It is generally accepted that the left ventricle (LV) hypertrophies (LVH) to normalize systolic wall stress (sigma(s)) in chronic pressure overload. However, LV filling pressure (P(v)) may be elevated as well, supporting the alternative hypothesis of end-diastolic wall stress (sigma(d)) normalization in LVH. We used an LV time-varying elastance model coupled to an arterial four-element lumped-p...

The common idea of typical cell wall architecture in archaea consists of a pseudo-crystalline proteinaceous surface layer (S-layer), situated upon the cytoplasmic membrane. This is true for the majority of described archaea, hitherto. Within the crenarchaea, the S-layer often represents the only cell wall component, but there are various exceptions from this wall architecture. Beside (glycosyla...

For the realization of noninvasive and regional myocardial tissue characterization, in the present study, we attempted to elucidate the characteristics of the myocardial response to electrical excitation and its propagation by an ex vivo experiment using a rat left ventricular wall. To visualize such a propagation phenomenon, whose speed is up to several m/s, high-frame-rate ultrasound was used...

S. aureus combats cell wall antibiotic stress by altered gene expression mediated by various environmental signal sensors. In this study, we examined the transcriptional regulation of trfA, a gene related to mecA of Bacillus subtilis encoding an adaptor protein implicated in multiple roles, notably, proteolysis and genetic competence. Despite strong sequence similarity to B. subtilis mecA, the ...

Peptidoglycan is a major cell wall constituent of gram-positive bacteria. It is a dynamic macromolecule that is actively remodeled to enable cell growth and differentiation through a tightly choreographed interplay of hydrolytic and biosynthetic enzyme activities. The filamentous bacterium Streptomyces coelicolor has a complex life cycle that likely requires considerable cell wall remodeling to...

Spike mosses are among the most basal vascular plants, and one species, Selaginella moellendorffii, was recently selected for full genome sequencing by the Joint Genome Institute (JGI). Glycosyltransferases (GTs) are involved in many aspects of a plant life, including cell wall biosynthesis, protein glycosylation, primary and secondary metabolism. Here, we present a comparative study of the S. ...

As an aggressive pathogen, Staphylococcus aureus poses a significant public health threat and is becoming increasingly resistant to currently available antibiotics, including vancomycin, the drug of last resort for gram-positive bacterial infections. S. aureus with intermediate levels of resistance to vancomycin (vancomycin-intermediate S. aureus [VISA]) was first identified in 1996. The resist...

Flow stasis in an artificial heart may provide a situation where thrombus develops. Should part, or all, of the clot dislodge, a thromboembolism may lead to stroke(s), neurologic deficits, or even death. In an effort to determine if the regime of low shear or stasis exists, a two-dimensional particle image velocimetry (PIV) system was implemented to measure the velocity field within the 50 cc P...

in spite of the fact that cementitious and concrete materials are mainly used on a large scale and inhuge quantities for roads, dams, bridges and building constructions, the mechanical behavior of thesematerials depends to a great extend on structural elements and phenomena which are effective on amicro and nanoscale. although this is well known by researchers, material producers and engineersf...

A 36-year-old man presented to our emergency department complaining of right-sided chest pain after a motor vehicle collision. Physical examination revealed bilateral breath sounds and a supine chest radiograph was unremarkable. A 10-5 MHz linear transducer (SonoSite MicroMaxx, Bothell, WA, USA) was used to obtain ultrasound images at the patient’s left anterior chest wall [Figure 1], right ant...