290 research outputs found
A finite-difference method for the one-dimensional time-dependent schrödinger equation on unbounded domain
AbstractA finite-difference scheme is proposed for the one-dimensional time-dependent Schrödinger equation. We introduce an artificial boundary condition to reduce the original problem into an initial-boundary value problem in a finite-computational domain, and then construct a finite-difference scheme by the method of reduction of order to solve this reduced problem. This scheme has been proved to be uniquely solvable, unconditionally stable, and convergent. Some numerical examples are given to show the effectiveness of the scheme
Gender Differences in Giving Motivations for Bequest Donors and Non-Donors
This study explores gender differences in the inclusion of a charitable provision in one’s will.
We found that overall among representative samples of households polled in different regions of the U.S., gender is not a statistically significant predictor of the intent to leave a charitable bequest, after controlling for other factors, such as age, income, and marital status.Made possible by an Association of Fundraising Professionals (AFP) research grant supported by Legacy Leader
Adaptive absorbing boundary conditions for Schrodinger-type equations: application to nonlinear and multi-dimensional problems
We propose an adaptive approach in picking the wave-number parameter of
absorbing boundary conditions for Schr\"{o}dinger-type equations. Based on the
Gabor transform which captures local frequency information in the vicinity of
artificial boundaries, the parameter is determined by an energy-weighted method
and yields a quasi-optimal absorbing boundary conditions. It is shown that this
approach can minimize reflected waves even when the wave function is composed
of waves with different group velocities. We also extend the split local
absorbing boundary (SLAB) method [Z. Xu and H. Han, {\it Phys. Rev. E},
74(2006), pp. 037704] to problems in multidimensional nonlinear cases by
coupling the adaptive approach. Numerical examples of nonlinear Schr\"{o}dinger
equations in one- and two dimensions are presented to demonstrate the
properties of the discussed absorbing boundary conditions.Comment: 18 pages; 12 figures. A short movie for the 2D NLS equation with
absorbing boundary conditions can be downloaded at
http://home.ustc.edu.cn/~xuzl/movie.avi. To appear in Journal of
Computational Physic
Enterocyte STAT5 promotes mucosal wound healing via suppression of myosin light chain kinase-mediated loss of barrier function and inflammation
Epithelial myosin light chain kinase (MLCK)-dependent barrier dysfunction contributes to the pathogenesis of inflammatory bowel diseases (IBD). We reported that epithelial GM-CSF–STAT5 signalling is essential for intestinal homeostatic response to gut injury. However, mechanism, redundancy by STAT5 or cell types involved remained foggy. We here generated intestinal epithelial cell (IEC)-specific STAT5 knockout mice, these mice exhibited a delayed mucosal wound healing and dysfunctional intestinal barrier characterized by elevated levels of NF-κB activation and MLCK, and a reduction of zonula occludens expression in IECs. Deletion of MLCK restored intestinal barrier function in STAT5 knockout mice, and facilitated mucosal wound healing. Consistently, knockdown of stat5 in IEC monolayers led to increased NF-κB DNA binding to MLCK promoter, myosin light chain phosphorylation and tight junction (TJ) permeability, which were potentiated by administration of tumour necrosis factor-α (TNF-α), and prevented by concurrent NF-κB knockdown. Collectively, enterocyte STAT5 signalling protects against TJ barrier dysfunction and promotes intestinal mucosal wound healing via an interaction with NF-κB to suppress MLCK. Targeting IEC STAT5 signalling may be a novel therapeutic approach for treating intestinal barrier dysfunction in IBD
Rapid assessment of early biophysical changes in K562 cells during apoptosis determined using dielectrophoresis
Apoptosis, or programmed cell death, is a vital cellular process responsible for causing cells to self-terminate at the end of their useful life. Abrogation of this process is commonly linked to cancer, and rapid detection of apoptosis in vitro is vital to the discovery of new anti-cancer drugs. In this paper, we describe the application of the electrical phenomenon dielectrophoresis for detecting apoptosis at very early stages after drug induction, on the basis of changes in electrophysiological properties. Our studies have revealed that K562 (human myelogenous leukemia) cells show a persistent elevation in the cytoplasmic conductivity occurring as early as 30 minutes following exposure to staurosporine. This method therefore allows a far more rapid detection method than existing biochemical marker methods
An integrated software for virus community sequencing data analysis
BACKGROUND: A virus community is the spectrum of viral strains populating an infected host, which plays a key role in pathogenesis and therapy response in viral infectious diseases. However automatic and dedicated pipeline for interpreting virus community sequencing data has not been developed yet.RESULTS: We developed Quasispecies Analysis Package (QAP), an integrated software platform to address the problems associated with making biological interpretations from massive viral population sequencing data. QAP provides quantitative insight into virus ecology by first introducing the definition "virus OTU" and supports a wide range of viral community analyses and results visualizations. Various forms of QAP were developed in consideration of broader users, including a command line, a graphical user interface and a web server. Utilities of QAP were thoroughly evaluated with high-throughput sequencing data from hepatitis B virus, hepatitis C virus, influenza virus and human immunodeficiency virus, and the results showed highly accurate viral quasispecies characteristics related to biological phenotypes.CONCLUSIONS: QAP provides a complete solution for virus community high throughput sequencing data analysis, and it would facilitate the easy analysis of virus quasispecies in clinical applications.</p
The beneficial effects of curcumin supplementation on blood lipid levels among patients with metabolic related diseases in Asia area: a systematic review and meta-analysis of randomized controlled trials
ObjectivePublished studies suggest that the effects of curcumin on blood lipids in adults are controversial, and it is unclear whether there is a dose response to lipid changes following curcumin supplementation. Therefore, we conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the effects of curcumin on triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL), and high-density lipoprotein cholesterol (HDL) in the Asian populations with metabolic diseases.MethodsWe systematically searched four electronic databases, including Web of Science, PubMed, Google Scholar, and Cochrane Library, for randomized controlled trials (RCTs) of the effects of curcumin on TG, TC, LDL, and HDL in the Asian populations with metabolic diseases. Mean difference (MD) indicates effect size with combined 95% confidence interval (95% CI). Heterogeneity among studies was assessed by I2. Subgroup analyses were performed to explore potential sources of heterogeneity.ResultsEvidence from 23 RCTs for TG, 21 RCTs for TC and LDL, and 22 RCTs for HDL showed that curcumin supplementation significantly reduced TG (MD: −18.07 mg/dL, 95% CI: −30.30, −5.85, P < 0. 01), TC (MD: −13.29 mg/dL, 95% CI: −20.43, −6.16, P < 0.01), and LDL (MD: −10.44 mg/dL, 95% CI: −16.87, −4.00, P < 0.01), but no effect on HDL (MD: 1.66 mg/dL, 95% CI: −0.13, 3.44, P = 0.07). In the non-linear dose-response analysis, we observed a significant effect of curcumin supplementation dose on TG levels (P-non-linearity = 0.022).ConclusionIn conclusion, curcumin may be beneficial in reducing TG, TC, and LDL levels in the Asian populations with metabolic diseases. The dose of curcumin intervention may be an underlying factor influencing TG levels
A unified approach to split absorbing boundary conditions for nonlinear Schr\"{o}dinger equations
An efficient method is proposed for numerical solutions of nonlinear
Schr\"{o}dinger equations in an unbounded domain. Through approximating the
kinetic energy term by a one-way equation and uniting it with the potential
energy equation, absorbing boundary conditions are designed to truncate the
unbounded domain, which are in nonlinear form and can perfectly absorb the
waves outgoing from the truncated domain. We examine the stability of the
induced initial boundary value problems defined on the computational domain
with the boundary conditions by a normal mode analysis. Numerical examples are
given to illustrate the stable and tractable advantages of the method.Comment: 17 pages, 6 figures, 40 conference
Characterization of gene expression profiles in HBV-related liver fibrosis patients and identification of ITGBL1 as a key regulator of fibrogenesis
Although hepatitis B virus (HBV) infection is the leading cause of liver fibrosis (LF), the mechanisms underlying liver fibrotic progression remain unclear. Here, we investigated the gene expression profiles of HBV-related LF patients. Whole genome expression arrays were used to detect gene expression in liver biopsy samples from chronically HBV infected patients. Through integrative data analysis, we identified several pathways and key genes involved in the initiation and exacerbation of liver fibrosis. Weight gene co-expression analysis revealed that integrin subunit β-like 1 (ITGBL1) was a key regulator of fibrogenesis. Functional experiments demonstrated that ITGBL1 was an upstream regulator of LF via interactions with transforming growth factor β1. In summary, we investigated the gene expression profiles of HBV-related LF patients and identified a key regulator ITGBL1. Our findings provide a foundation for future studies of gene functions and promote the development of novel antifibrotic therapies
Human Pluripotent Stem Cell-Derived Mesenchymal Stem Cells for Oncotherapy
Mesenchymal stem/stromal cells (MSCs) with hematopoietic-supporting and immunoregulatory properties have aroused great expectations in the field of regenerative medicine and the concomitant pathogenesis. However, many obstacles still remain before the large-scale preparation of homogeneous and standardized MSCs with high cellular vitality for clinical purposes ascribe to elusive nature and biofunction of MSCs derived from various adult and fetal sources. Current progress in human pluripotent stem cells (hPSCs), including embryonic stem cells (ESCs) and induced PSCs (iPSCs), have highlighted the feasibility of MSC development and disease remodeling, together with robust MSC generation dispense from the inherent disadvantages of the aforementioned MSCs including ethical and pathogenic risks, donor heterogeneity and invasiveness. Herein, we review the state-of-the-art updates of advances for MSC preparation from hPSCs and multiple tissues (perinatal tissue, adult tissue) as well as tumor intervention with biomaterials, and thus propose a framework for MSCs-based oncotherapy in regenerative medicine. Collectively, we describe the landscape of in vitro generation and functional hierarchical organization of hPSC-MSCs, which will supply overwhelming new references for further dissecting MSC-based tissue engineering and disease remodeling
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