<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet type="text/xsl" href="static/style.xsl"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-09-19T16:23:30Z</responseDate><request verb="GetRecord" identifier="oai:dspace.mit.edu:1721.1/81140" metadataPrefix="dim">https://dspace.mit.edu/server/oai/request</request><GetRecord><record><header><identifier>oai:dspace.mit.edu:1721.1/81140</identifier><datestamp>2022-01-13T07:55:22Z</datestamp><setSpec>com_1721.1_7582</setSpec><setSpec>com_1721.1_7581</setSpec><setSpec>col_1721.1_131024</setSpec></header><metadata><dim:dim xmlns:dim="http://www.dspace.org/xmlns/dspace/dim" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:doc="http://www.lyncode.com/xoai" xsi:schemaLocation="http://www.dspace.org/xmlns/dspace/dim http://www.dspace.org/schema/dim.xsd">
   <dim:field mdschema="dc" element="contributor" qualifier="advisor" lang="en_US">Michael Cima.</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="author" lang="en_US">Cochran, Alicia (Alicia M.)</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="other" lang="en_US">Massachusetts Institute of Technology. Department of Materials Science and Engineering.</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="department">Massachusetts Institute of Technology. Department of Materials Science and Engineering</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="accessioned">2013-09-24T19:45:26Z</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="available">2013-09-24T19:45:26Z</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="copyright" lang="en_US">2013</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="issued" lang="en_US">2013</dim:field>
   <dim:field mdschema="dc" element="identifier" qualifier="uri">http://hdl.handle.net/1721.1/81140</dim:field>
   <dim:field mdschema="dc" element="identifier" qualifier="oclc" lang="en_US">858281935</dim:field>
   <dim:field mdschema="dc" element="description" lang="en_US">Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2013.</dim:field>
   <dim:field mdschema="dc" element="description" lang="en_US">Cataloged from PDF version of thesis.</dim:field>
   <dim:field mdschema="dc" element="description" lang="en_US">Includes bibliographical references (p. 22).</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="abstract" lang="en_US">Knowledge of the oxygen levels in a tumor is a current goal of cancer research due to the importance of hypoxia on tumor growth and treatment. Previous work by the Cima group at MIT has shown that an oxygen sensor made from low molecular weight siloxanes (LMWS) in a PDMS matrix can be implanted during a biopsy and effectively measure oxygen levels in rat tumors with MRI. The Cima group also found that the sensors experienced signal loss over time when stored in air. The purpose of this investigation was to explore the loss of signal over time of the sensor when stored in aqueous solution. The signal reduction over time in environments similar to the body could be approximated by measuring the spin-lattice relaxation times of the sensor in various aqueous solutions. It was hypothesized that diffusion of the LMWS from the sensor to the surrounding environment was the potential cause of the signal loss over time, so the amount of LMWS that escaped into aqueous solution was investigated.</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="statementofresponsibility" lang="en_US">by Alicia Cochran.</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="degree" lang="en_US">S.B.</dim:field>
   <dim:field mdschema="dc" element="format" qualifier="extent" lang="en_US">22 p.</dim:field>
   <dim:field mdschema="dc" element="language" qualifier="iso" lang="en_US">eng</dim:field>
   <dim:field mdschema="dc" element="publisher" lang="en_US">Massachusetts Institute of Technology</dim:field>
   <dim:field mdschema="dc" element="rights" lang="en_US">M.I.T. theses are protected by 
copyright. They may be viewed from this source for any purpose, but 
reproduction or distribution in any format is prohibited without written 
permission. See provided URL for inquiries about permission.</dim:field>
   <dim:field mdschema="dc" element="rights" qualifier="uri" lang="en_US">http://dspace.mit.edu/handle/1721.1/7582</dim:field>
   <dim:field mdschema="dc" element="subject" lang="en_US">Materials Science and Engineering.</dim:field>
   <dim:field mdschema="dc" element="title" lang="en_US">Investigating escape of low MW siloxanes from PDMS matrix in aqueous solution</dim:field>
   <dim:field mdschema="dc" element="title" qualifier="alternative" lang="en_US">Investigating escape of low molecular weight siloxanes from polydimethylsiloxane matrix in aqueous solution</dim:field>
   <dim:field mdschema="dc" element="type" lang="en_US">Thesis</dim:field>
   <dim:field mdschema="dc" element="format" qualifier="mimetype">application/pdf</dim:field>
   <dim:field mdschema="dspace" element="authorsordered">false</dim:field>
   <dim:field mdschema="dspace" element="entity" qualifier="type">Publication</dim:field>
   <dim:field mdschema="others" element="access-status">unknown</dim:field>
   <dim:field mdschema="others" element="access-status">unknown</dim:field>
   <dim:field mdschema="cerif" element="openaire" authority="" confidence="-1">&lt;Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="88db9249-855f-4995-a934-5cfd1e6c5827">
	&lt;Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843&lt;/Type>
	&lt;Language>eng&lt;/Language>
   	&lt;Title>Investigating escape of low MW siloxanes from PDMS matrix in aqueous solution&lt;/Title>
   	&lt;Subtitle>Investigating escape of low molecular weight siloxanes from polydimethylsiloxane matrix in aqueous solution&lt;/Subtitle>
   	&lt;PublishedIn>
    	&lt;Publication>
      	&lt;/Publication>
   	&lt;/PublishedIn>
   	&lt;PublicationDate>2013&lt;/PublicationDate>
   	&lt;Authors>
      	&lt;Author>
        	&lt;DisplayName>Cochran, Alicia (Alicia M.)&lt;/DisplayName>
         	&lt;Affiliation>
         		&lt;OrgUnit>
         		&lt;/OrgUnit>
         	&lt;/Affiliation>
      	&lt;/Author>
	&lt;/Authors>
   	&lt;Editors>
	&lt;/Editors>
    &lt;Publishers>
        &lt;Publisher>
            &lt;DisplayName>Massachusetts Institute of Technology&lt;/DisplayName>
            &lt;OrgUnit />
        &lt;/Publisher>
    &lt;/Publishers>
    &lt;License>http://dspace.mit.edu/handle/1721.1/7582&lt;/License>
    &lt;Keyword>Materials Science and Engineering.&lt;/Keyword>
   	&lt;Abstract>Knowledge of the oxygen levels in a tumor is a current goal of cancer research due to the importance of hypoxia on tumor growth and treatment. Previous work by the Cima group at MIT has shown that an oxygen sensor made from low molecular weight siloxanes (LMWS) in a PDMS matrix can be implanted during a biopsy and effectively measure oxygen levels in rat tumors with MRI. The Cima group also found that the sensors experienced signal loss over time when stored in air. The purpose of this investigation was to explore the loss of signal over time of the sensor when stored in aqueous solution. The signal reduction over time in environments similar to the body could be approximated by measuring the spin-lattice relaxation times of the sensor in various aqueous solutions. It was hypothesized that diffusion of the LMWS from the sensor to the surrounding environment was the potential cause of the signal loss over time, so the amount of LMWS that escaped into aqueous solution was investigated.&lt;/Abstract>
	&lt;Access xmlns="http://purl.org/coar/access_right" 
    >
    &lt;/Access>
&lt;/Publication>
</dim:field>
</dim:dim>
</metadata></record></GetRecord></OAI-PMH>