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Lee K Kim C Young Yang J Lee H Ahn B Xu L Yoon Kang J Oh KW 《Biomicrofluidics》2012,6(1):14114-141147
We propose a simple method for forming massive and uniform three-dimensional (3-D) cell spheroids in a multi-level structured microfluidic device by gravitational force. The concept of orienting the device vertically has allowed spheroid formation, long-term perfusion, and retrieval of the cultured spheroids by user-friendly standard pipetting. We have successfully formed, perfused, and retrieved uniform, size-controllable, well-conditioned spheroids of human embryonic kidney 293 cells (HEK 293) in the gravity-oriented microfluidic device. We expect the proposed method will be a useful tool to study in-vitro 3-D cell models for the proliferation, differentiation, and metabolism of embryoid bodies or tumours. 相似文献
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Shen B Reinhart-Lee T Janisse H Brogan K Danford C Jen KL 《Research quarterly for exercise and sport》2012,83(2):168-174
The purpose of this study was to describe the physical activity levels of urban inner city preschoolers while attending Head Start, the federally funded preschool program for children from low-income families. Participants were 158 African American children. Their physical activity during Head Start days was measured using programmed RT-3 accelerometers. Results revealed that the children spent the most time in sedentary and light physical activity, while their participation in moderate-to-vigorous physical activities was low. Given the sedentary class format and limited physical space for the Head Start programs observed, we suggest adding a structured physical activity component to Head Start schools to fight the overweight and obesity crisis. 相似文献
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A new distributed fusion receding horizon filtering problem is investigated for uncertain linear stochastic systems with time-delay sensors. First, we construct a local receding horizon Kalman filter having time delays (LRHKFTDs) in both the system and measurement models. The key technique is the derivation of recursive error cross-covariance equations between LRHKFTDs in order to compute the optimal matrix fusion weights. It is the first time to present distributed fusion receding horizon filter for linear discrete-time systems with delayed sensors. It has a parallel structure that enables processing of multisensory time-delay measurements, so the calculation burden can be reduced and it is more reliable than the centralized version if some sensors turn faulty. Simulations for a multiple time-delays system show the effectiveness of the proposed filter in comparison with centralized receding horizon filter and non-receding versions. 相似文献
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Su Ye Sohn Gi Young Jang Byung Min Choi 《Journal of Zhejiang University. Science. B》2010,11(7):539-541
Congenital atresia of the left main coronary artery is a rare occurrence, and surgical revascularizationbypass graft is required.
We here report a rare case of congenital coronary anomaly in an infant. A 10-month-old male infant was admitted to the hospital
with heart failure symptoms. Echocardiographic examinations revealed mitral valve regurgitation and ischemic changes of the
anterolateral papillary muscle and chordae. Coronary angiography showed atresia of the left main coronary artery with a severe
hypoplastic left anterior descending artery and a circumflex coronary artery. Unfortunately, sudden cardiac arrest occurred
after catheterization and the infant did not recover despite of immediate cardiopulmonary resuscitation. Further studies are
needed to find a newer diagnostic method to detect coronary anomaly in an infant, and coronary angiography, if necessary,
has to be performed very carefully. 相似文献
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