20 research outputs found
The Elastic Deformation of Lubricated Carbon Fiber Bundles: Comparison of Theory and Experiments
On the Use of Darcy Permeability in Sheared Fabrics
Determination of a set of processing parameters for a given material type is a complex process, and much work has been done using the framework developed in the last century by Darcy. While this model, assuming Newtonian flow through a granular (essentially a smoothed, porous) medium, has produced useful flow front progression simulation tools, a commonly arising problem in the fabrication of complex components is the modeling of flow front through regions of locally high shear. Several current approaches stem from a modification of the Darcy description using "local" permeabilities for these regions, differing from the permeabilities experimentally obtained in the unsheared or undeformed state. The work presented here investigates the applicability of a transformation of the permeability in the unsheared state, and conjectures that the driving forces for the fluid flow may be sufficiently complex to merit more detailed constitutive modeling in complex fabric architectures. Experiments on sheared fabrics have been performed, and permeabilities are compared with those obtained by tensor-transformation of unsheared fabric permeabilities.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68427/2/10.1177_073168449901800507.pd
Recommended from our members
Liver Transplantation for Hepatocellular Carcinoma in the Model for End-Stage Liver Disease Era
Since March 2002, the United Network for Organ Sharing liver allocation policy has given extra priority to patients with hepatocellular carcinoma (HCC) who meet specific medical criteria. This study reviews our experience with liver transplantation for HCC under this system.
Between March 2002 and April 2009, 244 patients with HCC underwent primary liver or liver-kidney transplantation under the current allocation system at the University of Miami. Outcomes including HCC recurrence-free survival (RFS) and patient survival (PS) were assessed retrospectively. Clinical variables that predicted outcomes were analyzed.
The median time from listing to transplantation was 48 days. The median follow-up was 27.4 months, with an observed recurrence rate of 10.7%. The RFS rates at 1, 3, and 5 years after transplantation were 96.0%, 89.0%, and 83.6%, respectively. The PS rates at 1, 3, and 5 years after transplantation were 86.3%, 71.5%, and 61.7%, respectively. Among patients diagnosed with T2 HCC, a trend toward improved RFS was observed for those who received preoperative ablative therapy; PS was similar (p > 0.05). Outcomes (RFS and PS) for patients with T3 HCC were similar to those in patients with T2 HCC (p > 0.05). Patients with an alpha-fetoprotein >100 ng/mL had an RFS that was inferior to that in patients with an alpha-fetoprotein ≤100 ng/mL (p < 0.0001).
Under the current allocation system, transplantation for HCC results in excellent RFS; PS depends on factors other than HCC; the value of preoperative ablative therapy for patients with T2 HCC is uncertain; the current criteria could be expanded to include selected patients with T3 HCC; and an elevated AFP level is associated with an increased risk of HCC recurrence after transplantation
Viscous Permeability of Random Fiber Structures: Comparison of Electrical and Diffusional Estimates with Experimental and Analytical Results
Recommended from our members
Functional CRISPR dissection of gene networks controlling human regulatory T cell identity.
Human regulatory T (Treg) cells are essential for immune homeostasis. The transcription factor FOXP3 maintains Treg cell identity, yet the complete set of key transcription factors that control Treg cell gene expression remains unknown. Here, we used pooled and arrayed Cas9 ribonucleoprotein screens to identify transcription factors that regulate critical proteins in primary human Treg cells under basal and proinflammatory conditions. We then generated 54,424 single-cell transcriptomes from Treg cells subjected to genetic perturbations and cytokine stimulation, which revealed distinct gene networks individually regulated by FOXP3 and PRDM1, in addition to a network coregulated by FOXO1 and IRF4. We also discovered that HIVEP2, to our knowledge not previously implicated in Treg cell function, coregulates another gene network with SATB1 and is important for Treg cell-mediated immunosuppression. By integrating CRISPR screens and single-cell RNA-sequencing profiling, we have uncovered transcriptional regulators and downstream gene networks in human Treg cells that could be targeted for immunotherapies