1,573 research outputs found
Silver Staining of Proteins in 2DE Gels
Silver staining detects proteins after electrophoretic separation on
polyacrylamide gels. Its main positive features are its excellent sensitivity
(in the low nanogram range) and the use of very simple and cheap equipment and
chemicals. The sequential phases of silver staining are protein fixation, then
sensitization, then silver impregnation, and finally image development. Several
variants of silver staining are described here, which can be completed in a
time range from 2 h to 1 day after the end of the electrophoretic separation.
Once completed, the stain is stable for several weeks
Detergents and Chaotropes for Protein Solubilization before Two-Dimensional Electrophoresis
Because of the outstanding separating capabilities of two-dimensional
electrophoresis for complete proteins, it would be advantageous to be able to
apply it to all types of proteins. Unfortunately, severe solubility problems
hamper the analysis of many classes of proteins, but especially membrane
proteins. These problems arise mainly in the extraction and isoelectric
focusing steps, and solutions are sought to improve protein solubility under
the conditions prevailing during isoelectric focusing. These solutions deal
mainly with chaotropes and new detergents, which are both able to enhance
protein solubility. The input of these compounds in proteomics analysis of
membrane proteins is discussed, as well as future directions.Comment: link to publisher's site http://biomed.humanapress.com
L'INDAGINE SUI PALAZZI PRETORI SOTTO IL GOVERNO DI PIETRO LEOPOLDO
La tesi si basa sull’analisi di tre filze conservate nell’Archivio di Stato di Firenze ascrivibili agli anni ’70 e ’80 del XVIII secolo nelle quali si descrive la “riduzione di buon grado di palazzi pretori di varie Cancellerie”. I tre faldoni contengono una serie di relazioni tecniche, talvolta corredate da pregevole documentazione grafica, e un abbondante epistolario che ha per oggetto la visita e sistemazione dei palazzi pretori dell’area fiorentina, secondo quanto prescritto dalla legge di riforma dei governi provinciali del 1772, nella quale si richiede “che tutti i palazzi pretori siano posti in buon grado”.
L’idea di intraprendere una campagna di indagine sistematica dei palazzi, nasce tuttavia da una successiva proposta del soprassindaco della Camera delle comunità di Firenze, Giovanni Battista Nelli, avallata dal sovrano con successivo rescritto del 14 agosto 1777, ragione per la quale essa riguarda la sola giurisdizione fiorentina, con l’unica eccezione di Portoferraio.
Il presente lavoro si sofferma in particolare sull’analisi di sette casi, Certaldo, Castelfiorentino, Fucecchio, Marradi, Montepulciano, Monte San Savino e Pontremoli, selezionati in base alla quantità di informazioni e al materiale grafico presente. Per ciascuno viene fatta una breve descrizione dell’aspetto odierno dell’edificio e vengono forniti alcuni cenni storici; successivamente si espone la vicenda relativa restauro settecentesco, ricavata dalla lettura delle fonti, ponendo particolare attenzione all’illustrazione dei progetti elaborati
Improved proteomic analysis of nuclear proteins, as exemplified by the comparison of two myelo\"id cell lines nuclear proteomes
One of the challenges of the proteomic analysis by 2D-gel is to visualize the
low abundance proteins, particularly those localized in organelles. An
additional problem with nuclear proteins lies in their strong interaction with
nuclear acids. Several experimental procedures have been tested to increase, in
the nuclear extract, the ratio of nuclear proteins compared to contaminant
proteins, and also to obtain reproducible conditions compatible with 2D-gel
electrophoresis. The NaCl procedure has been chosen. To test the interest of
this procedure, the nuclear protein expression profiles of macrophages and
dendritic cells have been compared with a proteomic approach by 2D-gel
electrophoresis. Delta 2D software and mass spectrometry analyses have allowed
pointing out some proteins of interest. We have chosen some of them, involved
in transcriptional regulation and/or chromatin structure for further
validations. The immunoblotting experiments have shown that most of observed
changes are due to post-translational modifications, thereby a exemplifying the
interest of the 2D gel approach. Finally, this approach allowed us to reach not
only high abundance nuclear proteins but also lower abundance proteins, such as
the HP1 proteins and reinforces the interest of using 2DE-gel in proteomics
because of its ability to visualize intact proteins with their modifications
La narraciĂłn como encuentro con el Otro en El Hablador de Mario Vargas LLosa
El presente texto se propone mostrar la manera en la que Vargas Llosa trata el tema histĂłrico del encuentro-desencuentro entre la cultura occidental y la cultura indĂgena en AmĂ©rica Latina. La novela cuenta el clásico intento de un personaje de convertirse en el Otro y muestra cĂłmo la Ăşnica manera para lograrlo sea la de escuchar las historias y la cosmogonia del Otro y volver a contar, re-elaborándolas, las historia escuchadas y al mismo tiempo traducir a su lenguaje narrativo la propia tradiciĂłn.The paper aims to explain the perspective from which Vargas Llosa in The Storyteller faces the historical theme of the clash-encounter between Western culture and Indian culture in Latin America. The novel tells the classic attempt of a character to become Another and shows how the only way to achieve it is to hear the stories and the cosmogony of the Other, to re-tell the story heard and at the same time to translate into the Other narrative language one's own tradition
Escapades bibliothéconomiques en Flandres et Pas-de-Calais
En deux « escapades » automnales, le groupe régional proposait à plus d’une vingtaine de participants de visiter cinq équipements récents, un SCD et quatre médiathèques de petites villes du Nord
Mitochondrial proteomics: analysis of a whole mitochondrial extract with two-dimensional electrophoresis
Mitochondria are complex organelles, and their proteomics analysis requires a
combination of techniques. The emphasis in this chapter is made first on
mitochondria preparation from cultured mammalian cells, then on the separation
of the mitochondrial proteins with two-dimensional electrophoresis (2DE),
showing some adjustment over the classical techniques to improve resolution of
the mitochondrial proteins. This covers both the protein solubilization, the
electrophoretic part per se, and the protein detection on the gels, which makes
the interface with the protein identification part relying on mass
spectrometry
A multi-method approach to radial-velocity measurement for single-object spectra
The derivation of radial velocities from large numbers of spectra that
typically result from survey work, requires automation. However, except for the
classical cases of slowly rotating late-type spectra, existing methods of
measuring Doppler shifts require fine-tuning to avoid a loss of accuracy due to
the idiosyncrasies of individual spectra. The radial velocity spectrometer
(RVS) on the Gaia mission, which will start operating very soon, prompted a new
attempt at creating a measurement pipeline to handle a wide variety of spectral
types.
The present paper describes the theoretical background on which this software
is based. However, apart from the assumption that only synthetic templates are
used, we do not rely on any of the characteristics of this instrument, so our
results should be relevant for most telescope-detector combinations.
We propose an approach based on the simultaneous use of several alternative
measurement methods, each having its own merits and drawbacks, and conveying
the spectral information in a different way, leading to different values for
the measurement. A comparison or a combination of the various results either
leads to a "best estimate" or indicates to the user that the observed spectrum
is problematic and should be analysed manually.
We selected three methods and analysed the relationships and differences
between them from a unified point of view; with each method an appropriate
estimator for the individual random error is chosen. We also develop a
procedure for tackling the problem of template mismatch in a systematic way.
Furthermore, we propose several tests for studying and comparing the
performance of the various methods as a function of the atmospheric parameters
of the observed objects. Finally, we describe a procedure for obtaining a
knowledge-based combination of the various Doppler-shift measurements.Comment: 16 pages, 4 figure
Evaluation of nonionic and zwitterionic detergents as membrane protein solubilizers in two-dimensional electrophoresis
The solubilizing power of various nonionic and zwitterionic detergents as
membrane protein solubilizers for two-dimensional electrophoresis was
investigated. Human red blood cell ghosts and Arabidopsis thaliana leaf
membrane proteins were used as model systems. Efficient detergents could be
found in each class, i.e. with oligooxyethylene, sugar or sulfobetaine polar
heads. Among the commercially available nonionic detergents, dodecyl maltoside
and decaethylene glycol mono hexadecyl ether proved most efficient. They
complement the more classical sulfobetaine detergents to widen the scope of
useful detergents for the solubilization of membrane proteins in proteomics.Comment: website publisher http://www.interscience.wiley.co
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