排序方式： 共有6条查询结果，搜索用时 156 毫秒
1
1.
Microfluidic devices have been established as useful platforms for cell culture for a broad range of applications, but challenges associated with controlling gradients of oxygen and other soluble factors and hemodynamic shear forces in small, confined channels have emerged. For instance, simple microfluidic constructs comprising a single cell culture compartment in a dynamic flow condition must handle tradeoffs between sustaining oxygen delivery and limiting hemodynamic shear forces imparted to the cells. These tradeoffs present significant difficulties in the culture of mesenchymal stem cells (MSCs), where shear is known to regulate signaling, proliferation, and expression. Several approaches designed to shield cells in microfluidic devices from excessive shear while maintaining sufficient oxygen concentrations and transport have been reported. Here we present the relationship between oxygen transport and shear in a "membrane bilayer" microfluidic device, in which soluble factors are delivered to a cell population by means of flow through a proximate channel separated from the culture channel by a membrane. We present an analytical model that describes the characteristics of this device and its ability to independently modulate oxygen delivery and hemodynamic shear imparted to the cultured cells. This bilayer configuration provides a more uniform oxygen concentration profile that is possible in a single-channel system, and it enables independent tuning of oxygen transport and shear parameters to meet requirements for MSCs and other cells known to be sensitive to hemodynamic shear stresses. 相似文献
2.
Epshteyn AA Maher S Taylor AJ Holton AB Borenstein JT Cuiffi JD 《Biomicrofluidics》2011,5(4):46501-465016
The design and fabrication of a membrane-integrated microfluidic cell culture device (five layers,≤500 μm total thickness) developed for high resolution microscopy is reported here. The multi-layer device was constructed to enable membrane separated cell culture for tissue mimetic in vitro model applications and pharmacodynamic evaluation studies. The microdevice was developed via a unique combination of low profile fluidic interconnect design, substrate transfer methodology, and wet silane bonding. To demonstrate the unique high resolution imaging capability of this device, we used oil immersion microscopy to image stained nuclei and mitochondria in primary hepatocytes adhered to the incorporated membrane 相似文献
3.
JT.O'Donnell 《海外英语》2008,(11):30-31
Never before have Americans been as responsible for keeping themselves skilled and employable as they are today.I tell people to expect to have as many as nine different careers in their lifetime,with an average of three jobs in every one.…… 相似文献
4.
Jason Borenstein 《Science & Education》2008,17(8-9):999-1010
5.
As we near a time when robots may serve a vital function by becoming caregivers, it is important to examine the ethical implications
of this development. By applying the capabilities approach as a guide to both the design and use of robot caregivers, we hope
that this will maximize opportunities to preserve or expand freedom for care recipients. We think the use of the capabilities
approach will be especially valuable for improving the ability of impaired persons to interface more effectively with their
physical and social environments. 相似文献
6.
1