521 research outputs found

    Transcription of satellite DNAs in insects

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    Chromatin condensation is an important regulatory mechanism of gene silencing as well as gene activation for the hundreds of functional protein genes harbored in heterochromatic regions of different insect species. Being the major heterochromatin constituents, satellite DNAs serve important roles in heterochromatin regulation in insect in general. Their expression occurs in all developmental stages, being the highest during embryogenesis. Satellite DNA transcrips range from small RNAs, corresponding in size to siRNA, and piwiRNAs, to large, a few Kb long RNAs. The long transcripts are preferentially nonpolyadenylated and remain in the nucleus. The actively regulated expression of satDNAs by cis or trans elements as well as by environmental stress, rather than constitutive transcription, speaks in favour of their involvement in differentiation, development, and environmental response

    Stent-armed kyphoplasty in osteoporotic thoracolumbar fractures—clinical and functional results and a center experience over 10 years

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    Background: The optimal treatment of osteoporotic vertebral fractures is still a controversial and under discussion topic. Armed kyphoplasty with expansive intravertebral implants is an emerging procedure, which, in theory, it not only makes it possible to achieve instant analgesia, and to get stabilization gains of benefits of kyphoplasty and vertebroplasty, but also, allows for a more effective maintenance of the restored vertebral height. Methods: A retrospective observational study is presented, in which 30 patients participated, including a total of 33 osteoporotic thoracolumbar compression burst vertebral fractures with involvement of one or both vertebral platforms and of more than one fifth of the posterior wall. These individuals underwent armed kyphoplasty with VBS® stents (or stentoplasty) filled with bone cement over 10 years (between 2012 and 2022) at the same center. Clinical (visual analogue scale, Oswestry Disability Index and Patient Global Impression of Change) and imaging results (restoration and maintenance of vertebral body heights) achieved were investigated. The mean follow-up time was 4.5 years (range, 1-10 years). Results: There was a statistically significant improvement in all clinical and functional parameters evaluated, as well as a statistically significant difference in the various vertebral body heights between preoperative and end of follow-up time [increase of 10.7-15.2-5.0 mm (anterior-median-posterior) in the sagittal plane and 6.7-11.6-9.7 mm (right-median-left) in the coronal plane]. There was a statistically significant direct correlation between vertebral heights in the coronal plane, and between the Beck index assessed at the end of the follow-up period and the improvement in functional disability. Conclusions: The percutaneous transpedicular posterior approach, the ability to anatomically restore the fractured vertebra and to maintain it in the medium-long term, as well as the reduced risk of adverse effects, make stent-armed kyphoplasty a very attractive treatment option for osteoporotic compressive thoracolumbar fractures. A clinical-morphological correlation was demonstrated regarding the surgical treatment of these fractures, it was found that a more effective morphological restoration of vertebral heights in both the sagittal and coronal planes is associated with superior satisfactory clinical functional parameters.info:eu-repo/semantics/publishedVersio

    Fragmentation and complexity: analyzing structural change in the Chicago regional economy

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    In this paper, two dimensions are differentiated within the fragmentation process: a spatial and a functional one. On the one hand, due to fragmentation and industrial relocation, regional and national economies might be losing some internal linkages. This spatial fragmentation determines a decrease in the complexity of the production systems. On the other hand, outsourcing, as a form of functional fragmentation, increases the density of transactions and linkages within an economy. The overall impact of fragmentation on the complexity of the regional and national economic systems depends on the net effect of these two fragmentation forces. In this paper, the effects of fragmentation on the complexity of the economy of the Chicago region are studied from a set of input-output tables estimated for the period 1978-2014 using Average Propagation Lengths (APLs)

    Una experiencia de formación matemática de maestros usando recursos informáticos

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    En este trabajo describimos el diseño e implementación de un módulo de clases prácticas en el aula de informática, que se ha llevado a cabo en el programa de formación inicial de maestros de educación primaria en el área de matemáticas de la Universidad de Granada. Analizamos la organización de las sesiones prácticas y el tipo de activida- des basadas en la exploración y análisis de una colección de “applets” sobre aritmética, geometría, medida y estadística. Presentamos también algunos resultados de la experien- cia y unas primeras conclusiones sobre las cuestiones de investigación que plantea la incorporación de las nuevas tecnologías en los procesos de enseñanza y aprendizaje de las matemáticas cuando se realiza en este tipo de escenarios presenciales

    Effects of oral glutamine during abdominal radiotherapy on chronic radiation enteritis: a randomized controlled trial

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    [Abstract] Objective. Glutamine has been proposed as a preventive treatment for toxicity related to cancer therapies. The aim of this study was to test the efficacy of glutamine in the prevention of radiation enteritis. Methods. A randomized, double-blind, controlled trial was performed including 69 patients who were assigned to receive either glutamine (Gln, 30 g/d) or placebo while they were receiving abdominal radiotherapy. Patients were re-evaluated 1 y after completion of treatment. The presence of chronic enteritis was assessed using the Radiation Therapy Oncology Group scale. Nutritional status was evaluated using subjective global assessment, weight, and bioimpedance. Relative risk (RR) and its confidence interval (CI) were also calculated. Results. The trial initially included 69 patients (34 Gln, 35 placebo), but 11 patients were lost during follow-up (4 Gln, 7 placebo; P = 0.296). Chronic enteritis was developed by 14 % of patients: Gln 16.7 % versus placebo 11.1% (RR = 1.33; 95 % CI, 0.35–5.03; P = 0.540). Most cases of enteritis were grade I (75 %), with no differences between groups. The stool frequency increased after radiotherapy in patients who received Gln (from 1 ± 1 to 2 ± 2 stools per day, P = 0.012), but remained unchanged with placebo (1 ± 1 stools per day, P = 0.858; difference between groups P = 0.004). There were no differences between the two groups in terms of weight, fat mass, or fat-free mass index, or between patients with enteritis and those without intestinal toxicity. Conclusions. Chronic enteritis is a relatively infrequent phenomenon, and Gln administration during radiotherapy does not exert a protective effect.Castilla y León. Consejería de Sanidad; GRS 326/B/0

    Crecimiento in-vitro de raíces de Manihot esculenta en distintas condiciones de iluminación y temperatura

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    Se determinó el crecimiento in-vitro de raíces de Manihot esculenta en condiciones de iluminación y temperatura diferentes.Se utilizaron raíces obtenidas de ápices cultivados in-vitro en medio de Torrey (sólido), en cuartos, invernáculos y estufas, haciendo tres variantes: 1)- Luz contínua durante las 24 hs.; 2)- Día natural (de 11 hs. de luz y 13 hs. de oscuridad); 3)- Oscuridad durante las 24 hs. En cada variante se estudiaron dos subvariantes: a)- con temperaturas elevadas día y noche yb)- temperatura alta de día y baja de noche. La fuente de iluminación en la variante de luz contínua fue el sol durante el día y luz artificial de noche.Se encontró que la composición del medio nutritivo influye en el crecimiento de los ápices y en la rizogénesis, dando mejor resultado el medio de Torrey que el de White; que la temperatura Alta de día y Alta de noche con luz contínua o natural, coayudan al crecimiento de las raíces cultivadas invitro. Además se encontró una coloración verde en las raíces, posiblemente debido a la formación de clorofila por efecto de la iluminación

    Efectos tisulares de la glutamina en pacientes con cáncer de recto tratados con quimorradioterapia preoperatoria

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    [Abstract] Background: The aim was to evaluate the effects of glutamine on tumor regression and histological damage in patients with rectal patients following chemoradiotherapy previous to surgery. Material and methods: Ten patients with rectal cancer surgically removed after chemoradiotherapy were included, a subgroup of a randomized trial that compared glutamine and placebo in the prevention of acute radiation enteritis. Samples of neoplasm and healthy tissue were evaluated by an expert pathologist searching for signs of tumor regression, muciphages, and signs of radiation-induced damage. Results: There were no differences in the grade of tumor regression with either glutamine or placebo. All patients who received glutamine presented muciphages, compared with 28.6% of the placebo group (p = 0.038). Histological damage was similar in patients receiving glutamine or placebo, and between those with radiation enteritis or without toxicity. Conclusion: Glutamine did not exert a protective effect over chemoradiotherapy in rectal cancer or healthy rectal tissue.[Resumen] Introducción: El objetivo fue evaluar los efectos de la administración de glutamina sobre la regresión tumoral y sobre el tejido sano en pacientes con cáncer rectal que recibieron quimiorradioterapia. Material y métodos: Se incluyó 10 pacientes con cáncer rectal operado después de quimiorradioterapia, un subgrupo de un ensayo clínico que comparó glutamina con placebo en la prevención de enteritis aguda. Un patólogo experto analizó las muestras de tumor y tejido sano, buscando datos de regresión tumoral, mucífagos y daño por radiación. Resultados: No hubo diferencias entre placebo y glutamina en el grado de regresión tumoral. Todos los pacientes con glutamina presentaron mucífagos, frente al 28,6% con placebo (p = 0,038). El daño sobre tejido sano fue similar en los pacientes con glutamina y placebo, y entre aquellos con y sin enteritis. Conclusión: La glutamina no ejerce un efecto protector frente a la quimiorradioterapia sobre el tumor o el tejido rectal sano

    The impact of plant-based coatings in “ROCHA” pear preservation during cold storage: a metabolomic approach

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    Although new storage technologies have been emerging in recent years, preservation of pear (Pyrus communis L.) remains a challenge for suppliers. Maintenance of desired organoleptic properties throughout cold storage using non-chemical strategies has been investigated and the use of edible coatings has shown potential to delay fruit quality deterioration during cold storage. Thus, the objective of this study is to evaluate the impact of pectin coatings including plant extracts, in “Rocha” pear (Pyrus communis L. cv. Rocha) preservation. A four-month pilot scale assay was performed in both dynamic controlled atmosphere (DCA) (−0.5 °C, 0.5% O2, and 0.4% CO2) and normal atmospheric (NA) conditions (2 °C). For each storage condition, the following three coatings were tested: pectin (3% w/v) (PCT), pectin (3% w/v) + strawberry tree leaves extract (9.5 mg/mL) (CT1), and pectin (3% w/v) + apple pomace extract (16 mg/mL) (CT2). Volatile compounds, potentially related to aroma or ripening status of “Rocha” pear, were monitored alongside with conjugated trienols (CTs) and maturity parameters. The combination of DCA conditions and the application of pectin coatings were able to reduce the release of Rocha pear volatiles associated with ripening status, (particularly esters and sesquiterpenes), as well as reduce CTs, which could contribute to the preservation of Rocha pear for longer periods.info:eu-repo/semantics/publishedVersio

    Efficacy of glutamine in the prevention of acute radiation enteritis: a randomized controlled trial

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    [Abstract] Background: Acute radiation enteritis is a common adverse effect related to radiotherapy (RT). Glutamine is an immune modulator and antioxidant amino acid that can exert a protective role in patients receiving abdominal or pelvic radiation. The aim of this study was to test if glutamine prevents radiation enteritis during RT. Materials and Methods: Double-blind, randomized, controlled trial including 69 patients who needed RT because of pelvic or abdominal malignancies and received glutamine (30 g/d) or placebo (casein, 30 g/d). Enteritis was evaluated according to the Radiation Therapy Oncology Group scale, intestinal inflammation using fecal calprotectin, and gut integrity with citrulline. The incidence of enteritis was analyzed by Kaplan-Meier curves, and the hazard ratio (HR) was calculated using Cox regression. Results: Patients were predominantly male (65.2%), with an average (SD) age of 66.6 (9.9) years, with urologic (44.9%), rectal (24.6%), or gynecological cancer (23.1%). More patients developed enteritis with glutamine than with the placebo (55.9% vs 22.0%; P =.002), with an HR of 1.59 (95% confidence interval, 0.62-4.05). There were no differences in final calprotectin levels (glutamine, 57.9 [85.8] mg/kg vs placebo, 54.0 [57.7] mg/kg; P =.182) or the number of patients with values >50 mg/kg (glutamine, 58.1% vs placebo, 54.6%; P =.777). Final citrulline levels were similar between groups (glutamine, 26.31 [10.29] mmol/L vs placebo, 27.69 [12.31] mmol/L; P =.639), without differences in the number of patients with <20 mmol/L (glutamine, 24.1% vs placebo, 25.0%; P =.938). Citrulline concentration was reduced during RT with placebo but remained unchanged with glutamine. Conclusion: Glutamine does not prevent the development of enteritis during RT. © 2013 American Society for Parenteral and Enteral Nutrition.Castilla y León. Consejería de Sanidad, SACYL GRS 326/B/0

    Influencia de la intensidad lumínica en el crecimiento in-vitro de ápices radiculares de mandioca

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    Yemas caulinares se pusieron a crecer in-vitro en medio de Torrey. Unas tenían como fuente hidrocarbonada sacarosa al 3%, otras glucosa al 3% y las restantes lactosa al 3%. Cuando estas yemas caulinares formaron raíces, se procedió a repicar los ápices radiculares in-vitro en medio de Torrey con sacarosa al 3% y se colocaron los matraces en las siguientes intensidades lumínícas: a)- 50.000 luxes (luz natural) durante 12 horas diarias; b)- 3.000 luxes (luz artificial) durante 12 horas diarias; c)- 600 luxes (luz artificial) durante 12 horas diarias; d)- Oscuridad durante las 24 horas del día y e)- 600 luxes (luz artificial) durante las 24 horas del día. En cada variante se puso igual cantidad de ápices radiculares que se habían formado en las distintasfuentes hidrocarbonadas.La; temperatura de todas las variantes fue durante el día 319 C y de noche 219 C, con peqUEñas variaciones.Además se analizó el contenido de HCN de los ápices que se "sembraron". Se mantuvieron en ese medio durante 2 meses (con repiques cada 15 días).Los resultados demostraron que los ápices que mas crecieron y que tuvieron mayor peso fresco, fueron los que recibieron la mayor intensidad lumínica.Los que menos crecieron y tuvieron menor peso fresco, fueron los que estuvieron en oscuridad. Además, los resultados demostraron que la fuente hidrocarbonada en la que crecieron las yemas caulinares que dieron origen a las raíces, tiene influencia sobre el crecimiento posterior del ápice radicular. Después de dos meses de crecimiento in-vitro, las raíces no habían aumentado su contenido en HCN y en la mayoría de los casos éste disminuyó
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