Assuntos
COVID-19/epidemiologia , Carcinoma de Células Renais/complicações , Hospitalização/estatística & dados numéricos , Neoplasias Renais/complicações , Idoso , COVID-19/complicações , COVID-19/diagnóstico , COVID-19/terapia , Carcinoma de Células Renais/diagnóstico , Carcinoma de Células Renais/patologia , Carcinoma de Células Renais/terapia , Progressão da Doença , Feminino , Humanos , Neoplasias Renais/diagnóstico , Neoplasias Renais/patologia , Neoplasias Renais/terapia , Masculino , Pessoa de Meia-Idade , Mortalidade , Estadiamento de Neoplasias , Sistema de Registros/estatística & dados numéricos , Federação Russa , SARS-CoV-2/imunologia , SARS-CoV-2/isolamento & purificação , Índice de Gravidade de DoençaRESUMO
A long-standing conundrum is how mitotic chromosomes can compact, as required for clean separation to daughter cells, while maintaining close parallel alignment of sister chromatids. Pursuit of this question, by high resolution 3D fluorescence imaging of living and fixed mammalian cells, has led to three discoveries. First, we show that the structural axes of separated sister chromatids are linked by evenly spaced "mini-axis" bridges. Second, when chromosomes first emerge as discrete units, at prophase, they are organized as co-oriented sister linear loop arrays emanating from a conjoined axis. We show that this same basic organization persists throughout mitosis, without helical coiling. Third, from prophase onward, chromosomes are deformed into sequential arrays of half-helical segments of alternating handedness (perversions), accompanied by correlated kinks. These arrays fluctuate dynamically over <15 s timescales. Together these discoveries redefine the foundation for thinking about the evolution of mitotic chromosomes as they prepare for anaphase segregation.
Assuntos
Proteínas de Ciclo Celular/genética , Cromossomos/genética , Proteínas de Ligação a DNA/genética , Mitose/genética , Adenosina Trifosfatases/genética , Anáfase/genética , Animais , Proteínas de Ciclo Celular/isolamento & purificação , Cromátides/genética , Proteínas Cromossômicas não Histona , DNA Topoisomerases Tipo II/genética , Proteínas de Ligação a DNA/isolamento & purificação , Imageamento Tridimensional , Mamíferos , Metáfase/genética , Prófase/genéticaRESUMO
Molecular recognition is one of the most important phenomena in Chemistry and Biology. Here we present a new way of enantiomeric molecular recognition using intrinsically chiral semiconductor nanocrystals as assays. Real-time confocal microscopy studies supported by circular dichroism spectroscopy data and theoretical modelling indicate an ability of left-handed molecules of cysteine and, to a smaller extent, histidine and arginine to discriminate between surfaces of left- and right-handed nanocrystals.