Infectivity of Cryptosporidium parvum oocysts after storage of experimentally contaminated apples

Irrigation water and washing water have been inferred to be associated with contamination of fresh fruits and vegetables with pathogenic microorganisms infectious for humans. The objective of the present study was to determine whether apples experimentally contaminated with Cryptosporidium oocysts represent a food safety concern. Laser scanning confocal microscopy revealed no morphological changes in Cryptosporidium parvum oocysts attached to apples after 6 weeks of cold storage, suggesting that oocysts might remain viable and possibly infectious during prolonged storage. Mice were fed apple peels from experimentally contaminated apples to determine whether oocysts had remained infectious on apples stored for 4 weeks. All mice developed cryptosporidiosis. To evaluate the strength of oocyst attachment to apples, washing methods that have been reported to be helpful for recovery of oocysts from various foodstuffs were evaluated, except that the intensity of washing was increased in the present study. None of the tested washing methods succeeded in completely removing oocysts from the apple peel. The most efficient removal (37.5%) was achieved by rigorous manual washing in water with a detergent and by agitation in an orbital shaker with Tris-sodium dodecyl sulfate buffer. Glycine and phosphate-buffered saline buffers had no effect on oocyst removal. Scanning electron microscopy revealed that some oocysts were attached in deep natural crevices in the apple exocarp and others were attached to the smooth surface of the peel. Some oocysts were closely associated with what appeared to be an amorphous substance with which they might have been attached to the apple surface.     

Heat and mass transport impact on MHD second-grade fluid: A comparative analysis of fractional operators

The effect of the magnetic flux plays a major role in convective flow. The process of heat transfer is accompanied by a mass transfer process; for instance, condensation, evaporation, and chemical process. Due to the applications of the heat and mass transfer combined effects in different fields, the main aim of this paper is to do a comprehensive analysis of heat and mass transfer of magnetohydrodynamic (MHD) unsteady second-grade fluid in the presence of ramped conditions. The new governing equations of MHD second-grade fluid have been fractionalized by means of singular and nonsingular differentiable operators. To have an accurate physical significance of imposed conditions on the geometry of second-grade fluid, the constant concentration with ramped temperature and ramped velocity is considered. The fractional solutions of temperature, concentration, and velocity have been investigated by means of integral transform and inversion algorithm. The influence of physical parameters and flow is analyzed graphically via computational software (MATHCAD-15). The velocity profile decreases by increasing the Prandtl number. The existence of a Prandtl number may reflect the control of the thickness and enlargement of the thermal effect.     

Synthesis and characterization of side-chain poly(methacrylate)s bearing new azo-moieties

New side-chain poly(methacrylate)s with azo moieties were prepared by free radical copolymerization, starting from methyl methacrylate (MMA) and some original azo-monomers. The chromophore content was evaluated from ¹H-NMR spectroscopy and elemental analyses; all structures exhibited a high content of azobenzene units. UV–Vis measurements have also supported this fact. Reactivity ratios for the methacrylate systems and their corresponding Q–e values were calculated based on several initial feed compositions (MMA and the newly synthesized azo-monomers) using an integral method with its appropriate software. The polymers were also characterized by FTIR, SEC and DSC-TGA techniques. The coloured poly(methacrylate)s exhibited glass transition temperatures between 141 and 168 °C and thermal stabilities up to 306 °C.     

Glycine fluoromethylketones as SENP-specific activity based probes

We report here the synthesis and biochemical properties of a new peptidyl activity-based probe 1 for SUMO proteases, SENPs. The activity-based probe has at its C terminus a glycine-derived fluoromethylketone moiety as a reactive group designed to target the active-site cysteine of SENPs. Based on a study of the interactions between SENPs and SUMOs, we introduced further design elements that allow the activity-based probe to selectively target SENPs at low micromolar to high nanomolar concentrations. Moreover, 1 out-competes SUMO1 from the reversible SUMO1-SENP1 complex, thus suggesting that 1 and SUMO1 share a common binding site on SENP1.     

BiFeO3-synthesis,characterization and its photocatalytic activity towards doxorubicin degradation from water

Pure bismuth ferrite was successfully obtained through the thermolysis of new bismuth ferrioxalate coordination compound, namely BiFe(C₂O₄)₃·3H₂O. The synthesized precursor was characterized by chemical analysis, infrared spectroscopy and thermal analysis. The bismuth ferrite obtained after a heating treatment of the precursor for at 450–800?°C/1?h was investigated by X-ray diffraction, FE-SEM, TEM and HRTEM. The obtained pure bismuth ferrite nanoparticles (480?°C) was tested as photocatalyst towards the degradation of doxorubicin (DOX), a well-known anti-cancer drug commonly used for the treatment of various cancer types, which has been detected in hospital effluent water. The comparative results of DOX degradation through photolysis and photocatalysis under UV irradiation showed a great photocatalytic activity of bismuth ferrite towards DOX degradation and mineralization from water. The kinetics aspects were discussed based on the first-order kinetics model that fitted the best the experimental photocatalysis results.     

Enhanced in vivo Optical Imaging of the Inflammatory Response to Acute Liver Injury in C57BL/6 Mice Using a Highly Bright Near-Infrared BODIPY Dye

Delving deeper is possible in whole-body in vivo imaging using a super-bright membrane-targeting BODIPY dye ( BD ). The dye was used to monitor homing of ex vivo fluorescently labelled neutrophils to an injured liver of dark-pigmented C57BL/6 mice. In vivo imaging system (IVIS) data conclusively showed an enhanced signal intensity and a higher signal-to-noise ratio in mice receiving neutrophils labelled with the BD dye relative to those labelled with a gold standard dye at 2 h post in vivo administration of fluorescently labelled cells. Fluorescence-activated cell sorting (FACS) confirmed that BD is nontoxic, and an exceptional cell labelling dye that opens up precision deep-organ in vivo imaging of inflammation in mice routinely used for biomedical research. The origin of enhanced performance is identified with the molecular structure and the distinct localisation of the dye within cells that enable remarkable changes in its optical parameters.     

Synthesis of a new oxazoline macromonomer for dispersion polymerization

We synthesized new macromonomers containing vinylsilane moiety by cationic ring-opening polymerization of 2-ethyl-2-oxazoline. Kinetic studies proved that initiation with vinylsilane derivative, bearing chloride counterion, is a fast process followed by a slow propagation and absence of termination. We used the dispersion polymerization of styrene as test for the stabilizing efficiency of the newly synthesized macromonomer. The dispersion polymerization tests allowed the investigation of the effect of the macromonomer concentration on the number average diameter of the prepared polystyrene microspheres and its polydispersity index. In addition, we compared the stabilizing efficiency of commercial poly(N-vinylpyrollidone) with that of our macromonomer. Copolymerization of styrene with 10 wt% oxazoline macromonomer yielded stable and monodisperse microspheres, having the number average diameter of 1.8 μm and a good size polydispersity index of 1.05.     

Poly(4-vinylpyridine)-based hydrogen bonded side-chain liquid crystal polymers

Novel liquid crystalline (LC) poly(4-vinylpyridine) (PVP)-based side-chain polymers were prepared from PVP and cyanobiphenyl (HOCnB) derivatives through intermolecular hydrogen-bonding between hydroxyl groups of the cyanobiphenyl derivatives and the nitrogen of PVP. PVP was used as a hydrogen bond acceptor polymer. A series of HOCnB having a linear alkoxy chain HOCnH_2n + 1O–(n = 2–6) have been used as H-bond donor. The existence of H-bonding was confirmed using FTIR spectroscopy. The polymeric complexes behave as LC polymers and exhibit stable mesophases. DSC and optical microscopy were used to investigate LC behaviour. All PVP–LC-complexes exhibited stable and homogeneous nematic phases. On increasing spacer length or concentration of the hydrogen bonded mesogenic unit in the complex, the clearing temperature and the temperature range of the nematic phase increased. The binary phase diagram of the polymeric complexes PVP–HOCnB showed complete miscibility over the entire range of composition. Molecular interactions of self-assembled SCLCP presented the idea that various LC-complexes could be prepared through mixing a functionalised polymer with various low molar mass mesogens.