scholarly journals Fluctuating noise drives Brownian transport

2012 ◽  
Vol 9 (77) ◽  
pp. 3554-3563 ◽  
Author(s):  
Yoshihiko Hasegawa ◽  
Masanori Arita
Keyword(s):  
Noise Intensity ◽  
Continued Fraction ◽  
Molecular Mechanisms ◽  
Time Correlation ◽  
Optimal Time ◽  
Extrinsic Noise ◽  
Maximum Current ◽  
The Matrix ◽  
Matrix Continued Fraction ◽  
Fraction Method

The transport properties of Brownian ratchet were studied in the presence of stochastic intensity noise in both overdamped and underdamped regimes. In the overdamped case, an analytical solution using the matrix-continued fraction method revealed the existence of a maximum current when the noise intensity fluctuates on intermediate timescale regions. Similar effects were observed for the underdamped case by Monte Carlo simulations. The optimal time-correlation for Brownian transport coincided with the experimentally observed time-correlation of the extrinsic noise in Escherichia coli gene expression and implied the importance of environmental noise for molecular mechanisms.

scholarly journals A Novel Regulatory Axis, CHD1L-MicroRNA 486-Matrix Metalloproteinase 2, Controls Spermatogonial Stem Cell Properties

2018 ◽  
Vol 39 (4) ◽  
Author(s):  
Shan-Shan Liu ◽  
Eithne Margaret Maguire ◽  
Yin-Shan Bai ◽  
Li Huang ◽  
Yurong Liu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cell ◽  
Matrix Metalloproteinase ◽  
Molecular Mechanisms ◽  
Nuclear Translocation ◽  
Expression Profiles ◽  
Matrix Metalloproteinase 2 ◽  
Small Rna Sequencing ◽  
Growth Properties ◽  
The Matrix

ABSTRACT Spermatogonial stem cells (SSCs) are unipotent germ cells that are at the foundation of spermatogenesis and male fertility. However, the underlying molecular mechanisms governing SSC stemness and growth properties remain elusive. We have recently identified chromodomain helicase/ATPase DNA binding protein 1-like (Chd1l) as a novel regulator for SSC survival and self-renewal, but how these functions are controlled by Chd1l remains to be resolved. Here, we applied high-throughput small RNA sequencing to uncover the microRNA (miRNA) expression profiles controlled by Chd1l and showed that the expression levels of 124 miRNA transcripts were differentially regulated by Chd1l in SSCs. KEGG pathway analysis shows that the miRNAs that are differentially expressed upon Chd1l repression are significantly enriched in the pathways associated with stem cell pluripotency and proliferation. As a proof of concept, we demonstrate that one of the most highly upregulated miRNAs, miR-486, controls SSC stemness gene expression and growth properties. The matrix metalloproteinase 2 (MMP2) gene has been identified as a novel miR-486 target gene in the context of SSC stemness gene regulation and growth properties. Data from cotransfection experiments showed that Chd1l, miR-486, and MMP2 work in concert in regulating SSC stemness gene expression and growth properties. Finally, our data also revealed that MMP2 regulates SSC stemness gene expression and growth properties through activating β-catenin signaling by cleaving N-cadherin and increasing β-catenin nuclear translocation. Our data demonstrate that Chd1l–miR-486–MMP2 is a novel regulatory axis governing SSC stemness gene expression and growth properties, offering a novel therapeutic opportunity for treating male infertility.

scholarly journals Molecular Pathogenesis and Immune Evasion of Vesicular Stomatitis New Jersey Virus Inferred from Genes Expression Changes in Infected Porcine Macrophages

Pathogens ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1134
Author(s):  
Lauro Velazquez-Salinas ◽  
Jessica A. Canter ◽  
James J. Zhu ◽  
Luis L. Rodriguez
Keyword(s):  
Immune Evasion ◽  
Matrix Protein ◽  
Molecular Mechanisms ◽  
Primary Cultures ◽  
Molecular Pathogenesis ◽  
Interferon Stimulated Genes ◽  
Cytokines And Chemokines ◽  
The Matrix ◽  
Vesicular Stomatitis ◽  
Endemic Strain

The molecular mechanisms associated with the pathogenesis of vesicular stomatitis virus (VSV) in livestock remain poorly understood. Several studies have highlighted the relevant role of macrophages in controlling the systemic dissemination of VSV during infection in different animal models, including mice, cattle, and pigs. To gain more insight into the molecular mechanisms used by VSV to impair the immune response in macrophages, we used microarrays to determine the transcriptomic changes produced by VSV infection in primary cultures of porcine macrophages. The results indicated that VSV infection induced the massive expression of multiple anorexic, pyrogenic, proinflammatory, and immunosuppressive genes. Overall, the interferon (IFN) response appeared to be suppressed, leading to the absence of stimulation of interferon-stimulated genes (ISG). Interestingly, VSV infection promoted the expression of several genes known to downregulate the expression of IFN. This represents an alternate mechanism for VSV control of the IFN response, beyond the recognized mechanisms mediated by the matrix protein. Although there was no significant differential gene expression in macrophages infected with a highly virulent epidemic strain compared to a less virulent endemic strain, the endemic strain consistently induced higher expression of all upregulated cytokines and chemokines. Collectively, this study provides novel insights into VSV molecular pathogenesis and immune evasion that warrant further investigation.

Study on the preparation and properties of polyamide/chitosan nanocomposite fabricated by electrospinning method

2021 ◽  
Author(s):  
Mahyar Fazeli ◽  
Faegheh Fazeli ◽  
Tamrin Nuge ◽  
Omid Abdoli ◽  
Shokooh Moghaddam
Keyword(s):  
Structural Characteristics ◽  
Decomposition Temperature ◽  
X Ray Diffraction ◽  
Good Adhesion ◽  
Sem Images ◽  
Electrospinning Method ◽  
Maximum Current ◽  
The Matrix ◽  
Ft Ir ◽  
Amine Groups

Abstract The principal intention of this work is to fabricate and characterize the polyamide/chitosan nanocomposite by a novel single solvent method through the electrospinning procedure. The thermal properties and morphology of prepared nanocomposite are studied by thermogravimetric analysis (TGA) and field-emission scanning electron microscopy (FE-SEM). TGA exposed that the primary decomposition temperature is reduced with rising of chitosan content in the nanocomposites and origin disintegration temperature for polyamide/chitosan nanocomposites is perceived to be in the range from 300 to 500°C. Also, FE-SEM images demonstrated that the nanofibers of chitosan have good adhesion on the matrix and are well-oriented. Besides, the crystallinity and structural characteristics of the polyamide/chitosan nanocomposites are investigated by using X-ray diffraction (XRD) and Fourier transform-infrared spectroscopy (FT-IR), respectively. The results of XRD proved that the successful blending of chitosan in polyamide is achieved via the electrospinning method. FT-IR results demonstrate that the nanofibers are consist of amine groups. Also, the electrical properties of the nanocomposite improved with the increasing content of chitosan and the conductivity of the polyamide/chitosan 5 wt% demonstrates the maximum current of 0.3 nA. Besides, the sheet resistance of the composite reduced 118 to 20 × 109 Ω with raising the chitosan volume from 0 to 5 wt%.

LATTICE DYNAMICS OF AN F-TYPE ICOSAHEDRAL QUASICRYSTAL

1993 ◽  
Vol 07 (06n07) ◽  
pp. 1487-1504 ◽  
Author(s):  
G. KASNER ◽  
H. BÖTTGER
Keyword(s):  
Lattice Dynamics ◽  
Continued Fraction ◽  
Pair Interaction ◽  
Icosahedral Quasicrystal ◽  
Cluster Approach ◽  
Vibrational States ◽  
Lennard Jones ◽  
Cluster Calculations ◽  
Face Centered ◽  
Matrix Continued Fraction

By using a matrix-continued fraction approach we calculate the density of vibrational states (DOS) of a tiling model based on the 6D face centered lattice. Parameters of the Lennard-Jones pair interaction are obtained from relaxation calculations. With a ternary decoration the tiling was found to be stable. The DOS was approximated by weighting the local DOS (LDOS) of the allowed vertex configurations by their relative frequencies in the infinite tiling. These frequencies were obtained by using extended deflation rules. Results of this approach are compared to exact finite cluster calculations and an embedded cluster approach. We find the DOS to consist of a single band (in our resolution) and a rich structure at higher frequencies.

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