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Younan Xia

Bio: Younan Xia is an academic researcher from The Wallace H. Coulter Department of Biomedical Engineering. The author has contributed to research in topics: Nanocages & Nanowire. The author has an hindex of 216, co-authored 943 publications receiving 175757 citations. Previous affiliations of Younan Xia include Washington University in St. Louis & University of Texas at Dallas.


Papers
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Journal ArticleDOI
TL;DR: A smart release system responsive to near‐infrared (NIR) light is developed for intracellular drug delivery, demonstrating that the DOX trapped in the nanoparticles can be efficiently released into the cytosol under NIR irradiation, resulting in enhanced anticancer activity.
Abstract: A smart release system responsive to near-infrared (NIR) light is developed for intracellular drug delivery. The concept is demonstrated by coencapsulating doxorubicin (DOX) (an anticancer drug) and IR780 iodide (IR780) (an NIR-absorbing dye) into nanoparticles made of a eutectic mixture of naturally occurring fatty acids. The eutectic mixture has a well-defined melting point at 39 °C, and can be used as a biocompatible phase-change material for NIR-triggered drug release. The resultant nanoparticles exhibit prominent photothermal effect and quick drug release in response to NIR irradiation. Fluorescence microscopy analysis indicates that the DOX trapped in the nanoparticles can be efficiently released into the cytosol under NIR irradiation, resulting in enhanced anticancer activity. A new platform is thus offered for designing effective intracellular drug-release systems, holding great promise for future cancer therapy.

153 citations

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TL;DR: In this paper, it was shown that thin films of camphorsulphonic acid-doped polyaniline spin from chloroform or NMP have a coil-like conformation and shorter conjugation length.
Abstract: It is shown that thin films of camphorsulphonic acid-doped polyaniline spun from chloroform or NMP have a coil-like conformation and shorter conjugation length while those films spun from m-cresol have an expanded coil-like conformation and longer conjugation length. The coil-like conformation can be irreversibly converted to the expanded coil-like conformation by exposure to m-cresol vapor at room temperature

152 citations

Journal ArticleDOI
TL;DR: In this paper, a solution-based method for the large-scale synthesis of selenium nanowires was described, where trigonal Se seeds were formed during sonication and grew over the course of hours at the expense of amorphous Se colloids in a process similar to Ostwald ripening.
Abstract: This paper describes a solution-based method for the large-scale synthesis of selenium nanowires. Sonication was used as the driving force for both nucleation and dispersion. The trigonal Se seeds were formed during sonication and grew over the course of hours at the expense of the amorphous Se colloids in a process similar to Ostwald ripening. The resultant nanowires were typically single crystals of trigonal Se whose morphologies could be tuned by adjusting the reaction conditions. A variety of solvents are demonstrated for use with this process. We also demonstrate patterned growth of these nanowires on substrates to form extensive 2D networks and isolated clusters. The morphologies of the products were examined with a combination of microscopic and spectroscopic techniques.

152 citations

Journal ArticleDOI
TL;DR: Realization of stretchable electrodes has been explored with a number of different approaches to generate the stretchable structures of metals, including using a composite material made of an elastomer and conducting metal or carbon nanotubes.
Abstract: Stretchable electrodes have gained ever-increasing interest for a wide range of applications including smart clothing, [ 1 ] dielectric elastomer actuators (DEAs), [ 2 ] stretchable and rollable displays, [ 3 ] and fl exible electronics. [ 4 ] The required strain varies depending on the application. For example, a stretchable display needs about 10 to 30% strain, but more than 100% strain is desired for DEAs. Realization of stretchable electrodes has been explored with a number of different approaches. One of them is to generate the stretchable structures of metals. [ 5 ] Inplane S-shaped [ 6 ] or z-shaped [ 7 ] metal strips, or out-of-plane wavy geometry [ 8 ] can have a large net elongation. Although a large strain ( ≈ 60%) without electrical failure has been reported, fabrication of a fi ne-structured electrode is yet to be achieved. Another approach is to use a composite material made of an elastomer and conducting metal fi llers or carbon nanotubes. [ 9 ]

152 citations

Journal ArticleDOI
TL;DR: In this article, the authors showed that poly(benzobisimidazobenzophenanthroline) (BBL) nanobelts can be prepared by a simple high-yield, solution-phase process.
Abstract: We have found that poly(benzobisimidazobenzophenanthroline) (BBL) nanobelts can be prepared by a simple high-yield, solution-phase process, which enables dispersions of the nanobelts in a large number of solvents including environmentally benign solvents such as methanol and water. Characterization of the nanobelts by transmission electron and atomic force microscopies, electron diffraction, and X-ray diffraction showed that the BBL polymer chains are oriented parallel to the long axis of each nanobelt. This unique packing motif is unlike the reported packing of polymer chains in other nanostructures, such as poly(3-hexylthiophene) nanowires, where the polymer backbone packs face-to-face along the nanowire direction. This unusual molecular packing in BBL nanobelts is explained by the rather strong intermolecular interactions, which are a result of the rigid and planar polymer chains. We investigated electron transport in single nanobelts and nanobelt networks via field-effect transistors and observed mobi...

151 citations


Cited by
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01 May 1993
TL;DR: Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems.
Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

29,323 citations

28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Journal ArticleDOI
TL;DR: A review of gold nanoparticles can be found in this article, where the most stable metal nanoparticles, called gold colloids (AuNPs), have been used for catalysis and biology applications.
Abstract: Although gold is the subject of one of the most ancient themes of investigation in science, its renaissance now leads to an exponentially increasing number of publications, especially in the context of emerging nanoscience and nanotechnology with nanoparticles and self-assembled monolayers (SAMs). We will limit the present review to gold nanoparticles (AuNPs), also called gold colloids. AuNPs are the most stable metal nanoparticles, and they present fascinating aspects such as their assembly of multiple types involving materials science, the behavior of the individual particles, size-related electronic, magnetic and optical properties (quantum size effect), and their applications to catalysis and biology. Their promises are in these fields as well as in the bottom-up approach of nanotechnology, and they will be key materials and building block in the 21st century. Whereas the extraction of gold started in the 5th millennium B.C. near Varna (Bulgaria) and reached 10 tons per year in Egypt around 1200-1300 B.C. when the marvelous statue of Touthankamon was constructed, it is probable that “soluble” gold appeared around the 5th or 4th century B.C. in Egypt and China. In antiquity, materials were used in an ecological sense for both aesthetic and curative purposes. Colloidal gold was used to make ruby glass 293 Chem. Rev. 2004, 104, 293−346

11,752 citations