ABSTRACT
【Objective】 To study the effect of air inlet modes on the temperature variation, fluctuation, uniformity and coefficient of variation(CV), so as to evaluate the stability and uniformity of the temperature field in refrigerated warehouse for blood. 【Methods】 The temperature changes of blood refrigerated warehouse under different modes of air inlet during compressor operation were analyzed. The stability of the temperature field in the storehouse was evaluated by the changes, fluctuation, uniformity, CV and deviation of temperature at each testing point. 【Results】 The average value of temperature in the storehouse, adopting air inlet via straight blow, was (4.98±0.92)℃, while that of air inlet via micro-hole mode was(4.15±0.25)℃, with significant differences between each other(P<0.05). As to the CV of temperature, air inlet via straight blow was significantly different from that via micro hole(P<0.01). The fluctuation, uniformity and deviation of temperature created by straight blow and micro hole were 1.85±1.11 vs 0.49±0.38, 1.00±0.68 vs 0.47±0.37, and 0.61±0.45 vs 0.27±0.21, respectively, with significant differences between each other(P<0.01). 【Conclusion】 Compared with straight blow, the mean temperature created by micro hole was closer to the median value (4℃) of the temperature range, i. e.(4±2)℃, during blood storage. Otherwise, micro hole demonstrated a smaller CV of temperature, and superior performance in fluctuation, uniformity and deviation of the temperature at the testing points, which was conducive to ensure the stability of storehouse temperature field.
ABSTRACT
AIM:Long bone growth plate injury induced by wound and infection may cause limb reduction or angular deformity. Tissue engineering provides a promising treatment of growth plate injuries. In this study,we investigated the feasibility of establishing tissue-engineered growth-plate by allograft demineralized bone matrix(DBM) co-cultured with rabbit iliac growth-plate cells. METHODS:The experiment was performed at Department of Orthopaedics,Fourth Military Medical University of Chinese PLA from June 2005 to June 2006. ①Two 3-week-old New Zealand rabbits irrespective of gender(clean grade,2.0-2.5 kg) were selected. Growth plate cells were harvested from iliac crest epiphyseal cartilage of the rabbits by dissection and digestion with type Ⅱ collagenase. The third passage cells cultured were collected and incubated on allograft demineralized bone matrix. ② Histology,immunohistochemical staining and electronic scanning microscope(SEM) examinations were performed to observe cell growth on DBM 24 hours,7,14 and 21 days after culture. RESULTS:①Growth plate chondrocytes exhibited polygonal in monolayer culture,and immunohistochemical staining for type Ⅱ collagen was positive. ②SEM examination showed that twenty-four hours after coculture,the cells adhered to DBM scaffolds;Seven days after culture,the growth-plate chondrocytes rapidly proliferated and began to secret extracellular matrix;cells covered the whole scaffold and became overlapped on the 21st day. ③HE staining showed after 14 days of culture,growth plate cells adhered DBM scaffold in spherical shape with abundant cytoplasm. CONCLUSION:Tissue-engineered growth-plate is successfully constructed by allograft mineralized bone matrix co-cultured with rabbit iliac growth-plate cells.
ABSTRACT
Objective To evaluate the effect of pressure load of avascular necrosis of the femoral head(ANFH) by percutaneous injection of polymethylmethacrylate(PMMA).Methods Models of ANFH were established in 20 adult white rabbits with 40 femoral heads which were induced by injection of hydrochloride(HCL) and hormone.DR was performed to observe the bony density of femoral head in all rabbits,the cystic degeneration and collapse of femoral head were detected in 21 femoral heads,then DSA was done to observe the blood supply and they were divided into three groups at random,group A in 5 was examined by pathology,group B in 8 was injected with PMMA and group C was as control.The test of pressure loading was performed in group B and C.Results Of 21 femoral heads with cystic degeneration and collaps,8 were in the HCL-induced group and 13 were in the hormone-induced group.DSA showed that the blood supply was decreased,and the arteria were decreased in diameter.After the percutaneous injection of PMMA,all of 8 rabbits in experimental group were successful.The distinction between the means of two samples was significant in loading test(P