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Properties and Therapeutic Potentials of Adult Stem Cells from Bone Marrow Stroma (MSCs)
Published in Richard K. Burt, Alberto M. Marmont, Stem Cell Therapy for Autoimmune Disease, 2019
Stem cells or stem-like cells from multiple sources are now under investigation but much of the information on the similarities and differences among the cells is incomplete. A few distinctions, however, can be made. hMSCs are not immortal,2,64 do not express telomerase,70 and have not formed tumors after infusion into animals in extensive experiments carried out over the last 30 years.1,2 Therefore, they do not have the tumorogenic propensities of embryonic stem cells (ES),5 and other immortal cell lines. With the exception of one report suggesting rare engraftment as thymocytes in utero,20 standard preparations of MSCs have not been observed to give rise to hematopoietic cells. Therefore, they differ from CD34+ hematopoietic cells, side population (SP) hematopoietic cells (SP cells are a small homogeneous population of hematopoietic stem cells able to efflux Hoechst dye)38,72 or embryonic stem (ES) cells73 and they are not as pluripotent as ES cells. However, some of the data suggesting broad pluripotentiality of some stem cells such as neural stem cells74 must be reevaluated. As indicated by recent reports,75 the apparent plasticity observed in some experiments may be explained by cell fusion and formation of tetraploid cells. The cell fusion events are rare but can mimic cell differentiation in experiments in which stem cells are injected into embryos or blastocytes and the fused cells are then extensively amplified during development.
A Review of Tubeless Microfluidic Devices
Published in Eric Lagally, Krzysztof Iniewski, Microfluidics and Nanotechnology, 2017
Pedro J. Resto, David J. Beebe, Justin C. Williams
Another approach to studying and manipulating cells in microfluidic devices is to integrate electrodes into the devices. This contrasts with biochemical analysis, which involves assaying and staining to obtain results from an experiment. Ju et al.42 used passive pumping as the fluid actuation mechanism for an cellular electrofusion chip (Figure 9.45). Cell fusion is an important cellular process that occurs during muscle and bone cell differentiation, during embryogenesis, and during morphogenesis. Studying fusion in vitro is important for understanding the properties of cells. The advantage of using passive pumping is that it allows for the slow delivery of cells without the need for an expensive pump, and it reduces dead volume.
Entropy Generation due to Combined Natural Convection and Thermal Radiation within a Rectangular Enclosure
Published in Heat Transfer Engineering, 2018
Fadhila Hajji, Akram Mazgar, Abir Sakly, Fayçal Ben Nejma
As can be seen through the local velocity profiles of Figure 9, it is useful to mention the appearance of two symmetrical convection cells (for θ = 0 rad) with velocity values tending towards zero at the centers of the vortexes, independently of thermal radiation effect. In fact, the velocity fields are significant because of the specifications of the cold lateral walls, facilitating the fluid downward flow in the vicinities of these surfaces and contributing to cells' development. These cells are deformed and become more circular, resulting in more pronounced fluid dead zones, as reported in Figure 9a. In addition, the velocity profiles present a dominance of one convection cell as the inclination angle of the enclosure increases, inducing cell fusion. It is worth noticing that for an inclination angle of π/2, the profiles of the velocity fields doesn't dispose of any stratified flow regime. In parallel with this, and as presented in Figure 9b, the radiative effect remarkably contributes to the acceleration of the vortexes.
Effect of ultrasonic power on moisture migration and microstructure of contact ultrasound enhanced far-infrared radiation drying on taro slices
Published in Drying Technology, 2023
Yu Yang, Jinghan Zhong, Xinge Ma, Fang Li, Xiaoyan Fan, Yunhong Liu
Figure 8 illustrated the distribution of cross sectional area of taro slices dried by CUFRD at different CU powers. From the figure, we could see that the initial cross sectional area of taro cells was distributed in 100 ∼ 3000 μm2, and the cell cross sectional area was greater than 2025 μm2 only accounted for 5.59%. When CU power was 0 W, the cross sectional area of the taro cells decreased continuously with the drying process, and the distribution curve moved to the left. And at the end of drying, 84.48% of the cells with a cross sectional area was distributed in 100 ∼ 1125 μm2. When the CU power was 40 W, the cell cross sectional area exhibited a trend of increasing first and then decreasing. When the taro slices ware dried to 20 min, the cell cross sectional area was greater than 2025 μm2 accounted for 20.65%, with an increase of 15.06% over the initial period. The reason may be that the CU could cause a certain damage of the cell wall, and resulting in cell fusion to form large cells. At the later stage of drying, the cell cross sectional area decreased, but it was larger than that without ultrasound. At the end of drying, 82.44% of the cells with a cross sectional area was distributed in 100 ∼ 1425 μm2. When CU power was 80 W, the increase of cell cross sectional area was more obvious than that of 40 W. When the taro slices ware dried to 20 min, the cell cross sectional area was greater than 2025 μm2 accounted for 25%, which was 19.41% higher than the initial one. At the end of drying, 83.47% of the cells with a cross sectional area was distributed in 100 ∼ 1575 μm2.
Metal resistant rhizobia and ultrastructure of Anthyllis vulneraria nodules from zinc and lead contaminated tailing in Poland
Published in International Journal of Phytoremediation, 2018
Marzena Sujkowska-Rybkowska, Rafał Ważny
In second type of Anthyllis nodules, we also observed the rapture of the cell walls between uninfected and infected cells and the fusion of adjacent protoplasts (Figure 5G, H). These cells contained only bacteria without peribacteroid membranes and no plant organelles. This wall crack may be a result of the unequal thickening of the wall between infected and uninfected cells (Figure 5I–L). The fusion of several cells resulted in the formation of large areas occupied by bacteria (Figure 5H, K). This phenomenon may be typical of Anthyllis nodules development since similar observations were made of the control nodules (Figure 7). Moreover, to the best of our knowledge, this is the first case of cell fusion observed in nodules.