3,741 research outputs found
Optimization-Based Peptide Mass Fingerprinting for Protein Mixture Identification
*Motivation:* In current proteome research, peptide sequencing is probably the most widely used method for protein mixture identification. However, this peptide-centric method has its own disadvantages such as the immense volume of tandem Mass Spectrometry (MS) data for sequencing peptides. With the fast development of technology, it is possible to investigate other alternative techniques. Peptide Mass Fingerprinting (PMF) has been widely used to identify single purified proteins for more than 15 years. Unfortunately, this technique is less accurate than peptide sequencing method and cannot handle protein mixtures, which hampers the widespread use of PMF technique. If we can remove these limitations, PMF will become a useful tool in protein mixture identification. 
*Results:* We first formulate the problem of PMF protein mixture identification as an optimization problem. Then, we show that the use of some simple heuristics enables us to find good solutions. As a result, we obtain much better identification results than previous methods. Moreover, the result on real MS data can be comparable with that of the peptide sequencing method. Through a comprehensive simulation study, we identify a set of limiting factors that hinder the performance of PMF method in protein mixtures. We argue that it is feasible to remove these limitations and PMF can be a powerful tool in the analysis of protein mixtures
Q-enhanced fold-and-bond MEMS inductors
This work presents a novel coil fabrication technology
to enhance quality factor (Q factor) of microfabricated inductors
for implanted medical wireless sensing and data/power transfer
applications. Using parylene as a flexible thin-film device
substrate, a post-microfabrication substrate folding-and-bonding
method is developed to effectively increase the metal thickness of
the surface-micromachined inductors, resulting in their lower
self-resistance so their higher quality factor. One-fold-and-bond
coils are successfully demonstrated as an example to verify the
feasibility of the fabrication technology with measurement results
in good agreements with device simulation. Depending on target
specifications, multiple substrate folding-and-bonding can be
extensively implemented to facilitate further improved electrical
characteristics of the coils from single fabrication batch. Such Q-enhanced
inductors can be broadly utilized with great potentials
in flexible integrated wireless devices/systems for intraocular
prostheses and other biomedical implants
Interaction-induced Metal to Topological Insulator Transition
By means of exact diagonalizations, the Bernevig-Hughes-Zhang model at
quarter-filling in the limit of strong Hubbard on-site repulsion is
investigated. We find that the non-interacting metallic state will be turned
into a Chern insulator with saturated magnetization under strong correlations.
That is, at such a metal-insulator transition, both the topological and the
magnetic properties of the system are changed due to spontaneous breaking of
time reversal symmetry in the ground states. According to our findings, this
topological phase transition seems to be of first order. Our results illustrate
the interesting physics in topological Mott transitions and provide guidance to
the search of more interaction-induced topological phases in similar systems.Comment: 6 pages, 4 figure
A Web-Services-Based P2P Computing-Power Sharing Architecture
As demands of data processing and computing power are increasing, existing information system architectures become insufficient. Some organizations try to figure out how to keep their systems work without purchasing new hardware and software. Therefore, a Webservices-based model which shares the resource over the network like a P2P network will be proposed to meet this requirement in this paper. In addition, this paper also discusses some problems about security, motivation, flexibility, compatibility and workflow management for the traditional P2P power sharing models. Our new computing architecture - Computing Power Services (CPS) - will aim to address these problems. For the shortcomings about flexibility, compatibility and workflow management, CPS utilizes Web Services and Business Process Execution Language (BPEL) to overcome them. Because CPS is assumed to run in a reliable network where peers trust each other, the concerns about security and motivation will be negated. In essence, CPS is a lightweight Web-Services-based P2P power sharing environment and suitable for executing computing works in batch in a reliable networ
{μ-6,6′-Dimethoxy-2,2′-[ethane-1,2-diylbis(nitrilomethanylylidene)]diphenolato-1κ4 O 6,O 1,O 1′,O 6′;2κ4 O 1,N,N′,O 1′}(methanol-1κO)(tetrafluoridoborato-1κ2 F,F′)-2-copper(II)-1-sodium
In the dinuclear salen-type title complex, [CuNa(BF4)(C18H18N2O4)(CH3OH)], the CuII atom is chelated by two O atoms and two N atoms of the deprotonated Schiff base in a square-planar geometry. The Na atom is seven-coordinate as it is linked to four O atoms of the same Schiff base ligand, one O atom of the methanol and two tetrafluoridoborate F atoms. The remaining two F atoms of the anion are disordered over two sites in a 0.598 (18):0.402 (18) ratio
catena-Poly[[bis(μ-2-formyl-6-methoxyphenolato-1:2κ4 O 1,O 6:O 1,O 2)copper(II)sodium]-μ-tetrafluoridoborate-1:1′κ2 F:F′]
In the title heterodinuclear complex, [CuNa(BF4)(C8H7O3)2]n, the CuII ion is four-coordinated by four O atoms of two 2-formyl-6-methoxyphenolate ligands, giving rise to a square-planar geometry. The Na+ ion is six-coordinated by four O atoms from the two ligands and two F atoms of two tetrafluoridoborate anions. The tetrafluoridoborate anion links the Na+ ions, forming a one-dimensional structure along [001]. Three F atoms of the tetrafluoridoborate anion are disordered over two sets of sites, with an occupancy ratio of 0.790 (11):0.210 (11)
Endogenous innovation scale and patent policy in a monetary Schumpeterian growth model
This paper develops a monetary R&D-driven endogenous growth model featuring endogenous innovation scales and the price-marginal cost markup. To endogenize the step size of quality improvement, we propose a trade-off mechanism between the risk of innovation failure and the benefit of innovation success in R&D firms. Several findings emerge from the analysis. First, a rise in the nominal interest rate decreases economic growth; however, its relationship with social welfare is ambiguous. Second, either strengthening patent protection or raising the professional knowledge of R&D firms leads to an ambiguous effect on economic growth. Third, the Friedman rule of a zero nominal interest rate fails to be optimal in view of the social welfare maximum. Finally, our numerical analysis indicates that the extent of patent protection and the level of an R&D firm’s professional knowledge play a crucial role in determining the optimal interest rate
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