Modeling the effect of oxidative stress on Bordetella pertussis fermentations.

A mathematical model is proposed for Bordetella pertussis with the main goal to better understand and describe the relation between cell growth, oxidative stress and NADPH levels under different oxidative conditions. The model is validated with flask experiments conducted under different conditions of oxidative stress induced by high initial glutamate concentrations, low initial inoculum and secondary culturing following exposure to starvation. The model exhibited good accuracy when calibrated and validated for the different experimental conditions.

Applications of flow cytometry sorting in the pharmaceutical industry: A review.

The article reviews applications of flow cytometry sorting in manufacturing of pharmaceuticals. Flow cytometry sorting is an extremely powerful tool for monitoring, screening and separating single cells based on any property that can be measured by flow cytometry. Different applications of flow cytometry sorting are classified into groups and discussed in separate sections as follows: (a) isolation of cell types, (b) high throughput screening, (c) cell surface display, (d) droplet fluorescent-activated cell sorting (FACS).

Peptide and peptide-carbon nanotube hydrogels as scaffolds for tissue & 3D tumor engineering.

Unlabelled: The use of hybrid self-assembling peptide (EFK8)-carbon nanotube (SWNT) hydrogels for tissue engineering and in vitro 3D cancer spheroid formation is reported. These hybrid hydrogels are shown to enhance the attachment, spreading, proliferation and movement of NIH-3T3 cells relative to that observed using EFK8-only hydrogels. After five days, ∼30% more cells are counted when the hydrogel contains SWNTs.

Multigrain platinum nanowires consisting of oriented nanoparticles anchored on sulfur-doped graphene as a highly active and durable oxygen reduction electrocatalyst.

Direct growth of multigrain platinum nanowires on sulfur-doped graphene (PtNW/SG) is reported. The growth mechanism, including Pt nanoparticle nucleation on SG, followed by nanoparticle attachment with orientation along the <111> direction is highlighted. PtNW/SG demonstrates improved Pt mass and specific activity compared with commercial catalysts toward oxygen reduction, in addition to dramatically improved stability through accelerated durability testing.

Mesoscopic modeling of Li insertion in phase-separating electrode materials: application to lithium iron phosphate.

A simple mesoscopic model is presented which accounts for the inhomogeneity of physical properties and bi-stable nature of phase-change insertion materials used in battery electrodes. The model does not include any geometric detail of the active material and discretizes the total active material domain into meso-scale units featuring basic thermodynamic (non-monotonic equilibrium potential as a function of Li content) and kinetic (insertion-de-insertion resistance) properties. With only these two factors incorporated, the model is able to simultaneously capture unique phenomena including the memory effect observed in lithium iron phosphate electrodes.

Ionic-complementary peptide matrix for enzyme immobilization and biomolecular sensing.

A novel electrochemical biosensing platform is described using biocompatible, self-assembled ionic-complementary peptide nanofibers. The compatibility of a graphite electrode modified by these peptide nanofibers with enzymes is demonstrated using a model enzyme glucose oxidase (GOx). A glucose biosensor has been successfully fabricated by incorporating this enzyme into the modified electrode.

Ionic-complementary peptide-modified highly ordered pyrolytic graphite electrode for biosensor application.

Ionic-complementary peptides are promising new biomaterials with potential applications in bionanotechnology. In the present investigation, a typical ionic-complementary peptide, EFK16-II, was used to modify a highly ordered pyrolytic graphite (HOPG) electrode. Upon modification, peptide nanofibers, parallel or oriented 60 degrees or 120 degrees to each other, were formed on the surface of HOPG electrode.

Modification of hydrophilic and hydrophobic surfaces using an ionic-complementary peptide.

Ionic-complementary peptides are novel nano-biomaterials with a variety of biomedical applications including potential biosurface engineering. This study presents evidence that a model ionic-complementary peptide EAK16-II is capable of assembling/coating on hydrophilic mica as well as hydrophobic highly ordered pyrolytic graphite (HOPG) surfaces with different nano-patterns. EAK16-II forms randomly oriented nanofibers or nanofiber networks on mica, while ordered nanofibers parallel or oriented 60 degrees or 120 degrees to each other on HOPG, reflecting the crystallographic symmetry of graphite (0001).

Surface-assisted assembly of an ionic-complementary peptide: controllable growth of nanofibers.

Numerous studies have shown that a surface can direct and regulate molecular assembly. In this study, the nanofiber growth of an ionic-complementary peptide, EAK16-II, on a mica surface was investigated under various solution conditions via in situ atomic force microscopy. In comparison to the assembly in bulk solution, nanofiber growth of EAK16-II on mica is surface-assisted and involves two steps: (1) adsorption of nanofibers and fiber clusters (from the bulk solution) on the surface, serving as the "seeds"; (2) fiber elongation of the "seeds" from their active ends.

Effect of NaCl and peptide concentration on the self-assembly of an ionic-complementary peptide EAK16-II.

Previous work has examined the effects of such factors as pH and peptide concentration on the self-assembly of ionic-complementary peptides. This work focused on the effect of sodium chloride on the molecular self-assembly of an ionic-complementary peptide EAK16-II (AEAEAKAKAEAEAKAK). Surface tensions and dimensions of the self-assembled nanostructures were determined for a wide range of peptide and sodium chloride concentrations using axisymmetric drop shape analysis-profile (ADSA-P) and atomic force microscopy (AFM), respectively.

Lack of usefulness of electron beam computed tomography for detecting coronary allograft vasculopathy.

Fifty-five patients with cardiac allografts were studied by electron beam computed tomography for coronary calcification (EBCT CC) and coronary arteriography, and from the latter, a coronary index was calculated using the size, degree of obstruction, and linear extent of disease of each vessel. There was a significant correlation between EBCT CC score and coronary index, but receiver-operating characteristic (ROC) analysis demonstrated unsatisfactory performance of EBCT CC, and 6 patients had no coronary calcification despite having very abnormal coronary indexes. There are pathologic differences between coronary allograft vasculopathy and atherosclerosis, and correspondingly, EBCT CC has limited usefulness in the cardiac transplant population.

Pulmonary hypertension in type 1 Gaucher's disease: genetic and epigenetic determinants of phenotype and response to therapy.

Type 1 Gaucher's disease (GD) is recognized for striking but unexplained phenotypic diversity. Rarely, severe pulmonary hypertension (PH) may occur in GD but its clinical spectrum, determinants or its response to enzyme replacement therapy (ERT)+/-vasodilators is not known. One hundred and thirty-four consecutive patients with Type 1 GD were screened to estimate right ventricular systolic pressure (RVSP) by Doppler echocardiography.