Efficient overcoming of the nucleosomal barrier and accurate maintenance of associated histone marks during chromatin replication are essential for normal functioning of the cell. Recent studies revealed new protein factors and histone modifications contributing to overcoming the nucleosomal barrier, and suggested an important role for DNA looping in survival of the original histones during rep...

The vascular barrier is an important function of the endothelium and its dysfunction is involved in several diseases. The barrier function of the endothelial cell monolayer is governed by cell-cell, cell-extracellular matrix (cell-ECM) contacts, and inflammatory factors such as thrombin, histamine or vascular endothelial growth factor. Several in vivo and in vitro assays that measure the vascul...

The intestinal barrier is formed by enterocyte membranes, tight junctions, secreted mucus, and immunologic factors, such as tissue macrophages. Dysfunction of this barrier can be caused by different types of stress (e.g., physiological, pathological, psychological, pharmacological) and can lead to increased intestinal permeability. Increased permeability to endotoxin, a component of the walls o...

t-shape profile barriers are one of the most successful barriers among many different profiles. it has been shown that using welled diffusers on the top of t-shaped barriers makes a reactive barrier that shows better performance than that of any other used profile barriers compared with their equivalent absorbent barrier. the contribution of the top surface of reactive t-profile barriers to the...

On the basis of the traditional structure of noise barrier, this paper seeks aerodynamic load to reduce the variation of maximum surface configuration (porous structure). Using the numerical simulation method, this paper builds a three-dimensional numerical model of deloading type noise barriers and trains. The large fluid calculation software, Fluent, is adopted to conduct simulation calculati...

Airway epithelium contributes significantly to the barrier function of airway tract. Mucociliary escalator, intercellular apical junctional complexes which regulate paracellular permeability and antimicrobial peptides secreted by the airway epithelial cells are the three primary components of barrier function of airway tract. These three components act cooperatively to clear inhaled pathogens, ...

The small G-protein Rap1 plays an important role in the regulation of endothelial barrier function, a process controlled largely by cellâ€"cell adhesions and their connection to the actin cytoskeleton. During the various stages of barrier dynamics, different guanine nucleotide exchange factors (GEFs) control Rap1 activity, indicating that Rap1 integrates multiple input signals. Once activated, ...

BACKGROUND This study aimed to determine barriers to accessing human immunodeficiency virus (HIV) counseling and testing (HCT) services among a commuter population. METHODS A cross-sectional, venue-based intercept survey was conducted. Participants were recruited during a 2-day community campaign at the Noord Street taxi rank in Johannesburg, South Africa. Data were collected using a self-adm...

Several experimental evidences show that prions are non-conventional pathogens, which physical support consists only in proteins. This finding raised questions regarding the observed prion strain-to-strain variations and the species barrier that happened to be crossed with dramatic consequences on human health and veterinary policies during the last 3 decades. This review presents a focus on a ...

Atopic dermatitis is a chronic inflammatory skin disease with a complex pathogenesis, where changes in skin barrier and imbalance of the immune system are relevant factors. The skin forms a mechanic and immune barrier, regulating water loss from the internal to the external environment, and protecting the individual from external aggressions, such as microorganisms, ultraviolet radiation and ph...