Molecular wire construction using DNA-directed self-assembly of multi-walled carbon nanotubes (MWNTs) has been attempted. MWNTs were selected owing to their exceptional electrical and structural properties. DNA, which...
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Molecular wire construction using DNA-directed self-assembly of multi-walled carbon nanotubes (MWNTs) has been attempted. MWNTs were selected owing to their exceptional electrical and structural properties. DNA, which possesses specific molecular recognition properties, served as the engine for the assembly. Non-crosshybridizing (NCH) sequences were designed to impart specificity and high throughput reaction. Stepwise manufacturing of the wire was accomplished by first functionalizing the NCH 20 base pair single-stranded sequences to the tips of MWNT using amide linkage. The adducts were then utilized to self-assemble 1D nanotube wire through DNA hybridization reactions between two complementary ssDNAs functionalized to the MWNT tips. TEM, epi-fluorescent microscopy and AFM analyses showed successful assemblies of micrometer-scale 1D MWNT-DNA wires, ranging from 2.7-20 mum. The results demonstrate great potentials of the DNA-guided self-assembly process, which would provide an uncomplicated, versatile and inexpensive way to manufacture micrometer-scale molecular wires.
In this study, stable air/liquid interfaces and high-aspect ratio polymer micro membranes with complex and controlled structures were formed within microfluidic channels. The air/liquid interfaces were formed at hydro...
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In this study, stable air/liquid interfaces and high-aspect ratio polymer micro membranes with complex and controlled structures were formed within microfluidic channels. The air/liquid interfaces were formed at hydrophilic/hydrophobic boundaries defined by patterned and alkanethiols treated Cu surfaces. The two-phase interfaces were further utilized for interfacial polymerization with two immiscible liquid phases containing the reagents for polymer membrane in the microchannel, to generate polymer micro membranes with not only complex in-plane shapes but also z-direction configurations. To demonstrate this method, high quality and complex nylon membranes were fabricated in microchannels. Straight membranes as long as 15mm, 50 mum thick and 500 mum tall in a microfluidic channel were successfully fabricated, and membranes with different structures were realized.
The urgent need in the field of nanotechnology is functional, reliable, and scalable techniques for more complicated and controlled nanostructures in order to realize nanoscale materials and devices that have practica...
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The urgent need in the field of nanotechnology is functional, reliable, and scalable techniques for more complicated and controlled nanostructures in order to realize nanoscale materials and devices that have practical use and more capability than existing technologies. This paper addresses this need by presenting an in vitro protocol to select large non-crosshybridizing (NCH) libraries of oligonucleotides that provide a large address space of DNA sequences with which to increase both complexity and control in DNA-directed self-assembly processes. The selection protocol was experimentally verified and confirmed. The resultant large NCH libraries would allow self-assembling complex nanostructures with more precise control, leading to reliable, scaled-up, cost-effective manufacturing of nanoscale devices and systems.
Intrusion detection is the process of monitoring the events occurring in a computer system or network and analyzing them for signs of intrusions, defined as attempts to compromise the confidentiality, integrity, avail...
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Intrusion detection is the process of monitoring the events occurring in a computer system or network and analyzing them for signs of intrusions, defined as attempts to compromise the confidentiality, integrity, availability, or to bypass the security mechanisms of a computer or net-work. This paper proposes the development of an Intrusion Detection program (IDP) which could detect known attack patterns. An IDP does not eliminate the use of any preventive mechanism but it works as the last defensive mechanism in securing the system. Three variants of genetic programming techniques namely Linear Ge-netic programming (LGP), Multi-Expression programming (MEP) and Gene Expression programming (GEP) were evaluated to design IDP. Several indices are used for comparisons and a detailed analysis of MEP technique is provided. Empirical results reveal that genetic programming technique could play a major role in developing IDP, which are light weight and accurate when compared to some of the conventional intrusion detection systems based on machine learning paradigms.
This study presents preliminary results of a randomized controlled trial comparing a novel passive arm orthosis training system, the Therapy Wilmington Robotic Exoskeleton (T-WREX), with conventional self-directed upp...
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This study presents preliminary results of a randomized controlled trial comparing a novel passive arm orthosis training system, the Therapy Wilmington Robotic Exoskeleton (T-WREX), with conventional self-directed upper extremity exercises. Chronic stroke survivors (n = 23) with moderate to severe upper limb hemiparesis trained three times per week for eight weeks with minimal supervision from an occupational therapist. Both groups demonstrated significant improvements in arm movement ability according to the Fugl-Meyer (3.7 point mean improvement in T-WREX group, p = 0.001, and 2.7 point improvement in control group, p = 0.003). Individuals who completed T-WREX training also demonstrated significant gains in self-rated quality of arm movement on the Motor Activity Log (p=0.05), and showed a trend towards greater gains on all clinical measures, although this trend was not significant at the current study size. Post-treatment surveys revealed a subjective preference for T-WREX training over conventional gravity-supported exercises. These preliminary results suggest that the T-WREX is a safe device feasible for clinical use, and effective in enhancing upper extremity motor recovery and patient motivation. Next steps are discussed.
The accumulation of genomic and proteomic data of many organisms presents an opportunity to analyze entire phylogenetic trees in a systematic, quantified manner. The universal tree of life, constructed by genomic data...
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Lattice Boltzmann algorihms are a mesoscopic representation of nonlinear continuum physics (like Navier-Stokes, magnetohydrodynamics (MHD), Gross-Pitaevskii equations) which are ideal for parallel supercomputers becau...
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This paper provides an overview of quantitative and qualitative outcome of the national program for e-learning in Taiwan (ELNP for short). The national program was planned and initiated in 2002 by the National science...
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This paper provides an overview of quantitative and qualitative outcome of the national program for e-learning in Taiwan (ELNP for short). The national program was planned and initiated in 2002 by the National science Council. Taiwan government wished to promote e-learning industry and make all people have same opportunity to learn knowledge via e-learning. A five-year national program for e-learning started from 2003. This paper shows both of quantitative and qualitative outcomes of national program in the past four years from four different ways: public welfare, academic researching output, e-learning industry, technological results.
Numerous genome projects have produced a large and ever increasing amount of genomic sequence data. However, the biological functions of many proteins encoded by the sequences remain unknown. Protein function annotati...
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With a very modest investment in computer hardware and the open source local data manger (LDM) software from UCAR's Unidata program Center, an individual researcher can receive a variety of NEXRAD Level III gridde...
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ISBN:
(纸本)9780784409275
With a very modest investment in computer hardware and the open source local data manger (LDM) software from UCAR's Unidata program Center, an individual researcher can receive a variety of NEXRAD Level III gridded rainfall products, and the unprocessed Level II data in real-time from most NEXRAD radars. Additionally, the National Climatic Data Center has vast archives of these products and Level II data. Still, significant obstacles remain in order to unlock the full potential of the data. One set of obstacles is related to effective management of multi-terrabyte data sets: storing, compressing, and backing up. A second set of obstacles, for hydrologists and hydrometeorologists in particular, is that the NEXRAD Level III products are not well suited for application in hydrology. There is a strong need for the generation of high-quality products directly from the Level II data with well-documented steps that include quality control, removal of false echoes, rainfall estimation algorithms with variety of corrections, coordinate conversion and georeferencing, conversion to a convenient data format(s), and integration with GIS. For hydrologists it is imperative that these procedures are basin-centered as opposed to radar-centered. Thirdly, the amount of data present in a multi-year, multi-radar dataset is such that simple cataloging and indexing of the data is not sufficient. Rather, sophisticated metadata extraction and management techniques are required. The authors describe and discuss the Hydro-NEXRAD software system that addresses the above three challenges. With support from the National science Foundation through its ITR program, the authors are developing a basin-centered framework for addressing all these issues in a comprehensive manner, tailored specifically for use of NEXRAD data in hydrology and hydrometeorology. Through a flexible web interface users can search a large metadata database base, managed by a relational database, for subsets of interest. Well
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