Rapid and fully automated bacterial pathogen detection on a centrifugal-microfluidic LabDisk using highly sensitive nested PCR with integrated sample preparation

Diagnosis of infectious diseases suffers from long turnaround times for gold standard culture-based identification of bacterial pathogens, therefore impeding timely specific antimicrobial treatment based on laboratory evidence. Rapid molecular diagnostics-based technologies enable detection of microorganisms within hours however cumbersome workflows and complex equipment still prevent their widespread use in the routine clinical microbiology setting. We developed a centrifugal-microfluidic "LabDisk" system for rapid and highly-sensitive pathogen detection on a point-of-care analyser. The unit-use LabDisk with pre-stored reagents features fully automated and integrated DNA extraction, consensus multiplex PCR pre-amplification and geometrically-multiplexed species-specific real-time PCR. Processing merely requires loading of the sample and DNA extraction reagents with minimal hands-on time of approximately 5 min. We demonstrate detection of as few as 3 colony-forming-units (cfu) of Staphylococcus warneri, 200 cfu of Streptococcus agalactiae, 5 cfu of Escherichia coli and 2 cfu of Haemophilus influenzae in a 200 μL serum sample. The turnaround time of the complete analysis from "sample-to-result" was 3 h and 45 min. The LabDisk consequently provides an easy-to-use molecular diagnostic platform for rapid and highly-sensitive detection of bacterial pathogens without requiring major hands-on time and complex laboratory instrumentation.

Magnetic chemiluminescent immunoassay for human C-reactive protein on the centrifugal microfluidics platform

Schematic of the LabDisk-based hCRP MCIA. The antibody-coated dynabeads are sequentially transported through the immunoassay buffers by magnetic actuation. Finally the chemiluminescence signal is acquired from a detection cavity.

A high-yielding serum-free, suspension cell culture process to manufacture recombinant adenoviral vectors for gene therapy

We have developed an efficient, reproducible, and scaleable cell culture process for a recombinant adenoviral vector expressing therapeutic transgenes for clinical trials. HEK 293 cells - which support the propagation of E1 deficient adenovirus - were first adapted to serum free media and suspension growth. Subsequent studies focused on the infection, virus production and harvest from suspension culture bioreactors. Future studies are planned to address the kinetics of adenovirus production in HEK 293 as well as in other cell lines.

Magnetic spin structure of pyroxene-type MnGeO(3)

Polycrystalline MnGeO(3) material was synthesized at 1473 K and ambient pressures using ceramic sintering techniques. Under these conditions the pyroxene-type compound crystallizes in the orthorhombic modification with space group Pbca, as determined from the refinement of the neutron diffraction data. The monoclinic modification, space group C 2/c, was also present at a level of 8.8(4) wt% and the magnetic structures for the two polymorphs at low temperatures have been found simultaneously. The monoclinic form orders magnetically below 34 K; the spin structure can be described using k = (0, 0, 0) in the magnetic space group C 2'/c, having an antiferromagnetic spin arrangement within and between the chains of M1 and M2 sites. The orthorhombic phase of MnGeO(3) transforms to a magnetically ordered state with k = (0, 0, 0) and magnetic space group Pb'c'a below 12 K. Spins on M1 sites are aligned along the crystallographic a-axis with a slight non-collinear antiferromagnetic spin arrangement with and between the M1 chains. Spins on M2 sites are also antiferromagnetically coupled; however, one of the three different M1-M2 superexchange pathways within the band of M1 and M2 sites displays a ferromagnetic interaction, while the other two allow antiferromagnetic interaction.

The role of early sensory experience in the prey catching responses of Salamandra salamandra to stationary prey

Two groups of newly metamorphosed Salamandra salamandra (L.) were raised with living and with stationary prey, respectively. One year later, the group which had experience exclusively with stationary prey was significantly better in responding to stationary prey than the group which only had experience with moving prey. This was the case both under light and dark conditions. The experiments show that prey-catching behavior in salamanders can be considerably modified by experience.

Structural variations in the aegirine solid-solution series (Na,Li)FeSi2O6 at 298 K and 80 K

The structural variations within the aegirine (NaFeSi2O6) – Li–aegirine (LiFeSi2O6) solid-solution series have been determined from structure refinements of single–crystal X-ray diffraction data of synthetic compounds at 298 K and 85 K. At 298 K, all compounds have space group C2/c. Replacing Na+ by Li+ in aegirine causes a distinct decrease of the b lattice parameter by 1.54% and an increase of the monoclinic angle β by 2.60%. The oxygen coordination of the M2 cation decreases from 6 + 2–fold in aegirine to 6–fold in pure LiFeSi2O6, the bond length decreases by 7.1% with increasing replacement of Na+ by Li+. The decrease of the M2–oxygen coordination number correlates with a straightening of the tetrahedral chains which are slightly kinked in aegirine and fully extended in Li–aegirine (O3-O3-O3 bridging angle = 174.2(1)° and 180.8(1)° respectively). Small variations of individual and mean Si-O bond lengths and distinct changes in O-Si-O bond angles were also found. Within the Fe3+O6 – M1 octahedra, structural rearrangements mainly affect the O-O interatomic distances (= edges of the octahedra). At 85 K, the compounds Na1- x Li x FeSi2O6 with Li+ concentrations x > 0.75 crystallize in the space group P21/c. For the compounds with x < 0.75, no phase transition from C2/c → P21/c was observed down to low temperatures (30 K). A x – T phase diagram for the stability of the low temperature P21/c structure is provided. The characteristica of the P21/c low temperature form of the (Na,Li)FeSi2O6 compounds agree with those of pure LiFeSi2O6, recently described by Redhammer et al. (2001).