Lactobacillus reuteri inhibition of Enteropathogenic Escherichia coli adherence to human intestinal epithelium

Enteropathogenic Escherichia coli (EPEC) is a major cause of diarrheal infant death in developing countries, and probiotic bacteria have been shown to provide health benefits in gastrointestinal infections. In this study, we have investigated the influence of the gut symbiont Lactobacillus reuteri on EPEC adherence to the human intestinal epithelium. Different host cell model systems including non-mucus-producing HT-29 and mucus-producing LS174T intestinal epithelial cell lines as well as human small intestinal biopsies were used. Adherence of L. reuteri to HT-29 cells was strain-specific, and the mucus-binding proteins CmbA and MUB increased binding to both HT-29 and LS174T cells. L. reuteri ATCC PTA 6475 and ATCC 53608 significantly inhibited EPEC binding to HT-29 but not LS174T cells. While pre-incubation of LS174T cells with ATCC PTA 6475 did not affect EPEC attaching/effacing (A/E) lesion formation, it increased the size of EPEC microcolonies. ATCC PTA 6475 and ATCC 53608 binding to the mucus layer resulted in decreased EPEC adherence to small intestinal biopsy epithelium. Our findings show that L. reuteri reduction of EPEC adhesion is strain-specific and has the potential to target either the epithelium or the mucus layer, providing further rationale for the selection of probiotic strains

Rotavirus Infection: A Systemic Illness?

Candy discusses a new study inPLoS Medicine that challenges the view that in children with rotavirus diarrhea, the virus is confined to the upper small intestine

Increasing work-place healthiness with the probiotic Lactobacillus reuteri: A randomised, double-blind placebo-controlled study

BACKGROUND: Short term illnesses, usually caused by respiratory or gastrointestinal diseases are disruptive to productivity and there is relatively little focus on preventative measures. This study examined the effect of the probiotic Lactobacillus reuteri protectis (ATCC55730) on its ability to improve work-place healthiness by reducing short term sick-leave caused by respiratory or gastrointestinal infections. METHODS: 262 employees at TetraPak in Sweden (day-workers and three-shift-workers) that were healthy at study start were randomised in a double-blind fashion to receive either a daily dose of 10(8 )Colony Forming Units of L. reuteri or placebo for 80 days. The study products were administered with a drinking straw. 181 subjects complied with the study protocol, 94 were randomised to receive L. reuteri and 87 received placebo. RESULTS: In the placebo group 26.4% reported sick-leave for the defined causes during the study as compared with 10.6% in the L. reuteri group (p < 0.01). The frequency of sick-days was 0.9% in the placebo group and 0.4% in the L. reuteri group (p < 0.01). Among the 53 shift-workers, 33% in the placebo group reported sick during the study period as compared with none in the L. reuteri group(p < 0.005)

Surface spin magnetism controls the polarized exciton emission from CdSe nanoplatelets

The surface of nominally diamagnetic colloidal CdSe nanoplatelets can demonstrate paramagnetism owing to the uncompensated spins of dangling bonds (DBSs). We reveal that by optical spectroscopy in high magnetic fields up to 15 Tesla using the exciton spin as probe of the surface magnetism. The strongly nonlinear magnetic field dependence of the circular polarization of the exciton emission is determined by the DBS and exciton spin polarization as well as by the spin-dependent recombination of dark excitons. The sign of the exciton-DBS exchange interaction can be adjusted by the nanoplatelet growth conditions

Modelling of the process of controlling technical systems with the help of diffusion Markov random processes

The objective of the research is to create the methods of controlling technical systems formed on the basis of diffusion Markov random processes

Electron and hole g-factors and spin dynamics of negatively charged excitons in CdSe/CdS colloidal nanoplatelets with thick shells

We address spin properties and spin dynamics of carriers and charged excitons in CdSe/CdS colloidal nanoplatelets with thick shells. Magneto-optical studies are performed by time-resolved and polarization-resolved photoluminescence, spin-flip Raman scattering and picosecond pump-probe Faraday rotation in magnetic fields up to 30 T. We show that at low temperatures the nanoplatelets are negatively charged so that their photoluminescence is dominated by radiative recombination of negatively charged excitons (trions). Electron g-factor of 1.68 is measured and heavy-hole g-factor varying with increasing magnetic field from -0.4 to -0.7 is evaluated. Hole g-factors for two-dimensional structures are calculated for various hole confining potentials for cubic- and wurtzite lattice in CdSe core. These calculations are extended for various quantum dots and nanoplatelets based on II-VI semiconductors. We developed a magneto-optical technique for the quantitative evaluation of the nanoplatelets orientation in ensemble

Addressing the exciton fine structure in colloidal nanocrystals: the case of CdSe nanoplatelets

We study the band-edge exciton fine structure and in particular its bright-dark splitting in colloidal semiconductor nanocrystals by four different optical methods based on fluorescence line narrowing and time-resolved measurements at various temperatures down to 2 K. We demonstrate that all these methods provide consistent splitting values and discuss their advances and limitations. Colloidal CdSe nanoplatelets with thicknesses of 3, 4 and 5 monolayers are chosen for experimental demonstrations. The bright-dark splitting of excitons varies from 3.2 to 6.0 meV and is inversely proportional to the nanoplatelet thickness. Good agreement between experimental and theoretically calculated size dependence of the bright-dark exciton slitting is achieved. The recombination rates of the bright and dark excitons and the bright to dark relaxation rate are measured by time-resolved techniques

Cu-Expanded Graphite Composite Material Preparation and Thermal Properties

A composite material based on expanded graphite (EG) and copper compounds was obtained by natural graphite oxidation with 95% nitric acid, copper (II) nitrate and granular carbamide addition with further rapid heat treatment at three different exfoliation temperatures: 800, 1000 and 1200 °С. It was found that the composition of copper containing graphite material depends on the temperature and the atmosphere of thermal expansion. The formation of copper oxides can be eliminated if rapid heat treatment is conducted in nitrogen at 1200 °С. Thermal conductive properties: thermal diffusivity and specific heat capacity of obtained Cu-expanded graphite samples were measured. It was revealed that the dependence of thermal conductivity (TC) of Cu-graphite material has non-linear character in the studied range of copper content. The incorporation of 3% copper into expanded graphite allows to increase its thermal conductivity by 20% while the further Cu content growth leads to the TC decrease from 6 to 4.5 W/(m∙K). The specific heat capacity is constant at ω(Cu)<3% and reduces in the range (3‒8)% Cu. The advantage of proposed technique of Cu-expanded graphite materials preparation is exclusion graphite intercalation compounds hydrolysis step with further drying because of carbamide addition