MARC details
| 000 -LEADER |
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| fixed length control field |
02783nam a2200277Ia 4500 |
| 003 - CONTROL NUMBER IDENTIFIER |
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| control field |
MX-MdCICY |
| 005 - DATE AND TIME OF LATEST TRANSACTION |
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| control field |
20250625153926.0 |
| 040 ## - CATALOGING SOURCE |
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| Transcribing agency |
CICY |
| 090 ## - LOCALLY ASSIGNED LC-TYPE CALL NUMBER (OCLC); LOCAL CALL NUMBER (RLIN) |
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| Classification number (OCLC) (R) ; Classification number, CALL (RLIN) (NR) |
B-13624 |
| 008 - FIXED-LENGTH DATA ELEMENTS--GENERAL INFORMATION |
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| fixed length control field |
250602s9999 xx |||||s2 |||| ||und|d |
| 245 10 - TITLE STATEMENT |
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| Title |
Enzyme-induced biodegradation of polycarbonate-polyurethanes: Dependence on hard-segment chemistry |
| 490 0# - SERIES STATEMENT |
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| Volume/sequential designation |
J Biomed Mater Res, 57(4), p.597-611, 2001 |
| 520 3# - SUMMARY, ETC. |
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| Summary, etc. |
Polycarbonate urethanes (PCNUs)have been used as a replacement for traditional biomedical polyetherurethanes due to their reported resistance to oxidative biodegradation. However, relatively little is known about their hydrolytic stability in the presence of inflammatory derived enzymes. This has in part motivated the current study relating to the effect of hard segment chemistry and the microdomain structures generated by such chemistry, on the cholesterol esterase (CE)catalyzed hydrolysis of PCNUs. The bulk structures of the studied materials were characterized using gel permeation chromatography (GPC), differential scanning calorimetry (DSC), small-angle X-ray scattering (SAXS), Fourier transform infrared spectroscopy (FTIR)for their bulk structures, and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR)for their subsurface structures. 14C-labeled PCNUs were incubated with CE (400 units/mL), for a period of 10 weeks (pH 7.0 at 37°C), and radiolabel release was used to monitor the degradation. The results showed that all of the polymers synthesized in this study were susceptible to CE-catalyzed hydrolytic degradation, and that the extent of degradation was highly dependent on the nature of hard segment interactions within the polymer and at the surface. More specifically, the degree of phase separation and soft segment crystallinity were found to be less important in comparison to the hydrogen bonding among the carbonate and urethane linkages. The rank of the different chemical groups' susceptibility to hydrolysis was as follows: nonhydrogen bonded carbonate > nonhydrogen bonded urethane > drogen bonded carbonate > hydrogen bonded urethane. The findings suggest that the degree of hydrogen bonding, when processed into a polyurethane material could be an important parameter to consider in the design of new biostable polyurethane products. |
| 650 14 - SUBJECT ADDED ENTRY--TOPICAL TERM |
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| Topical term or geographic name entry element |
POLYURETHANES |
| 650 14 - SUBJECT ADDED ENTRY--TOPICAL TERM |
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ENZYMES |
| 650 14 - SUBJECT ADDED ENTRY--TOPICAL TERM |
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ESTERASE |
| 650 14 - SUBJECT ADDED ENTRY--TOPICAL TERM |
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| Topical term or geographic name entry element |
HARD SEGMENTS |
| 650 14 - SUBJECT ADDED ENTRY--TOPICAL TERM |
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| Topical term or geographic name entry element |
BIODEGRADATION |
| 650 14 - SUBJECT ADDED ENTRY--TOPICAL TERM |
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| Topical term or geographic name entry element |
PHASE STRUCTURE |
| 650 14 - SUBJECT ADDED ENTRY--TOPICAL TERM |
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| Topical term or geographic name entry element |
HYDROGEN BONDING |
| 700 12 - ADDED ENTRY--PERSONAL NAME |
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| Personal name |
Tang, Y. W. |
| 700 12 - ADDED ENTRY--PERSONAL NAME |
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| Personal name |
Labow, R. S. |
| 700 12 - ADDED ENTRY--PERSONAL NAME |
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| Personal name |
Santerre, J. P. |
| 856 40 - ELECTRONIC LOCATION AND ACCESS |
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| Uniform Resource Identifier |
<a href="https://drive.google.com/file/d/1p4zMyUxE9U8KuOwb1i_7KCNduBVmScAF/view?usp=drivesdk">https://drive.google.com/file/d/1p4zMyUxE9U8KuOwb1i_7KCNduBVmScAF/view?usp=drivesdk</a> |
| Public note |
Para ver el documento ingresa a Google con tu cuenta: @cicy.edu.mx |
| 942 ## - ADDED ENTRY ELEMENTS (KOHA) |
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| Source of classification or shelving scheme |
Clasificación local |
| Koha item type |
Documentos solicitados |
