| 1. |
- Morrison, Hilary G., et al.
(author)
-
Genomic minimalism in the early diverging intestinal parasite Giardia lamblia
- 2007
-
In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 317:5846, s. 1921-1926
-
Journal article (peer-reviewed)abstract
- The genome of the eukaryotic protist Giardia lamblia, an important human intestinal parasite, is compact in structure and content, contains few introns or mitochondrial relics, and has simplified machinery for DNA replication, transcription, RNA processing, and most metabolic pathways. Protein kinases comprise the single largest protein class and reflect Giardia's requirement for a complex signal transduction network for coordinating differentiation. Lateral gene transfer from bacterial and archaeal donors has shaped Giardia's genome, and previously unknown gene families, for example, cysteine-rich structural proteins, have been discovered. Unexpectedly, the genome shows little evidence of heterozygosity, supporting recent speculations that this organism is sexual. This genome sequence will not only be valuable for investigating the evolution of eukaryotes, but will also be applied to the search for new therapeutics for this parasite.
|
|
| 2. |
- Spirkoska, D., et al.
(author)
-
Structural and optical properties of high quality zinc-blende/wurtzite GaAs nanowire heterostructures
- 2009
-
In: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121. ; 80:24
-
Journal article (peer-reviewed)abstract
- The structural and optical properties of three different kinds of GaAs nanowires with 100% zinc-blende structure and with an average of 30% and 70% wurtzite are presented. A variety of shorter and longer segments of zinc-blende or wurtzite crystal phases are observed by transmission electron microscopy in the nanowires. Sharp photoluminescence lines are observed with emission energies tuned from 1.515 eV down to 1.43 eV when the percentage of wurtzite is increased. The downward shift of the emission peaks can be understood by carrier confinement at the interfaces, in quantum wells and in random short period superlattices existent in these nanowires, assuming a staggered band offset between wurtzite and zinc-blende GaAs. The latter is confirmed also by time-resolved measurements. The extremely local nature of these optical transitions is evidenced also by cathodoluminescence measurements. Raman spectroscopy on single wires shows different strain conditions, depending on the wurtzite content which affects also the band alignments. Finally, the occurrence of the two crystallographic phases is discussed in thermodynamic terms.
|
|
| 3. |
- Balocco, C, et al.
(author)
-
Microwave detection at 110 GHz by nanowires with broken symmetry
- 2005
-
In: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 5:7, s. 1423-1427
-
Journal article (peer-reviewed)abstract
- By using arrays of nanowires with intentionally broken symmetry, we were able to detect microwaves up to 110 GHz at room temperature. This is, to the best of our knowledge, the highest speed that has been demonstrated in different types of novel electronic nanostructures to date. Our experiments showed a rather stable detection sensitivity over a broad frequency range from 100 MHz to 110 GHz. The novel working principle enabled the nanowires to detect microwaves efficiently without a dc bias. In principle, the need for only one high-resolution lithography step and the planar architecture allow an arbitrary number of nanowires to be made by folding a linear array as many times as required over a large area, for example, a whole wafer. Our experiment on 18 parallel nanowires showed a sensitivity of approximately 75 mV dc output/mW of nominal input power of the 110 GHz signal, even though only about 0.4% of the rf power was effectively applied to the structure because of an impedance mismatch. Because this array of nanowires operates simultaneously, low detection noise was achieved, allowing us to detect -25 dBm 110 GHz microwaves at zero bias with a standard setup.
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
- Thelander, Claes, et al.
(author)
-
Fabrication and modeling of a combined gold nanoparticle-carbon nanotube single electron transistor
- 2002
-
In: 7th International Conference on Nanometer-Scale Science and Technology and 21st European Conference on Surface Science.
-
Conference paper (peer-reviewed)abstract
- Scanning probe manipulation has been used to electrically connect two carbon nanotubes to an individual 7 nm gold particle, resulting in a system with multiple tunnel junctions. Single-electron charging effects in the gold particle was found to dominate the electrical transport measurements at T=4.2 K, whereas charging effects in the two carbon nanotube leads appeared as a fine structure. A simulation of the electrical transport in the system has been carried out using SIMON*, which is a Monte Carlo based simulation program for single-electronics. Using this program we have been able to fit a model to the experimental data and to explain the electrical transport characteristics
|
|
| 7. |
- Thelander, Claes, et al.
(author)
-
Nanowire-based one-dimensional electronics
- 2006
-
In: Materials Today. - 1369-7021. ; 9:10, s. 28-35
-
Journal article (peer-reviewed)abstract
- During the last half century, a dramatic downscaling of electronics has taken place, a miniaturization that the industry expects to continue for at least a decade. We present efforts to use the self-assembly of one-dimensional semiconductor nanowires(1) in order to bring new, high-performance nanowire devices as an add-on to mainstream Si technology. The nanowire approach offers a coaxial gate-dielectric-channel geometry that is ideal for further downscaling and electrostatic control, as well as heterostructure-based devices on Si wafers.
|
|
| 8. |
- Bleszynski-Jayich, Ania C., et al.
(author)
-
Imaging a one-electron InAs quantum dot in an InAs/InP nanowire
- 2008
-
In: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121. ; 77:24
-
Journal article (peer-reviewed)abstract
- Nanowire heterostructures define high-quality few-electron quantum dots for nanoelectronics, spintronics, and quantum information processing. We use a cooled scanning probe microscope (SPM) to image and control an InAs quantum dot in an InAs/InP nanowire using the tip as a movable gate. Images of dot conductance vs tip position at T=4.2 K show concentric rings as electrons are added, starting with the first electron. The SPM can locate a dot along a nanowire and individually tune its charge, abilities that will be very useful for the control of coupled nanowire dots.
|
|
| 9. |
- Cano, F., et al.
(author)
-
Partial protection to respiratory syncytial virus (RSV) elicited in mice by intranasal immunization using live staphylococci with surface-displayed RSV-peptides
- 2000
-
In: Vaccine. - 0264-410X .- 1873-2518. ; 18:24, s. 2743-2752
-
Journal article (peer-reviewed)abstract
- A live bacterial vaccine-delivery system based on the food-grade bacterium Staphylococcus carnosus was used for delivery of peptides from the G glycoprotein of human respiratory syncytial virus, subtype A (RSV-A). Three peptides, corresponding to the G protein amino acids, 144-159 (denoted G5), 190-203 (G9) and 171-188 (G4 S), the latter with four cysteine residues substituted for serines, were expressed by recombinant means as surface-exposed on three different bacteria, and their surface accessibility on the bacteria was verified by fluorescence-activated cell sorting (FACS). Intranasal immunization of mice with the live recombinant staphylococci elicited significant anti-peptide as well as anti-virus serum IgG responses of balanced IgG1/IgG2a isotype profiles, and upon viral challenge with 10(5) tissue culture infectious doses(50) (TCID50), lung protection was demonstrated for approximately half of the mice in the G9 and G4 S immunization groups. To our knowledge, this is the first study in which protective immunity to a viral pathogen has been evoked using food-grade bacteria as vaccine-delivery vehicles.
|
|
| 10. |
|
|
