High sulphur oil of Type II kerogen of the oil shales from Western Central Jordan based on molecular structure and kinetics.

Organic rich sedimentary rocks of the Late Cretaceous Muwaqqar Formation from the Lajjun outcrop in the Lajjun Sub-basin, Western Central Jordan were geochemically analyzed. This study integrates kerogen microscopy of the isolated kerogen from 10 oil shale samples with a new finding from unconventional geochemical methods [i.e., ultimate elemental (CHNS), fourier transform infrared spectroscopy and pyrolysis-gas chromatography (Py-GC)] to decipher the molecular structure of the analyzed isolated kerogen fraction and evaluate the kerogen composition and characteristics. The optical kerogen microscopy shows that the isolated kerogen from the studied oil shales is originated from marine assemblages [i.e., algae, bituminite and fluorescence amorphous organic matter] with minor amounts of plant origin organic matter (i.e., spores). This finding suggests that the studied kerogen is hydrogen-rich kerogen, and has the potential to generate high paraffinic oil with low wax content. The dominance of such hydrogen-rich kerogen (mainly Type II) was confirmed from the multi-geochemical ratios, including high hydrogen/carbon atomic of more than 1.30 and high A-factor of more than 0.60. This claim agrees with the molecular structure of the kerogen derived from Py-GC results, which suggest that the studied kerogen is mainly Type II-S kerogen exhibiting the possibility of producing high sulphur oils during earlier stages of diagenesis, according to bulk kinetic modeling. The kinetic models of the isolated kerogen fraction suggest that the kerogen conversion, in coincidence with a vitrinite reflectance range of 0.55-0.60%, commenced at considerably lower temperature value ranges between 100 and 106 °C, which have produced oils during the early stage of oil generation. The kinetic models also suggest that the commercial amounts of oil can generate by kerogen conversion of up to 50% during the peak stage of oil window (0.71-0.83%) at relatively low geological temperature values in the range of 122-138 °C. Therefore, further development of the Muwaqqar oil shale successions is highly approved in the shallowly buried stratigraphic succession in the Lajjun Sub-basin, Western Central Jordan.

A direct technique for magnetic functionalization of living human cells.

Functionalized living cells are regarded as effective tools in directed cell delivery and tissue engineering. Here we report the facile functionalization of viable isolated HeLa cells with superparamagnetic cationic nanoparticles via a single-step biocompatible process. Nanoparticles are localized on the cellular membranes and do not penetrate into the cytoplasm. The magnetically responsive cells are viable and able to colonize and grow on substrates. Magnetically facilitated microorganization of functionalized cells into viable living clusters is demonstrated. We believe that the technique described here may find a number of potential applications in cell-based therapies and in development of whole-cell biosensors.

Historical Y. pestis Genomes Reveal the European Black Death as the Source of Ancient and Modern Plague Pandemics.

Ancient DNA analysis has revealed an involvement of the bacterial pathogen Yersinia pestis in several historical pandemics, including the second plague pandemic (Europe, mid-14(th) century Black Death until the mid-18(th) century AD). Here we present reconstructed Y. pestis genomes from plague victims of the Black Death and two subsequent historical outbreaks spanning Europe and its vicinity, namely Barcelona, Spain (1300-1420 cal AD), Bolgar City, Russia (1362-1400 AD), and Ellwangen, Germany (1485-1627 cal AD). Our results provide support for (1) a single entry of Y. pestis in Europe during the Black Death, (2) a wave of plague that traveled toward Asia to later become the source population for contemporary worldwide epidemics, and (3) the presence of an historical European plague focus involved in post-Black Death outbreaks that is now likely extinct.

Interfacing living unicellular algae cells with biocompatible polyelectrolyte-stabilised magnetic nanoparticles.

Green algae are a promising platform for the development of biosensors and bioelectronic devices. Here we report a reliable single-step technique for the functionalisation of living unicellular green algae Chlorella pyrenoidosa with biocompatible 15 nm superparamagnetic nanoparticles stabilised with poly(allylamine hydrochloride). The magnetised algae cells can be manipulated and immobilised using external permanent magnets. The distribution of the nanoparticles on the cell walls of C. pyrenoidosa was studied by optical and fluorescence microscopy, TEM, SEM and EDX spectroscopy. The viability and the magnetic properties of the magnetised algae are studied in comparison with the native cells. The technique may find a number of potential applications in biotechnology and bioelectronics.

Magnetically responsive calcium carbonate microcrystals.

Here we report the fabrication of magnetically responsive calcium carbonate microcrystals produced by coprecipitation of calcium carbonate in the presence of citrate-stabilized iron oxide nanoparticles. We demonstrate that the calcite microcrystals obtained possess superparamagnetic properties due to incorporated magnetite nanoparticles and can be manipulated by an external magnetic field. The microcrystals doped with magnetic nanoparticles were utilized as templates for the fabrication of hollow polyelectrolyte microcapsules, which retain the magnetic properties of the sacrificial cores and might be spatially manipulated using a permanent magnet, thus providing the magnetic-field-facilitated delivery and separation of materials templated on magnetically responsive calcite microcrystals.