1,831 research outputs found
Characterisation of Hybrid Pixel Detectors with capacitive charge division
In order to fully exploit the physics potential of the future high energy e+
e- linear collider, a Vertex Tracker providing high resolution track
reconstruction is required. Hybrid pixel sensors are an attractive technology
due to their fast read-out capabilities and radiation hardness. A novel pixel
detector layout with interleaved cells between the readout nodes has been
developed to improve the single point resolution. The results of the
characterisation of the first processed prototypes are reported.Comment: 5 pages, 2 figures, presented at LCWS2000, Linear Collider Workshop,
October 24-28 2000, Fermi National Accelerator Laboratory, Batavia, Illinois,
U.S.A. Proceedings to be published by the American Institute of Physic
Hybrid Pixel Detector Development for the Linear Collider Vertex Tracker
In order to fully exploit the physics potential of the future high energy
e+e- linear collider, a Vertex Tracker able to provide particle track
extrapolation with very high resolution is needed. Hybrid Si pixel sensors are
an attractive technology due to their fast read-out capabilities and radiation
hardness. A novel pixel detector layout with interleaved cells has been
developed to improve the single point resolution. Results of the
characterisation of the first processed prototypes by electrostatic
measurements and charge collection studies are discussed.Comment: 5 pages, 1 figure, to appear in the Proceedings of the 9th Int.
Workshop on Vertex Detectors, Lake Michigan MI (USA), September~200
A Pixel Vertex Tracker for the TESLA Detector
In order to fully exploit the physics potential of a e+e- linear collider,
such as TESLA, a Vertex Tracker providing high resolution track reconstruction
is required. Hybrid Silicon pixel sensors are an attractive sensor technology
option due to their read-out speed and radiation hardness, favoured in the high
rate TESLA environment, but have been so far limited by the achievable single
point space resolution. A novel layout of pixel detectors with interleaved
cells to improve their spatial resolution is introduced and the results of the
characterisation of a first set of test structures are discussed. In this note,
a conceptual design of the TESLA Vertex Tracker, based on hybrid pixel sensors
is presentedComment: 20 pages, 11 figure
High resolution pixel detectors for e+e- linear colliders
The physics goals at the future e+e- linear collider require high performance
vertexing and impact parameter resolution. Two possible technologies for the
vertex detector of an experimental apparatus are outlined in the paper: an
evolution of the Hybrid Pixel Sensors already used in high energy physics
experiments and a new detector concept based on the monolithic CMOS sensors.Comment: 8 pages, to appear on the Proceedings of the International Workshop
on Linear Colliders LCWS99, Sitges (Spain), April 28 - May 5, 199
Photo-Organocatalysis, Photo-Redox, and Electro- Organocatalysis Processes
The research involving photo-organocatalysis, photoredox, and electro-organocatalysis processes is revised in this chapter. Modern synthetic processes enable the formation of large arrays of organic molecules with precise control over their three-dimensional structure, which is important in a variety of fields ranging from pharmaceutical to materials science. Photochemical reactions may have a substantial impact on these fields by affording direct access to specific structural motifs that are difficult to construct otherwise. The conjugate structural feature shown by most of the photo-organocatalysts seems to enable the production of free radicals or radical ions in an easy fashion. Electro-organocatalysis has also received recent interest from both academia and industry. In this chapter, we mainly review recent remarkable advancements in organocatalysis involving photo-, photoredox, and electrochemical processes with particular emphasis on asymmetric protocols
Recent advances of metallocenes for medicinal chemistry
This work was supported by LAQV-REQUIMTE; Fundacao para a Ciencia e Tecnologia (FCT, Portugal), through projects and the IF researcher consolidator contract (IF/0041/2013/CP1161/CT005), and Solchemar Company.Background: The recent advances for the synthesis and application of different metallocenes for Medicinal Chemistry is reviewed. Objective: This manuscript presents the different metallocene scaffolds, with special emphasis on ferrocene derivatives, and their potential pharmaceutical application. Over the last years, the synthesis of new metallocene compounds and their biological and medicinal effects against some types of diseases (e.g. anti-tumoral, antibiotics, anti-viral) have been reported. From the medicinal point of view, the attractive properties of metallocene derivatives, such as their high stability, low toxicity and appealing redox behaviors are particularly relevant. Results: This area has attracted many researchers as well as the pharmaceutical industry due to the promising results of some metallocenes, in particular ferrocene compounds, in breast cancer and malaria.authorsversionpublishe
Hybrid pixel detector development for the Linear collider Vertex Detector
In order to fully exploit the Physics potential of future e+ e- linear
collider, a Vertex Detector providing high resolution track reconstruction is
required. Hybrid Silicon pixel detectors are an attractive option for the
sensor technology due to their read-out speed and radiation hardness but have
been so far limited by the achievable single point resolution. A novel layout
of hybrid pixel sensor with interleaved cells to improve the spatial resolution
has been developed. The characterisation of the first processed prototypes is
reported.Comment: 5 pages, 5 figures. Presented at the IEEE Nuclear Science Symposium
and Medical Imaging Conference, October 15-20 2000, Lyon, Franc
High Resolution Hybrid Pixel Sensors for the e+e- TESLA Linear Collider Vertex Tracker
In order to fully exploit the physics potential of a future high energy e+e-
linear collider, a Vertex Tracker, providing high resolution track
reconstruction, is required. Hybrid Silicon pixel sensors are an attractive
option, for the sensor technology, due to their read-out speed and radiation
hardness, favoured in the high rate environment of the TESLA e+e- linear
collider design but have been so far limited by the achievable single point
space resolution. In this paper, a conceptual design of the TESLA Vertex
Tracker, based on a novel layout of hybrid pixel sensors with interleaved cells
to improve their spatial resolution, is presented.Comment: 12 pages, 5 figures, to appear in the Proceedings of the Vertex99
Workshop, Texel (The Netherlands), June 199
Analysis of the unique structural and physicochemical properties of the DraD/AfaD invasin in the context of its belonging to the family of chaperone/usher type fimbrial subunits
<p>Abstract</p> <p>Background</p> <p>DraD invasin encoded by the dra operon possesses a classical structure characteristic to fimbrial subunits of the chaperone/usher type. The Ig-fold of the DraD possesses two major characteristics distinguishing it from the family of fimbrial subunits: 1) a distortion of the β-barrel structure in the region of the acceptor cleft, demonstrated by a disturbance of the main-chain hydrogen bonds network, and 2) an unusually located disulfide bond connecting B and F strands - the localization exclusively observed in the subfamily of DraD/AfaD-type subunits.</p> <p>Results</p> <p>To evaluate the influence of the DraD-sc specific structural features on its stability and mechanism of thermal denaturation, a series of DSC and FT-IR denaturation experiments were performed giving following conclusions. 1) The DraD-sc is characterized by a low stability (standard Gibbs free energy and enthalpy of unfolding of 18.4 ±1.4 kJ mol<sup>-1 </sup>and 131 ±25 kJ mol<sup>-1</sup>, respectively) that contrasts strongly with almost infinite stability of the described previously DraE-sc fimbrial protein. 2) The DraD-sc unfolds thermally according to the two state equilibrium model, in contrast to the irreversible kinetically controlled transition of the DraE-sc. 3) The DraD specific disulfide bond is crucial at the folding stage and has little stability effect in the mature protein.</p> <p>Conclusions</p> <p>Data published so far emphasize unique biological properties of the DraD invasin as fimbrial subunit: a chaperone independent folding, an usher independent surface localization and the possibility to exist in two forms: as unbound subunits and as loosely bound at fimbrial tip.</p> <p>Presented calorimetric and FT-IR stability data combined with structural correlations has underlined that the DraD invasin is also characterized by unique physicochemical and structural attributes in the context of its belonging to the family of fimbrial subunits.</p
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