6,865 research outputs found
Circadian Entrainment Triggers Maturation of Human In Vitro Islets
Stem-cell-derived tissues could transform disease research and therapy, yet most methods generate functionally immature products. We investigate how human pluripotent stem cells (hPSCs) differentiate into pancreatic islets in vitro by profiling DNA methylation, chromatin accessibility, and histone modification changes. We find that enhancer potential is reset upon lineage commitment and show how pervasive epigenetic priming steers endocrine cell fates. Modeling islet differentiation and maturation regulatory circuits reveals genes critical for generating endocrine cells and identifies circadian control as limiting for in vitro islet function. Entrainment to circadian feeding/fasting cycles triggers islet metabolic maturation by inducing cyclic synthesis of energy metabolism and insulin secretion effectors, including antiphasic insulin and glucagon pulses. Following entrainment, hPSC-derived islets gain persistent chromatin changes and rhythmic insulin responses with a raised glucose threshold, a hallmark of functional maturity, and function within days of transplantation. Thus, hPSC-derived tissues are amenable to functional improvement by circadian modulation
Thermal Pions at Finite Isospin Chemical Potential
The density corrections, in terms of the isospin chemical potential ,
to the mass of the pions are studied in the framework of the SU(2) low energy
effective chiral lagrangian. The pion decay constant is
also analized. As a function of temperature for , the mass remains
quite stable, starting to grow for very high values of , confirming previous
results. However, there are interesting corrections to the mass when both
effects (temperature and chemical potential) are simultaneously present. At
zero temperature the should condensate when . This is not longer valid anymore at finite . The mass of the
acquires also a non trivial dependence on due to the finite
temperature.Comment: 13 pages, 5 figure
Struma Ovarii associated with Pseudo-Meigs Syndrome and elevated serum Ca 125: Case report and literature review
Struma Ovarii is a highly specialized monodermal teratoma in which the major component is thyroid tissue. Its relationship with Pseudo Meigs syndrome, hyperthyroidism and elevation of Ca 125 is a rare condition; this could mimic malignancy. Ultrasound and axial tomography may be useful in diagnosis; but histopathological criteria play a very important role in the definitive diagnosis. Our objective is to present a case report of Struma ovarii, ascites, pleural effusion (pseudo meigs syndrome), elevation of Ca 125, hyperthyroidism, and review the published literature in relation to epidemiology and diagnostic characteristics
Perivellosa disease massive fibrin deposition, association with Down syndrome: case report and literature review
The disease perivellosa massive fibrin deposition (MPFD), is a condition characterized by uncontrolled mainly fibrin deposition intervillous space. The incidence worldwide is 0.028% per 1000 live births, there is only one case report where this condition is associated with trisomy 21, in our country there are no reports of this disease. The MPFD has high morbidity, obstetric mortality, recurrence, as well as neurodevelopmental significance of newborns. The etiology until the moment is unknown, difficult diagnosis and management for the obstetrician. The aim is to report MPFD association with trisomy 21 (T21) and a review of the medical literature regarding this condition
Genoma completo, diagnóstico y resistencia a Ralstonia solanacearum en hibridos de plátano
La marchitez vascular del banano y el plátano, también conocida como enfermedad de Moko, es causada por Ralstonia solanacearum (Rs) filotipo II y es la principal enfermedad bacteriana que afecta a estos cultivos en Colombia. Tras obtener el genoma completo de un aislado colombiano (CIAT-078) y el análisis de secuencia comparativo con otros 44 genomas de Rs, desarrollamos un protocolo de PCR mejorado. Esto se basa en la secuencia de nucleótidos de un gen que codifica una proteína hipotética del dominio DUF3313, que se encontró que estaba presente solo en el filotipo II de Rs y además es conservada y polimórfica. El protocolo se probó con dos métodos de inoculación de Rs (con herida y sin herida), para validar la resistencia de campo reportado en el genotipo híbrido de plátano FHIA-21, previamente reportado como susceptible a la enfermedad de Moko en condiciones de invernadero. Mediante el uso de un método de inoculación sin herida en las raíces, confirmamos la resistencia en FHIA-21 a la enfermedad de Moko (no se detectó Rs por PCR en plantas inoculadas). En contraste, el genotipo Dominico Hartón susceptible al campo desarrolló síntomas severos independientemente de que las raíces tuvieran heridas o no. El genotipo FHIA-21 mostró un área bajo la curva de progresión de la enfermedad (AUDPC) cercana a cero, mientras que las plantas de Dominico Hartón mostraron valores de AUDPC que variaron de 65,8 a 88,4
Meson - nucleon vertex form factors at finite temperature
In this paper the dependence of meson-nucleon-nucleon vertex form factors is
studied as a function of termperature. The results are obtained starting from a
zero temperature Bonn potential. The temperature dependence of the vertex form
factors and radii is studied in the thermofield dynamics, a real-time operator
formalism of finite temperature field theory. It is anticipated that these
results will have an impact on the study of relativistic heavy-ion collisions
as the critical temperature for the phase transition from hadronic to
quark-gluon system is approached.Comment: 19 pages, Revtex, 11 figures (Ps), 171k
Proteins involved in mitochondrial metabolic functions and fertilization predominate in stallions with better motility
Even in stallions with sperm quality within normal reference ranges at ejaculation, subtle differences in sperm quality exist that in many cases lead to reduced time frames for conservation of the ejaculate and/or reduced fertility. The spermatozoon is a cell highly suitable for proteomics studies, and the use of this technique is allowing rapid advances in the understanding of sperm biology. The aim of the present study was to investigate differences among stallions of variable sperm quality (based on motility and sperm velocities), although all horses had sperm characteristics within normal ranges. The proteome was studied using UHPLC/MS/MS and posterior bioinformatic and enrichment analysis; data are available via ProteomeXchange with identifier PXD025807. Sperm motility, linear motility and circular, straight line and average velocities (VCL, VSL, VAP) were measured using computer assisted sperm analysis (CASA). In stallions showing better percentages of motility, circular and average velocity predominated mitochondrial proteins with roles in the Citric acid cycle, pyruvate metabolism and oxidative phosphorylation. Interestingly, in stallions with better percentages of total motility, sperm proteins were also enriched in proteins within the gene ontology (G0) terms, single fertilization (G0: 0007338), fertilization (G0: 0009566), and zona pellucida receptor complex (GO:0002199). The enrichment of this proteins in samples with better percentages of total motility may offer a molecular explanation for the link between this parameter and fertility. Significance: Proteomic analysis identified a high degree of specificity of stallion sperm proteins with discriminant power for motility, linear motility, and sperm velocities (VCL, VAP and VSL). These findings may represent an interesting outcome in relation to the molecular biology regulating the movement of the spermatozoa, and the biological meaning of the measurements that computer assisted sperm analysis (CASA) provide. Of a total of 903 proteins identified in stallion spermatozoa, 24 were related to the percentage of total motility in the sample; interestingly, gene ontology (G0) analysis revealed that these proteins were enriched in terms like single fertilization and fertilization, providing a molecular link between motility and fertility. Field studies indicate that the percentage of total motility is the CASA derived parameter with the best correlation with fertility in stallions
Complete genome sequence of the plant pathogen Ralstonia solanacearum strain ciat-078, isolated in Colombia, obtained using Oxford Nanopore Technology
Moko is one of the main diseases affecting banana and plantain in Colombia. Here, we report the genome sequence of the causal agent, the bacterium Ralstonia solanacearum (Smith) strain CIAT-078, collected in 2004 from affected plantains in central-west Colombia. The assembled genome was obtained using Oxford Nanopore Technology
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