1,177 research outputs found
TUMOR NECROSIS FACTOR BETA (TNF-P) INDUCES BINDING OF THE NF-KB TRANSCRIPTION FACTOR TO A HIGH-AFFINITY KB ELEMENT IN THE TNF-BETA PROMOTER
Human Therapies as a Successful Liaison between Chemistry and Biology
The development of novel therapies is arguably one of the most important roles of modern chemistry and biology. Here, we shed light on a particular class of human therapies in which synthetic chemical entities are attached to expressed biologicals (proteins) with the goal to enhance clinical activity. We focus our discussion on three key categories of these derivatized biologicals: proteins conjugated with biologically inert molecules, proteins conjugated with biologically active small molecules and peptides (e.g., antibody drug conjugates [ADCs]), and proteins conjugated with radio isotopes. Overall, it is apparent by the impact on clinical activity as well as the commercial success that chemical modification of recombinant proteins is becoming of increasing importance. Therefore, we argue that deeper understanding of the chemical reactions between large proteinaceous molecules and small molecule reagents will allow for more precise and elegant solutions to existing limitations in this field
Developmental and tissue-specific expression of the Q5k gene
Expression of the Q5k gene was examined by
northern blot analysis and polymerase chain reaction
(PCR) in the AKR mouse and various cell lines, each of
the H-2k haplotype. Our results show that Q5k mRNA is
present during the whole postimplantational development
of the AKR embryo/fetus (gestation day 6 to 15). In the
juvenile mouse (week 2 to 4) transcription of the Q5k
gene persisted in all organs examined. In contrast, in the
adult animal expression of the Q5k gene was limited to
the thymus and uterus of the pregnant mouse. Upon malignant
transformation, the amount of Q5k-specific mRNA
increased dramatically in thymus and could also be
observed in the spleen of thymoma bearing animals. Expression
of the Q5k gene was also detectable in several
transformed mouse cell lines. Mitogen stimulation or
treatment with cytokines induced Q5k expression in
primary spleen cell cultures. A possible explanation for
the tissue-restricted expression in the adult AKR mouse
is discussed
A high-reflectivity high-Q micromechanical Bragg-mirror
We report on the fabrication and characterization of a micromechanical
oscillator consisting only of a free-standing dielectric Bragg mirror with high
optical reflectivity and high mechanical quality. The fabrication technique is
a hybrid approach involving laser ablation and dry etching. The mirror has a
reflectivity of 99.6%, a mass of 400ng, and a mechanical quality factor Q of
approximately 10^4. Using this micromirror in a Fabry Perot cavity, a finesse
of 500 has been achieved. This is an important step towards designing tunable
high-Q high-finesse cavities on chip.Comment: 3 pages, 2 figure
Self-cooling of a micro-mirror by radiation pressure
We demonstrate passive feedback cooling of a mechanical resonator based on
radiation pressure forces and assisted by photothermal forces in a high-finesse
optical cavity. The resonator is a free-standing high-reflectance micro-mirror
(of mass m=400ng and mechanical quality factor Q=10^4) that is used as
back-mirror in a detuned Fabry-Perot cavity of optical finesse F=500. We
observe an increased damping in the dynamics of the mechanical oscillator by a
factor of 30 and a corresponding cooling of the oscillator modes below 10 K
starting from room temperature. This effect is an important ingredient for
recently proposed schemes to prepare quantum entanglement of macroscopic
mechanical oscillators.Comment: 11 pages, 9 figures, minor correction
cDNA Cloning of Biologically Active Chicken Interleukin-18
By searching a chicken EST database, we identified a cDNA clone that appeared to contain the entire open
reading frame (ORF) of chicken interleukin-18 (ChIL-18). The encoded protein consists of 198 amino acids
and exhibits approximately 30% sequence identity to IL-18 of humans and various others mammals. Sequence
comparisons reveals a putative caspase-1 cleavage site at aspartic acid 29 of the primary translation product,
indicating that mature ChIL-18 might consist of 169 amino acids. Bacterially expressed ChIL-18 in which the
N-terminal 29 amino acids of the putative precursor molecule were replaced by a histidine tag induced the
synthesis of interferon-γ (IFN-γ) in cultured primary chicken spleen cells, indicating that the recombinant
protein is biologically active
Optical interconnect solution with plasmonic modulator and Ge photodetector array
We report on an optical chip-to-chip interconnect solution, thereby demonstrating plasmonics as a solution for ultra-dense, high-speed short-reach communications. The interconnect comprises a densely integrated plasmonic Mach-Zehnder modulator array that is packaged with standard driving electronics. On the receiver side, a germanium photodetector array is integrated with trans-impedance amplifiers. A multicore fiber provides a compact optical interface to the array. We demonstrate 4 × 20 Gb/s on-off keying signaling with direct detection.ISSN:1041-1135ISSN:1941-017
Counting defects with the two-point correlator
We study how topological defects manifest themselves in the equal-time
two-point field correlator. We consider a scalar field with Z_2 symmetry in 1,
2 and 3 spatial dimensions, allowing for kinks, domain lines and domain walls,
respectively. Using numerical lattice simulations, we find that in any number
of dimensions, the correlator in momentum space is to a very good approximation
the product of two factors, one describing the spatial distribution of the
defects and the other describing the defect shape. When the defects are
produced by the Kibble mechanism, the former has a universal form as a function
of k/n, which we determine numerically. This signature makes it possible to
determine the kink density from the field correlator without having to resort
to the Gaussian approximation. This is essential when studying field dynamics
with methods relying only on correlators (Schwinger-Dyson, 2PI).Comment: 11 pages, 7 figures
Cross-Over between universality classes in a magnetically disordered metallic wire
In this article we present numerical results of conduction in a disordered
quasi-1D wire in the possible presence of magnetic impurities. Our analysis
leads us to the study of universal properties in different conduction regimes
such as the localized and metallic ones. In particular, we analyse the
cross-over between universality classes occurring when the strength of magnetic
disorder is increased. For this purpose, we use a numerical Landauer approach,
and derive the scattering matrix of the wire from electron's Green's function.Comment: Final version, accepted for publication in New Journ. of Physics, 27
pages, 28 figures. Replaces the earlier shorter preprint arXiv:0910.427
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