183 research outputs found

    On the global well-posedness of 3D inhomogeneous incompressible Navier-Stokes system with density-dependent viscosity

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    In this paper, we are concerned with the global well-posedness of 3D inhomogeneous incompressible Navier-Stokes equations with density-dependent viscosity when the initial velocity is sufficiently small in the critical Besov space B˙12\dot{B}^{\frac 12}. Compared with the previous result of Abidi and Zhang (Science China Mathematics 58 (6) (2015) 1129-1150), we remove the smallness assumption of the viscosity μ(ρ0)1\mu(\rho_0)-1 in LL^{\infty}-norm.Comment: 36 page

    Global well-posedness of 3D inhomogenous incompressible Navier-Stokes equations with density-dependent viscosity

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    The issue of global well-posedness for the 3D inhomogenous incompressible Navier-Stokes equations was first addressed by Kazhikov in 1974. In this manuscript, we obtain its global well-posedness for the system with density-dependent viscosity under the smallness assumption of initial velocity in the critical space B˙p,11+3p\dot{B}_{p,1}^{-1+\frac 3p} with p]1,9/2]p\in ]1, 9/2]. To the best of our knowledge, this is the first result about the global well-posedness for which one does not assume any smallness condition on the density when the initial density is far away from vacuum.Comment: 39 Pages. arXiv admin note: substantial text overlap with arXiv:2401.0985

    Vanishing Porosity Limit of the Coupled Stokes-Brinkman System

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    We investigate the small porosity asymptotic behavior of the coupled Stokes-Brinkman system in the presence of a curved interface between the Stokes region and the Brinkman region. in particular, we derive a set of approximate solutions, validated via rigorous analysis, to the coupled Stokes-Brinkman system. of particular interest is that the approximate solution satisfies a generalized Beavers-Joseph-Saffman-Jones interface condition (1.9) with the constant of proportionality independent of the curvature of the interface

    The Relationship between Nursing Home Quality of Care and Potentially Preventable Hospitalization

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    University of Minnesota Ph.D. dissertation.July 2016. Major: Health Services Research, Policy and Administration. Advisor: Robert Kane. 1 computer file (PDF); v, 84 pages.Hospitalizations are very common among nursing home (NH) residents. Unfortunately many of these are deemed inappropriate or preventable. There is great variation in rates of potentially preventable hospitalization (PPH) across NHs beyond what can be explained by resident heterogeneity. Little is known about how NH quality of care is related to hospitalization, especially PPH. The purpose of this study was to examine the relationship between available quality indicators (QIs) and hospitalization and PPH among Medicaid beneficiaries aged 65 years and older receiving care at NHs in Minnesota. Twenty three risk-adjusted QIs were used to assess NH quality of care. Quality indicators and other facility-level variables from the Minnesota Nursing Home Report Card were merged with resident level variables from the Minimum Data Set. This merged data was linked with Medicaid claims to obtain the hospitalization information during the 2011 to 2012 period. Adjusted analyses controlled for resident and facility characteristics using the Generalized Linear Mixed Model. The results showed that about 44% of hospitalizations were PPHs. Available QIs were not strongly or consistently associated with the risk of hospitalization (neither overall nor PPH). Among these 23 QIs, only 6 QIs were related to hospitalization or death and only 4 were related to PPH. Most QIs did not capture the aspects of quality that directly related to hospitalization. Quality indicators and hospitalizations may tap different aspects of NH quality. Quality reform efforts based on improving performance on QIs may fail to result in large-scale reductions in hospitalization

    MiR-196a-5p facilitates progression of estrogen-dependent endometrial cancer by regulating FOXO1

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    Background and Purpose. Estrogen-dependent endometrial cancer mainly occurs in younger pre-menopausal and post-menopausal women and threatens their health. Recently, microRNAs (miRNAs) have been considered as novel targets in endometrial cancer treatment. Therefore, we aimed to explore the effect of miRNA (miR)-196a-5p in estrogen-dependent endometrial cancer. Methods. 17β-estradiol (E2; 2.5, 5, 10 and 20 nM) was used to treat RL95-2, HEC-1B and ECC-1 cells followed by cell viability assessment using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). The level of miR-196a-5p was measured by reverse transcription-quantitative PCR (RT-qPCR). We then transfected miR-196a-5p mimic/inhibitor and Forkhead box protein O1 (FOXO1) small interfering RNA (siRNA) into E2-treated cells. Apoptotic cells were measured by flow cytometry. Wound healing and Transwell assays were implemented to assess migration and invasion. Bioinformatics and luciferase reporter assays were applied to confirm the interaction between miR-196a-5p and FOXO1. Immunoblotting determined the levels of FOXO1, Bcl-2, Bax, Caspase 3. Results. E2 promoted cell viability and miR-196a-5p expression in RL95-2 and ECC-1 cells. miR-196a-5p mimic enhanced cell viability, migration and invasion but suppressed apoptosis and FOXO1, whilst miR-196a-5p inhibitor blocked these processes. In addition, miR-196a-5p upregulated Bcl-2, but down regulated Bax and Caspase 3 expression, an effect that was reversed by miR-196a-5p inhibitor. We determined that miR-196a-5p targeted FOXO1, and that si-FOXO1 blocked the effects of miR-196a-5p inhibitor on viability, apoptosis, migration and invasion of E2-treated RL95-2 and ECC-1 cells. Conclusions. Our findings suggested potential diagnostic and therapeutic applications for miR-196a-5p and its FOXO1 target in patients suffering from estrogen-dependent endometrial cancer

    Separation of the bacterial species, Escherichia coli, from mixed-species microbial communities for transcriptome analysis

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    Abstract Background The study of bacterial species interactions in a mixed-species community can be facilitated by transcriptome analysis of one species in the community using cDNA microarray technology. However, current applications of microarrays are mostly limited to single species studies. The purpose of this study is to develop a method to separate one species, Escherichia coli as an example, from mixed-species communities for transcriptome analysis. Results E. coli cells were separated from a dual-species (E. coli and Stenotrophomonas maltophilia) community using immuno-magnetic separation (IMS). High recovery rates of E. coli were achieved. The purity of E. coli cells was as high as 95.0% separated from suspended mixtures consisting of 1.1 - 71.3% E. coli, and as high as 96.0% separated from biofilms with 8.1% E. coli cells. Biofilms were pre-dispersed into single-cell suspensions. The reagent RNAlater (Ambion, Austin, TX) was used during biofilm dispersion and IMS to preserve the transcriptome of E. coli. A microarray study and quantitative PCR confirmed that very few E. coli genes (only about eight out of 4,289 ORFs) exhibited a significant change in expression during dispersion and separation, indicating that transcriptional profiles of E. coli were well preserved. Conclusions A method based on immuno-magnetic separation (IMS) and application of RNAlater was developed to separate a bacterial species, E. coli as an example, from mixed-species communities while preserving its transcriptome. The method combined with cDNA microarray analysis should be very useful to study species interactions in mixed-species communities.http://deepblue.lib.umich.edu/bitstream/2027.42/112838/1/12866_2011_Article_1346.pd
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