ i ( A φ ) , where σ 1 ( A φ ) ≥ σ 2 ( A φ ) ≥ ⋯ ≥ σ n ( A φ ) ≥ 0 are the singular values of the matrix A φ . We will show that in case φ = R is the Randic index, the spectral norm of A R is equal to 1, and rank of A R is equal to rank of the adjacency matrix of D. Immediately after, we illustrate by means of examples, that these properties do not hold for most well-known VDB topological indices. Taking advantage of nice properties the Randic matrix has, we derive new upper and lower bounds for the Randic energy E R in digraphs. Some of these generalize known results for the Randic energy of graphs. Also, we deduce a new upper bound for the Randic energy of graphs in terms of rank, concretely, we show that E R ( G ) ≤ r a n k ( G ) for all graphs G, and equality holds if and only if G is a disjoint union of complete bipartite graphs.

Etiology and Risk Factors for Admission to the Pediatric Intensive Care Unit in Children With Encephalitis in a Developing Country.

OBJECTIVE: To describe a cohort of pediatric patients with encephalitis and their risk factors for admission to the pediatric intensive care unit (PICU). STUDY DESIGN: Children (<18 years old), with encephalitis evaluated by conventional microbiology and syndromic, multiplex test in cerebrospinal fluid (CSF) between July 2017 and July 2020, were recruited from 14 hospitals that comprise the Colombian Network of Encephalitis in Pediatrics. Multivariate analyses were used to evaluate risk factors associated with the need for PICU admission. RESULTS: Two hundred two children were included, of which 134 (66.3%) were male. The median age was 23 months (IQR 5.7-73.2). The main etiologies were bacteria (n = 55, 27%), unspecified viral encephalitis (n = 44, 22%) and enteroviruses (n = 27, 13%), with variations according to age group. Seventy-eight patients (38.6%) required management in the PICU. In multivariate analysis, factors associated with admission to the PICU were the presence of generalized seizures (OR 2.73; 95% CI: 1.82-4.11), status epilepticus (OR 3.28; 95% CI: 2.32-4.62) and low leukocyte counts in the CSF (OR 2.86; 95% CI: 1.47-5.57). Compared with enterovirus, bacterial etiology (OR 7.50; 95% CI: 1.0-56.72), herpes simplex encephalitis (OR 11.81; 95% CI: 1.44-96.64), autoimmune encephalitis (OR 22.55; 95% CI: 3.68-138.16) and other viral infections (OR 5.83; 95% CI: 1.09-31.20) increased the risk of PICU admission. CONCLUSIONS: Data from this national collaborative network of pediatric patients with encephalitis allow early identification of children at risk of needing advanced care and can guide the risk stratification of admission to the PICU.

Association of Cancer Diagnosis and Therapeutic Stage With Mortality in Pediatric Patients With COVID-19, Prospective Multicenter Cohort Study From Latin America.

Background: Children with cancer are at risk of critical disease and mortality from COVID-19 infection. In this study, we describe the clinical characteristics of pediatric patients with cancer and COVID-19 from multiple Latin American centers and risk factors associated with mortality in this population. Methods: This study is a multicenter, prospective cohort study conducted at 12 hospitals from 6 Latin American countries (Argentina, Bolivia, Colombia, Ecuador, Honduras and Peru) from April to November 2021. Patients younger than 14 years of age that had an oncological diagnosis and COVID-19 or multisystemic inflammatory syndrome in children (MIS-C) who were treated in the inpatient setting were included. The primary exposure was the diagnosis and treatment status, and the primary outcome was mortality. We defined "new diagnosis" as patients with no previous diagnosis of cancer, "established diagnosis" as patients with cancer and ongoing treatment and "relapse" as patients with cancer and ongoing treatment that had a prior cancer-free period. A frequentist analysis was performed including a multivariate logistic regression for mortality. Results: Two hundred and ten patients were included in the study; 30 (14%) died during the study period and 67% of patients who died were admitted to critical care. Demographics were similar in survivors and non-survivors. Patients with low weight for age (<-2SD) had higher mortality (28 vs. 3%, p = 0.019). There was statistically significant difference of mortality between patients with new diagnosis (36.7%), established diagnosis (1.4%) and relapse (60%), (p <0.001). Most patients had hematological cancers (69%) and they had higher mortality (18%) compared to solid tumors (6%, p= 0.032). Patients with concomitant bacterial infections had higher mortality (40%, p = 0.001). MIS-C, respiratory distress, cardiovascular symptoms, altered mental status and acute kidney injury on admission were associated with higher mortality. Acidosis, hypoxemia, lymphocytosis, severe neutropenia, anemia and thrombocytopenia on admission were also associated with mortality. A multivariate logistic regression showed risk factors associated with mortality: concomitant bacterial infection OR 3 95%CI (1.1-8.5), respiratory symptoms OR 5.7 95%CI (1.7-19.4), cardiovascular OR 5.2 95%CI (1.2-14.2), new cancer diagnosis OR 12 95%CI (1.3-102) and relapse OR 25 95%CI (2.9-214). Conclusion: Our study shows that pediatric patients with new onset diagnosis of cancer and patients with relapse have higher odds of all-cause mortality in the setting of COVID-19. This information would help develop an early identification of patients with cancer and COVID-19 with higher risk of mortality.

Entangled Photon Spectroscopy.

The enhanced interest in quantum-related phenomena has provided new opportunities for chemists to push the limits of detection and analysis of chemical processes. As some have called this the second quantum revolution, a time has come to apply the rules learned from previous research in quantum phenomena toward new methods and technologies important to chemists. While there has been great interest recently in quantum information science (QIS), the quest to understand how nonclassical states of light interact with matter has been ongoing for more than two decades. Our entry into this field started around this time with the use of materials to produce nonclassical states of light. Here, the process of multiphoton absorption led to photon-number squeezed states of light, where the photon statistics are sub-Poissonian. In addition to the great interest in generating squeezed states of light, there was also interest in the formation of entangled states of light. While much of the effort is still in foundational physics, there are numerous new avenues as to how quantum entanglement can be applied to spectroscopy, imaging, and sensing. These opportunities could have a large impact on the chemical community for a broad spectrum of applications.In this Account, we discuss the use of entangled (or quantum) light for spectroscopy as well as applications in microscopy and interferometry. The potential benefits of the use of quantum light are discussed in detail. From the first experiments in porphyrin dendrimer systems by Dr. Dong-Ik Lee in our group to the measurements of the entangled two photon absorption cross sections of biological systems such as flavoproteins, the usefulness of entangled light for spectroscopy has been illustrated. These early measurements led the way to more advanced measurements of the unique characteristics of both entangled light and the entangled photon absorption cross-section, which provides new control knobs for manipulating excited states in molecules.The first reports of fluorescence-induced entangled processes were in organic chromophores where the entangled photon cross-section was measured. These results would later have widespread impact in applications such as entangled two-photon microscopy. From our design, construction and implementation of a quantum entangled photon excited microscope, important imaging capabilities were achieved at an unprecedented low excitation intensity of 107 photons/s, which is 6 orders of magnitude lower than the excitation level for the classical two-photon image. New reports have also illustrated an advantage of nonclassical light in Raman imaging as well.From a standpoint of more precise measurements, the use of entangled photons in quantum interferometry may offer new opportunities for chemistry research. Experiments that combine molecular spectroscopy and quantum interferometry, by utilizing the correlations of entangled photons in a Hong-Ou-Mandel (HOM) interferometer, have been carried out. The initial experiment showed that the HOM signal is sensitive to the presence of a resonant organic sample placed in one arm of the interferometer. In addition, parameters such as the dephasing time have been obtained with the opportunity for even more advanced phenomenology in the future.

Sombor index of directed graphs.

Let D be a digraph with set of arcs A. The Sombor index of D is defined as SO ( D ) = 1 2 ∑ u v ∈ A ( d u + ) 2 + ( d v - ) 2 , where d u + and d v - are the out-degree and in-degree of the vertices u and v of D. When D is a graph, we recover the Sombor index of graphs, a molecular descriptor recently introduced with a good predictive potential and a great research activity this year. In this paper we initiate the study of the Sombor index of digraphs. Specifically, we find sharp upper and lower bounds for SO over the class D n of digraphs with n non-isolated vertices, the classes C n and S n of connected and strongly connected digraphs on n vertices, respectively, the class of oriented trees OT ( n ) with n vertices, and the class O ( G ) of orientations of a fixed graph G.

A global point prevalence survey of antimicrobial use in neonatal intensive care units: The no-more-antibiotics and resistance (NO-MAS-R) study.

BACKGROUND: Global assessment of antimicrobial agents prescribed to infants in the neonatal intensive care unit (NICU) may inform antimicrobial stewardship efforts. METHODS: We conducted a one-day global point prevalence study of all antimicrobials provided to NICU infants. Demographic, clinical, and microbiologic data were obtained including NICU level, census, birth weight, gestational/chronologic age, diagnoses, antimicrobial therapy (reason for use; length of therapy), antimicrobial stewardship program (ASP), and 30-day in-hospital mortality. FINDINGS: On July 1, 2019, 26% of infants (580/2,265; range, 0-100%; median gestational age, 33 weeks; median birth weight, 1800 g) in 84 NICUs (51, high-income; 33, low-to-middle income) from 29 countries (14, high-income; 15, low-to-middle income) in five continents received ≥1 antimicrobial agent (92%, antibacterial; 19%, antifungal; 4%, antiviral). The most common reasons for antibiotic therapy were "rule-out" sepsis (32%) and "culture-negative" sepsis (16%) with ampicillin (40%), gentamicin (35%), amikacin (19%), vancomycin (15%), and meropenem (9%) used most frequently. For definitive treatment of presumed/confirmed infection, vancomycin (26%), amikacin (20%), and meropenem (16%) were the most prescribed agents. Length of therapy for culture-positive and "culture-negative" infections was 12 days (median; IQR, 8-14) and 7 days (median; IQR, 5-10), respectively. Mortality was 6% (42%, infection-related). An NICU ASP was associated with lower rate of antibiotic utilization (p = 0·02). INTERPRETATION: Global NICU antibiotic use was frequent and prolonged regardless of culture results. NICU-specific ASPs were associated with lower antibiotic utilization rates, suggesting the need for their implementation worldwide. FUNDING: Merck & Co.; The Ohio State University College of Medicine Barnes Medical Student Research Scholarship.

Efficient Modeling of Organic Chromophores for Entangled Two-Photon Absorption.

The use of a nonclassical light source for studying molecular electronic structure has been of great interest in many applications. Here we report a theoretical study of entangled two-photon absorption (ETPA) in organic chromophores, and we provide new insight into the quantitative relation between ETPA and the corresponding unentangled TPA based on the significantly different line widths associated with entangled and unentangled processes. A sum-over-states approach is used to obtain classical TPA and ETPA cross sections and to explore the contribution of each electronic state to the ETPA process. The transition moments and energies needed for this calculation were obtained from a second linear-response (SLR) TDDFT method [J. Chem. Phys., 2016, 144, 204105], which enables the treatment of relatively large polythiophene dendrimers that serve as two-photon absorbers. In addition, the SLR calculations provide estimates of the excited state radiative line width, which we relate to the entangled two-photon density of states using a quantum electrodynamic analysis. This analysis shows that for the dendrimers being studied, the line width for ETPA is orders of magnitude narrower than for TPA, corresponding to highly entangled photons with a large Schmidt number. The calculated cross sections are in good agreement with the experimentally reported values. We also carried out a state-resolved analysis to unveil pathways for the ETPA process, and these demonstrate significant interference behavior. We emphasize that the use of entangled photons in TPA process plays a critical role in probing the detailed electronic structure of a molecule by probing light-matter interference nature in the quantum limit.

Secuelas neurológicas del síndrome de Guillain-Barré en pacientes adultos / Neurologic sequelae of Guillain-Barré syndrome in adults

Introducción:el síndrome de Guillain-Barré (SGB) es una polineurorradiculopatía desmielinizante aguda inmunomediada. El síntoma principal es la debilidad muscular. El objetivo del presente estudio es describir las características del episodio agudo, las secuelas neurológicas a largo plazo y cómo estas afectan la situación laboral y las actividades de tiempo libre. Materiales y métodos: estudio realizado en dos fases: primera, descripción retrospectiva de casos; segunda, corte transversal donde se interrogaron las secuelas neurológicas y sus implicaciones. Resultados: se identificaron 63 casos de SGB con edad promedio de 50,79 años (DE 17.8), más frecuente en hombres (61,9%) y cuyo promedio de la escala Hughes en el episodio agudo fue 3,2 (DE ± 10,1). Las principales complicaciones durante la fase aguda fueron neumonía (7,94 %) y úlceras por presión (3,17 %). Se logró contactar vía telefónica a 28 pacientes, 82,1% presentó al menos un síntoma como secuela, 60,7% parestesias, 57,1% fatiga, 50% calambres y 46,4% dolor de características neuropáticas. El 32,1% tuvo cambios o retiro de su trabajo por las secuelas; 21,43% debió modificar sus actividades de tiempo libre. Conclusión: existe alta prevalencia de síntomas residuales discapacitantes después del episodio agudo de SGB con predominio de síntomas sensitivos, coincidiendo con estudios realizados en países desarrollados. Estas alteraciones ocasionan un impacto negativo en la actividad laboral y en la de tiempo libre de los pacientes.

Introduction: Guillain-Barré syndrome (GBS) is an acute immune-mediated demyelinating polyneuropathy. The main symptom encountered is muscle weakness. This study seeks to describe the characteristics of an acute episode, the long-term neurologic sequelae and how they affect patients ́ work and leisure activities. Materials and Methods: a two-phase study comprising a retrospective case description in the first phase followed by a cross sectional study during the second phase in which patients were asked to describe their neurologic sequelae and how they affected them Results: we identified 63 cases of GBS, mean age was 50.79 years (SD 17.8), there was a male preponderance (61.9%) with a 3.2 (SD ± 10.1) average score on the Hughes scale during the acute episode. Major complications during the acute phase were pneumonia (7.94 %) and pressure sores (3.17 %). Phone contact was achieved with 28 patients, 82.1% presented at least one sequelae 60.7% paresthesia, 57.1% fatigue, 50% cramps and 46.4% neuropathic pain. In 32.1% of cases patients ́ work was adjusted or they were removed from work because of their sequelae; 21.43% had to modify their free-time activities. Conclusion: there is a high prevalence of disabling residual symptoms after a GBS acute episode predominantly sensory signs, which coincide with the results of studies conducted in developed countries. Said alterations negatively impact patients ́ work and leisure activities

Influence of Hyrax screw position on dental movement and cortical bone: A study of finite elements.

BACKGROUND: Rapid maxillary expansion (RME) has effects on the dental and periodontal structures of the parts involved, which vary according to the design and position of the expansion screw. The purpose of the study was to determine the optimal three-dimensional position of the Hyrax screw to obtain precise control of the dental movement and effect on the bone cortex using the finite element method (FEM). MATERIAL AND METHODS: RME was performed from the patient whom two Cone-Beam computerized tomography scans (CBCT) were obtained: T1 before expansion, and T2 three months after stabilization of RME. The FEM model was designed with T1 and of Hyrax photographs. FEM was obtained by comparing the simulation, T2, and clinical results. Three sagittal screw positions (anterior-middle-posterior) and vertical (upper-medium-low) were evaluated. RESULTS: A coronal- buccal displacement of premolars and first molars was found which decreased in the occlusal-apical direction, presenting different types of dental movement in the screw positions; besides, a tendency of translational movement in the posterior-high location was observed. In the posterior-high position a higher concentration of efforts and homogeneous deformations in the periodontal ligament and vestibular cortex of the cervical area of first molars, first and second premolars were observed, with variations according to the screw position and the distribution of stresses. CONCLUSIONS: The ideal location of the expansion screw for controlling dental movement and periodontal side effects was the high-posterior position. Key words:Maxillary expansion, dental movement, finite element analysis, orthodontic appliances.

El capital humano y estructural a través de lógica difusa 2 / Human and Structural Capital Through Diffuse Logic 2 / Capital humano e estrutural através da lógica difusa 2

Resumen Introducción. La gestión del conocimiento como proceso innovador y clave para organizaciones inteligentes permitió llevar su aplicación a centros de investigación de educación superior, basados en el capital intelectual (CI), como eje fundamental en la creación de activos intangibles, haciendo uso del modelo Intellectus, el cual enfatiza como componentes del CI: el Capital Humano (CH), Estructural (CE) y Relacional (CR). Objetivo. Desarrollar una metodología en la medición del CH y CE para centros de investigación. Materiales y métodos. Haciendo uso de la técnica de lógica difusa 2 y el toolbox Matlab®, se generaron algoritmos para obtener una herramienta inteligente. Para su validación, el modelo se aplicó al grupo de investigaciones de Ciencias Administrativas del Instituto Tecnológico Metropolitano de Medellín. Mediante la técnica Delfi, seis expertos dictaminaron que las variables decisivas a evaluar son, del CH: valores y aptitudes, actitudes, y conocimiento; del CE organizativo: aprendizaje organizativo y del CE tecnológico: I+D. La información se obtuvo de la aplicación en 16 investigadores en un formato con 54 preguntas, medidas en escala de Likert. Resultados. Con lógica difusa 2 se logró una base de reglas que, junto al tipo de reducción Karnik-Mendel, permitieron la toma de decisiones sobre las variables, a través de la superficie de control. Conclusión. La combinación entre capacidades y esfuerzo, I+D aporta mayor valor. La relación actitudes con aprendizaje organizativo es significativa, aunque no prioritaria en la generación de valor y la generación de valor, entre las variables valores y aptitudes, con aprendizaje organizativo, no es significativa.

Abstract Introduction: Knowledge management as an innovative and key process for smart organizations allowed its application in higher education research centers, based on intellectual capital (IC), as a fundamental axis in the creation of intangible assets, using the Intellectus model, which emphasizes as components of the IC: Human Capital (HC), Structural Capital (SC) and Relational Capital(RC). Objective: The work seeks to develop a measurement methodology for HC and SC for research centers. Materials and methods: Using the fuzzy logic technique 2 and the Matlab® toolbox, algorithms were generated to obtain an intelligent tool. The model validation was applied to the Administrative Sciences research group of the Metropolitan Technological Institute of Medellin. Through the Delphi technique, six experts determined that the decisive variables to be evaluated, according to the model, were from the HC: values and aptitudes, attitudes, and knowledge; from organizational SC: organizational learning; and from technological SC: R&D. The information was obtained from the application of a questionnaire with 54 questions to 16 researchers, measured with a Likert scale. Results: With fuzzy logic 2, a base of rules was achieved that, together with the Karnik-Mendel type of reduction, allowed decision making on the variables through the control surface. Conclusion: The combination of capabilities and effort and R&D brings greater value. The relationship between attitudes and organizational learning is significant, although not a priority in the generation of value; and the generation of value, between the values and skills variables, with organizational learning, is not significant.

Resumo Introdução. A gestão do conhecimento como processo inovador e chave para organizações inteligentes permitiu levar sua aplicação à centros de pesquisa de educação superior, baseados no capital intelectual (CI), como eixo fundamental na criação de ativos intangíveis, fazendo uso do modelo Intellectus, o qual enfatiza como componentes do CI: o Capital Humano (CH), Estrutural (CE) e Relacional (CR). Objetivo. Desenvolver uma metodologia na medição do CH e CE para centros de pesquisa. Materiais e métodos. Fazendo o uso da técnica de lógica difusa 2 e o toolbox Matlab®, se geraram algoritmos para obter uma ferramenta inteligente. Para a sua validação, o modelo se aplicou ao grupo de pesquisas de Ciências Administrativas do Instituto Tecnológico Metropolitano de Medellín. Mediante a técnica Delfi, seis expertos ditaram que as variáveis decisivas à avaliar são, do CH: valores e aptidões, atitudes e conhecimento; do CE organizativo: aprendizagem organizativo e do CE tecnológico: P&D. A informação se obteve da aplicação em 16 pesquisadores em um formato com 54 perguntas, medidas em escala de Likert. Resultados. Com lógica difusa 2 se conseguiu uma base de regras que, junto ao tipo de redução Karnik-Mendel, permitiram a tomada de decisões sob as variáveis, através da superfície de controle. Conclusão. A combinação entre as capacidades e o esforço, P&D aporta maior valor. A relação atitudes com aprendizagem organizativo é significativa, embora não seja prioritária na geração de valor, e a geração de valor entre as variáveis valores e aptidões, com aprendizagem organizativo, não é significativa.

Modern Anesthetic Ethers Demonstrate Quantum Interactions with Entangled Photons.

Despite decades of research, the mechanism of anesthetic-induced unconsciousness remains incompletely understood, with some advocating for a quantum mechanical basis. Despite associations between general anesthesia and changes in physical properties such as electron spin, there has been no empirical demonstration that general anesthetics are capable of functional quantum interactions. In this work, we studied the linear and non-linear optical properties of the halogenated ethers sevoflurane (SEVO) and isoflurane (ISO), using UV-Vis spectroscopy, time dependent-density functional theory (TD-DFT) calculations, classical two-photon spectroscopy, and entangled two-photon spectroscopy. We show that both of these halogenated ethers interact with pairs of 800 nm entangled photons while neither interact with 800 nm classical photons. By contrast, nonhalogenated diethyl ether does not interact with entangled photons. This is the first experimental evidence that halogenated anesthetics can directly undergo quantum interaction mechanisms, offering a new approach to understanding their physicochemical properties.

Two-Photon Excitation of Flavins and Flavoproteins with Classical and Quantum Light.

In this contribution, the entangled two-photon absorption (ETPA) process on naturally occurring flavoproteins was studied. Low temperature responsive protein (LOT6P) and b-type dihydroorotate dehydrogenase (DHOD B), which possess flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) chromophores embedded in the protein environment, were investigated. The ETPA cross-section was measured, and we found that it increases when going from an aqueous solution of the free flavin chromophore to the chromophore embedded in the protein. This enhancement is particularly evident when entangled photons are used as excitation light compared to classical light. Our results prove the potential of ETPA as a sensing technique for fluorescent proteins even for those whose classical TPA cross-section is small compared to well-known fluorescent proteins.

Entangled Two Photon Absorption Cross Section on the 808 nm Region for the Common Dyes Zinc Tetraphenylporphyrin and Rhodamine B.

We report the measurement of the entangled two-photon absorption (ETPA) cross section, σE, at 808 nm on organic chromophores in solution in a low photon flux regime. We performed measurements on zinc tetraphenylporphyrin (ZnTPP) in toluene and rhodamine B (RhB) in methanol. This is, to the best of our knowledge, the first time that σE is measured for RhB. Additionally, we report a study of the dependence of σE on the molecular concentration for both molecular systems. In contrast to previous experiments, our measurements are based on detecting the pairs of photons that are transmitted by the molecular system. By using a coincidence count circuit it was possible to improve the signal-to-noise ratio. This type of work is important for the development of spectroscopic and microscopic techniques using entangled photons.

Síndrome de Melas: correlación clínica con hallazgos imagenológicos en espectroscopia y tractografía, reporte de caso / Melas syndrome: clinical correlation with imaging findings in spectroscopy and tractography, case report

El síndrome de Melas es una enfermedad de herencia mitocondrial caracterizada por encefalopatía mitocondrial, acidosis láctica y eventos similares a ataque cerebrovascular, secundaria a una mutación en los genes que codifican las proteínas transportadoras de electrones, limitando la producción energética y generando disfunción multiorgánica, que afecta principalmente el sistema músculo esquelético y el sistema nervioso, lo que está en correlación con las características clínicas que presentan los pacientes. El diagnostico se basa en la sospecha clínica, los hallazgos paraclínicos e imagenológicos y la confirmación de la mutación a través del estudio genético. No existe tratamiento específico, se basa únicamente en el manejo sintomático y requiere apoyo multidisciplinario. Presentamos el caso de un paciente con antecedente de Melas, que ingresó por evento cerebrovascular isquémico bioccipital y correlación con hallazgos en neuroimágenes (espectroscopia y tractografía).

Melas syndrome is a disease characterized by mitochondrial inheritance of mitochondrial encephalopathy, lactic acidosis and events like stroke secondary to a mutation in the gene encoding the electron transport proteins limiting energy production and generating multiorgan dysfunction being affected mainly musculoskeletal system and the nervous system which correlates with the clinical characteristics presented by patients. The diagnosis is based on clinical suspicion, laboratory, and imaging findings and confirmation of the mutation through genetic study. No specific treatment is Is available, but symptomatic treatment is needed and requires multidisciplinary support. We report a patient with a history of Melas who who had bioccipital cerebral ischemic event and correlation with findings in neuroimaging (spectroscopy and tractography).

[Intravenous thrombolysis for ischemic stroke: Experience in 54 patients]. / Trombolisis intravenosa en accidente cerebro vascular isquémico agudo en un hospital público de Chile: Análisis prospectivo de 54 casos.

BACKGROUND: Intravenous thrombolysis with recombinant tissue plasminogen activator (rt-PA) reduces disability in patients with ischemic stroke. However, its implementation in Chilean public general hospitals has been slow and faces some difficulties. AIM: To analyze the results of an intravenous thrombolysis protocol implementation in a public general hospital. MATERIAL AND METHODS: During a lapse of 28 months a standardized protocol for intravenous thrombolysis implemented in the emergency room of a public hospital, was prospectively evaluated. Fifty four patients with ischemic stroke were treated and assessed three months later as outpatients. RESULTS: At three months of follow-up, 66.4% of patients subjected to thrombolysis had a favorable evolution, defined as having 0 to 1 points in the modified Rankin scale. Intracerebral hemorrhage rate was 11.1%, including 5.5% of symptomatic intracerebral hemorrhage. Four percent of patients had systemic bleeding complications after thrombolysis. The mortality rate was 14.8%. CONCLUSIONS: The success rates, mortality, and complications rate were comparable to the results obtained in international studies, despite of the absence of a stroke unit to manage stroke and its complications.

Trombolisis intravenosa en accidente cerebro vascular isquémico agudo en un hospital público de Chile: análisis prospectivo de 54 casos / Intravenous thrombolysis for ischemic stroke: experience in 54 patients

Background: Intravenous thrombolysis with recombinant tissue plasminogen activator (rt-PA) reduces disability in patients with ischemic stroke. However, its implementation in Chilean public general hospitals has been slow and faces some difficulties. Aim: To analyze the results of an intravenous thrombolysis protocol implementation in a public general hospital. Material and Methods: During a lapse of 28 months a standardized protocol for intravenous thrombolysis implemented in the emergency room of a public hospital, was prospectively evaluated. Fifty four patients with ischemic stroke were treated and assessed three months later as outpatients. Results: At three months of follow-up, 66.4% of patients subjected to thrombolysis had a favorable evolution, defined as having 0 to 1 points in the modified Rankin scale. Intracerebral hemorrhage rate was 11.1%, including 5.5% of symptomatic intracerebral hemorrhage. Four percent of patients had systemic bleeding complications after thrombolysis. The mortality rate was 14.8%. Conclusions: The success rates, mortality, and complications rate were comparable to the results obtained in international studies, despite of the absence of a stroke unit to manage stroke and its complications.

Measuring different types of transverse momentum correlations in the biphoton's Fourier plane.

In this Letter, we present a theoretical and experimental study about the spatial correlations of paired photons generated by Type II spontaneous parametric down-conversion. In particular, we show how these correlations can be positive or negative, depending on the direction in which the far-field plane is scanned and the polarization postselected. Our results provide a straightforward way to observe different kind of correlations that complement other well-known methods to tune the spatial correlations of paired photons.