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Yu Huang

Bio: Yu Huang is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Medicine & Materials science. The author has an hindex of 136, co-authored 1492 publications receiving 89209 citations. Previous affiliations of Yu Huang include The Chinese University of Hong Kong & Samsung.


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TL;DR: Apelin treatment modulates the abnormal aortic vascular tone in response to Ang II and acetylcholine by potentiating phosphorylation of Akt and eNOS in diabetic mice, suggesting that the apelin-APJ system might be an important regulator of vascular function in diabetes.
Abstract: Objective : The apelin receptor APJ is a putative receptor protein related to angiotensin (Ang) type 1 receptor. The apelin-APJ system has been implicated in diabetes, but its role in the diabetic vasculature and the mechanisms involved remain unclear. Our aim here was to explore the regulatory role of apelin in the aortic vascular tone in diabetic mice. Methods : A Multi Myograph system was used to determine the isometric vessel tone in aortic rings from diabetic db / db and control db / m + mice. The mRNA, phosphorylation, and protein levels of APJ, Akt, and endothelial nitric oxide synthase (eNOS) were analyzed by reverse transcription–polymerase chain reaction and Western blotting, respectively. Results : There is depressed expression of APJ, enhanced contractile response to Ang II, and reduced relaxation response to acetylcholine in aortas from db / db mice. Apelin treatment strikingly reversed the altered aortic vascular responsiveness to Ang II and acetylcholine in db / db mice, both of which were abolished by the eNOS inhibitor N G-nitro-l-arginine methyl ester. Finally, in db / db mice, considerable increases in phosphorylation of Akt on serine 473 and of eNOS on serine 1177 were found in aortas pretreated with apelin. Conclusions : Apelin treatment modulates the abnormal aortic vascular tone in response to Ang II and acetylcholine by potentiating phosphorylation of Akt and eNOS in diabetic mice, suggesting that the apelin-APJ system might be an important regulator of vascular function in diabetes.

170 citations

Journal ArticleDOI
TL;DR: Electrical measurements show nearly perfect p-channel enhancement mode transistor behavior with a normalized transconductance of 0.3 mS/microm, field-effect hole mobility of 168 cm2/V.s, and on/off ratio>10(7), demonstrating the best performing device from intrinsic silicon nanowires.
Abstract: We report the formation of PtSi nanowires, PtSi/Si/PtSi nanowire heterostructures, and nanodevices from such heterostructures. Scanning electron microscopy studies show that silicon nanowires can be converted into PtSi nanowires through controlled reactions between lithographically defined platinum pads and silicon nanowires. High-resolution transmission electron microscopy studies show that PtSi/Si/PtSi heterostructure has an atomically sharp interface with epitaxial relationships of Si[110]//PtSi[010] and Si(111)//PtSi(101). Electrical measurements show that the pure PtSi nanowires have low resistivities approximately 28.6 microOmega.cm and high breakdown current densities>1x10(8) A/cm2. Furthermore, using single crystal PtSi/Si/PtSi nanowire heterostructures with atomically sharp interfaces, we have fabricated high-performance nanoscale field-effect transistors from intrinsic silicon nanowires, in which the source and drain contacts are defined by the metallic PtSi nanowire regions, and the gate length is defined by the Si nanowire region. Electrical measurements show nearly perfect p-channel enhancement mode transistor behavior with a normalized transconductance of 0.3 mS/microm, field-effect hole mobility of 168 cm2/V.s, and on/off ratio>10(7), demonstrating the best performing device from intrinsic silicon nanowires.

170 citations

Journal ArticleDOI
TL;DR: Baicalein is a potent free radical scavenger and xanthine oxidase inhibitor, thus improving endothelial function and conferring cardiovascular protective actions against oxidative stress-induced cell injury, and inhibiting thrombin-induced production of plasminogen activator inhibitor-1, and interleukin-1beta- and tumor necrosis factor-alpha-induced adhesion molecule expression in cultured human umbilical vein endothelial cells.
Abstract: The dried roots of Scutellaria baicalensis (S. baicalensis) Georgi (common name: Huangqin in China) have been widely employed for many centuries in traditional Chinese herbal medicine as popular antibacterial and antiviral agents. They are effective against staphylococci, cholera, dysentery, pneumococci and influenza virus. Baicalein, one of the major flavonoids contained in the dried roots, possesses a multitude of pharmacological activities. The glycoside of baicalein, baicalin is a potent anti-inflammatory and anti-tumor agent. This review describes the biological properties of baicalein (Table 1), which are associated with the prevention and treatment of cardiovascular diseases. Baicalein is a potent free radical scavenger and xanthine oxidase inhibitor, thus improving endothelial function and conferring cardiovascular protective actions against oxidative stress-induced cell injury. Baicalein lowers blood pressure in renin-dependent hypertension and the in vivo hypotensive effect may be partly attributed to its inhibition of lipoxygenase, resulting in reduced biosynthesis and release of arachidonic acid-derived vasoconstrictor products. On the other hand, baicalein enhances vasoconstricting sensitivity to receptor-dependent agonists such as noradrenaline, phenylephrine, serotonin, U46619 and vasopressin in isolated rat arteries. The in vitro effect is likely caused by inhibition of an endothelial nitric oxide-dependent mechanism. The anti-thrombotic, anti-proliferative and anti-mitogenic effects of the roots of S. baicalensis and baicalein are also reported. Baicalein inhibits thrombin-induced production of plasminogen activator inhibitor-1, and interleukin-1beta- and tumor necrosis factor-alpha-induced adhesion molecule expression in cultured human umbilical vein endothelial cells. The pharmacological findings have highlighted the therapeutic potentials of using plant-derived baicalein and its analogs for the treatment of arteriosclerosis and hypertension.

170 citations

Journal ArticleDOI
TL;DR: The results reported herein suggest that enhanced catalysts can be developed by engineering the structure/composition of the nanocry crystals by simply treating the highly composition segregated Pt-Ni nanocrystals with acetic acid overnight, which are far better than those of commercial Pt/C catalyst.
Abstract: Highly open metallic nanoframes represent an emerging class of new nanostructures for advanced catalytic applications due to their fancy outline and largely increased accessible surface area. However, to date, the creation of bimetallic nanoframes with tunable structure remains a challenge. Herein, we develop a simple yet efficient chemical method that allows the preparation of highly composition segregated Pt-Ni nanocrystals with controllable shape and high yield. The selective use of dodecyltrimethylammonium chloride (DTAC) and control of oleylamine (OM)/oleic acid (OA) ratio are critical to the controllable creation of highly composition segregated Pt-Ni nanocrystals. While DTAC mediates the compositional anisotropic growth, the OM/OA ratio controls the shapes of the obtained highly composition segregated Pt-Ni nanocrystals. To the best of our knowledge, this is the first report on composition segregated tetrahexahedral Pt-Ni NCs. Importantly, by simply treating the highly composition segregated Pt-Ni nanocrystals with acetic acid overnight, those solid Pt-Ni nanocrystals can be readily transformed into highly open Pt-Ni nanoframes with hardly changed shape and size. The resulting highly open Pt-Ni nanoframes are high-performance electrocatalysts for both oxygen reduction reaction and alcohol oxidations, which are far better than those of commercial Pt/C catalyst. Our results reported herein suggest that enhanced catalysts can be developed by engineering the structure/composition of the nanocrystals.

165 citations

Journal ArticleDOI
TL;DR: In this article, a facile one-pot strategy was proposed to synthesize highly dispersive PtNi octahedra directly on various carbon materials without using any bulky capping agents.
Abstract: Bimetallic PtNi nanocrystals represent an emerging class of newly discovered electrocatalysts which are expected to exhibit exciting oxygen reduction reaction (ORR) activity. Colloidal syntheses have been proven to be suitable for controlling PtNi nanocrystals with well-defined morphologies and tunable compositions with the use of capping agents or ligands. However, these colloidal PtNi nanocrystals have inherent limitations associated with the ligand-covered surfaces, which not only limit the free access of surface active sites but also hinder electron transport between the catalyst and the support, leading to deteriorated ORR performance. Herein, we report a facile one-pot strategy to synthesize highly dispersive PtNi octahedra directly on various carbon materials without using any bulky capping agents, which enhances the surface exposure of the PtNi octahedra and their catalytic activity over ORR while largely reduces the preparation costs. The obtained octahedral PtNi/C catalysts have high ORR activities of 2.53 mA cm−2 and 1.62 A mgPt−1 at 0.9 V versus RHE, which are far better than those of commercial Pt/C catalysts (0.131 mA cm−2 and 0.092 A mgPt−1, all the ORR measurements were performed at room temperature in O2-purged 0.1 M HClO4 solutions at a sweep rate of 10 mV s−1). This strategy has been extended to fabricate trimetallic PtNiCo octahedra on carbon black with further enhanced activities up to 3.88 mA cm−2 and 2.33 A mgPt−1 at 0.9 V versus RHE. The octahedral PtNiCo/C catalyst is also more stable than the commercial Pt/C under the ORR conditions and shows small activity change after 6000 potential sweeps. The work demonstrates that the carbon-supported Pt-based materials reported herein are promising material candidates with enhanced performances for practical electrocatalytic applications.

165 citations


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08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

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