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781.
M. Endres M.L. Zenclussen P.A. Casalis U. Freymann S. Gil Garcia J.P. Krueger U.-W. Thomale C. Woiciechowsky C. Kaps 《Tissue & cell》2014,46(6):505-513
Disc degeneration alters disc height and mechanics of the spinal column and is associated with lower back pain. In preclinical studies gel-like materials or resorbable polymer-based implants are frequently used to rebuild the nucleus pulposus, aiming at tissue regeneration and restoration of tissue function. To compare the outcome of tissue repair, freeze-dried resorbable polyglycolic acid–hyaluronan (PGA/HA) implants without any bioactive components or bioactivated fibrin (fibrin-serum) was used in a degenerated disc disease model in New Zealand white rabbits. Animals with partial nucleotomy only served as controls. The T2-weighted/fat suppression sequence signal intensity in the nuclear region of operated discs as assessed by magnet resonance imaging was reduced in operated compared to healthy discs, indicating loss of water and did not change from week 1 to month 6 after surgery. Quantification of histological and immunohistochemical staining indicated that the implantation of PGA/HA leads to significantly more repair tissue compared to nucleotomy only. Type II collagen content of the repair tissue formed after PGA/HA or fibrin-serum treatment is significantly increased compared to controls with nucleotomy only. The data indicate that intervertebral disc augmentation after nucleotomy has a positive effect on repair tissue formation and type II collagen deposition as shown in the rabbit model. 相似文献
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The functional response ofTelenomus reynoldsi Gordh & Coker was determined at 5 constant temperatures using a dish arena. Functional response curves at all temperatures
were of Holling's Type II. Handling rate increased linearly with increasing temperature, whereas the relationship of search
rate to temperature was best described by a quadratic model. Search rate was highest at 32°C. Using Rogers' random parasite
equation, analysis of the functional response in a more complex arena containing an artificial plant provided estimates of
search and handling rates that may be more appropriate in the field environment. Search rate was 6,680 cm2/day. Handling rate was 13 hosts/day.
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Effler Steven W. Matthews David A. Perkins MaryGail Johnson David L. Peng Feng Penn Michael R. Auer Martin T. 《Hydrobiologia》2002,482(1-3):137-150
Inorganic tripton in the upper waters of Cayuga Lake, NY, is characterized, quantified and contrasted for shallow (<6 m) and deep (>100 m) water regions based on analyses with scanning electron microscopy equipped with automated image analysis and X-ray energy spectroscopy (SAX) of samples collected in 1999 and 2000. The impacts of this material on water clarity and the phosphorus (P) pool are evaluated based on paired measurements of turbidity (T
n), Secchi disc transparency (SD), chlorophyll, and four fractions of particulate P (PP) determined according to selective extraction protocols. The major components of inorganic tripton in the lake are reported to be clay minerals and quartz, received from the watershed, and calcium carbonate (CaCO3), that is produced internally. Clay minerals are the dominant component in a shallow region that receives tributary inflows. CaCO3, precipitated during a mid-summer whiting event, is reported to be the dominant component of inorganic tripton for the deep water region for a low runoff year, while clays can become dominant in these areas after prolonged intervals of high runoff. It is demonstrated that inorganic tripton, rather than phytoplankton, is the primary regulator of T
n and SD, it represents most of the PP, and is primarily responsible for the higher T
n, lower SD, and higher TP in the shallow area compared to the deep water region. Efforts to improve clarity in this shallow region of the lake should consider the feasibility of controlling the input of terrigenous suspensoids rather than reductions in P loading. 相似文献