3,753 research outputs found

    Planetary Nebulae as Probes of Stellar Evolution and Populations

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    Planetary Nebulae (PNe) have been used satisfactory to test the effects of stellar evolution on the Galactic chemical environment. Moreover, a link exists between nebular morphology and stellar populations and evolution. We present the latest results on Galactic PN morphology, and an extension to a distance unbiased and homogeneous sample of Large Magellanic Cloud PNe. We show that PNe and their morphology may be successfully used as probes of stellar evolution and populations.Comment: to appear in: Chemical Evolution of the Milky Way: stars versus clusters, ed. F. Giovannelli and F. Matteucci, Kluwer (2000), in pres

    Pregnant patients diagnosed with COVID-19 simulate a clinical picture of preeclampsia

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    The current pandemic caused by the coronavirus 2019 (COVID-19) has been a relevant event; we have seen how it spreads rapidly and has an increased risk of becoming severe if the patient has any comorbidity. It is essential to consider that although COVID-19 is a respiratory disease, it can have systemic effects that can trigger various complications. This study is focused on how a COVID-19 infection can present symptoms similar to preeclampsia

    Headache as a COVID-19 onset symptom and post-COVID-19 symptom in hospitalized COVID-19 survivors infected with the Wuhan, Alpha, or Delta SARS-CoV-2 variants

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    OBJECTIVE: This study looked at differences in the presence of headache as an onset symptom of coronavirus disease 2019 (COVID‐19) and as a post‐COVID‐19 symptom in individuals previously hospitalized owing to infection with the Wuhan, Alpha, or Delta variants of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). BACKGROUND: Headache can be present in up to 50% of individuals during the acute phase of SARS‐CoV‐2 infection and in 10% of subjects during the post‐COVID‐19 phase. There are no data on differences in the occurrence of headache in the acute‐ and post‐COVID‐19 phase according to the SARS‐CoV‐2 variants. METHODS: A cross‐sectional cohort study was conducted. Unvaccinated subjects previously hospitalized for COVID‐19 caused by the Wuhan (n = 201), Alpha (n = 211), or Delta (n = 202) SARS‐CoV‐2 variants were scheduled for a telephone interview 6 months after hospital discharge. Hospitalization data were collected from hospital medical records. RESULTS: The presence of headache as a COVID‐19 onset symptom at hospitalization was higher in subjects with the Delta variant (66/202, 32.7%) than in those infected with the Wuhan (42/201, 20.9%; odds ratio [OR] 1.83, 95% confidence interval [CI] 1.17–2.88) or Alpha (25/211, 11.8%; OR 3.61, 95% CI, 2.16–6.01) variants. The prevalence of post‐COVID‐19 headache 6 months after hospital discharge was higher in individuals infected with the Delta variant (26/202, 12.9%) than in those infected with the Wuhan (11/201, 5.5%; OR 2.52, 95% CI 1.22–5.31) or Alpha (eight of 211, 3.8%; OR 3.74, 95% CI 1.65–8.49) variants. The presence of headache as a COVID‐19 onset symptom was associated with post‐COVID‐19 headache in subjects infected with the Wuhan (OR 7.75, 95% CI 2.15–27.93) and Delta variants (OR 2.78, 95% CI 1.20–6.42) but not with the Alpha variant (OR 2.60, 95% CI 0.49–13.69). CONCLUSION: Headache was a common symptom in both the acute‐ and post‐COVID‐19 phase in subjects infected with the Wuhan, Alpha, and Delta variants but mostly in those infected with the Delta variant

    GenotipificaciĂłn de mycobacterium leprae colombiano para la determinaciĂłn de patrones de transmisiĂłn de la enfermedad

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    Objetivo Evaluar la variabilidad de VNTR (variable-number tandem repeat) de My­cobacterium leprae de pacientes colombianos con y sin tratamiento previo para identificar posibles fuentes de infecciĂłn y entender los patrones de transmisiĂłn de la enfermedad. MetodologĂ­a Estudio transversal descriptivo, en donde mediante un muestreo elec­tivo a conveniencia se tomaron 161 biopsias de pacientes multibacilares de lepra, que habĂ­an sido solicitadas para diagnĂłstico y seguimiento de la enfermedad, de las cuales se realizĂł extracciĂłn de ADN de M. leprae  y usando la tĂ©cnica de PCR para VNTRs de M. leprae estandarizada, se establecieron los genotipos y los diferentes clusters mediante el agrupamiento apareado UPGMA.Resultados En las 161 muestras totales se hallaron 22 genotipos VNTRs diferentes, de las cuales 100 muestras (62,1 %) pertenecĂ­an al genotipo Ășnico VNTRU, y de los genotipos restantes, los mayoritarios, es decir los que dieron lugar a formaciĂłn de grupos o clusters fueron VNTR17 (5,6 %),  VNTR20 (4,3 %), VNTR18 (4,3 %), VNTR14 (4,3 %)   y VNTR13 (3,7 %). ConclusiĂłn En este estudio se evidencia por anĂĄlisis de agrupamiento que se pue­den detectar clones con diferente grado de virulencia/agresividad, lo cual implica la necesidad de incrementar varias de las actividades del programa de control que darĂĄn como resultado la verdadera disminuciĂłn de la transmisiĂłn del microorga­nismo

    Efecto de la refinaciĂłn fĂ­sica sobre la calidad quĂ­mica y sensorial del aceite de coco

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    The effect of the physical refining stages (degumming, bleaching and deodorization) on some coconut oil quality and sensory parameters was evaluated. The fatty acid profile was within the range reported for this oil. The free fatty acids level (FFA) and the moisture content were significantly reduced (p 0.05) were found in p-anisidine value (AV). The tocopherols content was lower than the reported for this oil (6.57 ppm).The sterol level (899 ppm) was similar to the level reported for this oil. Both tocopherols and sterols content were significantly reduced (p 0.05) en ninguna de las etapas. El contenido de tocoferoles (6.57 ppm) estuvo por debajo de lo reportado para aceite de coco. El nivel de esteroles (899 ppm) determinado correspondió a lo reportado en la bibliografía. Tanto los tocoferoles como los esteroles se redujeron significativamente (p < 0.05) en todas las etapas de la refinación, siendo la etapa de blanqueo donde hubo mayor pérdida de estos compuestos. Se evaluó sensorialmente el aceite de coco usando una prueba con escalas. La calidad sensorial fue mejorada por el proceso de refinación. El aceite de coco desodorizado obtuvo la mejor calificación sensorial

    Quantification of glycated hemoglobin and glucose in vivo using Raman spectroscopy and artificial neural networks

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    Undiagnosed type 2 diabetes (T2D) remains a major public health concern. The global estimation of undiagnosed diabetes is about 46%, being this situation more critical in developing countries. Therefore, we proposed a non-invasive method to quantify glycated hemoglobin (HbA1c) and glucose in vivo. We developed a technique based on Raman spectroscopy, RReliefF as a feature selection method, and regression based on feed-forward artificial neural networks (FFNN). The spectra were obtained from the forearm, wrist, and index finger of 46 individuals. The use of FFNN allowed us to achieve an error in the predictive model of 0.69% for HbA1c and 30.12 mg/dL for glucose. Patients were classified according to HbA1c values into three categories: healthy, prediabetes, and T2D. The proposed method obtained a specificity and sensitivity of 87.50% and 80.77%, respectively. This work demonstrates the benefit of using artificial neural networks and feature selection techniques to enhance Raman spectra processing to determine glycated hemoglobin and glucose in patients with undiagnosed T2D

    Acute and long-term success of ventricular tachycardia ablation in patients with ischemic heart disease in a Mexican center

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    Objective. To report the results of ventricular tachycardia (VT) catheter ablation in ischemic heart disease (IHD), and to identify risk factors associated with recurrence in a Mexican center. Materials and methods. We made a retrospective review of the cases of VT ablation performed in our center from 2015 to 2022. We analyzed the characteristics of the patients and those of the procedures separately and we determined factors associated with recurrence. Results. Fifty procedures were performed in 38 patients (84% male; mean age 58.1 years). Acute success rate was 82%, with a 28% of recurrences. Female sex (OR 3.33, IC 95% 1.66–6.68, p=0.006), atrial fibrillation (OR 3.5, IC 95% 2.08–5.9, p=0.012), electrical storm (OR 2.4, IC 95% 1.06–5.41, p=0.045), functional class greater than II (OR 2.86, IC 95% 1.34–6.10, p=0.018) were risk factors for recurrence and the presence of clinical VT at the time of ablation (OR0.29, IC95% 0.12–0.70, p=0.004) and the use of more than 2 techniques for mapping (OR 0.64, IC 95% 0.48–0.86, p=0.013) were protective factors. Conclusions. Ablation of ventricular tachycardia in ischemic heart disease has had good results in our center. The recurrence is similar to that reported by other authors and there are some factors associated with it.Objective. To report the results of ventricular tachycardia (VT) catheter ablation in ischemic heart disease (IHD), and to identify risk factors associated with recurrence in a Mexican center. Materials and methods. We made a retrospective review of the cases of VT ablation performed in our center from 2015 to 2022. We analyzed the characteristics of the patients and those of the procedures separately and we determined factors associated with recurrence. Results. Fifty procedures were performed in 38 patients (84% male; mean age 58.1 years). Acute success rate was 82%, with a 28% of recurrences. Female sex (OR 3.33, IC 95% 1.66–6.68, p=0.006), atrial fibrillation (OR 3.5, IC 95% 2.08–5.9, p=0.012), electrical storm (OR 2.4, IC 95% 1.06–5.41, p=0.045), functional class greater than II (OR 2.86, IC 95% 1.34–6.10, p=0.018) were risk factors for recurrence and the presence of clinical VT at the time of ablation (OR0.29, IC95% 0.12–0.70, p=0.004) and the use of more than 2 techniques for mapping (OR 0.64, IC 95% 0.48–0.86, p=0.013) were protective factors. Conclusions. Ablation of ventricular tachycardia in ischemic heart disease has had good results in our center. The recurrence is similar to that reported by other authors and there are some factors associated with it

    Aptitud combinatoria y heterosis en hĂ­bridos de lĂ­neas endogĂĄmicas de maĂ­z/Combining ability and heterosis in hybrids from inbred lines corn

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    El trabajo se realizĂł en dos etapas, en la primera se formaron las cruzas en el campo experimental de la Universidad AutĂłnoma Agraria Antonio Narro Unidad Laguna (UAAAN-UL), y en la segunda la evaluaciĂłn en el campo experimental de la UAAAN-UL en los ciclos agrĂ­cola primavera y verano, y en el ejido NiĂĄgara, en el municipio de Aguascalientes, Aguascalientes, en primavera. El material genĂ©tico fueron 17 lĂ­neas endogĂĄmicas, cuatro de la UAAAN-UL, dos del INIFAP y 11 del CIMMYT. El objetivo fue estimar la aptitud combinatoria general (ACG) de las lĂ­neas, la aptitud combinatoria especĂ­ca (ACE) y cuanticar los efectos genĂ©ticos y la heterosis de las cruzas. Para la ACG sobresalieron las lĂ­neas macho LAN-388P, LB-32 y LB-40, y las lĂ­neas hembras CML-319, CML-318 y CML-278; para la ACE los mayores valores lo tuvieron las cruzas LAN-123xCML-278 (3.28 t ha−1 ), LAN-123xCML-318 (1.9 t ha−1 ), LB-40xCML-319 (1.7 t ha−1 ) y LAN-388PxCML-264 (1.52 t ha−1 ). Mientras que el mayor rendimiento de grano, lo tuvieron las cruzas LB-40xCML-319 (14.49 t ha−1 ), LB-32xCML-319 (14.17 t ha−1 ), LAN-388PxCML-264 (13.68 t ha−1 ), LAN-123xCML-278 (13.55 t ha−1 ) y LAN-388PxCML-278 (13.44 t ha−1 ). La varianza de dominancia superĂł a la varianza aditiva en rendimiento de grano (RG) y en los principales componentes del rendimiento. Se encontraron efectos positivos de heterosis para rendimiento de grano con respecto al progenitor superior en las cruzas LB-40xCML-319 y LB-32 x CML-31

    High-resolution observations of SN 2001gd in NGC 5033

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    We report on 8.4 GHz VLBI observations of SN2001gd in the spiral galaxy NGC5033 made on 26 June 2002 and 8 April 2003. Our data nominally suggests a relatively strong deceleration for the expansion of SN2001gd, but we cannot dismiss the possibility of a free supernova expansion. From our VLBI observations on 8 April 2003, we inferred a minimum total energy in relativistic particles and magnetic fields in the supernova shell of E_min =(0.3-14) 10^{47} ergs, and a corresponding equipartition average magnetic field of B_min = (50--350) mG. We also present multiwavelength VLA measurements of SN2001gd, which are well fit by an optically thin, synchrotron spectrum, partially absorbed by thermal plasma. We obtain a supernova flux density of (1.02 +/- 0.05) mJy at the observing frequency of 8.4 GHz for the second epoch, which results in an isotropic radio luminosity of (6.0 +/- 0.3) * 10^{36} ergs between 1.4 and 43.3 GHz, at an adopted distance of 13.1 Mpc. Finally, we report on an XMM-Newton X-ray detection of SN2001gd on 18 December 2002. The supernova X-ray spectrum is consistent with optically thin emission from a soft component (associated with emission from the reverse shock) at a temperature around 1 keV. The observed flux corresponds to an isotropic X-ray luminosity of L_X = 1.4 +/- 0.4 * 10^{39} ergs/s in the (0.3-5) keV band. We suggest that both radio and X-ray observations of SN2001gd indicate that a circumstellar interaction similar to that displayed by SN1993J in M81 is taking place.Comment: 9 pages, 6 figures, 2 tables, accepted for publication in MNRA

    The RabGEF ALS2 is a hypoxia inducible target associated with the acquisition of aggressive traits in tumor cells

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    Indexación ScopusTumor hypoxia and the hypoxia inducible factor-1, HIF-1, play critical roles in cancer progression and metastasis. We previously showed that hypoxia activates the endosomal GTPase Rab5, leading to tumor cell migration and invasion, and that these events do not involve changes in Rab protein expression, suggesting the participation of intermediate activators. Here, we identified ALS2, a guanine nucleotide exchange factor that is upregulated in cancer, as responsible for increased Rab5-GTP loading, cell migration and metastasis in hypoxia. Specifically, hypoxia augmented ALS2 mRNA and protein levels, and these events involved HIF-1α-dependent transcription, as shown by RNAi, pharmacological inhibition, chromatin immunoprecipitation and bioinformatics analyses, which identified a functional HIF-1α-binding site in the proximal promoter region of ALS2. Moreover, ALS2 and Rab5 activity were elevated both in a model of endogenous HIF-1α stabilization (renal cell carcinoma) and by following expression of stable non-hydroxylatable HIF-1α. Strikingly, ALS2 upregulation in hypoxia was required for Rab5 activation, tumor cell migration and invasion, as well as experimental metastasis in C57BL/6 mice. Finally, immunohistochemical analyses in patient biopsies with renal cell carcinoma showed that elevated HIF-1α correlates with increased ALS2 expression. Hence, this study identifies ALS2 as a novel hypoxia-inducible gene associated with tumor progression and metastasis. © 2020, The Author(s).https://www-nature-com.recursosbiblioteca.unab.cl/articles/s41598-020-79270-
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