1,658 research outputs found
The politics of fashion: perceptions of power in female clothing and ornamentation as reflected in the sixteenth-century Chinese novel Jin Ping Mei
No full textThis thesis examines issues of female power and influence in sixteenth-century China focusing on how women and their roles were perceived in the changing social environment of the mid-late Ming dynasty. Using aspects of a New Historicist approach, information from contemporary literary and historical sources are analysed alongside each other. With its emphasis on the lives of women and preoccupation with the description of material objects, the late Ming novel Jin Ping Mei forms an important element in the thesis. China in the sixteenth century saw expanding urbanisation, the emergence of a new wealthy merchant class, increasing visibility of women and a questioning of traditional morality. Fashion consciousness, as one of the most conspicuous aspects of the new material culture, is a possible indicator of these trends. Traditional Western theories contend that fashion began in the particular context of Renaissance Europe. However, this study argues that a similar fashion awareness existed in China too, and was manifested in a competitive striving for social status, in this case specifically among women. In contrast to previous studies which downplayed the impact women had on defining traditional Chinese culture, this thesis demonstrates how women and their sartorial choices began to redefine the boundaries of material culture, influencing literati discourse which, in turn, re- influenced female behaviour
Dirac structures and dynamical -matrices
No full textThe purpose of this paper is to establish a connection between various objects such as dynamical r-matrices, Lie bialgebroids, and Lagrangian subalgebras. Our method relies on the theory of Dirac structures and Courant algebroids. In particular, we give a new method of classifying dynamical r-matrices of simple Lie algebras g, and prove that dynamical r-matrices are in one-one correspondence with certain Lagrangian subalgebras of g circle plus g.MathematicsSCI(E)4ARTICLE3835-+5
Influence of the incorporation of metals on the optical properties of MCM-41 and CdSe quantum dots
No full text在本論文中，我們詳細的研究了置入金屬對MCM-41和CdSe的光學性質影響。光激螢光光譜及光激營光激發光譜測量被用來探究其物理性質。這論文主要包括下面兩個部分：
1. 置入金屬對MCM-41和的光學性質影響
我們詳細的研究了置入金屬對MCM-4的光學性質影響。 利用光激螢光光譜及光激營光激發光譜探究一系列置入不同比例鋁成份的多孔氧化矽。我們發現當Si/Al比減少到14的時候，螢光增強了百倍以上。這原因機制來自於多孔氧化矽的帶電氧缺陷。而當金加入多孔氧化矽鋁之中時，利用電子順磁震盪及光激營光激發光譜的研究，我們發現在金奈米顆粒和多孔氧化矽鋁的帶電氧缺陷間有很強的交互作用力，也因此使得螢光光譜的強度劇烈的減弱。
2. Au/CdSe奈米複合物的巨大增強螢光的增強機制
內文討論金和硒化鎘奈米複合物的螢光增強和衰弱的機制。其機制被發現分別來自表面電漿波使得電子電動對變多以及電子由量子點硒化鎘轉移到金奈米粒子的費米能階。由我們提出的機制模型，量子點硒化鎘的螢光增強達到前所未有的140倍。我們的結果可以用來澄清以往利用金屬奈米結構的表面電漿現象在半導體奈米晶體在螢光增強機制上的困惑。我們呈現的機制在半導體奈米粒子在光電儀器上的運用和高效能生物標籤及固態發光體都相當的有用。In this thesis, we report the studies of Influence of the incorporation of metals on the optical properties of MCM-41 and CdSe will be reported. Photoluminescence (PL) and photoluminescence excitation (PLE) measurements are employed to characterize their physical properties. This thesis consists of two parts as described as following.
1. Influence of the incorporation of metals on the optical properties of
MCM-41
We presented the influence of the incorporation of metals on the optical properties of MCM-41. A series of Al-MCM-41 samples with different Al contents were investigated with photoluminescence (PL) and photoluminescence excitation (PLE). PL measurements revealed an enhancement in intensity by two orders as the Si : Al ratio decreases to 14. The transitions involved with charged oxygen vacancies as well as excess defects have been identified. When Au nanoparticles were deposited onto Al-MCM-41, the PL intensity decreases dramatically. With the help of electron paramagnetic resonance (EPR) and PLE, we found that there is a strong interaction between Au nanoparticles and charged oxygen defects, which is responsible for the reduction of related luminescent intensity.
2. Origin of giant emission enhancement in Au/CdSe nanocomposites
A mechanism responsible for the emission enhancement and quenching in Au and CdSe nanocomposites is presented. It is found that the underlying origin arises from the interlay between electron-hole pairs generation by surface plasmon wave and electrons transfer from CdSe quantum dots (QDs) to the Fermi level of Au nanoparticles. Based on our proposed mechanism, the enhancement of CdSe QDs emission can be tuned to reach a factor of up to 140 times, which is the largest value ever reported. It can be used to clarify the confusion in controlling the emission enhancement of semiconductor nanocrystals by using the interaction with surface plasmon of metal nanostructures. The mechanism presented here is very useful for the implementation of semiconductor nanoparticles in optoelectronic devices for applications as high efficiency biolabels and solid state emitters.Contents
Chapter 1.
Introduction 1
1.1 Incorporate metals on mesoporous aluminosilicate MCM-41…………………………....1
1.2 Incorporate nanoparticles Au on nano-crystals semiconductor CdSe………………...….4
1.3 References……………………………………………………..……………………...……6
Chapter 2.
Techniques for measurements 9
2.1 Techniques for optical measurements………………..………..…….9
2.2 Electron paramagnetic resonance (EPR)………………………………..………13
2.3 References….……………………….……..…………………………………..…….14
Chapter 3.
Influence of the incorporation of metals on the optical properties of MCM-41 16
3.1 Introduction …………………………………………………………………….…….…16
3.2 Sample preparation……………… ………………….……………………….……..18
3.3 Experiments……….…………………………………………………………….……..20
3.4 Results and discussion ………………………………………………………….……..20
3.5 Summary ……………………………………………………………………..….….33
3.6 References……………………………………………………………………..….….34
Chapter 4.
Origin of giant emission enhancement in Au/CdSe nanocomposites 37
4.1 Introduction ……………………………………………………………………….…..….37
4.2 Sample preparation……………………………………………………………….…..….38
4.3 Experiment ………………………………………………………………….……....…39
4.4 Results and discussion …………………………………………………………...……39
4.5 Summary ……………………………………………………………………….…..50
4.6 References ……………………………………………………………………….…..52
Chapter 5.
Conclusions 5
Optimization of Enzymatic Gas-Phase Reactions by Increasing the Long-Term Stability of the Catalyst
No full textEnzymatic gas-phase reactions are usually performed in continuous reactors, and thus very stable and active catalysts are required to perform such transformations on cost-effective levels. The present work is concerned with the reduction of gaseous acetophenone to enantiomerically pure (R)-1-phenylethanol catalyzed by solid alcohol dehydrogenase from Lactobacillus brevis (LBADH), immobilized onto glass beads. Initially, the catalyst preparation displayed a half-life of 1 day under reaction conditions at 40 °C and at a water activity of 0.5. It was shown that the observed decrease in activity is due to a degradation of the enzyme itself (LBADH) and not of the co-immobilized cofactor NADP. By the addition of sucrose to the cell extract before immobilization of the enzyme, the half-life of the catalyst preparation (at 40 °C) was increased 40 times. The stabilized catalyst preparation was employed in a continuous gas-phase reactor at different temperatures (25-60 °C). At 50 °C, a space-time yield of 107 g/L/d was achieved within the first 80 h of continuous reaction.
FIGURE 5 in Notes on a new marine peritrichous ciliate (Ciliophora: Peritrichida), Zoothamnium xuianum n. sp., with redescription of Z. paraentzii Song, 1991 from northern China
No full textFIGURE 5. Comparison of some closely related morphotypes. (A, B) Zoothamnium chlamydis (from Hu & Song, 2001). (C, D) Z. plumula (from Song et al., 2002). (E) Z. alternans (from Greeff, 1870). (F) Z. alternans (from Claparède & Lachmann, 1858). (G) Z. alternans (from Kent, 1881). (H, I) Z. sinense (from Song, 1991b). (J, K) Z. dichotomum (after Kahl, 1935). (L, M) Zoothamnopsis mengi (from Song, 1997). (N, O) Zoothamnium paragammari (from Song, 1991b). (P) Z. marinum (after Kahl, 1935). (Q, R) Z. intermedium (from Song, 1991b). Scale bars in (H, N, Q) = 20 µm, in (A) = 30 µm, in (C) = 40 µm, in (L) = 50 µm, in (P) = 100 µm.Published as part of Sun, Ping, Ji, Daode & Song, Weibo, 2005, Notes on a new marine peritrichous ciliate (Ciliophora: Peritrichida), Zoothamnium xuianum n. sp., with redescription of Z. paraentzii Song, 1991 from northern China, pp. 41-53 in Zootaxa 1075 on page 52, DOI: 10.5281/zenodo.17031
Stereochemistry of an Agonist Determines Coupling Preference of beta(2)-Adrenoceptor to Different G Proteins in Cardiomyocytes
No full textA fundamental question regarding receptor-G protein interaction is whether different agonists can lead a receptor to different intracellular signaling pathways. Our previous studies have demonstrated that although most beta(2)-adrenoceptor agonists activate both G(s) and G(i) proteins, fenoterol, a full agonist of beta(2)adrenoceptor, selectively activates G(s) protein. Fenoterol contains two chiral centers and may exist as four stereoisomers. We have synthesized a series of stereoisomers of fenoterol and its derivatives and characterized their receptor binding and pharmacological properties. We tested the hypothesis that the stereochemistry of an agonist determines selectivity of receptor coupling to different G protein(s). We found that the R, R isomers of fenoterol and methoxyfenoterol exhibited more potent effects to increase cardiomyocyte contraction than their S, R isomers. It is noteworthy that although (R,R)-fenoterol and (R,R)-methoxyfenoterol preferentially activate G(s) signaling, their S, R isomers were able to activate both G(s) and G(i) proteins as evidenced by the robust pertussis toxin sensitivities of their effects on cardiomyocyte contraction and on phosphorylation of extracellular signal-regulated kinase 1/2. The differential G protein selectivities of the fenoterol stereoisomers were further confirmed by photoaffinity labeling studies on G(s), G(i2), and G(i3) proteins. The inefficient G(i) signaling with the R, R isomers is not caused by the inability of the R, R isomers to trigger the protein kinase A (PKA)-mediated phosphorylation of the beta(2)-adrenoceptor, because the R, R isomers also markedly increased phosphorylation of the receptor at serine 262 by PKA. We conclude that in addition to receptor subtype and phosphorylation status, the stereochemistry of a given agonist plays an important role in determining receptor-G protein selectivity and downstream signaling events.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000261854500017&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Pharmacology & PharmacySCI(E)58ARTICLE1158-1657
Skyrmion-skyrmion and skyrmion-edge repulsions in skyrmion-based racetrack memory
No full textMagnetic skyrmions are promising for building next-generation magnetic memories and spintronic devices due to their stability, small size and the extremely low currents needed to move them. In particular, skyrmion-based racetrack memory is attractive for information technology, where skyrmions are used to store information as data bits instead of traditional domain walls. Here we numerically demonstrate the impacts of skyrmion-skyrmion and skyrmion-edge repulsions on the feasibility of skyrmion-based racetrack memory. The reliable and practicable spacing between consecutive skyrmionic bits on the racetrack as well as the ability to adjust it are investigated. Clogging of skyrmionic bits is found at the end of the racetrack, leading to the reduction of skyrmion size. Further, we demonstrate an effective and simple method to avoid the clogging of skyrmionic bits, which ensures the elimination of skyrmionic bits beyond the reading element. Our results give guidance for the design and development of future skyrmion-based racetrack memory
A multi-stage genome-wide association study of bladder cancer identifies multiple susceptibility loci.
No full textWe conducted a multi-stage, genome-wide association study of bladder cancer with a primary scan of 591,637 SNPs in 3,532 affected individuals (cases) and 5,120 controls of European descent from five studies followed by a replication strategy, which included 8,382 cases and 48,275 controls from 16 studies. In a combined analysis, we identified three new regions associated with bladder cancer on chromosomes 22q13.1, 19q12 and 2q37.1: rs1014971, (P = 8 × 10⁻¹²) maps to a non-genic region of chromosome 22q13.1, rs8102137 (P = 2 × 10⁻¹¹) on 19q12 maps to CCNE1 and rs11892031 (P = 1 × 10⁻⁷) maps to the UGT1A cluster on 2q37.1. We confirmed four previously identified genome-wide associations on chromosomes 3q28, 4p16.3, 8q24.21 and 8q24.3, validated previous candidate associations for the GSTM1 deletion (P = 4 × 10⁻¹¹) and a tag SNP for NAT2 acetylation status (P = 4 × 10⁻¹¹), and found interactions with smoking in both regions. Our findings on common variants associated with bladder cancer risk should provide new insights into the mechanisms of carcinogenesis
Luminosity measurements for the R scan experiment at BESIII
No full textBy analyzing the large-angle Bhabha scattering events e+e- → (γ)e+e- and diphoton events e+e- → (γ)γγ for the data sets collected at center-of-mass (c.m.) energies between 2.2324 and 4.5900 GeV (131 energy points in total) with the upgraded Beijing Spectrometer (BESIII) at the Beijing Electron-Positron Collider (BEPCII), the integrated luminosities have been measured at the different c.m. energies, individually. The results are important inputs for the R value and J/ψ resonance parameter measurements
Tyrosine 308 Is Necessary for Ligand-directed G(s) Protein-biased Signaling of beta(2)-Adrenoceptor
No full textInteraction of a given G protein-coupled receptor to multiple different G proteins is a widespread phenomenon. For instance, beta(2)-adrenoceptor (beta(2)-AR) couples dually to G(s) and G(i) proteins. Previous studies have shown that cAMP-dependent protein kinase (PKA)-mediated phosphorylation of beta(2)-AR causes a switch in receptor coupling from G(s) to G(i). More recent studies have demonstrated that phosphorylation of beta(2)-AR byGproteincoupled receptor kinases, particularly GRK2, markedly enhances the G(i) coupling. Wehave previously shown that although most beta(2)-AR agonists cause both G(s) and G(i) activation, (R,R')fenoterol preferentially activates beta(2)-AR-G(s) signaling. However, the structural basis for this functional selectivity remains elusive. Here, using docking simulation and site-directed mutagenesis, we defined Tyr-308 as the key amino acid residue on beta(2)-AR essential for G(s)-biased signaling. Following stimulation with a beta(2)-AR-G(s)-biased agonist (R,R')-4'-aminofenoterol, the G(i) disruptor pertussis toxin produced no effects on the receptor-mediated ERK phosphorylation in HEK293 cells nor on the contractile response in cardiomyocytes expressing the wild-type beta(2)-AR. Interestingly, Y308F substitution on beta(2)-AR enabled (R,R')-4'-aminofenoterol to activate G(i) and to produce these responses in a pertussis toxin-sensitive manner without altering beta(2)-AR phosphorylation by PKA or G protein-coupled receptor kinases. These results indicate that, in addition to the phosphorylation status, the intrinsic structural feature of beta(2)-AR plays a crucial role in the receptor coupling selectivity to G proteins. We conclude that specific interactions between the ligand and the Tyr-308 residue of beta(2)-AR stabilize receptor conformations favoring the receptor-G(s) protein coupling and subsequently result in G(s)-biased agonism.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000339326800012&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Biochemistry & Molecular BiologySCI(E)[email protected]; [email protected]
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