Targeted Stimuli-Responsive Dextran Conjugates for Doxorubicin Delivery to Hepatocytes

A targeted, stimuli-responsive, polymeric drug delivery vehicle is being developed in our lab to help alleviate severe side-effects caused by narrow therapeutic window drugs. Targeting specific cell types or organs via proteins, specifically, lectin-mediated targeting holds potential due to the high specificity and affinity of receptor-ligand interactions, rapid internalization, and relative ease of processing. Dextran, a commercially available, biodegradable polymer has been conjugated to doxorubicin and galactosamine to target hepatocytes in a three-step, one-pot synthesis. The loading of doxorubicin and galactose on the conjugates was determined by absorbance at 485 nm and elemental analysis, respectively. Conjugation efficiency based on the amount loaded of each reactant varies from 20% to 50% for doxorubicin and from 2% to 20% for galactosamine. Doxorubicin has also been attached to dextran through an acid-labile hydrazide bond. Doxorubicin acts by intercalating with DNA in the nuclei of cells. The fluorescence of doxorubicin is quenched when it binds to DNA. This allows a fluorescence-based cell-free assay to evaluate the efficacy of the polymer conjugates where we measure the fluorescence of doxorubicin and the conjugates in increasing concentrations of calf thymus DNA. Fluorescence quenching indicates that our conjugates can bind to DNA. The degree of binding increases with polymer molecular weight and substitution of doxorubicin. In cell culture experiments with hepatocytes, the relative uptake of polymer conjugates was evaluated using flow cytometry, and the killing efficiency was determined using the MTT cell proliferation assay. We have found that conjugate uptake is much lower than that of free doxorubicin. Lower uptake of conjugates may increase the maximum dose of drug tolerated by the body. Also, non-galactosylated conjugate uptake is lower than that of the galactosylated conjugate. Microscopy indicates that doxorubicin localizes almost exclusively at the nucleus, whereas the conjugates are present throughout the cell. Doxorubicin linked to dextran through a hydrazide bond was used to achieve improved killing efficiency. Following uptake, the doxorubicin dissociates from the polymer in an endosomal compartment and diffuses to the nucleus. The LC₅₀ of covalently linked doxorubicin is 7.4 μg/mL, whereas that of hydrazide linked doxorubicin is 4.4 μg/mL.

Local WMR navigation with monocular data

This article presents recent WMR (wheeled mobile robot) navigation experiences using local perception knowledge provided by monocular and odometer systems. A local narrow perception horizon is used to plan safety trajectories towards the objective. Therefore, monocular data are proposed as a way to obtain real time local information by building two dimensional occupancy grids through a time integration of the frames. The path planning is accomplished by using attraction potential fields, while the trajectory tracking is performed by using model predictive control techniques. The results are faced to indoor situations by using the lab available platform consisting in a differential driven mobile robot

ICTINEUAUV wins the First SAUC-E competition

A pioneer team of students of the University of Girona decided to design and develop an autonomous underwater vehicle (AUV) called ICTINEU-AUV to face the Student Autonomous Underwater Challenge-Europe (SAUC-E). The prototype has evolved from the initial computer aided design (CAD) model to become an operative AUV in the short period of seven months. The open frame and modular design principles together with the compatibility with other robots previously developed at the lab have provided the main design philosophy. Hence, at the robot's core, two networked computers give access to a wide set of sensors and actuators. The Gentoo/Linux distribution was chosen as the onboard operating system. A software architecture based on a set of distributed objects with soft real time capabilities was developed and a hybrid control architecture including mission control, a behavioural layer and a robust map-based localization algorithm made ICTINEU-AUV the winning entry

A distributed environment for virtual and/or real experiments for underwater robots

This paper presents the distributed environment for virtual and/or real experiments for underwater robots (DEVRE). This environment is composed of a set of processes running on a local area network composed of three sites: 1) the onboard AUV computer; 2) a surface computer used as human-machine interface (HMI); and 3) a computer used for simulating the vehicle dynamics and representing the virtual world. The HMI can be transparently linked to the real sensors and actuators dealing with a real mission. It can also be linked with virtual sensors and virtual actuators, dealing with a virtual mission. The aim of DEVRE is to assist engineers during the software development and testing in the lab prior to real experiments

EdShare: collaboration in a University for learning and teaching

Poster for the School of Electronics and Computer Science, Learning Societies Lab Open Day, 27 February 2008 at the University of Southampton. Profile and presentation of the EdShare resource. The poster illustrates the philosophy of EdShare, how it relates to the Web 2.0 environment and its relationship to the education agenda in a University.

Postgraduate Demonstration Skills

A PowerPoint presentation used to support a skills development session for postgraduate students who wish to act as demonstrators in lab and workshop sessions.

Estrategias y políticas institucionales para captura de contenidos en la Universidad de Los Andes. Mérida-Venezuela

Primera conferencia. Bibliotecas y Repositorios Digitales: Gestión del Conocimiento, Acceso Abierto y Visibilidad Latinoamericana. (BIREDIAL) Mayo 9 al 11 de 2011. Bogotá, Colombia.

Eficacia diagnostica del ácido láctico en liquido cefalorraquídeo en meningitis postclipaje de aneurisma cerebral y hemorragia subaracnoidea

La concentración de ácido láctico en LCR en pacientes con sospecha de meningitis postquirúrgica luego de clipaje de aneurisma cerebral y hemorragia subaracnoidea espontánea se midió prospectivamente por un período de tres años. Se analizaron un total de 32 muestras de líquido cefalorraquídeo, se midió la concentración de ácido láctico y se comparó con el cultivo de LCR. Los cultivos fueron positivos en cinco pacientes, con una prevalencia de infección del 15%. Se utilizó un valor umbral de ácido láctico de 4 mmol/L. y se encontró una sensibilidad del 80%, especificidad del 52%, VPP del 23%, VPN del 93%, y likelihood ratio (LHR) positivo de 1,66 con una probabilidad post test de 15% de la concentración del ácido láctico en el diagnóstico de meningitis postquirúrgica en pacientes con hemorragia subaracnoidea aneurismática. La concentración de ácido láctico en LCR tiene un desempeño limitado en el diagnóstico de meningitis postquirúrgica en pacientes con hemorragia subaracnoidea aneurismática.

Adherencia a criterios de pertinencia de revascularización coronaria del colegio americano de cardiología, servicio de hemodinamia Fundación Cardioinfantil- Bogotá 2011

Titulo: Adherencia a criterios de pertinencia de revascularización coronaria del colegio americano de cardiología 2009, en el servicio de hemodinámica de la fundación cardioinfantil Bogotá 2011. Introducción: La enfermedad cardiovascular es la principal causa de morbimortalidad a nivel mundial, teniendo mayor prevalencia enfermedad coronaria. Existen guías especificas para el manejo de esta enfermedad sin embargo su aplicación se entorpece por factores diversos. Este estudio quiere evaluar la adherencia, en el laboratorio de hemodinamia de la Fundación Cardioinfantil, a las guías de pertinencia de intervencionismo coronario de la ACCF (American college of cardiology foundation). Objetivo General: Evaluar el nivel de adherencia a criterios de pertinencia de revascularización coronaria del colegio americano de cardiología 2009, en el servicio de hemodinámia de la fundación cardioinfantil Bogotá 2011. Métodos: Se revisaron 200 historias clínicas pacientes con diagnóstico de síndrome coronario agudo, llevados a intervención coronaria, según características de pacientes , intervención, y nivel de adherencia se clasifico la intervención como apropiada, incierta e inadecuada . Resultados: De la población analizada, el 71% (n=142) de las intervenciones fueron clasificados como apropiadas, 20% (N=40) como inapropiadas y 8,5% (n=17) como inciertas. Los desenlaces y complicaciones no tuvieron asociación estadísticamente significativa (p> 0,005) con la adherencia a los criterios de pertinencia. Conclusiones: Respecto a la literatura existente el número de intervenciones inapropiadas es mayor en la FCI, comparado con estudios practicados en América Latina y Norte América, sin embargo una adherencia del 80 %, ubica a esta institución en un adecuado nivel de adherencia.

Diode VE

Virtual Experiment of the Diode Lab for ECS students

Web Design Labs (E-assessment)

Multiple choice quizzes for each lab

E Assessment for Web Design Labs

Small quizzes designed to reinforce learning from web design labs.

How The Web Devalues Creativity

By lowering the barriers to communication, the Web has not made it possible for writers to make more money; instead large corporate aggregators are taking advantage of creators to make themselves rich. MaryAnn Johanson is the creator of one of the oldest independent film review sites on the web (flickfilosopher.com). In this lecture she addresses the problems of the long tail for the long tailees. How can a creative professional make a living through the Web, when all the power is held by the aggregators? So much for radical disintermediation... This share contains the lecture slides (see slide #29-30 for the summary of her argument), the lecture audio, further reading, a link to her web site and a critique of The Longer Tail from students at another Web Science Trust Network lab.

Transformers 2

A 44 minute introduction to the concepts of equivalent circuits, voltage regulation and per unit notation by Prof Jan Sykulski of the University of Southampton.

Transformers 3

A 36 minute covering transformer testing, use in three-phase connections and power systems by Prof Jan Sykulski of the University of Southampton.