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1.
Biochem Biophys Res Commun ; 560: 27-31, 2021 06 30.
Article in English | MEDLINE | ID: mdl-33964504

ABSTRACT

In enteric bacteria such as Escherichia coli, there are two homologs of the DNA-binding nucleoid associated protein (NAP) known as HU. The two homologs are known as HU-A and HU-B, and exist either in the form of homodimers (HU-AA, or HU-BB) or as heterodimers (HU-AB), with different propensities to form higher-order oligomers. The three different dimeric forms dominate different stages of bacterial growth, with the HU-AB heterodimer dominating cultures in the stationary phase. Due to similarities in their properties, and the facile equilibrium that exists between the dimeric forms, the dimers are difficult to purify away from each other. Although HU-AA and HU-BB can be purified through extensive ion-exchange chromatography, reestablishment of equilibrium interferes with the purification of the HU-AB heterodimer (which constitutes ∼90% of any population with equal numbers of HU-B and HU-A chains). Here, we report the creation of a functional analog of HU-AB that does not appear to partition to generate any minority populations of HU-AA or HU-BB. The analog was constructed through genetic fusion of the HU-B and HU-A chains into a single polypeptide (HU-B-A) with a glycine/serine-rich linker of 11 amino acids separating HU-B from HU-A, and a histidine tag at the N-terminus of HU-B. HU-B-A folds to bind 4-way junction DNA, and displays a significant tendency to form dimers (i.e., analogs of HU tetramers), and a higher thermodynamic stability than HU-BB or HU-AA, thus explaining why it dominates mixtures of HU-B and HU-A chains.


Subject(s)
DNA-Binding Proteins/chemistry , Escherichia coli Proteins/chemistry , DNA/metabolism , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Dimerization , Escherichia coli Proteins/genetics , Escherichia coli Proteins/metabolism , Protein Conformation, alpha-Helical , Protein Folding , Protein Multimerization , Protein Unfolding , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/metabolism , Thermodynamics , Urea
2.
Lipids ; 51(2): 211-27, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26662048

ABSTRACT

A construct called a simulacrum is defined that provides all possible solutions to a sum of two mass spectral abundances, based on values (abundances) or ratios of those values. The defined construct is applied to atmospheric pressure chemical ionization mass spectrometry (MS) of triacylglycerols (TAG). A simulacrum has precisely defined components, specifically a simulacrum sum, four Possibilities to Observe, two Cases, and eight solutions. A simulacrum with no restrictions is the First General Form of a Simulacrum. When one value is specified to be 1 (as in MS), the construct is called a Unit Simulacrum, also called the First Specified Form of a Simulacrum. When one value is 1 and no value can be greater than 1 (the two specifications dictated by mass spectrometry), the construct is called the Second Specified Form of a Simulacrum, or the Mass Spectrometry Simulacrum. Simulacra are used with three Critical Ratios calculated from raw abundances in mass spectra of TAG to provide structural information about the degree of unsaturation in TAG, the identity and quantity of regioisomers, and other structural characteristics. Three-level-deep nested simulacrum solutions yield the recently reported Updated Bottom Up Solution, from which the protonated molecule, [MH](+), and all diacylglycerol-like fragments, [DAG](+), of TAG can be reproduced from the Critical Ratios. Thus, the simulacrum solutions constitute a reduced data set in which more information is provided in fewer values than raw abundances, such that the Critical Ratios constitute a compact library of mass spectra.


Subject(s)
Mass Spectrometry/methods , Triglycerides/isolation & purification , Animals , Chromatography, High Pressure Liquid/methods , Humans , Triglycerides/chemistry
3.
Psicol. soc. (Online) ; 24(1): 46-55, jan.-abr. 2012.
Article in Portuguese | LILACS | ID: lil-624166

ABSTRACT

Este artigo discute a crise ambiental por meio de um diálogo entre a psicanálise, filosofia e ciências sociais. Busca-se introduzir um eixo comum de compreensão das relações entre a psiquê e a natureza, a partir de um texto reflexivo sobre a natureza humana, sua complexidade e suas sociopatias. A crise socioambiental em que vivemos é tratada a partir das seguintes proposições: (i) a humanidade se distanciou da sua condição natural; (ii) a humanidade pode estar psicologicamente doente; (iii) a humanidade não está moralmente apta para delegar a superação da crise às futuras gerações, pois vivemos num simulacro que envolve consumismo e alienação. Conclui-se que há uma dimensão subjetiva na raiz da crise ambiental, de cuja análise depende a solução real do impasse civilizacional com o qual nos defrontamos.


This article discusses the environmental crisis through a dialogue between psychoanalysis, philosophy and the social sciences. It intends to introduce a common axis to the understanding of the relations between psyche and nature in a reflective text about human nature, its complexities and sociopathologies. The environmental crisis in which we are imbedded is approached through the followed propositions: (i) humanity has broken its links with its natural condition; (ii) humanity may be psychologically ill; (iii) humanity is not morally able to delegate the overcoming of the environmental crisis to the new generations because we live in a simulacrum associated with consumerism and alienation. We conclude that there is a subjective root in the environmental crisis, the analysis of which depends on finding the adequate answers to the civilization impasse that we currently face.


Subject(s)
Mental Health/trends , Human Characteristics , Antisocial Personality Disorder , Societies/trends , Dangers on the Environment
4.
Cogito ; 13: 76-80, nov. 2012.
Article in Portuguese | Index Psychology - journals | ID: psi-62226

ABSTRACT

Este trabalho discute, por meio do filme O 13º andar e do livro correspondente Simulacron 3, questões referentes à irrealidade do cogito e suas relações com a irrealidade do mundo externo.


Subject(s)
Humans , Psychoanalysis , Speech
5.
Rev. Inst. Nac. Enfermedades Respir ; 20(1): 71-82, ene.-mar. 2007. tab
Article in Spanish | LILACS | ID: lil-632618

ABSTRACT

La influenza, enfermedad respiratoria altamente contagiosa causada por un influenza virus, se ha presentado desde tiempos remotos. En tiempos de Hipócrates se describieron eventos con todas las características de probables epidemias de influenza sucedidas en la época helénica. El término se originó en Italia, siglo XV, pues las epidemias sucedidas en esa época se atribuían a la "influencia de las estrellas". No se puede determinar cuándo ocurrirá una pandemia; sin embargo, se sabe que se presenta con cierta regularidad. La primera epidemia de influenza descrita como tal y generalmente aceptada, ocurrió en Europa en diciembre de 1173; la primera pandemia descrita que afectó a Europa, Asia y el Norte de África fue en 1580, y la primera que afectó al Continente Americano ocurrió en 1647¹. Es por ello que la Organización Mundial de la Salud solicitó a los países participantes desarrollar los planes de preparación y respuesta para hacer frente a esta eventualidad. México participa por medio de numerosas entidades a nivel federal, instituciones y organismos nacionales con el objeto de proteger a la población de una pandemia mediante acciones efectivas y oportunas. El Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, desarrolló una estrategia propia basándose en las seis líneas de acción contenidas en el Plan Nacional, lo que le permitirá tener las guías y elementos necesarios para formular su propio Plan de Preparación y Respuesta ante una Pandemia de Influenza. Las seis líneas de acción de acuerdo con el Plan Nacional son: 7. Difusión y comunicación social, 2. Coordinación, 3. Vigilancia epidemiológica, 4. Atención médica, 5. Reserva estratégica y 6. Investigación y desarrollo. Se describen los preparativos, curso y resultados de un simulacro de pandemia de influenza.


Influenza is a highly contagious disease caused by a virus; the disease is known since the times of Hippocrates, who described events with all the characteristics of influenza epidemics during his times. Apparently, the term was coined in Italy during the XV century because the disease was attributed to the "influence" of the stars. The first formally described influenza epidemic probably dates back to December 1173; the first pandemic, in 1580, affected Europe, Asia and North Africa; the first affecting the American Continent occurred in 1647. The countries from the WHO have been asked to develop plans to face the real possibility of a new pandemic, this caused by an avian virus; Mexico has participated through the joint effort of many institutions at federal, state and municipal levels, including the Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas (National Institute of Respiratory Diseases) were we have developed a strategy of six lines of action to face this pandemia: Diffusion and social communication, coordination, epidemiologic surveillance, medical services, strategic reserve, development and research. The preparations, course and results of an influenza pandemic simulacrum are described.

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