15,316 research outputs found
A Credit Risk Model To Develop The Credit Insurance Market
The globalization of the markets, as well as the deregulation of the economies, are world-wide tendencies that have created the necessity for the institutions to count on tools that collaborate in the identification, measurement and control of the risks in which they are exposed. It is necessary that all kind of companies be able to identify generic risks and to assure they count with the appropriate measurement systems that allow them to conceptualize, to quantify and to measure credit risks. This investigation has as main goals: to propose a credit risk model for Mexico and all Latin America that allow entrepreneurs of medium and large sized companies to measure and control their credit risk position; an alternative goal would be to propose some tools that can be used to make this kind of risks less damaging
Dipole formation at metal/PTCDA interfaces: Role of the Charge Neutrality Level
The formation of a metal/PTCDA (3, 4, 9, 10-perylenetetracarboxylic
dianhydride) interface barrier is analyzed using weak-chemisorption theory. The
electronic structure of the uncoupled PTCDA molecule and of the metal surface
is calculated. Then, the induced density of interface states is obtained as a
function of these two electronic structures and the interaction between both
systems. This induced density of states is found to be large enough (even if
the metal/PTCDA interaction is weak) for the definition of a Charge Neutrality
Level for PTCDA, located 2.45 eV above the highest occupied molecular orbital.
We conclude that the metal/PTCDA interface molecular level alignment is due to
the electrostatic dipole created by the charge transfer between the two solids.Comment: 6 page
Design and construction of a compact rotary substrate heater for deposition systems
We have designed and constructed a compact rotary substrate heater for the
temperature range from 25 C to 700 C. The heater can be
implemented in any deposition system where crystalline samples are needed. Its
main function is to provide a heat treatment in situ during film growth. The
temperature is monitored and controlled by a temperature controller coupled to
a type K thermocouple. A heater case was designed to host a resistive element
and at the same time to allow the substrate holder to freely rotate. Rotation
is crucial not only for film homogeneity during deposition but also for the
elimination of temperature gradients on the substrate holder. To tolerate
oxidizing and corrosive environments, the instrument was made of stainless
steel which also works as "coolant" taking advantage of heat dissipation. The
instrument performs well for long periods of time with stable temperatures. We
hope that this project is useful for laboratories wishing to have a compact
rotary heater that meets the requirements for crystal growth and film
homogeneity.Comment: 7 pages, 8 figure
RedLabRA; a Spanish Network of Microbiology Laboratories for the Surveillance of Antibiotic Resistant Microorganisms
Factor de impacto: 1,553 Q4There is an urgent need to control the clinical and public health impact that antibiotic resistance (AR) causes worldwide. Any measure for its control must be based on an up-to-date and comprehensive knowledge of the situation. However, it is difficult to determine the current dimension of AR because a large part of the available information is based on heterogeneous, insufficiently unified and retrospective data. The integration of genomic information in the surveillance of AR is another important factor for improvement. The Spanish Network of Laboratories for the Surveillance of Resistant Microorganisms (RedLabRA) is a structured network of interconnected microbiology laboratories developed within the Spanish National Plan against Antibiotic Resistance. Its main objective is to support the diagnosis of resistance to antibiotics, integrating molecular characterization in the surveillance.S
Regulation of tumor angiogenesis by the crosstalk between innate immunity and endothelial cells
Endothelial cells and immune cells are major regulators of cancer progression and prognosis. Endothelial cell proliferation and angiogenesis are required for providing nutrients and oxygen to the nascent tumor and infiltration of immune cells to the tumor is dependent on endothelial cell activation. Myeloid cells and innate lymphocytes have an important role in shaping the tumor microenvironment by crosstalking with cancer cells and structural cells, including endothelial cells. Innate immune cells can modulate the activation and functions of tumor endothelial cells, and, in turn, endothelial cell expression of adhesion molecules can affect immune cell extravasation. However, the mechanisms underlying this bidirectional crosstalk are not fully understood. In this review, we will provide an overview of the current knowledge on the pathways regulating the crosstalk between innate immune cells and endothelial cells during tumor progression and discuss their potential contribution to the development of novel anti-tumor therapeutic approaches
Ultra Low-Power Analog Median Filters
The design and implementation of three analog median filter topologies, whose transistors operate in the deep weak-inversion region, is described. The first topology is a differential pairs array, in which drain currents are driven into two nodes in a differential fashion, while the second topology is based on a wide range OTA, which is used to maximize the dynamic range. Finally, the third topology uses three range-extended OTAs. The proposed weak-inversion filters were designed and fabricated in ON Semiconductor 0.5 micrometer technology through MOSIS. Experimental results of three-input fabricated prototypes for all three topologies are show, where power consumptions of 90nW in the first case, and 270nW in the other two cases can be noticed. A dual power supply +/-1.5 Volts were used
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